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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

ERP effects of impoverishment and object type on the N3 complex. (A,B) Shown are sites of the N3 complex maxima (left frontopolar site 3, right frontocentral site 30, right occipitotemporal site 22). Frontal effects inverted polarity to positivity at occipitotemporal sites, especially on the right (“P3[N3]” maximal at site 22), including an N250; note, a D220 index of task difficulty for decisions also inverted polarity between frontocentral and occipitotemporal sites. (A) N3 effects of impoverishment shown for real objects and pseudo objects. The frontal N3 showed an impoverished-real-object effect, including a frontopolar P250 component: The frontal N3 components were more negative for MI than LI real objects but not pseudo objects; note, the N3 showed no such effect for pseudo objects, but, in contrast, briefly at the peak, the N3 was instead slightly more negative for LI than MI pseudo objects. The occipitotemporal N250 but not later posterior N3 counterparts showed impoverishments effects for real objects. (B) N3 effects of object type shown on LI and MI trials. The N3 complex was larger for real than pseudo objects, and this type effect was larger on LI than MI trials. (C,D) To compare with other publications, the reference was computed using the average of all scalp sites (i.e., “common average reference”), and ERPs were plotted positive up. Shown are left frontopolar site 3 and occipitotemporal site 22. (C) N3 effects of impoverishment shown, for real and pseudo objects. (D) N3 effects of object type shown on LI and MI trials. Here, with the average reference, the effects over occipitotemporal sites become larger than when the bilateral mastoid reference is used instead (see A,B): Notice the similarity of effects between frontopolar site 3 in (A,B) and occipitotemporal site 22 here [also site 22 in (A,B) is more like site 3 here]. Crucially, the frontopolar ERPs with a mastoid reference [e.g., P250, N3 in (A,B)] correspond, with the average reference shown here, to the occipitotemporal ERPs (e.g., N250, P3(N3) at site 22 here). This demonstrated a clear link between the present and prior research on the frontocentral N3 complex and its subcomponents, and prior research on the occipitotemporal N250 and Ncl, which were defined using the nose or average reference, as shown here; note scalp distribution shapes with nose and average reference are similar. Like the frontopolar P250/N3 with the mastoid reference (see A,B), here with an average reference, the occipitotemporal N250 and P3(N3) show the impoverished-real-object effect, being more positive for MI than LI real objects but not pseudo objects, and this effect inverts polarity over frontopolar sites to P250 and N3 effects. Further, like the frontopolar P250 and N3 with the mastoid reference (see A,B), here with an average reference, the occipitotemporal N250 and P3(N3) show object type effects, being more positive for pseudo than real objects on LI and MI trials, and these effects invert polarity over frontopolar sites. The whole head ERPs in Figure 4 demonstrate that this polarity inversion of effects occurs between frontal sites toward the midline (3–4, 11–12, 19–20, 29–30) and more lateral occipitotemporal sites with a right hemisphere maximum (22, 32, 34), especially for the N250, consistent with the known right lateralization of the N250 (i.e., N250r).
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Figure 5: ERP effects of impoverishment and object type on the N3 complex. (A,B) Shown are sites of the N3 complex maxima (left frontopolar site 3, right frontocentral site 30, right occipitotemporal site 22). Frontal effects inverted polarity to positivity at occipitotemporal sites, especially on the right (“P3[N3]” maximal at site 22), including an N250; note, a D220 index of task difficulty for decisions also inverted polarity between frontocentral and occipitotemporal sites. (A) N3 effects of impoverishment shown for real objects and pseudo objects. The frontal N3 showed an impoverished-real-object effect, including a frontopolar P250 component: The frontal N3 components were more negative for MI than LI real objects but not pseudo objects; note, the N3 showed no such effect for pseudo objects, but, in contrast, briefly at the peak, the N3 was instead slightly more negative for LI than MI pseudo objects. The occipitotemporal N250 but not later posterior N3 counterparts showed impoverishments effects for real objects. (B) N3 effects of object type shown on LI and MI trials. The N3 complex was larger for real than pseudo objects, and this type effect was larger on LI than MI trials. (C,D) To compare with other publications, the reference was computed using the average of all scalp sites (i.e., “common average reference”), and ERPs were plotted positive up. Shown are left frontopolar site 3 and occipitotemporal site 22. (C) N3 effects of impoverishment shown, for real and pseudo objects. (D) N3 effects of object type shown on LI and MI trials. Here, with the average reference, the effects over occipitotemporal sites become larger than when the bilateral mastoid reference is used instead (see A,B): Notice the similarity of effects between frontopolar site 3 in (A,B) and occipitotemporal site 22 here [also site 22 in (A,B) is more like site 3 here]. Crucially, the frontopolar ERPs with a mastoid reference [e.g., P250, N3 in (A,B)] correspond, with the average reference shown here, to the occipitotemporal ERPs (e.g., N250, P3(N3) at site 22 here). This demonstrated a clear link between the present and prior research on the frontocentral N3 complex and its subcomponents, and prior research on the occipitotemporal N250 and Ncl, which were defined using the nose or average reference, as shown here; note scalp distribution shapes with nose and average reference are similar. Like the frontopolar P250/N3 with the mastoid reference (see A,B), here with an average reference, the occipitotemporal N250 and P3(N3) show the impoverished-real-object effect, being more positive for MI than LI real objects but not pseudo objects, and this effect inverts polarity over frontopolar sites to P250 and N3 effects. Further, like the frontopolar P250 and N3 with the mastoid reference (see A,B), here with an average reference, the occipitotemporal N250 and P3(N3) show object type effects, being more positive for pseudo than real objects on LI and MI trials, and these effects invert polarity over frontopolar sites. The whole head ERPs in Figure 4 demonstrate that this polarity inversion of effects occurs between frontal sites toward the midline (3–4, 11–12, 19–20, 29–30) and more lateral occipitotemporal sites with a right hemisphere maximum (22, 32, 34), especially for the N250, consistent with the known right lateralization of the N250 (i.e., N250r).

