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Top-down modulation of visual processing and knowledge after 250 ms supports object constancy of category decisions.

Schendan HE, Ganis G - Front Psychol (2015)

Bottom Line: N3 impoverishment effects localized to both prefrontal and occipitotemporal cortex for real objects only.The N3 also showed knowledge effects by 230 ms that localized to occipitotemporal cortex.Finally, response activity in supplementary motor area during a posterior SW after 900 ms showed impoverishment effects that correlated with RTs.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, Cognition Institute, University of Plymouth Plymouth, UK.

ABSTRACT
People categorize objects more slowly when visual input is highly impoverished instead of optimal. While bottom-up models may explain a decision with optimal input, perceptual hypothesis testing (PHT) theories implicate top-down processes with impoverished input. Brain mechanisms and the time course of PHT are largely unknown. This event-related potential study used a neuroimaging paradigm that implicated prefrontal cortex in top-down modulation of occipitotemporal cortex. Subjects categorized more impoverished and less impoverished real and pseudo objects. PHT theories predict larger impoverishment effects for real than pseudo objects because top-down processes modulate knowledge only for real objects, but different PHT variants predict different timing. Consistent with parietal-prefrontal PHT variants, around 250 ms, the earliest impoverished real object interaction started on an N3 complex, which reflects interactive cortical activity for object cognition. N3 impoverishment effects localized to both prefrontal and occipitotemporal cortex for real objects only. The N3 also showed knowledge effects by 230 ms that localized to occipitotemporal cortex. Later effects reflected (a) word meaning in temporal cortex during the N400, (b) internal evaluation of prior decision and memory processes and secondary higher-order memory involving anterotemporal parts of a default mode network during posterior positivity (P600), and (c) response related activity in posterior cingulate during an anterior slow wave (SW) after 700 ms. Finally, response activity in supplementary motor area during a posterior SW after 900 ms showed impoverishment effects that correlated with RTs. Convergent evidence from studies of vision, memory, and mental imagery which reflects purely top-down inputs, indicates that the N3 reflects the critical top-down processes of PHT. A hybrid multiple-state interactive, PHT and decision theory best explains the visual constancy of object cognition.

No MeSH data available.


