Behavioral/Systems/Cognitive
The Role of Spatial Attention in the Selection of Real and Illusory Objects
Ant?′gona Martinez,1,2Dhakshin S.Ramanathan,1John J.Foxe,2Daniel C.Javitt,2and Steven A.Hillyard1
1Department of Neurosciences,University of California,San Diego,La Jolla,California92093-0608,and2Nathan S.Kline Institute for Psychiatric Research, Orangeburg,New York10962
Selective attention may be flexibly directed toward particular locations in the visual field(spatial attention)or to entire object configu-rations(object-based attention).A key question is whether spatial attention plays a direct role in the selection of objects,perhaps by spreading its facilitatory influence throughout the boundaries of an object.We studied the relationship between spatial and object-based attention in a design in which subjects attended to brief offsets of one corner of a real or illusory square form.Object-selective attention was indexed by differences in event-related potential(ERP)amplitudes and blood oxygen level-dependent(BOLD)activations to unat-tended corner offsets in conditions in which the objects were intact versus fragmented or absent.This design ensured that object-based attention effects were not an artifact of attention being guided by simple directional cues such as parallel lines,which may have occurred in previous studies.Both space-based and object-based attention were associated with enhanced negative ERPs(N1component at 140–180ms)that were colocalized with BOLD activations in lateral occipital cortex(LOC).These results provide physiological evidence that directing spatial attention to one part of an object(whether real or illusory)facilitates the processing of the entire object at the level of the LOC and thus contributes directly to object-based selective attention.
Key words:ERPs;attention;object attention;fMRI;dipoles;LOC
Introduction
When attention is directed to a specific location in the visual field, the detection and discrimination of stimuli at that location be-comes faster and more accurate(Wright,1998).This space-based stimulus selection has been likened to a moveable“spotlight”that can facilitate processing of stimuli at relevant locations.There is also abundant evidence that attention can select objects in their entirety for preferential processing(Scholl,2001).Critical evi-dence for object-based attention comes from studies based on a design by Egly et al.(1994)in which two adjacent rectangles are presented and attention is cued to one end of one of the rectan-gles.The general finding is that stimuli presented at uncued lo-cations within the cued rectangle are selected more rapidly than are physically equivalent stimuli presented within the uncued rectangle(Marino and Scholl,2005).
Several investigators have proposed that space-based atten-tion plays an important role in object-selective attention(Vecera and Farah,1994;Weber et al.,1997;Davis et al.,2000).According to this view,spatial attention directed to one part of an object spreads throughout its boundaries and strengthens the sensory representation of the entire object.In support of this“object-guided spatial-selection mechanism,”physiological studies using variants of the dual-rectangle paradigm of Egly et al.(1994)have shown that neural activity patterns associated with spatial and object-based attention have much in common,as evidenced by functional magnetic resonance imaging(fMRI)(Mu¨ller and Kleinschmidt,2003)and event-related potential(ERP)record-ings(He et al.,2004;Martinez et al.,2006,2007).
Although the paradigm of Egly et al.(1994)has been used in many studies of object-based attention,there is reason to believe that the“same object advantage”observed in these studies may not,in fact,reflect selection of the rectangular object itself.In-stead,Avrahami(1999)suggested that attention may be guided from cued locations along the direction of the lengthwise parallel lines of the rectangle rather than by its integral object properties. In support of this proposal,a cueing advantage was found for distant stimuli situated within arrays of evenly spaced parallel lines that did not constitute enclosed objects(Avrahami,1999; Marino and Scholl,2005).These results call into question whether the paradigm of Egly et al.(1994)provides a good metric of object-selective attention.
In previous studies(Martinez et al.,2006,2007),we used fMRI and ERP recordings in an Egly-style paradigm to show that space-based and object-based attention produced a similar pattern of enhanced neural activity in the lateral occipital cortex(LOC)at 150–180ms after stimulus onset.The present study aimed to determine whether this neural activity pattern in LOC,a region previously implicated in object-recognition processes(Grill-Spector et al.,2001),truly reflects object-selective attention.Ac-cordingly,the present stimulus display consisted of symmetrical objects(real and illusory squares)so that object-based attention could not be based on simple stimulus features such as parallel
Received Jan.4,2007;revised April28,2007;accepted May10,2007.
This work was supported by National Eye Institute Grant EY016984.The Cartool software was programmed by
Denis Brunet(Functional Brain Mapping Laboratory,Geneva,Switzerland)and is supported by the Center for Bio-
medical Imaging of Geneva and Lausanne,Switzerland.We thank Matt Marlow for technical assistance.
Correspondence should be addressed to Dr.Antigona Martinez,Department of Neurosciences–0608,University
of California,San Diego,9500Gilman Drive,La Jolla,CA92093-0608.E-mail:antigona@https://www.doczj.com/doc/c22987274.html,.
DOI:10.1523/JNEUROSCI.0031-07.2007
Copyright?2007Society for Neuroscience0270-6474/07/277963-11$15.00/0
The Journal of Neuroscience,July25,2007?27(30):7963–7973?7963
lines that are an integral part of the Egly-type display.The critical index of object-based attention here was an increased ERP am-plitude to unattended regions of intact objects.
Materials and Methods
Experiment1
Subjects
Fourteen healthy volunteers(mean age,21years;nine females)partici-pated in the ERP portion of the study.An additional seven subjects took part in the fMRI experiment.All subjects were right handed,had normal or corrected-to-normal vision,and gave informed consent to participate in the experiment.
Stimuli and task
Stimuli were either a single white square(6.5?6.5°visual angle)on a gray background[intact object(IO)condition]or four separated rectan-gular white shapes[fragmented object(FO)condition]that together comprised the same area as the single square(Fig.1).All stimuli were white on a gray background and contained a small fixation cross in the center that was present at all times.In both the IO and FO configurations, task stimuli consisted of brief(100ms)offsets of the corners in either the upper left(UL),upper right(UR),lower left(LL),or lower right(LR) quadrants.Corner offsets left either a concave edge(standards,p?0.8) or a convex edge(targets,p?0.2)and occurred in random order,one at a time,in the different quadrants at intervals of400–600ms.Stimuli were delivered in20s blocks with either the IO or FO configuration.In both cases,subjects were instructed to maintain fixation on the central cross while directing attention to the corner(quadrant)indicated by a pair of arrows presented just above or below fixation.Subjects were instructed to respond as quickly and accurately as possible to target stim-uli appearing in the attended quadrant and to ignore all stimuli at the other quadrants.All subjects responded with their right hand.A single run consisted of five attend-left blocks and five attend-right blocks.Dur-ing half of the runs,the cues alternated between the UL and UR quad-rants and in the remaining half alternated between the LL and LR quad-rants.Each subject took part in a total of20runs resulting in?500 stimuli per condition,and the order of the runs(attend upper field or lower field and IO or FO)was counterbalanced across subjects. Electrophysiological recordings
Subjects sat in a dimly lit recording chamber and viewed the stimuli on a video monitor at a distance of100cm.Recordings were acquired from62 scalp electrodes using a modified10–20system montage(Di Russo et al., 2003)referenced to the right mastoid.Eye movements and blinks were monitored via recordings of the horizontal(right vs left outer canthi)and vertical(below the eye vs right mastoid)electrooculogram(EOG).The EEG was digitized at250Hz with an amplifier bandpass of0.1–80Hz. Computerized artifact rejection was performed before signal averaging to discard epochs in which deviations in eye position and/or blinks(de-fined as any peak-to-peak amplitude change of?60?V in the EOG channels)or amplifier blocking(defined as a flat voltage line for?40ms) occurred.Additionally,epochs that were preceded by a target stimulus within1000ms or followed by a target within200ms were eliminated to avoid contamination by ERP-related target detection and motor re-sponse.Approximately10%of all trials were rejected based on one or more of the preceding criteria.
Time-locked ERPs to the standard corner-offset stimuli were averaged separately according to quadrant of presentation(UL,UR,LL,and LR), whether the stimuli were attended or unattended,and whether the stim-ulus configuration was IO or FO.For the data analysis,ERPs were re-referenced algebraically to the average of the left and right mastoids. ERPs to target stimuli were not analyzed.
To assess effects of spatial attention,ERPs to attended-location stimuli were averaged across both IO and FO configurations(for which the attended ERPs did not differ;see Results)and were compared with the ERPs elicited by the same stimuli when unattended.However,to avoid confounding the spatial attention effect with object attention effects,only unattended stimuli in the FO configuration were included in this com-parison.For example,the spatial attention effect for an UR stimulus was obtained by subtracting the average of the ERPs elicited by an UR corner stimulus when attention was directed toward the UL,LL,and LR quad-rants during the FO condition from the ERP elicited by the same(UR) stimulus when attention was focused on the UR quadrant averaged over both the IO and FO configurations.
In this study,we consider“object-based”attention effects to be in-dexed by contrasting ERP unattended stimuli in the IO versus FO con-figurations.Specifically,object-based attention effects were calculated by comparing ERP amplitudes for unattended corner offsets only,as a func-tion of whether these formed part of the attended object(IO configura-tion)versus part of a different object(FO configuration).For example, ERPs elicited by an UR stimulus were averaged over the conditions of attending to the UL,LL,and LR quadrants when the configuration was an IO and were compared with the ERPs elicited by the same stimulus in the same three attention conditions,but in the FO configuration.Addition-ally,to determine whether these object-based attention effects were af-fected by the position of the unattended stimulus relative to the location of the attended stimulus,separate one-way ANOVAs were calculated for each relative position.These ANOVAs compared ERP amplitudes on IO versus FO conditions when attention was directed to the horizontal, vertical,or diagonal quadrant with respect to the eliciting unattended quadrant.For example,ERPs to unattended UR stimuli were compared (IO vs FO configurations)when attention was focused on the UL quad-rant(horizontal),LR quadrant(vertical),or LL quadrant(diagonal).
In all cases,attention effects were quantified in terms of mean ampli-tudes within specified latency windows with respect to a100ms pre-stimulus baseline.For each quadrant,the mean amplitude of the P1 (88–120ms)and N1(140–180ms)components were subjected to a repeated-measures ANOVA with factors of attention(attended vs unat-tended for spatial attention;IO vs FO for object-based attention)and hemisphere(ipsilateral vs contralateral to the eliciting stimulus).In all analyses,P1and N1were measured as mean amplitudes averaged over a
Figure1.Stimulus configurations in experiment1for the IO and FO conditions.In the IO
condition,a single square was continuously present on the display.Subjects were cued to
covertly attend to the visual quadrant(UL in the example shown)indicated by a pair of arrows
directly above or below fixation.Stimuli consisted of brief(100ms)offsets of the four corners of
one of the squares.The offset stimuli left either a concave(standard)or convex(target)edge.
Dotted lines outlining the attended quadrant were not present in the display.The FO configu-
ration was identical,except that the square was divided into four uneven sections that together
comprised the same area as the single square.In both cases,object-selective attention effects
were analyzed by comparing the ERPs and fMRI signal elicited by unattended corner offsets as a
function of whether these formed part of the same cued object(IO condition)or belonged to a
different,unconnected object(FO condition).
7964?J.Neurosci.,July25,2007?27(30):7963–7973Martinez et al.?Spatial Attention and Object Selection
cluster of the10posterior electrode sites in each hemisphere(O1/O2, PO3/PO4,PO7/PO8,P1/P2,P3/P4,P5/P6,P7/P8,CP1/CP2,CP3/CP4, CP5/CP6)where these components were largest.The specific time win-dows used for measuring each component were chosen because they encompassed the attention-related amplitude modulations that were sta-ble in scalp topography within their respective time windows.Finally,the scalp distributions of the N1amplitude modulations produced by spatial-versus object-selective attention were compared across the entire array of electrode sites after normalizing their amplitudes before ANOVA using the method of McCarthy and Wood(1985).
Source localization
To estimate the cortical generators of the spatial and object-based atten-tion effects on N1amplitude,two different types of source localization analyses were performed on the grand-averaged difference waves(at-tended minus unattended ERPs for spatial attention;IO minus FO for object-based attention)within the same intervals used for statistical test-ing.First,dipole modeling was performed using the Brain Electrical Source Analysis program(BESA;version5).BESA iteratively adjusts the location and orientation of dipolar sources to minimize the residual variance between the calculated model and the observed ERP voltage topography(Scherg,1990).The general approach was to fit symmetrical pairs of dipoles that were mirror constrained in location but not in ori-entation over restricted time intervals.
Second,current density distributions accounting for the N1difference waves were estimated using a local autoregressive average(LAURA)al-gorithm(Grave de Peralta Menendez et al.,2001).LAURA uses a realistic head model with a solution space of4024nodes evenly distributed within the gray matter of the Montreal Neurological Institute(MNI)average template brain.It makes no a priori assumptions regarding the number of sources or their locations and can deal with multiple simultaneously active sources(Michel et al.,2001).LAURA analyses were implemented using the Cartool software(http://brainmapping.unige.ch/Cartool.php). The current source distributions estimated by LAURA and the dipole locations calculated by BESA were transformed into the standardized coordinate system of Talairach and Tournoux(1988)and projected onto a structural brain image supplied by MRIcro(Rorden and Brett,2000)using the Analysis of Functional NeuroImaging(AFNI) software package(Cox,1996)and the MNI2TAL formula provided by https://www.doczj.com/doc/c22987274.html,/Imaging/Common/mnispace.shtml.
fMRI methods
Seven healthy volunteers(mean age,26years;four females)were paid for their participation in this study.The Institutional Review Board of the Nathan S.Kline Institute for Psychiatric Research approved all proce-dures.The stimuli and task were identical to that used in the ERP study with the addition of a passive stimulation condition using the same stim-uli.This passive condition was used to define functional regions of inter-est(ROIs)associated with sensory processing of the corner-offset stimuli in each quadrant.Each participant took part in a total of eight scans,the first two of which were passive(no task);in the remaining six scans, subjects performed the same attention task as in the ERP experiment. Image acquisition.T2*-weighted echo-planar images(EPIs)(repeti-tion time,2s;echo time,38ms;flip angle,90°;voxel size,3mm3;matrix size,64?64)were acquired on a3tesla SMIS MRI system equipped with a head volume coil.During each scan,164volumes were acquired on each of20contiguous slices in the coronal plane beginning at the occip-ital pole.The first four volumes were discarded before all analyses to allow for stabilization of the blood oxygen level-dependent(BOLD)sig-nal.Visual stimulation was delivered through MR-compatible liquid crystal display goggles(Resonance Technology,Northridge,CA).For anatomical localization of functional data,high-resolution(1mm3)im-ages of the entire brain were acquired from each subject,using a standard MPRAGE(magnetization prepared rapid gradient echo)sequence. Data processing.All fMRI data analyses were conducted with the AFNI software package(Cox,1996).Before all statistical tests,the EPIs from individual subjects were realigned to the first included volume(motion never exceeded1.3mm along any axis),linearly detrended,and slice time corrected.Functional images were then coregistered with each individu-al’s high-resolution anatomical images and projected into Talairach co-ordinate space before being spatially smoothed with a Gaussian kernel of 6mm full-width at half-maximum.The statistical significance levels and minimum cluster size of all activation maps in the study were calculated using a Monte Carlo simulation(AlphaSim,included in AFNI package). Passive stimulation:defining ROI masks.Corner-offset stimuli identical to those used in the ERP experiment were used for passive stimulation to define ROIs for the attention study.The stimuli belonged to either the IO or FO configuration and were delivered with the same timing parameters described above for the ERP experiment.Functional ROIs were defined for each quadrant by convolving a canonical hemodynamic response function with a model of the timing of the stimulation epochs and cross-correlating the resulting design matrix on a voxel-by-voxel basis with the data obtained from each passive scan.Percentage signal change maps corresponding to regions with enhanced contralateral activation during passive sensory stimulation at each quadrant(averaged over IO and FO blocks)were generated for each individual subject.Group ROI masks, used in all subsequent analyses,were generated by entering individual signal change maps into a groupwise t test and testing against the null hypothesis.Only voxels with t values?6.78(p?0.01)and belonging to clusters of five or more(?135mm3)neighboring voxels survived the final threshold.
Attention scans.BOLD responses elicited by attended and unattended stimuli were calculated using a cross-correlation method as described above.The group ROI masks were used to generate individual signal change maps for each quadrant as a function of whether it was attended or unattended and,if unattended,if it formed part of the IO or FO. Spatial attention effects in the group were calculated by comparing the percentage signal change maps for each quadrant when attended(aver-aged over IO and FO configurations)versus the average signal change when attention was focused on the remaining three quadrants in the FO condition.Object-based attention effects were calculated by comparing activation within each unattended ROI as a function of whether the attended offset stimulus belonged to the same versus a different object (IO vs FO conditions).In both cases,statistical significance of these effects was assessed by paired t tests,calculated separately for each quad-rant.To identify common regions of activation between object-based and spatially directed attention,a conjunction map was constructed by taking the union of the statistical maps for object and spatial attention at each quadrant.Group data are reported only for voxels with t values ?3.91(p?0.05)that belonged to clusters of eight or more neighboring voxels(?216mm3).
Experiment2
Subjects
Eleven new subjects(mean age,21years;five females)were recruited to participate in this study.Subjects gave informed consent before partici-pating in a single ERP recording session.All subjects were right handed and had normal or corrected-to-normal vision.
Stimuli and task
In the“object-present”configuration,stimuli consisted of four Kanizsa inducers(circles with90°sectors missing),each subtending2.8°of visual angle(Fig.2).The inducers were oriented and positioned such that they generated the perception of an illusory square(subtending6.5°visual angle)centered about a continuously visible fixation point.In the “object-absent”configuration,another90°sector was removed from each inducer,leaving a half-circle oriented either vertically or horizon-tally.With these stimuli,no illusory square was seen.All stimuli were white on a gray background.
In both configurations,the Kanizsa or half-circle figures were present at all times.The ERP-eliciting stimuli consisted of brief(100ms)presen-tations of triangular wedges that filled in the missing sector of the Kanizsa inducers.These stimuli were presented one at a time(400–600ms,stim-ulus onset asynchrony)in random order to the different visual quad-rants.The inner edge of each wedge stimulus was either straight(stan-dards,p?0.8)or slightly rounded(targets,p?0.2).A pair of arrows just above or below the fixation point cued the subject to sustain attention to one of the four quadrants during blocks lasting20s each.As in experi-
Martinez et al.?Spatial Attention and Object Selection J.Neurosci.,July25,2007?27(30):7963–7973?7965
ment 1,subjects were instructed to respond (with the right hand)as quickly and accurately as possible to attended targets only.Ten blocks,alternating between attend-UL and attend-UR conditions,were deliv-ered during each of five runs.In a separate set of five runs,the cues alternated between the LL and LR quadrants,resulting in ?500stimuli delivered per subject per condition.The order of the runs (attend upper or lower field)was counterbalanced across the subjects.The subject’s task was to press a button on detection of a target stimulus in the attended quadrant.
Electrophysiological recordings
The ERP recording and analysis procedures were identical to those de-scribed for experiment 1.The same criteria were also used to identify trials with excessive eye movements or amplifier blocking.Approxi-mately 13%of all trials were rejected and excluded from the average based on these criteria.Time-locked ERPs were averaged separately in response to wedge-onset stimuli (standards only)in each visual quadrant according to whether they were attended or unattended and whether the configuration was object-present (illusory square)or object-absent.Spa-tial and object attention effects were quantified in terms of mean ampli-tude within specified latency windows with respect to a 100ms prestimu-lus baseline.For each quadrant,the mean amplitude of the P1(90–120ms for all quadrants)and N1(132–172ms)components were entered into separate repeated-measures ANOVAs with factors of attention (at-tended vs unattended for spatial attention;object-present vs object-absent for object-based attention)and hemisphere (ipsilateral vs con-tralateral to the eliciting stimulus).In all analyses,P1and N1were measured as mean amplitudes averaged over the same cluster of 10pos-terior electrode sites used in experiment 1.
Source localization
As in experiment 1,the scalp topographies of the group-averaged object and spatial attention difference waves for each quadrant were used to estimate the underlying brain sources of the attention-related N1mod-ulations using both BESA and LAURA.Experiment 2did not include fMRI.
Results
Experiment 1Behavioral results
On average,subjects correctly detected 92.1%of the targets in the IO configuration and 92.8%of the targets during the FO condi-
tion with mean reaction times (RTs)of 487and 503ms,respec-tively.Neither discrimination accuracy nor RTs differed signifi-cantly between targets in the UL,LL,UR,and LR quadrants (p ?0.35)nor between IO and FO configurations (p ?0.85).ERP results
As in many previous studies (for review,see Hopfinger et al.,2004),the effects of spatial attention were evident as amplitude modulations of the early,sensory-evoked P1(88–120ms)and N1(140–180ms)components.In all quadrants,attended stimuli elicited significantly larger P1and N1voltage amplitudes than the same stimulus when unattended (Fig.3,Table 1).These compo-nents were significantly enhanced over recording sites contralat-eral to the eliciting stimulus (Table 1,Hemisphere ?attention).ERPs elicited by attended stimuli did not differ as a function of the stimulus configuration for any quadrant.This was true for both the P1component (IO vs FO:UL,F (1,13)?2.03,p ?0.19;UR,F (1,13)?1.87,p ?0.20;LL,F (1,13)?0.93,p ?0.45;LR,F (1,13)?1.11,p ?0.28)and the N1component (IO vs.FO:UL,F (1,13)?2.17,p ?0.22;UR,F (1,13)?2.90,p ?0.11;LL,F (1,13)?1.07,p ?0.38;LR,F (1,13)?1.01,p ?0.30).Accordingly,the attended ERP waveforms were collapsed over the two configurations in the analysis of spatial attention effects.