Related in: MedlinePlus

Late ERP slow waves (SW) show main effects of impoverishment and object type after 900 ms until response, localize to supplementary motor area (SMA), and correlate with RT effects. (A) Grand average ERPs show effects of impoverishment (more [MI], less [LI] impoverished) and object type. ERPs at lateral sites of the SW (11–12), a posterior slow wave (pSW; 51–52), and type effects (21–22) are plotted negative up. Image type and impoverishment modulated distinct ERPs even after 900 and until the latest responses around 1400 ms for MI pseudo objects. An impoverished-real-object effect on a late pSW started after 900 ms (gray line). (B) Voltmap generated using sLORETA (default left mastoid reference) shows the distribution of voltage differences over the left hemisphere from 1100 to 1400 ms when only the SMA effect occurs; the distribution is similar from 900 to 1100 ms. Electrodes symbolized by half spheres. The + sites are where the pSW effect is strongest (MI - LI), whereas—sites are the location of the SW over frontal scalp (LI - MI). (C) Across subjects, the RT difference correlated significantly with the late pSW effect. Each diamond plots the RT and ERP values for each subject. RT difference on x-axis. ERP amplitude difference on y-axis. The computed linear regression line (solid) is shown. Impoverishment difference for real objects (MI minus LI) from 900 to 1100 ms at site 51 correlated such that, on MI relative to LI trials, as the pSW became more positive, RTs got slower. (D) Maps from sLORETA for 900 to 1100 ms on the left (L) medial surface show the late SMA (BA 6, −15 −10 55; 5 −5 65) impoverishment effect for real objects, extending into anterior cingulate gyrus (BA 24, −15 −10 50), and estimated intracranial ERPs show the SMA effect started after 900 ms. Specifically, from 900 to 1100 ms, sources of impoverishment effects for real objects continued in striate/extrastriate and anterior temporal cortex, and, for the first time, were located in left more than right SMA and anterior cingulate, and this effect appeared to correspond to the pSW. From 1100 to 1400 ms, the SMA effect continued, but extended dorsally into superior frontal gyrus (BA 6, −10 [−10 or −15] 70), and posterior effects were minimal or none. At these times, the impoverishment effect for pseudo objects localized to striate/extrastriate areas (BA 17/18) with weaker sources in temporal pole (BA 38, −40 20 −35) and inferior frontal gyrus (BA 47, −50 45 −10). Note, the sLORETA map shows estimated sources of the difference wave (MI - LI) in the grand average ERPs superimposed on an inflated, canonical MNI152 brain (Colin); dark areas represent sulci; light areas represent gyri. The depicted brain shows standardized cortical current density distributions, and source activity reflects the location of differential source activity between conditions but not the direction of effects. Scale shows yellow represents maximal current density value differences. Estimated intracranial ERPs from −100 to 1400 ms were extracted from the voxel showing maximum impoverished-real-object effects at MNI coordinates from 900 to 1400 ms in SMA (−10 −10 70). Solid tics mark the 0 ms stimulus onset and 400 ms intervals post-stimulus.
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Figure 9: Late ERP slow waves (SW) show main effects of impoverishment and object type after 900 ms until response, localize to supplementary motor area (SMA), and correlate with RT effects. (A) Grand average ERPs show effects of impoverishment (more [MI], less [LI] impoverished) and object type. ERPs at lateral sites of the SW (11–12), a posterior slow wave (pSW; 51–52), and type effects (21–22) are plotted negative up. Image type and impoverishment modulated distinct ERPs even after 900 and until the latest responses around 1400 ms for MI pseudo objects. An impoverished-real-object effect on a late pSW started after 900 ms (gray line). (B) Voltmap generated using sLORETA (default left mastoid reference) shows the distribution of voltage differences over the left hemisphere from 1100 to 1400 ms when only the SMA effect occurs; the distribution is similar from 900 to 1100 ms. Electrodes symbolized by half spheres. The + sites are where the pSW effect is strongest (MI - LI), whereas—sites are the location of the SW over frontal scalp (LI - MI). (C) Across subjects, the RT difference correlated significantly with the late pSW effect. Each diamond plots the RT and ERP values for each subject. RT difference on x-axis. ERP amplitude difference on y-axis. The computed linear regression line (solid) is shown. Impoverishment difference for real objects (MI minus LI) from 900 to 1100 ms at site 51 correlated such that, on MI relative to LI trials, as the pSW became more positive, RTs got slower. (D) Maps from sLORETA for 900 to 1100 ms on the left (L) medial surface show the late SMA (BA 6, −15 −10 55; 5 −5 65) impoverishment effect for real objects, extending into anterior cingulate gyrus (BA 24, −15 −10 50), and estimated intracranial ERPs show the SMA effect started after 900 ms. Specifically, from 900 to 1100 ms, sources of impoverishment effects for real objects continued in striate/extrastriate and anterior temporal cortex, and, for the first time, were located in left more than right SMA and anterior cingulate, and this effect appeared to correspond to the pSW. From 1100 to 1400 ms, the SMA effect continued, but extended dorsally into superior frontal gyrus (BA 6, −10 [−10 or −15] 70), and posterior effects were minimal or none. At these times, the impoverishment effect for pseudo objects localized to striate/extrastriate areas (BA 17/18) with weaker sources in temporal pole (BA 38, −40 20 −35) and inferior frontal gyrus (BA 47, −50 45 −10). Note, the sLORETA map shows estimated sources of the difference wave (MI - LI) in the grand average ERPs superimposed on an inflated, canonical MNI152 brain (Colin); dark areas represent sulci; light areas represent gyri. The depicted brain shows standardized cortical current density distributions, and source activity reflects the location of differential source activity between conditions but not the direction of effects. Scale shows yellow represents maximal current density value differences. Estimated intracranial ERPs from −100 to 1400 ms were extracted from the voxel showing maximum impoverished-real-object effects at MNI coordinates from 900 to 1400 ms in SMA (−10 −10 70). Solid tics mark the 0 ms stimulus onset and 400 ms intervals post-stimulus.