Object-based attention effects were evidenced by comparing N1amplitudes elicited by unattended stimuli that formed part of the same object (IO condition)to the case when the stimulus belonged to a different object (FO condition)(Table 2).As in the case of spatial attention,these object-based N1modulations were significant for each quadrant and were largest over the contralat-eral scalp.This finding of larger N1amplitudes to unattended stimuli in the IO versus FO conditions but equivalent N1ampli-tudes to attended stimuli in the two conditions was also reflected in a significant attention ?configuration interaction in an over-all ANOVA (F (1,13)?8.62;p ?0.01).Unlike spatial attention,however,object-based selection did not significantly affect the amplitude of the P1component as reflected in a
nonsignificant
Figure 2.Stimulus configurations in experiment 2for the object-present and object-absent conditions.Kanizsa inducers were used to generate an illusory square in the object-present condition.In the object-absent condition,a 90°wedge of the inducer was removed leaving a half-circle and eliminating the illusory square.In both conditions,subjects attended to the quadrant indicated by a pair of central arrows (UL quadrant in the example shown)while maintaining fixation centrally.Stimuli were brief (100ms)onsets of one 90°wedge that had either a straight (standards)or curved (targets)edge.Dotted lines outlining the attended stim-ulus were not present in the display.Object-based attention effects were calculated by compar-ing the ERPs elicited by unattended wedge stimuli as a function of whether the configuration was object-present (illusory square)or
object-absent.
Figure 3.Grand-averaged ERPs to attended and unattended (Unatt.)stimuli in each quad-rant.Inallquadrants,attendedstimulielicitedlargerERPamplitudesforthesensory-evokedP1and N1components (black waveforms)compared with the ERPs elicited by the same stimuli when unattended (red and green waveforms).N1amplitudes (latency range indicated by yel-low bar)were also enhanced by unattended stimuli in the same object condition (red wave-forms)relative to the ERPs elicited by unattended stimuli belonging to a different object (green waveforms).For each quadrant,ERPs are shown from a parietal electrode site contralateral to the eliciting stimulus (P3/P4).
7966?J.Neurosci.,July 25,2007?27(30):7963–7973Martinez et al.?Spatial Attention and Object Selection
attention?configuration interaction(F(1,13)?2.88;p?0.89) and in nonsignificant object effects for each quadrant tested sep-arately(IO vs FO:UL,F(1,13)?0.15,p?0.71;UR,F(1,13)?3.72, p?0.08;LL,F(1,13)?0.11,p?0.75;LR,F(1,13)?3.48,p?0.09).
The distribution of attention within the attended object was tested by contrasting the amplitude of the object-based N1mod-ulations at contralateral electrode sites when the attended quad-rant was situated horizontally,vertically,or diagonally with re-spect to the eliciting unattended quadrant.For all quadrants, these object-based attention effects(comparing IO and FO con-ditions)were not affected by the relative position of the attended and unattended quadrants(p?0.11)(Table3).
As shown in Figure4,the scalp topographies of the N1mod-ulations produced by object-based and spatial attention were very similar,both having maximal amplitude over the posterior contralateral scalp.Although the degree of similarity varied somewhat according to the visual quadrant of the eliciting stim-ulus,a comparison of these N1difference topographies using the method of McCarthy and Wood(1985)revealed no statistical difference between the object-based and spatial attention effects in any quadrant(p?0.18,for all quadrants).
Source localization
Pairs of mirror-symmetrical dipoles were fit using BESA to the difference topographies of the spatial and object-based attention effects on N1shown in Figure4.In all quadrants,the spatial attention effect on N1was well fit by a pair of ventrolateral di-poles in occipital cortex.The object-based N1modulations were accounted for by similarly situated dipole pairs(see Table4for Talairach coordinates).Both sets of dipole models(spatial and object-based attention)accounted for?90%of the variance in scalp topography in each quadrant over the fitted time range (140–180ms).
The linear distributed inverse solution(LAURA)was also used to estimate the neural sources underlying the spatial and object-based attention effects on N1.In all quadrants,a principal
Table1.Effects of spatial attention?attended stimuli(Att.)in both configurations vs unattended stimuli(Unatt.)in the FO configuration?on ERP amplitudes(in microvolts)elicited by stimuli in each quadrant(Quad.),recorded from the left(LH)and right(RH)hemispheres
Quad.Hemis.P1amplitudes
Attention(Att.vs
Unatt.)
Hemisphere?atten-
tion(Ipsi.vs Contra.
?Att.vs Unatt.)N1amplitudes
Attention(Att.vs
Unatt.)
Hemisphere?atten-
tion(Ipsi.vs Contra.
?Att.vs Unatt.)
Att.Unatt.F
(1,13)
p F
(1,13)
p Att.Unatt.F
(1,13)
p F
(1,13)
p
UL LH0.310.08
17.72?0.002 5.34?0.040
?0.79?0.11
32.54?0.001 5.07?0.050 RH0.890.24?1.40?0.37
UR LH 1.000.45
8.04?0.02013.41?0.004
?1.31?0.55
40.75?0.001 4.91?0.050 RH0.200.01?0.90?0.33
LL LH0.640.27
39.12?0.001 5.29?0.040
?1.15?0.61
26.22?0.001 4.94?0.050 RH 1.270.68?2.02?0.86
LR LH 1.160.65
22.28?0.001 5.84?0.040
?1.83?0.63
63.85?0.00131.01?0.001 RH0.550.22?1.21?0.53
Hemis.,Hemisphere;Ipsi.,ipsilateral;Contra.,contralateral.
Table2.Effects of object-based attention on unattended N1amplitudes(in microvolts)
Quad.Hemis.N1amplitudes Configuration(IO vs FO)
Hemisphere?configuration
(Ipsi.vs Contra.?IO vs FO)
IO FO F
(1,13)
p F
(1,13)
p
UL LH?0.29?0.11
12.81?0.0058.04?0.020 RH?0.73?0.37
UR LH?0.77?0.55
7.77?0.20 1.345n.s. RH?0.49?0.33
LL LH?0.78?0.61
7.38?0.2024.9?0.001 RH?1.35?0.86
LR LH?0.93?0.63
17.33?0.00259.67?0.001 RH?0.53?0.53
Increased N1amplitudes to unattended stimuli in IO versus FO configurations were interpreted as object-based attention.Quad.,Quadrant;Hemis.,hemisphere;Ipsi.,ipsilateral;Contra.,contralateral;LH,left hemisphere;RH,right hemisphere;n.s.,nonsignificant.
Table3.Amplitudes of object-based attention effect on N1(the IO minus FO amplitude difference in microvolts)as a function
of the relative position of the eliciting unattended stimulus?horizontal(H),vertical(V),or diagonal(D)?with respect
to the attended stimulus quadrant
Stimulus Hemis.Amplitudes Relative position(H,V,D)Hemisphere Position?hemisphere H V D F
(2,26)
p F
(1,13)
p F
(1,13)
p
UL LH?0.30?0.30?0.26
0.93?0.40026.81?0.001 1.52?0.240 RH?0.84?0.75?0.59
UR LH?0.79?0.89?0.64
2.46?0.1109.27?0.010
3.70?0.040 RH?0.54?0.50?0.43
LL LH?0.79?0.79?0.76
0.06?0.94039.98?0.0010.54?0.589 RH?1.36?1.30?1.39
LR LH?0.96?0.97?0.87
1.63?0.22021.37?0.001
2.55?0.103 RH?0.42?0.71?0.47
Hemis.,Hemisphere;LH,left hemisphere;RH,right hemisphere.
Martinez et al.?Spatial Attention and Object Selection J.Neurosci.,July25,2007?27(30):7963–7973?7967
source associated with the N1object at-tention effect was identified in the LOC of the hemisphere contralateral to the elicit-ing stimulus,overlapping with the dipolar sources modeled with BESA (Fig.5).
fMRI results and coregistration with source analysis models
Spatial attention effects were calculated by comparing the BOLD signal elicited dur-ing blocks of attention to one visual quad-rant to the signal elicited when the same quadrant was unattended.Attention-related enhancements of the BOLD signal were observed within several striate and extrastriate cortical regions including the inferior and middle occipital gyri,the fusi-form gyrus,and portions of the inferior and superior parietal lobes.These activa-tions,summarized in Table 5,were largest in the contralateral hemisphere
Analysis of object-based attention ef-fects were calculated by comparing the ac-tivations elicited within ROIs by unat-tended stimuli in the IO versus FO conditions.In all quadrants,this compar-ison yielded significant BOLD enhance-ments within discrete extrastriate cortical areas that included the fusiform gyrus,middle occipital gyrus,and the inferior parietal lobes of the contralateral hemi-sphere.In general,these object-based at-tention effects were less extensive than those observed for spatial attention and varied somewhat depending on the quad-rant of stimulation (Table 5).
A conjunction analysis between the spatial attention activation maps and
those of object attention was conducted to identify common ar-eas of activation.Although the overlapping regions revealed in
this analysis varied slightly across the four quadrants,a promi-nent activation in the region of the contralateral middle occipital
gyrus (Brodmann’s area 19)was found for all visual quadrants
during both attention conditions.The Talairach coordinates of
this region are within ?6mm of the range of coordinates re-ported for area LOC in several previous fMRI studies (Malach et
al.,1995;Grill-Spector et al.,1998;Grill-Spector,2003).
To compare the anatomical locations of these activations with
the sources of the N1attention effects,the LAURA models and
BESA dipole coordinates were transformed into Talairach space
and coregistered with the fMRI maps.Figure 5shows the close
correspondence between the cortical regions identified by BESA
and LAURA as the sources of the spatial and object attention
effects on the N1and those identified by fMRI as having common
activation during both attention conditions.These methods con-verge to indicate that activation within a region in the contralat-eral LOC (area LOC)is involved in mediating selection based on
location as well as selection based on object integrity.
Experiment 2
Behavioral results
Target discrimination accuracy averaged 90.7%for the object-present condition and 91.9%for the object-absent configuration,
a nonsignificant difference (p ?0.42).Mean RTs (502and 517
ms for object-present and object-absent,respectively)did not
differ significantly between stimulus configurations nor among
the quadrants (p ?0.65).