Mentions: For completeness and because RTs occurred after the SW, cortical dynamics closer to the motor response were also assessed. EEG was re-analyzed to reject artifacts both between 900 and 1400 ms post-stimulus and during a pre-stimulus baseline of −100 to 100 ms. Analysis times from 900 to 1099 ms captured most MI real object RTs, and 1100 to 1400 ms captured most MI pseudo object RTs. Results showed anterior SW effects of impoverishment continued until 1099 ms and type until 1400 ms. Greater positivity was also found on a left mid-occipital-parietal slow wave (pSW) for MI than LI real objects from 900 to 1400 ms, which inverted polarity anteriorly, and the pSW showed type effects for MI trials until 1099 ms (Figures 9A,B). Critically, no impoverishment by type interactions were found after 900 ms. Both times showed main effects of type and impoverishment laterally, and type at midline sites (Fs > 10.70, ps < 0.005), and type and impoverishment each interacted with lateral electrode (Fs > 4.33), type with midline electrode and with lobe (Fs > 29.33), and impoverishment with midline electrode by lobe (Fs > 28.76), ps < 0.003. From 900 to 1099 ms, results also showed interactions of impoverishment by hemisphere, by midline electrode, by lobe (Fs > 5.4), by electrode by hemisphere (F = 2.19), ps < 0.04, and by Type by midline electrode (F = 9.74, p = 0.006). Focal simple effects tests on frontal SW pair 11–12 showed all impoverishment and type effects were significant from 900 to 1099 ms and both type effects from 1100 to 1400 ms (Fs > 4.51, ps < 0.05). Parietal pair 51–52, where the pSW was large, showed impoverishment by hemisphere for real objects from 900 to 1400 ms (Fs > 5.22), and type on MI trials from 900 to 1099 ms (F = 4.68), ps < 0.05.


Top-down modulation of visual processing and knowledge after 250 ms supports object constancy of category decisions.

Schendan HE, Ganis G - Front Psychol (2015)