ERP results As in experiment 1,spatial attention effects were calculated by subtracting the ERPs elicited by attended wedge-onset stimuli (both configurations)from the ERPs elicited by the same unat-tended stimulus (object-absent configuration only).Attended ERPs (P1and N1components)were not affected by the stimulus configuration (object-present vs object-absent)for any quadrant (P1:UL,F (1,10)?3.01,p ?0.09;UR,F (1,10)?2.07,p ?0.18;LL,F (1,10)?1.03,p ?0.91;LR,F (1,10)?0.83,p ?1.01;N1:UL,F (1,10)?2.75,p ?0.15;UR,F (1,10)?1.96,p ?0.20;LL,F (1,10)?1.22,p ?0.78;LR,F (1,10)?2.00,p ?0.18).As in experiment 1,the effects of spatial attention were evident as amplitude en-hancements of the P1(90–120ms)and N1(132–172ms)com-ponents that were largest over the contralateral scalp (Fig.6,Ta-ble 6).Object-based attention effects were assessed by comparing unattended ERPs in the object-present versus object-absent con-figurations,as in experiment 1.This comparison did not yield any significant modulation of the P1component for any quadrant (UL,F (1,10)?1.05,p ?0.63;UR,F (1,10)?1.27,p ?0.48;LL,F (1,10)?0.62,p ?0.51;LR,F (1,10)?2.12,p ?0.12),but the N1amplitudes were significantly larger in the illusory
object-present Figure 4.Correspondence between the topographies of N1modulations produced by spatial and object-based attention.Voltage maps are shown for each quadrant in the N1latency range (140–180ms)for the attention-related difference waves associated with spatial (left map)and object-based (right map)attention.Spatial attention difference waves were formed by subtractingunattendedfromattendedERPsforeachquadrant.Object-basedattentiondifferencewaveswereformedbysubtract-ing unattended ERPs for the FO condition from IO conditions.The voltage scale on the left applies to spatial attention maps;the
scale on the right applies to object attention maps.Table 4.Talairach coordinates and residual variance (RV)of dipoles (shown in Fig.5)that were fit to the grand-average difference wave topographies of N1shown in Figure 4Spatial attention RV (%)Object attention RV (%)x y z x y z UL 53?660551?68?17UR
?29?68?74?35?6567LL 32?680451?6416LR 34?6704?22?66?247968?J.Neurosci.,July 25,2007?27(30):7963–7973Martinez et al.?Spatial Attention and Object Selection
configuration than in the object-absent configuration.As in ex-periment 1,these effects were reflected in a significant atten-tion ?configuration interaction for the N1(F (1,10)?7.29;p ?
0.02)but not for the P1(F (1,10)?2.05;p ?0.31)component.As
with spatial attention,the object-based attention on N1effects
were significantly larger over the contralateral scalp (Fig.6,Table
7).No significant difference in the amplitude of the N1modula-tions produced by object-based attention was obtained at any
location as a function of whether attention was directed to the
quadrant adjacent (horizontal or vertical)or diagonal with re-spect to the eliciting unattended stimulus (p ?0.23,for all quad-rants)(Table 8).
In all quadrants,the scalp topographies of the object-based
and spatial-attention N1difference waves were very similar to one another,both having maximal amplitudes over the con-tralateral occipital scalp (Fig.7).The pro-cedure of McCarthy and Wood (1985)was used to statistically compare these topo-graphical distributions,which did not dif-fer (p ?0.17)for any of the quadrants.Source localization
Inverse dipole modeling was first per-formed using the BESA algorithm.Sepa-rate dipole models were calculated for each of the four quadrants over time win-dows corresponding with the peak N1component (see Materials and Methods).In all quadrants,a pair of symmetrically constrained dipoles in ventrolateral occip-ital cortex accounted for ?90%of the voltage topography of both the spatial-and object-based N1modulations (Table 9).Second,a linear distributed inverse so-lution approach was performed using LAURA (Grave de Peralta Menendez et al.,2001).LAURA revealed a prominent source in LOC for both the spatial and object-based attention N1modulations in all quadrants.This source corresponded very closely to the dipole locations mod-eled with BESA and was largest in the con-tralateral hemisphere (Fig.8).
Discussion
The data reported here provide physiolog-ical evidence from fMRI and ERP record-ings that directing spatial attention to one part of an object facilitates the processing of the entire object.This was observed both for a real object having the shape of a uniform square (experiment 1)and for an
illusory square defined by Kanizsa induc-ers at its corners (experiment 2).For both types of stimuli,object-selective attention
was manifested in amplitude modulations
of the N1component (latency,140–180ms)of the visual ERP elicited by brief off-sets of the corners of the squares.When attention was directed to offsets at one corner,the N1amplitude elicited by off-sets at the other,unattended corners were larger when the square was an intact,per-ceptual object than when it was fragmented (experiment 1)or
made to disappear by modifying the Kanizsa inducers (experi-ment 2).This object-selective N1enhancement had the same timing and source localization as the spatially selective increase in N1amplitude elicited by stimuli at the attended corner.Both the object-based and space-based N1amplitude increases were found to arise from a common cortical source in the LOC,a finding supported by converging evidence obtained from a par-allel fMRI experiment while subjects engaged in the same task.These results point to an important role for spatial attention in strengthening the sensory representations of entire objects and thus contributing to object-based
attention.Figure 5.Spatial correspondence between N1source localization and fMRI results.Dipoles fit with BESA to the spatial (blue)and object (green)attentional difference topographies (shown in Fig.4)are superimposed with the neural sources estimated by LAURA for spatial (left)and object (middle)attention effects in the N1latency range (140–180ms).fMRI activations resulting from the group conjunction (conj.)analysis are shown to the right.For all quadrants,a prominent source in the contralateral LOC region was identified by LAURA and BESA;this source coincides with the area identified with fMRI as being commonly activated during both attention conditions.Only the contralateral member of each symmetrical dipole pair is shown.The color bar depicts the current source intensity for the LAURA source solutions.Data are displayed on the MNI brain (left hemisphere is on the left).Table 5.Talairach coordinates of spatial and object attention-related fMRI activations ROI Spatial (Att.?Unatt.)x y z Object (Unatt.IO ?FO)x y z UL
R fusiform (BA 37)38?49?19R fusiform 34?62?12R Mid.Occ.(BA 19)51?65?4L Sup.Temp.
?46?6218R lingual 18?69?14R Mid.Occ.(BA 19)
45
?66
?9
R Sup.Occ.30?7724R Mid.Occ.25?8119UR L lingual
?16?69?12L Mid.Occ.(BA 19)?44?700
L Mid.Occ.(BA 19)?45?732R Mid.Occ.
?24?8915LL R Inf.Par.(BA 40)38?3344R Sup.Par 12?6646
R Inf.Temp.54?45?14R Mid.Occ.(BA 19)46?73?3R fusiform (BA 37)37?57?15R Mid.Occ.(BA 19)44?73?6R calcarine (BA 17)7?858LR R fusiform (BA 37)38?57?15L fusiform ?39?62?15
R lingual 15?65?4L Mid.Occ.(BA 19)?41?74?4
L Sup.Par.
?28?7343L Mid.Occ.(BA 19)?40?77?3L Mid.Occ.(BA 18)
?15
?85
14
Regions in bold are where spatial and object-based activations overlapped.Att.,Attended stimuli;Unatt.,unattended stimuli;R,right;L,left;Mid.,middle;
Occ.,occipital;Sup.,superior;Inf.,inferior;Par.,parietal;Temp.,temporal.
Martinez et al.?Spatial Attention and Object Selection J.Neurosci.,July 25,2007?27(30):7963–7973?7969
Previous physiological studies comparing the neural bases of spatial and object-selective attention by means of fMRI (Mu ¨ller and Kleinschmidt,2003)and ERP recordings (He et al.,2004;Martinez et al.,2006,2007)used variations of the classic para-digm of Egly et al.(1994).In this design,two rectangles are pre-sented,and attention is cued to one end of one of the rectangles.Spatial attention is evidenced by findings of faster reaction times to a subsequent target at the cued location than at any of the other locations in the display.Object-based attention is inferred by findings of faster RTs to a target at the uncued end of the cued rectangle than to an equidistant target belonging to the uncued rectangle.Studies by Avrahami (1999)and Marino and Scholl (2005),however,found that similar attention effects could be obtained when the short ends of the rectangles were removed,so that the display consisted of an array of parallel lines rather than full-fledged enclosed objects.It was proposed that the flow of attention was guided from the cued location by a directional line tracing operation along the axis of the parallel lines rather than by true object-selective attention.These findings call into question whether the “same object effects”observed in the aforemen-tioned physiological studies using the Egly-type design were truly
a consequence of object-based selection of the entire bounded form.
In the current study,we compared the neural bases of spatial and object-based attention using symmetrical (square)objects so that attention would not be guided from the attended location by simple directional cues such as parallel lines.Importantly,for both real and illusory object forms,we found that the enhance-ment of the N1amplitude to unattended corner stimuli compar-ing object versus no-object conditions did not differ as a function of whether the unattended corner was situated horizontally,ver-tically,or diagonally with respect to the attended corner.This indicates that focusing attention on one part of the square re-sulted in selection of the entire square,even its most distant cor-ner.Whether this object-based selection is achieved through a systematic tracing of the entire boundary or by a filling in of the area within the object’s boundary is a matter for further investi-gation.In any case,the present results extend our previous find-ings (Martinez et al.2006,2007)by showing that a common pattern of ERP modulation (enhancement of the N1component)and fMRI activation (in area LOC)is shared by spatial attention and by bona fide object-based attention.
The object-based modulations of the N1component were vir-tually identical for the illusory square produced by Kanizsa in-ducers and for the real square produced by a luminance incre-ment.A similar equivalence was observed previously for ERP effects in an Egly-style paradigm using illusory and real rectangles (Martinez et al.,2007).The present findings with the illusory square strengthen the case that the observed N1modulations are associated with true object-based selection that occurs at a level of processing in which perceptual object forms are represented.Pre-vious studies have found that the perception of both illusory and real object forms is associated with enlarged N1components in the 140–200ms range (Pegna et al.,2002;Proverbio and Zani,2002),the neural generators of which have been localized to area LOC (Murray et al.,2002,2004,2006;Halgren et al.,2003).These findings are consistent with a broad range of evidence from fMRI (for review,see Grill-Spector,2002;Malach et al.,2002)and ERP (Doniger et al.,2001;Sehatpour et al.,2006)studies,which have implicated the LOC area as being critically involved in the initial encoding and recognition of objects.
Although the present results and those of previous studies (Mu ¨ller and Kleinschmidt,2003;He et al.,2004;Martinez et al.,2006,2007)have shown substantial overlap between the neural systems underlying spatial and object-based attention,these sys-tems were by no means identical.In the first place,spatially me-diated selection began earlier than the object-selective effects and were first evident as amplitude modulations of the P1component
Table 6.Effects of spatial attention ?attended stimuli (Att.)in both configurations vs unattended stimuli (Unatt.)in the object-absent configuration ?on ERP amplitudes (in microvolts)in experiment 2
Quad.Hemis.P1amplitudes Attention (Att.vs Unatt.)Hemisphere ?atten-tion (Ipsi.vs Contra.?Att.vs Unatt.)N1amplitudes Attention (Att.vs Unatt.)Hemisphere ?atten-tion (Ipsi.vs Contra.
?Att.vs Unatt.)Att.Unatt.F (1,10)p F (1,13)p Att.Unatt.F (1,10)p F (1,10)p UL LH
0.21?0.0914.83?0.003 3.9n.s.?0.86?0.2421.64?0.001 5.75?0.032RH 0.380.09?1.14?0.28UR LH 0.58?0.15 6.76?0.02644.27?0.001?1.21?0.3517.95?0.001 5.21?0.040RH 0.160.08?0.73?0.20LL LH 0.460.3710.68?0.0089.65?0.011?1.00?0.4212.22?0.00448.91?0.001RH 0.730.21?1.47?0.64LR
LH 0.780.148.61
?0.015
21.16
?0.001
?1.58?0.8711.12
?0.001
17.82
?0.005
RH
0.47
0.44
?0.77
?0.63
Data are shown for each quadrant (Quad.)and for ERPs recorded from the left (LH)and right (RH)hemispheres.Hemis.,Hemisphere;Ipsi.,ipsilateral;Contra.,
contralateral.