Late ERP slow waves (SW) show main effects of impoverishment and object type after 900 ms until response, localize to supplementary motor area (SMA), and correlate with RT effects. (A) Grand average ERPs show effects of impoverishment (more [MI], less [LI] impoverished) and object type. ERPs at lateral sites of the SW (11–12), a posterior slow wave (pSW; 51–52), and type effects (21–22) are plotted negative up. Image type and impoverishment modulated distinct ERPs even after 900 and until the latest responses around 1400 ms for MI pseudo objects. An impoverished-real-object effect on a late pSW started after 900 ms (gray line). (B) Voltmap generated using sLORETA (default left mastoid reference) shows the distribution of voltage differences over the left hemisphere from 1100 to 1400 ms when only the SMA effect occurs; the distribution is similar from 900 to 1100 ms. Electrodes symbolized by half spheres. The + sites are where the pSW effect is strongest (MI - LI), whereas—sites are the location of the SW over frontal scalp (LI - MI). (C) Across subjects, the RT difference correlated significantly with the late pSW effect. Each diamond plots the RT and ERP values for each subject. RT difference on x-axis. ERP amplitude difference on y-axis. The computed linear regression line (solid) is shown. Impoverishment difference for real objects (MI minus LI) from 900 to 1100 ms at site 51 correlated such that, on MI relative to LI trials, as the pSW became more positive, RTs got slower. (D) Maps from sLORETA for 900 to 1100 ms on the left (L) medial surface show the late SMA (BA 6, −15 −10 55; 5 −5 65) impoverishment effect for real objects, extending into anterior cingulate gyrus (BA 24, −15 −10 50), and estimated intracranial ERPs show the SMA effect started after 900 ms. Specifically, from 900 to 1100 ms, sources of impoverishment effects for real objects continued in striate/extrastriate and anterior temporal cortex, and, for the first time, were located in left more than right SMA and anterior cingulate, and this effect appeared to correspond to the pSW. From 1100 to 1400 ms, the SMA effect continued, but extended dorsally into superior frontal gyrus (BA 6, −10 [−10 or −15] 70), and posterior effects were minimal or none. At these times, the impoverishment effect for pseudo objects localized to striate/extrastriate areas (BA 17/18) with weaker sources in temporal pole (BA 38, −40 20 −35) and inferior frontal gyrus (BA 47, −50 45 −10). Note, the sLORETA map shows estimated sources of the difference wave (MI - LI) in the grand average ERPs superimposed on an inflated, canonical MNI152 brain (Colin); dark areas represent sulci; light areas represent gyri. The depicted brain shows standardized cortical current density distributions, and source activity reflects the location of differential source activity between conditions but not the direction of effects. Scale shows yellow represents maximal current density value differences. Estimated intracranial ERPs from −100 to 1400 ms were extracted from the voxel showing maximum impoverished-real-object effects at MNI coordinates from 900 to 1400 ms in SMA (−10 −10 70). Solid tics mark the 0 ms stimulus onset and 400 ms intervals post-stimulus.
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Figure 9: Late ERP slow waves (SW) show main effects of impoverishment and object type after 900 ms until response, localize to supplementary motor area (SMA), and correlate with RT effects. (A) Grand average ERPs show effects of impoverishment (more [MI], less [LI] impoverished) and object type. ERPs at lateral sites of the SW (11–12), a posterior slow wave (pSW; 51–52), and type effects (21–22) are plotted negative up. Image type and impoverishment modulated distinct ERPs even after 900 and until the latest responses around 1400 ms for MI pseudo objects. An impoverished-real-object effect on a late pSW started after 900 ms (gray line). (B) Voltmap generated using sLORETA (default left mastoid reference) shows the distribution of voltage differences over the left hemisphere from 1100 to 1400 ms when only the SMA effect occurs; the distribution is similar from 900 to 1100 ms. Electrodes symbolized by half spheres. The + sites are where the pSW effect is strongest (MI - LI), whereas—sites are the location of the SW over frontal scalp (LI - MI). (C) Across subjects, the RT difference correlated significantly with the late pSW effect. Each diamond plots the RT and ERP values for each subject. RT difference on x-axis. ERP amplitude difference on y-axis. The computed linear regression line (solid) is shown. Impoverishment difference for real objects (MI minus LI) from 900 to 1100 ms at site 51 correlated such that, on MI relative to LI trials, as the pSW became more positive, RTs got slower. (D) Maps from sLORETA for 900 to 1100 ms on the left (L) medial surface show the late SMA (BA 6, −15 −10 55; 5 −5 65) impoverishment effect for real objects, extending into anterior cingulate gyrus (BA 24, −15 −10 50), and estimated intracranial ERPs show the SMA effect started after 900 ms. Specifically, from 900 to 1100 ms, sources of impoverishment effects for real objects continued in striate/extrastriate and anterior temporal cortex, and, for the first time, were located in left more than right SMA and anterior cingulate, and this effect appeared to correspond to the pSW. From 1100 to 1400 ms, the SMA effect continued, but extended dorsally into superior frontal gyrus (BA 6, −10 [−10 or −15] 70), and posterior effects were minimal or none. At these times, the impoverishment effect for pseudo objects localized to striate/extrastriate areas (BA 17/18) with weaker sources in temporal pole (BA 38, −40 20 −35) and inferior frontal gyrus (BA 47, −50 45 −10). Note, the sLORETA map shows estimated sources of the difference wave (MI - LI) in the grand average ERPs superimposed on an inflated, canonical MNI152 brain (Colin); dark areas represent sulci; light areas represent gyri. The depicted brain shows standardized cortical current density distributions, and source activity reflects the location of differential source activity between conditions but not the direction of effects. Scale shows yellow represents maximal current density value differences. Estimated intracranial ERPs from −100 to 1400 ms were extracted from the voxel showing maximum impoverished-real-object effects at MNI coordinates from 900 to 1400 ms in SMA (−10 −10 70). Solid tics mark the 0 ms stimulus onset and 400 ms intervals post-stimulus.
Mentions: For completeness and because RTs occurred after the SW, cortical dynamics closer to the motor response were also assessed. EEG was re-analyzed to reject artifacts both between 900 and 1400 ms post-stimulus and during a pre-stimulus baseline of −100 to 100 ms. Analysis times from 900 to 1099 ms captured most MI real object RTs, and 1100 to 1400 ms captured most MI pseudo object RTs. Results showed anterior SW effects of impoverishment continued until 1099 ms and type until 1400 ms. Greater positivity was also found on a left mid-occipital-parietal slow wave (pSW) for MI than LI real objects from 900 to 1400 ms, which inverted polarity anteriorly, and the pSW showed type effects for MI trials until 1099 ms (Figures 9A,B). Critically, no impoverishment by type interactions were found after 900 ms. Both times showed main effects of type and impoverishment laterally, and type at midline sites (Fs > 10.70, ps < 0.005), and type and impoverishment each interacted with lateral electrode (Fs > 4.33), type with midline electrode and with lobe (Fs > 29.33), and impoverishment with midline electrode by lobe (Fs > 28.76), ps < 0.003. From 900 to 1099 ms, results also showed interactions of impoverishment by hemisphere, by midline electrode, by lobe (Fs > 5.4), by electrode by hemisphere (F = 2.19), ps < 0.04, and by Type by midline electrode (F = 9.74, p = 0.006). Focal simple effects tests on frontal SW pair 11–12 showed all impoverishment and type effects were significant from 900 to 1099 ms and both type effects from 1100 to 1400 ms (Fs > 4.51, ps < 0.05). Parietal pair 51–52, where the pSW was large, showed impoverishment by hemisphere for real objects from 900 to 1400 ms (Fs > 5.22), and type on MI trials from 900 to 1099 ms (F = 4.68), ps < 0.05.