Figure 6.Grand-averaged ERPs in experiment 2to attended and unattended (Unatt.)stim-uli in each quadrant.In all quadrants,the amplitudes of the P1and N1components were enhanced for attended stimuli (black waveforms)compared with the same stimuli when unat-tended (red and green waveforms).Unattended stimuli in the object-present (illusory square)configuration also elicited larger N1amplitudes relative to the object-absent condition during thetimeintervalindicatedbytheyellowsquare.ERPsfromaparietalelectrodesitecontralateral to the eliciting stimulus (P3/P4)are shown for each quadrant.
7970?J.Neurosci.,July 25,2007?27(30):7963–7973Martinez et al.?Spatial Attention and Object Selection
(90ms after stimulus onset),whereas unattended stimuli that
formed part of the attended object only elicited amplitude en-hancements of the subsequent N1component.This finding fol-lows from previous studies that have ascribed separate roles to the
P1and N1components in spatial attention,with the P1reflecting an early stage that suppresses unattended inputs and the N1reflecting a subsequent stage at which relevant inputs are discrim-inated in detail (Luck et al.,1994).Second,the spread of spatial attention throughout the attended objects’boundaries did not occur in a uniform manner.Attended stimuli elicited significantly larger N1am-plitudes than did unattended stimuli,re-gardless of whether the unattended stimu-lus formed part of the same or a different object.This is consistent with numerous studies reporting a gradient of attention-related selectivity as a function of distance from the attended location (Mu ¨ller and Kleinschmidt,2003).An object-based at-tentional gradient,as measured by N1am-plitudes elicited by stimuli at unattended locations,was not obtained in either study reported here when adjacent versus diag-onal quadrants were compared,possibly
because the distances separating these quadrants were not large enough.Finally,although fMRI and source localization converged to indicate a source in cortical area LOC for both the spatial and object-guided N1modulations,the fMRI activa-tions during spatial attention were signif-icantly larger and more widespread than those associated with object-based selection (see also Mu ¨ller and Kleinschmidt,2003;Martinez et al.,2006).Two major hypotheses have been put forward to account for the role of spatial attention in the selection of objects,which may
Table 7.Object-based attention effects on unattended N1amplitudes (in microvolts)in experiment 2
Quad.Hemis.N1amplitudes
Attention (Obj.-present vs Obj.-absent)Hemisphere ?attention (Ipsi.vs Contra.?Obj.-present vs Obj.-absent)Same Different F (1,10)p F (1,10)p UL LH ?0.43?0.2412.91?0.0037.5?0.017RH ?0.64?0.28UR LH ?0.64?0.3511.94?0.003 6.6?0.023RH ?0.36?0.20LL LH ?0.66?0.4210.80?0.0067.75?0.016RH ?0.99?0.64LR
LH ?1.07?0.87 6.07
?0.028
17.21
?0.001
RH
?0.65
?0.63
Object (Obj.)-based attention effects were defined as increased N1amplitudes in the object-present versus object-absent configuration.Quad.,Quadrant;Hemis.,hemisphere;Ipsi.,ipsilateral;Contra.,contralateral;LH,left hemisphere;RH,right hemisphere.
Table 8.Amplitudes of object-based attention effect on N1(in microvolts)as a function of the relative position of the eliciting unattended stimulus ?horizontal (H),vertical (V),or diagonal (D)?with respect to the attended stimulus quadrant in experiment 2
Stimulus Hemis.Amplitudes Relative position (H,V,D)Hemisphere Position ?hemisphere H V D F (2,20)p F (1,10)p F (2,20)p UL LH
?0.45?0.45?0.410.51?0.600 5.67?0.0400.69?0.510RH ?0.73?0.64?0.55UR LH ?0.70?0.59?0.630.83?0.4509.05?0.020 1.12?0.340RH ?0.41?0.37?0.30LL LH ?0.67?0.67?0.640.06?0.94013.36?0.0040.54?0.590RH ?1.00?0.94?1.03LR
LH ?1.10?1.11?1.01 1.67
?0.232
23.56
?0.001
3.11
?0.098
RH
?0.54
?0.83
?0.59
Hemis.,Hemisphere;LH,left hemisphere;RH,right
hemisphere.
Figure 7.Topographies of attention-related N1modulations produced by spatial and object-based attention in experiment 2.Voltage maps of the N1attention-related difference waves produced by object-based attention (right map)and spatial attention (left map)are shown for each quadrant for the time interval 132–172ms.Spatial attention effects were calculated by subtracting unattended from attended ERPs.Object-based attention effects for each quadrant were calculated by subtracting unattended ERPs in the object-absent condition from ERPs elicited by the same stimulus in the object-present condition.The voltage scale on
the left applies to spatial attention maps;the scale on the right applies to object attention maps.
Martinez et al.?Spatial Attention and Object Selection J.Neurosci.,July 25,2007?27(30):7963–7973?7971
be characterized as “object-guided spatial attention”(Weber et al.,1997;Davis et al.,2000)and “priority setting”(Shomstein and Yantis,2002),respectively.According to the priority setting view,object-specific benefits occur in trial-by-trial cueing tasks because attention is switched from the cued (attended)location to uncued loca-tions within the same object with a higher priority than to uncued locations within a different object.Because the present task required focal attention to only one loca-tion,however,and no other locations were relevant,it seems unlikely that a pri-oritized switching of attention to the other locations would take place.Instead,the object-selective modulations of ERPs and BOLD signals that were observed here are highly compatible with an object-guided spatial attention mechanism in which the deployment of spatial attention to one part of an object produces a graded facili-tation of the sensory processing of the en-tire object,whether its boundaries are de-fined by real or illusory contours.This sensory enhancement was manifested by an increased amplitude of the N1compo-nent,which was localized to the LOC where object forms are initially encoded and represented.We hypothesize that the spotlight of spatial attention gates sensory input into area LOC via an earlier filtering mechanism indexed by the P1compo-nent.At this earlier level,sensory input is facilitated solely according to its location,but in LOC,the facilitation is guided by object representations as well as by loca-tion.The facilitation of attended object representations in LOC may reinforce their perceptual integrity and underlie the performance benefits manifested in the same object advantage.
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五年级上册成语解释及近义词反义词和造句大全 囫囵吞枣；【解释】：囫囵：整个儿。把枣整个咽下去，不加咀嚼，不辨味道。比喻对事物不加分析考虑。【近义词】：不求甚解【反义词】融会贯穿[造句];学习不能囫囵吞枣而是要精益求精 不求甚解；bùqiúshènjiě【解释】：甚：专门，极。只求明白个大概，不求完全了解。常指学习或研究不认真、不深入【近义词】：囫囵吞枣【反义词】：精益求精 造句；1；在学习上，我们要理解透彻，不能不求甚解 2；学习科学文化知识要刻苦钻研，深入领会，不能粗枝大叶，不求甚解。 千篇一律；【解释】：一千篇文章都一个样。指文章公式化。也比喻办事按一个格式，专门机械。 【近义词】：千人一面、如出一辙【反义词】：千差万别、形形色色 造句；学生旳作文千篇一律，专门少能有篇与众不同旳，这确实是平常旳练习太少了。 倾盆大雨；qīngpéndàyǔ【解释】：雨大得象盆里旳水直往下倒。形容雨大势急。 【近义词】：大雨如柱、大雨滂沱【反义词】：细雨霏霏牛毛细雨 造句；3月旳天说变就变，瞬间下了一场倾盆大雨。今天下了一场倾盆大雨。 坚决果断；áobùyóuyù：意思；做事果断，专门快拿定了主意，一点都不迟疑，形容态度坚决 近义词；不假思索斩钉截铁反义词；犹豫不决 造句；1看到小朋友落水，司马光坚决果断地搬起石头砸缸。2我坚决果断旳承诺了她旳要求。 饥肠辘辘jīchánglùlù【近义词】：饥不择食【反义词】：丰衣足食 造句；1我放学回家已是饥肠辘辘。2那个饥肠辘辘旳小孩差不多两天没吃饭了 滚瓜烂熟gǔnguālànshóu〔shú)【解释】：象从瓜蔓上掉下来旳瓜那样熟。形容读书或背书流利纯熟。【近义词】：倒背如流【反义词】：半生半熟造句；1、这篇课文我们早已背得滚瓜烂熟了 流光溢彩【liúguāngyìcǎi】解释；光影，满溢旳色彩，形容色彩明媚 造句：国庆节，商场里装饰旳流光溢彩。 津津有味；jīnjīnyǒuwèi解释：兴趣浓厚旳模样。指吃得专门有味道或谈得专门有兴趣。 【近义词】：兴致勃勃有滋有味【反义词】：索然无味、枯燥无味 造句；1今天旳晚餐真丰富，小明吃得津津有味。 天长日久；tiānchángrìjiǔ【解释】：时刻长，生活久。【近义词】：天长地久【反义词】：稍纵即逝 造句：小缺点假如不立即改掉, 天长日久就会变成坏适应 如醉如痴rúzuìrúchī【解释】：形容神态失常，失去自制。【近义词】：如梦如醉【反义词】：恍然大悟造句；这么美妙旳音乐，我听得如醉如痴。 浮想联翩【fúxiǎngliánpiān解释】：浮想：飘浮不定旳想象；联翩：鸟飞旳模样，比喻连续不断。指许许多多旳想象不断涌现出来。【近义词】：思绪万千 造句；1他旳话让人浮想联翩。2:这幅画饱含诗情，使人浮想联翩，神游画外，得到美旳享受。 悲欢离合bēihuānlíhé解释；欢乐、离散、聚会。泛指生活中经历旳各种境遇和由此产生旳各种心情【近义词】：酸甜苦辣、喜怒哀乐【反义词】：平淡无奇 造句；1人一辈子即是悲欢离合,总要笑口常开,我们旳生活才阳光明媚. 牵肠挂肚qiānchángguàdù【解释】：牵：拉。形容十分惦念，放心不下 造句；儿行千里母担忧，母亲总是那个为你牵肠挂肚旳人 如饥似渴rújīsìkě：形容要求专门迫切，仿佛饿了急着要吃饭，渴了急着要喝水一样。 造句；我如饥似渴地一口气读完这篇文章。他对知识旳如饥似渴旳态度造就了他今天旳成功。 不言而喻bùyánéryù【解释】：喻：了解，明白。不用说话就能明白。形容道理专门明显。 【近义词】：显而易见【反义词】：扑朔迷离造句；1珍惜时刻，好好学习，那个道理是不言而喻旳 与众不同；yǔzhòngbùtóng【解释】：跟大伙不一样。 〖近义词〗别出心裁〖反义词〗平淡无奇。造句； 1从他与众不同旳解题思路中，看出他专门聪慧。2他是个与众不同旳小孩
The way 的用法 Ⅰ常见用法： 1)the way+ that 2)the way + in which（最为正式的用法） 3)the way + 省略（最为自然的用法） 举例：I like the way in which he talks. I like the way that he talks. I like the way he talks. Ⅱ习惯用法： 在当代美国英语中，the way用作为副词的对格，“the way+ 从句”实际上相当于一个状语从句来修饰整个句子。 1)The way =as I am talking to you just the way I’d talk to my own child. He did not do it the way his friends did. Most fruits are naturally sweet and we can eat them just the way they are—all we have to do is to clean and peel them. 2）The way= according to the way/ judging from the way The way you answer the question, you are an excellent student. The way most people look at you, you’d think trash man is a monster. 3）The way =how/ how much No one can imagine the way he missed her. 4）The way =because
悲惨的近义词反义词和造句 导读：悲惨的近义词 悲凉(注释:悲哀凄凉：～激越的琴声。) 悲惨的反义词 幸福(注释:个人由于理想的实现或接近而引起的一种内心满足。追求幸福是人们的普遍愿望，但剥削阶级把个人幸福看得高于一切，并把个人幸福建立在被剥削阶级的痛苦之上。无产阶级则把争取广大人民的幸福和实现全人类的解放看作最大的幸福。认为幸福不仅包括物质生活，也包括精神生活;个人幸福依赖集体幸福，集体幸福高于个人幸福;幸福不仅在于享受，而主要在于劳动和创造。) 悲惨造句 1.一个人要发现卓有成效的真理，需要千百个人在失败的探索和悲惨的错误中毁掉自己的生命。 2.贝多芬的童年尽管如是悲惨，他对这个时代和消磨这时代的地方，永远保持着一种温柔而凄凉的回忆。 3.卖火柴的小女孩在大年夜里冻死了，那情景十分悲惨。 4.他相信，他们每个人背后都有一个悲惨的故事。 5.在那次悲惨的经历之后，我深信自己绝对不是那种可以离家很远的人。 6.在人生的海洋上，最痛快的事是独断独航，但最悲惨的却是回头无岸。 7.人生是艰苦的。对不甘于平庸凡俗的人那是一场无日无夜的斗
争，往往是悲惨的、没有光华的、没有幸福的，在孤独与静寂中展开的斗争。……他们只能依靠自己，可是有时连最强的人都不免于在苦难中蹉跎。罗曼·罗兰 8.伟大的心胸，应该表现出这样的气概用笑脸来迎接悲惨的厄运，用百倍的勇气来应付开始的不幸。鲁迅人在逆境里比在在顺境里更能坚强不屈。遇厄运时比交好运时容易保全身心。 9.要抓紧时间赶快生活，因为一场莫名其妙的疾病，或者一个意外的悲惨事件，都会使生命中断。奥斯特洛夫斯基。 10.在我一生中最悲惨的一个时期，我曾经有过那类的想法：去年夏天在我回到这儿附近的地方时，这想法还缠着我;可是只有她自己的亲自说明才能使我再接受这可怕的想法。 11.他们说一个悲惨的故事是悲剧，但一千个这样的故事就只是一个统计了。 12.不要向诱惑屈服，而浪费时间去阅读别人悲惨的详细新闻。 13.那起悲惨的事件深深地铭刻在我的记忆中。 14.伟大的心胸，应该用笑脸来迎接悲惨的厄运，用百倍的勇气来应付一切的不幸。 15.一个人要发现卓有成效的真理，需要千百万个人在失败的探索和悲惨的错误中毁掉自己的生命。门捷列夫 16.生活需要爱，没有爱，那些受灾的人们生活将永远悲惨;生活需要爱，爱就像调味料，使生活这道菜充满滋味;生活需要爱，爱让生活永远充满光明。
The way的用法及其含义（二） 二、the way在句中的语法作用 the way在句中可以作主语、宾语或表语： 1.作主语 The way you are doing it is completely crazy.你这个干法简直发疯。 The way she puts on that accent really irritates me. 她故意操那种口音的样子实在令我恼火。The way she behaved towards him was utterly ruthless. 她对待他真是无情至极。 Words are important, but the way a person stands, folds his or her arms or moves his or her hands can also give us information about his or her feelings. 言语固然重要,但人的站姿,抱臂的方式和手势也回告诉我们他(她)的情感。 2.作宾语 I hate the way she stared at me.我讨厌她盯我看的样子。 We like the way that her hair hangs down.我们喜欢她的头发笔直地垂下来。 You could tell she was foreign by the way she was dressed. 从她的穿著就可以看出她是外国人。 She could not hide her amusement at the way he was dancing. 她见他跳舞的姿势，忍俊不禁。 3.作表语 This is the way the accident happened.这就是事故如何发生的。 Believe it or not, that's the way it is. 信不信由你, 反正事情就是这样。 That's the way I look at it, too. 我也是这么想。 That was the way minority nationalities were treated in old China. 那就是少数民族在旧中
定冠词the的用法： 定冠词the与指示代词this ,that同源,有“那(这)个”的意思,但较弱,可以和一个名词连用,来表示某个或某些特定的人或东西. (1)特指双方都明白的人或物 Take the medicine.把药吃了. (2)上文提到过的人或事 He bought a house.他买了幢房子. I've been to the house.我去过那幢房子. (3)指世界上独一无二的事物 the sun ,the sky ,the moon, the earth (4)单数名词连用表示一类事物 the dollar 美元 the fox 狐狸 或与形容词或分词连用,表示一类人 the rich 富人 the living 生者 (5)用在序数词和形容词最高级,及形容词等前面 Where do you live?你住在哪? I live on the second floor.我住在二楼. That's the very thing I've been looking for.那正是我要找的东西. (6)与复数名词连用,指整个群体 They are the teachers of this school.(指全体教师) They are teachers of this school.(指部分教师) (7)表示所有,相当于物主代词,用在表示身体部位的名词前 She caught me by the arm.她抓住了我的手臂. (8)用在某些有普通名词构成的国家名称,机关团体,阶级等专有名词前 the People's Republic of China 中华人民共和国 the United States 美国 (9)用在表示乐器的名词前 She plays the piano.她会弹钢琴. (10)用在姓氏的复数名词之前,表示一家人 the Greens 格林一家人(或格林夫妇) (11)用在惯用语中 in the day, in the morning... the day before yesterday, the next morning... in the sky... in the dark... in the end... on the whole, by the way...
“tｈｅwａｙ+从句”结构的意义及用法 首先让我们来看下面这个句子: Ｒead the foｌloｗｉnｇpassagｅａnd talkａbout ｉt wi ｔh your classmaｔes．Try tｏｔeｌl whaｔyｏu thiｎk ｏf Tom aｎd ｏｆｔhe ｗay the chiｌｄrenｔrｅated ｈim. 在这个句子中，ｔhe waｙ是先行词,后面是省略了关系副词that或in whｉch的定语从句。 下面我们将叙述“the ｗaｙ+从句”结构的用法。 1.tｈe wａy之后，引导定语从句的关系词是tｈat而不是hoｗ,因此，<<现代英语惯用法词典＞＞中所给出的下面两个句子是错误的：Ｔhｉs is ｔｈeｗayｈowｉtｈａppened. This is the way how he ａlwａｙs treats me. 2．在正式语体中,thaｔ可被in which所代替;在非正式语体中，ｔhat则往往省略。由此我们得到theｗay后接定语从句时的三种模式：1) tｈe ｗaｙ＋ｔhａt-从句２）the way +ｉn whiｃh－从句3) the ｗay +从句 例如：Ｔｈe way(in whiｃh ，thａt) ｔhｅｓｅｃomｒade ｓloｏｋａｔｐrobｌems is wrong．这些同志看问题的方法
不对。 Ｔｈｅｗａy(that ,ｉn ｗhiｃh)yoｕ’ｒe doinｇit is comple ｔeｌy crａzy.你这么个干法,简直发疯。 Wｅａdmiｒｅd him for thｅｗay ｉｎｗhｉch he fａｃeｓdiｆficultieｓ． Waｌlａｃe ａｎd Ｄarwiｎｇreed ｏn the way ｉｎwhi ｃh ｄｉfｆｅrｅnt forms ｏf life had ｂegｕn.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 Thｉs is ｔｈe ｗaｙ（tｈａｔ) hｅdｉd it. I lｉkeｄｔhe waｙ(ｔhat) ｓｈeｏｒganized ｔhe ｍeetｉng． 3.theｗay(tｈat)有时可以与hｏw(作“如何”解）通用。例如： That’s tｈe ｗaｙ(tｈaｔ) shｅspoke. = Tｈat’s how shｅspoke.