Bottom Line: N3 impoverishment effects localized to both prefrontal and occipitotemporal cortex for real objects only.The N3 also showed knowledge effects by 230 ms that localized to occipitotemporal cortex.Finally, response activity in supplementary motor area during a posterior SW after 900 ms showed impoverishment effects that correlated with RTs.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, Cognition Institute, University of Plymouth Plymouth, UK.

ABSTRACT
People categorize objects more slowly when visual input is highly impoverished instead of optimal. While bottom-up models may explain a decision with optimal input, perceptual hypothesis testing (PHT) theories implicate top-down processes with impoverished input. Brain mechanisms and the time course of PHT are largely unknown. This event-related potential study used a neuroimaging paradigm that implicated prefrontal cortex in top-down modulation of occipitotemporal cortex. Subjects categorized more impoverished and less impoverished real and pseudo objects. PHT theories predict larger impoverishment effects for real than pseudo objects because top-down processes modulate knowledge only for real objects, but different PHT variants predict different timing. Consistent with parietal-prefrontal PHT variants, around 250 ms, the earliest impoverished real object interaction started on an N3 complex, which reflects interactive cortical activity for object cognition. N3 impoverishment effects localized to both prefrontal and occipitotemporal cortex for real objects only. The N3 also showed knowledge effects by 230 ms that localized to occipitotemporal cortex. Later effects reflected (a) word meaning in temporal cortex during the N400, (b) internal evaluation of prior decision and memory processes and secondary higher-order memory involving anterotemporal parts of a default mode network during posterior positivity (P600), and (c) response related activity in posterior cingulate during an anterior slow wave (SW) after 700 ms. Finally, response activity in supplementary motor area during a posterior SW after 900 ms showed impoverishment effects that correlated with RTs. Convergent evidence from studies of vision, memory, and mental imagery which reflects purely top-down inputs, indicates that the N3 reflects the critical top-down processes of PHT. A hybrid multiple-state interactive, PHT and decision theory best explains the visual constancy of object cognition.

No MeSH data available.


Related in: MedlinePlus