知己的近义词反义词及知己的造句 本文是关于知己的近义词反义词及知己的造句，感谢您的阅读！ 知己的近义词反义词及知己的造句知己 基本解释：顾名思义是了解、理解、赏识自己的人，如"知己知彼，百战不殆";更常指懂你自己的挚友或密友，它是一生难求的朋友，友情的最高境界。正所谓:"士为知己者死"。 1.谓了解、理解、赏识、懂自己。 2.彼此相知而情谊深切的人。 【知己近义词】 亲信，好友，密友，心腹，挚友，深交，相知，知交，知友，知心，知音，石友，老友，至友 【知己反义词】 仇人敌人陌路 【知己造句】 1、我们想要被人爱、想拥有知己、想历经欢乐、想要安全感。 2、朋友本应是我们的亲密知己和支持者，但对于大多数人来说，有一些朋友比起帮助我们，更多的却是阻碍。 3、那么，为什么你就认为，随着年龄的增长，比起女人来男人们的知己和丰富的人际关系更少，因此一般容易更孤独呢？ 4、他成了我的朋友、我的知己、我的顾问。 5、无论在我当州长还是总统的时候，布鲁斯都是我的密友、顾问和知己。他这样的朋友人人需要，也是所有总统必须拥有的。
6、波兰斯基有着一段声名卓著的电影生涯，也是几乎所有电影界重要人物们的挚友和同事，他们是知己，是亲密的伙伴。 7、搜索引擎变成了可以帮追我们的忏悔室，知己，信得过的朋友。 8、这样看来，奥巴马国家安全团队中最具影响力的当属盖茨了――但他却是共和党人，他不会就五角大楼以外问题发表看法或成为总统知己。 9、我们的关系在二十年前就已经和平的结束了，但在网上，我又一次成为了他精神层面上的评论家，拉拉队，以及红颜知己。 10、这位“知己”，作为拍摄者，站在距离电视屏幕几英尺的地方对比着自己年轻版的形象。 11、父亲与儿子相互被形容为对方的政治扩音筒、知己和后援。 12、这对夫妻几乎没有什么至交或知己依然在世，而他们在后纳粹时期的德国也不可能会说出实话的。 13、她把我当作知己，于是，我便将她和情人之间的争吵了解得一清二楚。 14、有一种友谊不低于爱情；关系不属于暖昧；倾诉一直推心置腹；结局总是难成眷属；这就是知己！ 15、把你的治疗师当做是可以分享一切心事的知己。 16、莉莉安对我敞开心胸，我成了她的知己。 17、据盖洛普民意调查显示，在那些自我认同的保守党人中，尽管布什仍维持72%支持率，但他在共和党领导层中似乎很少有几位知
表示“方式”、“方法”，注意以下用法： 1.表示用某种方法或按某种方式，通常用介词in(此介词有时可省略)。如： Do it (in) your own way. 按你自己的方法做吧。 Please do not talk (in) that way. 请不要那样说。 2.表示做某事的方式或方法，其后可接不定式或of doing sth。 如： It’s the best way of studying [to study] English. 这是学习英语的最好方法。 There are different ways to do [of doing] it. 做这事有不同的办法。 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句，但是其后的从句不能由how 来引导。如： 我不喜欢他说话的态度。 正：I don’t like the way he spoke. 正：I don’t like the way that he spoke. 正：I don’t like the way in which he spoke. 误：I don’t like the way how he spoke. 4.注意以下各句the way 的用法： That’s the way (=how) he spoke. 那就是他说话的方式。 Nobody else loves you the way(=as) I do. 没有人像我这样爱你。 The way (=According as) you are studying now, you won’tmake much progress. 根据你现在学习情况来看，你不会有多大的进步。 2007年陕西省高考英语中有这样一道单项填空题： ——I think he is taking an active part insocial work. ——I agree with you_____. A、in a way B、on the way C、by the way D、in the way 此题答案选A。要想弄清为什么选A，而不选其他几项，则要弄清选项中含way的四个短语的不同意义和用法，下面我们就对此作一归纳和小结。 一、in a way的用法 表示：在一定程度上，从某方面说。如： In a way he was right.在某种程度上他是对的。注：in a way也可说成in one way。 二、on the way的用法 1、表示：即将来(去)，就要来(去)。如： Spring is on the way.春天快到了。 I'd better be on my way soon.我最好还是快点儿走。 Radio forecasts said a sixth-grade wind was on the way.无线电预报说将有六级大风。 2、表示：在路上，在行进中。如： He stopped for breakfast on the way.他中途停下吃早点。 We had some good laughs on the way.我们在路上好好笑了一阵子。 3、表示：(婴儿)尚未出生。如： She has two children with another one on the way.她有两个孩子，现在还怀着一个。 She's got five children，and another one is on the way.她已经有5个孩子了，另一个又快生了。 三、by the way的用法
仿照的近义词反义词和造句 仿照的近义词 【仿制解释】：仿造：～品 【模仿解释】：个体自觉或不自觉地重复他人的行为的过程。是社会学习的重要形式之一。尤其在儿童方面，儿童的动作、语言、技能以及行为习惯、品质等的形成和发展都离不开模仿。可分为无意识模仿和有意识模仿、外部模仿和内部模仿等多种类型。 仿照的反义词 【独创解释】：独特的创造：～精神ㄧ～一格。 仿照造句 一、老师让我们仿照黑板上的图画一幅画。 二、仿照下面的句式，以“只有”开头，写一结构与之相似的复句。 三、仿照例句的句子，在下面两句的横线上补写相应的内容。 四、仿照例句，以“记忆”或“友情”开头，另写一句话。 五、仿照下面两个例句，用恰当的词语完成句子，要求前后语意关联。 六、仿照开头两句句式，通过联想，在后面两句横线上填上相应的词语。 七、仿照所给例句，用下面的词展开联想，给它一个精彩的解释。 八、仿照例句，以“你”开头，另写一个句子。 九、仿照下列句式，续写两个句子，使之与前文组成意义相关的.句子。 十、我们也仿照八股文章的笔法来一个“八股”,以毒攻毒,就叫做八大罪状吧。
十一、仿照例句，任选一种事物，写一个句子。 十二、仿照下面一句话的句式和修辞，以“时间”开头，接着写一个句子。 十三、仿照例句，以“热爱”开头，另写一句子。 十四、仿照下面的比喻形式，另写一组句子。要求选择新的本体和喻体，意思完整。 十五、根据语镜，仿照划线句子，接写两句，构成语意连贯的一段话。 十六、仿照下面句式，续写两个句式相同的比喻句。 十七、自选话题，仿照下面句子的形式和修辞，写一组排比句。 十八、仿照下面一句话的句式，仍以“人生”开头，接着写一句话。 十九、仿照例句的格式和修辞特点续写两个句子，使之与例句构成一组排比句。 二十、仿照例句，另写一个句子，要求能恰当地表达自己的愿望。 二十一、仿照下面一句话的句式，接着写一句话，使之与前面的内容、句式相对应，修辞方法相同。 二十二、仿照下面一句话的句式和修辞，以“思考”开头，接着写一个句子。 二十三、仿照下面例句，从ABCD四个英文字母中选取一个，以”青春”为话题，展开想象和联想，写一段运用了比喻修辞格、意蕴丰富的话，要求不少于30字。 二十四、仿照下面例句，另写一个句子。 二十五、仿照例句，另写一个句子。 二十六、下面是毕业前夕的班会上，数学老师为同学们写的一句赠言，请你仿照它的特点，以语文老师的身份为同学们也写一句。
The way的用法及其含义（一） 有这样一个句子：In 1770 the room was completed the way she wanted. 1770年，这间琥珀屋按照她的要求完成了。 the way在句中的语法作用是什么？其意义如何？在阅读时，学生经常会碰到一些含有the way 的句子，如：No one knows the way he invented the machine. He did not do the experiment the way his teacher told him.等等。他们对the way 的用法和含义比较模糊。在这几个句子中，the way之后的部分都是定语从句。第一句的意思是，“没人知道他是怎样发明这台机器的。”the way的意思相当于how；第二句的意思是，“他没有按照老师说的那样做实验。”the way 的意思相当于as。在In 1770 the room was completed the way she wanted.这句话中，the way也是as的含义。随着现代英语的发展，the way的用法已越来越普遍了。下面，我们从the way的语法作用和意义等方面做一考查和分析： 一、the way作先行词，后接定语从句 以下3种表达都是正确的。例如：“我喜欢她笑的样子。” 1. the way+ in which +从句 I like the way in which she smiles. 2. the way+ that +从句 I like the way that she smiles. 3. the way + 从句(省略了in which或that) I like the way she smiles. 又如：“火灾如何发生的，有好几种说法。” 1. There were several theories about the way in which the fire started. 2. There were several theories about the way that the fire started.
暗示的近义词和反义词[暗示的近义词反义词和造句] 【暗示解释】：用含蓄、间接的方式使他人的心理、行为受到影响。下面小编就给大家整理暗示的近义词，反义词和造句，供大家学习参考。 暗示近义词 默示 示意 暗指 暗意暗示反义词 明说 表明 明言暗示造句 1. 他的顶级助手已经暗示那可能就在不久之后，但是避免设定具体的日期。 2. 一些观察家甚至暗示他可能会被送到了古拉格。 3. 要有积极的心理暗示，达成目标的好处不够充分，画面不够鲜明那它对你的吸引力就不够强烈，你就不易坚持下去! 4. 不要经常去试探男人，更不要以分手做为威胁，当你经常给他这种心理暗示，他的潜意识就会做好分手的打算。 5. 向读者暗示永远不必为主角担心，他们逢凶化吉，永远会吉人天相。 6. 约她一起运动，不要一下跳跃到游泳，可以从羽毛球网球开始，展示你的体魄和运动细胞，流汗的男人毫无疑问是最性感的，有意无意的裸露与靠近，向她暗示你的运动能力。 7. 正如在上一个示例所暗示的，只有在这些对象引用内存中同一个对象时，它们才是相同的。 8. 渥太华此时打出中国牌，巧妙地对美国这种行为作出警告，暗示美国如果长期这样下去的话，美国将自食其果。 9. 团长用震撼人心的嗓音喊道，这声音对他暗示欢乐，对兵团暗示森严，对前来校阅阅兵的首长暗示迎迓之意。 10. 渥太华此时打出中国牌，巧妙地对美国这种行为作出警告，暗示美国如果长期这样下去的话，美国将自食其恶果。 11. 我们需要邀请用户，为他们描述服务产品有多少好，给他们解释为什么他们需要填那些表单并且暗示他们会因此得到利益的回报。 12. 她对暗示她在说谎的言论嗤之以鼻。 14. 在力士参孙中，整首诗都强烈暗示着弥尔顿渴望他自己也能像参孙一样，以生命为代价，与敌人同归于尽。 15. 戴维既然问将军是否看见天花板上的钉子，这就暗示着他自己已看见了，当将军做了肯定的答复后，他又说自己看不见，这显然是自相矛盾。 16. 自我暗示在我们的生活中扮演着重要角色。如果我们不加以觉察，通常它会与我们作对。相反地，如果你运用它，它的力量就可以任你使唤。 17. 纳什建议太阳招兵买马，暗示去留取决阵容实力。 18. 同时，还暗示了菊既不同流俗，就只能在此清幽高洁而又迷漾暗淡之境中任芳姿憔悴。 19. 学习哲学的最佳途径就是将它当成一个侦探故事来处理：跟踪它的每一点蛛丝马迹每一条线索与暗示，以便查出谁是真凶，谁是英雄。 20. 不要经常去试探你的伴侣，更不要以分手做为威胁，试探本身就是一种不信任，当
放弃的近义词反义词和造句 下面就给大家整理放弃的近义词，反义词和造句，供大家学习参考。 放弃的近义词【废弃解释】：抛弃不用：把～的土地变成良田ㄧ旧的规章制度要一概～。 【丢弃解释】：扔掉;抛弃：虽是旧衣服，他也舍不得～。 放弃的反义词【保存解释】：使事物、性质、意义、作风等继续存在，不受损失或不发生变化：～古迹ㄧ～实力ㄧ～自己，消灭敌人。 放弃造句(1) 运动员要一分一分地拼，不能放弃任何一次取胜的机会。 (2) 我们不要放弃每一个成功的机会。 (3) 敌军招架不住，只好放弃阵地，狼狈而逃。 (4) 为了农村的教育事业，姐姐主动放弃了调回城市的机会。 (5) 都快爬到山顶了，你却要放弃，岂不功亏一篑?(6) 纵使遇到再大的困难，我们也要勇往直前，不轻言放弃。 (7) 逆境中的他始终没有放弃努力,仍满怀信心,期待着峰回路转的那一天。 (8) 听了同学的规劝,他如梦初醒,放弃了离家出走的想法。 (9) 因寡不敌众,我军放弃了阵地。 (10) 要日本帝国主义放弃侵华野心,无异于与虎谋皮。 (11) 永不言弃固然好，但有时放弃却也很美。
(12) 他这种放弃原则、瓦鸡陶犬的行径已经被揭露出来了。 (13) 适当放弃，做出斩钉截铁的决定，才能成为人生的赢家。 (14) 他委曲求全地放弃自己的主张，采纳了对方的意见。 (17) 我们要有愚公移山一样的斗志，坚持不懈，永远不放弃，去登上梦想的彼岸!(18) 只要有希望，就不能放弃。 (19) 为了大局着想，你应该委曲求全地放弃自己的看法。 (20) 既然考试迫在眉睫，我不得不放弃做运动。 (21) 即使没有人相信你，也不要放弃希望。 (22) 无论通往成功的路途有多艰辛，我都不会放弃。 (23) 在困难面前，你是选择坚持，还是选择放弃?(24) 无论前路多么的漫长，过程多么的艰辛，我都不会放弃并坚定地走下去。 (25) 你不要因为这点小事就英雄气短,放弃出国深造的机会。 (26) 像他这样野心勃勃的政客，怎么可能放弃追求权力呢?(27) 鲁迅有感于中国人民愚昧和麻木,很需要做发聋振聩的启蒙工作,于是他放弃学医,改用笔来战斗。 (28) 我们对真理的追求应该坚持不懈，锲而不舍，绝不能随便放弃自己的理想。 (29) 感情之事不比其他，像你这样期盼东食西宿，几个男友都捨不得放弃，最后必定落得一场空。 (30) 爷爷临终前的话刻骨铭心，一直激励着我努力学习，无论是遇到多大的困难险阻，我都不曾放弃。
way 的用法 【语境展示】 1. Now I’ll show you how to do the experiment in a different way. 下面我来演示如何用一种不同的方法做这个实验。 2. The teacher had a strange way to make his classes lively and interesting. 这位老师有种奇怪的办法让他的课生动有趣。 3. Can you tell me the best way of working out this problem? 你能告诉我算出这道题的最好方法吗？ 4. I don’t know the way (that / in which) he helped her out. 我不知道他用什么方法帮助她摆脱困境的。 5. The way (that / which) he talked about to solve the problem was difficult to understand. 他所谈到的解决这个问题的方法难以理解。 6. I don’t like the way that / which is being widely used for saving water. 我不喜欢这种正在被广泛使用的节水方法。 7. They did not do it the way we do now. 他们以前的做法和我们现在不一样。 【归纳总结】 ●way作“方法，方式”讲时，如表示“以……方式”，前面常加介词in。如例1； ●way作“方法，方式”讲时，其后可接不定式to do sth.，也可接of doing sth. 作定语，表示做某事的方法。如例2，例3；
体面的近义词|反义词及造句 我们还必须迅速采取行动，为实现社会包容和人人体面工作营造有利的环境。下面是小编精选整理的体面的近义词|反义词及造句，供您参考，欢迎大家阅读。 体面的近义词： 面子、合适、美观、颜面、场合、场面、排场、得体、好看、局面 体面的反义词： 难听、寒碜、邋遢、寒酸、难看 体面造句 1、我认为，帖在墙面上的证书，并不能使你成为一个体面的人。 2、他是那里唯一的看上去很体面的人;我认为他从来没有这样好看过。 3、所有的美国人都是好的，体面的人们每天都在践行着他们的责任。 4、美国人民慷慨、强大、体面，这并非因为我们信任我们自己，而是因为我们拥有超越我们自己的信念。 5、工人就是工人，无论他们来自哪里，他们都应该受到尊重和尊敬，至少因为他们从事正当的工作而获得体面的工资。 6、然而反之有些孩子可能就是多少有些体面的父母的不良种子这一概念却令人难以接受。
7、如果奥巴马能够成就此功，并且帮助一个体面的伊拉克落稳脚跟，奥巴马和民主党不仅是结束了伊拉克战争，而是积极从战争中挽救。 8、而且，等到年纪大了退休时，他们希望能得到尊重和体面的对待。 9、爸爸，您倒对这件事处理得很体面，而我想那可能是我一生中最糟糕的一个夜晚吧。 10、有一些积极的东西，低于预期的就业损失索赔和零售销售是体面的。 11、如果你努力工作，你就能有获得一份终生工作的机会，有着体面的薪水，良好的福利，偶尔还能得到晋升。 12、体面的和生产性的工作是消除贫困和建立自给自足最有效的方法之一。 13、同时，他是一个仁慈、温和、体面的人，一个充满爱的丈夫和父亲，一个忠实的朋友。 14、几周前我们刚讨论过平板电脑是如何作为一个体面且多产的电子设备，即使它没有完整的键盘，在进行输入时会稍慢些。 15、什么才是生活体面的标准? 16、我们还必须迅速采取行动，为实现社会包容和人人体面工作营造有利的环境。 17、她告诉我人们都担心是不是必须把孩子送到国外去学习，才能保证孩子们长大后至少能过上体面正派的生活。
t h e-w a y-的用法
The way 的用法 "the way+从句"结构在英语教科书中出现的频率较高, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或 in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 一.在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮.
近义词反义词大全有关聆听的反义词近义词和造句 【聆听解释】：1.汉扬雄《法言.五百》:"聆听前世﹐清视在下﹐鉴莫近于斯矣。"后多用于书面语﹐常指仔细注意地听。下面就给大家聆听的反义词，近义词和造句，供大家学习参考。 嘱咐 [注释]1.叮嘱，吩咐 倾听 [注释]1.侧着头听。 2.细听;认真地听 凝听 [注释]1.聚精会神地听 谛听 [注释]注意地听;仔细听：侧耳谛听 细听 [注释]… 1. 学校应充分利用社会的各种，调动一切可以调动的力量，应尽一切可能请进名师专家，让教师和学生有较多的机会聆听大师的声音、与大师对话。这多少会机器他们向往大师、成为大师的冲动，多少会使他们觉得大师就在身边，大师并不遥远。 2. 今天妈妈带我来到了这个美丽的大安森林公园玩，这儿有漂亮的花儿和绿油油的树，草，看起来像一个我好想好想要的花园。树
上有小鸟儿在唱歌，有蝉声在帮忙和弦，树下有小朋友再安静仔细聆听著这最自然的交响曲。 3. 静静聆听那滴滴答答的声音，不知在为谁倾诉?她在偶尔低语，偶尔高唱，偶尔呻吟，偶尔叹息，生动灵活，充满了立体与层次之美，在心灵中轻轻一吻，便触发了思绪，这思绪时而短暂，时而绵长，时而深沉，时而悠远…… 4. 九月的手掌拂去小溪夏日的狂躁，用心聆听着秋日的私语，温顺地弹唱着九月醉人的秋歌，惹得天空湛蓝高远，碧空如洗。 5. 我光着脚丫，踩着海水，注视着波光粼粼的海面，听着哗哗的响声，那声音好像高超演奏家的激越的钢琴曲，又像歌唱家的雄浑的进行曲，那声音使胸膛激荡，热血奔涌，啊，我多么愿意聆听大海老人的谆谆教诲啊! 6. 雪花飘飘，寒风阵阵，我细细地聆听着寒风谱写成的有声有色的乐谱，为雪花的舞步增添一些光彩。寒风真像一位默默为雪花服务的人。过了一会儿，又为雪花写了一篇朗朗上口的诗歌，一会儿又为她热烈地鼓起了清脆的掌声。
way的用法总结大全 way的用法你知道多少，今天给大家带来way的用法，希望能够帮助到大家，下面就和大家分享，来欣赏一下吧。 way的用法总结大全 way的意思 n. 道路,方法,方向,某方面 adv. 远远地，大大地 way用法 way可以用作名词 way的基本意思是“路,道,街,径”,一般用来指具体的“路,道路”,也可指通向某地的“方向”“路线”或做某事所采用的手段,即“方式,方法”。way还可指“习俗,作风”“距离”“附近,周围”“某方面”等。 way作“方法,方式,手段”解时,前面常加介词in。如果way前有this, that等限定词,介词可省略,但如果放在句首,介词则不可省略。
way作“方式,方法”解时,其后可接of v -ing或to- v 作定语,也可接定语从句,引导从句的关系代词或关系副词常可省略。 way用作名词的用法例句 I am on my way to the grocery store.我正在去杂货店的路上。 We lost the way in the dark.我们在黑夜中迷路了。 He asked me the way to London.他问我去伦敦的路。 way可以用作副词 way用作副词时意思是“远远地,大大地”,通常指在程度或距离上有一定的差距。 way back表示“很久以前”。 way用作副词的用法例句 It seems like Im always way too busy with work.我工作总是太忙了。 His ideas were way ahead of his time.他的思想远远超越了他那个时代。 She finished the race way ahead of the other runners.她第一个跑到终点,远远领先于其他选手。 way用法例句
终于的近义词，反义词及造句 …终究[注释]副词。 总：总归;毕竟;最终：我们只要把事情办好，人们终究会相信我们的|腐朽的东西终究要灭…到底[注释]1.直到尽头。 2.始终;从头到尾。 3.毕竟;究竟。 …结果[注释]结果1在一定阶段，事物发展所达到的最后状态：优良的成绩，是长期刻苦学习的～ㄧ经过一番争论…终归[注释]1.传说中神兽名。 2.终究;毕竟。 …究竟终于的反义词：起初、最初、原来、依旧、起先终于的造句：(1) 盼望了一个冬天的雪花，下午终于飘飘洒洒满天飞舞般降落。 同事们也如孩子般奔向办公室的走廊，欣喜地用手去接冰凉的小雪花再用盆子收拢些飘舞的小雪花。 隔窗望去，天地之间因突然多了这白色的小精灵而愈发显得美丽。 (2) 快乐的暑假终于到了，我可以开开心心痛痛快快地玩一顿了!当然，在这之前，我也会好好安排一下我的暑假生活，使我过个既快乐又充实的暑假，我快乐的暑假生活。 (3) 坚韧，让沙石煎熬住大海的蹂躏，终于化作璀璨的珍珠;坚韧，让天空忍受住雨水倾盆的阴霾，终于看见那一道彩虹;坚韧，让泉水忘记流进山谷崎岖的历程，终于汇入蔚蓝无垠的大海。
它的叶子正面是身绿色的，反面是浅绿的，经脉上还有一些毛绒绒的小细毛。 又过了几天，含羞草的花蕾也长出来了，圆溜溜的，紫红色，还有着一些像针一样的东西，非常美丽。 (5) 漫长而炎热的夏天终于过去了，凉爽怡人的秋天来到了。 (6) 随着天空被点燃，太阳也终于露出脸来，它没有害羞，而是大大方方地把它独特的热情展示给我们，毫不吝惜地奖光芒撒向大地。 (7) 大约过了二十分钟，太阳终于挣脱了大地妈妈的怀抱，在崇山俊岭之间冉冉升起，真像个大红球，又像气得涨红了脸。 (8) 半个月的低烧，终于有了好转，高烧了……(9) 夏天的雨后，太阳冲出乌云的包围，终于露出了整张脸，此时阳光直直的，却不呆板、单调，它们穿梭在树枝之间，织成一道道金色的丝，将鱼后的水珠串成一串金黄的珍珠。 夏天少有的凉意伴着美丽的阳光，令人沁透心脾。 (10) 终于到达了果园。 我们忽然发现，果园里还种了一些菊花。 这些菊花有红的蓝的黄的白的……它们颜色不同，姿态也不同：菊花们有的含苞欲放，有的开了一半，有的已经绽开了笑脸……千姿百态，十分美丽。 (11) 发改委终于超越了统计局，说北京人均绿地是巴黎两倍。 最牛回复：“是算上了开心农场吧?。
t h e_w a y的用法大全
The way 在the way+从句中, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或 in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 如果怕弄混淆，下面的可以不看了 另外，在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的