Mentions: Focal spatiotemporal results demonstrated that the frontal N3 was more negative for (a) MI than LI stimuli for real objects only (Figures 3, 5A) and (b) pseudo than real objects on LI more than MI trials (Figures 3, 5B). Occipitotemporal counterparts showed the same but with opposite polarity (i.e., more positive). Specifically, the results (Table 3) showed main effects of type were significant the entire time from 200 to 500 ms at frontopolar, frontocentral, and occipitotemporal sites. Main effects of impoverishment were significant at frontopolar sites the entire time, frontocentral sites from 400 to 500 ms, and occipitotemporal sites from 200 to 300 ms. The critical impoverishment by type interactions were significant at frontopolar sites from 300 to 400 ms; note, interactions were marginal at other times frontally and occipitotemporally from 200 to 300 ms. Planned contrasts (Table 3) showed that only real objects had significant impoverishment effects during the entire frontopolar N3 (200 to 500 ms) and later frontocentral N3 (300 to 500 ms); note, this effect was marginal on the occipitotemporal N250 from 200 to 300 ms. Further, type effects were significant, for LI, at all times and N3 sites and, for MI, from 200 to 400 ms at frontopolar sites and all times at occipitotemporal sites; note, for MI, type was marginal at frontocentral sites. With a common average reference, N3 effects split about evenly between frontal and occipitotemporal sites (Figures 4, 5C,D).


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

Schendan HE, Ganis G - Front Psychol (2015)

ERP effects of impoverishment and object type on the N3 complex. (A,B) Shown are sites of the N3 complex maxima (left frontopolar site 3, right frontocentral site 30, right occipitotemporal site 22). Frontal effects inverted polarity to positivity at occipitotemporal sites, especially on the right (“P3[N3]” maximal at site 22), including an N250; note, a D220 index of task difficulty for decisions also inverted polarity between frontocentral and occipitotemporal sites. (A) N3 effects of impoverishment shown for real objects and pseudo objects. The frontal N3 showed an impoverished-real-object effect, including a frontopolar P250 component: The frontal N3 components were more negative for MI than LI real objects but not pseudo objects; note, the N3 showed no such effect for pseudo objects, but, in contrast, briefly at the peak, the N3 was instead slightly more negative for LI than MI pseudo objects. The occipitotemporal N250 but not later posterior N3 counterparts showed impoverishments effects for real objects. (B) N3 effects of object type shown on LI and MI trials. The N3 complex was larger for real than pseudo objects, and this type effect was larger on LI than MI trials. (C,D) To compare with other publications, the reference was computed using the average of all scalp sites (i.e., “common average reference”), and ERPs were plotted positive up. Shown are left frontopolar site 3 and occipitotemporal site 22. (C) N3 effects of impoverishment shown, for real and pseudo objects. (D) N3 effects of object type shown on LI and MI trials. Here, with the average reference, the effects over occipitotemporal sites become larger than when the bilateral mastoid reference is used instead (see A,B): Notice the similarity of effects between frontopolar site 3 in (A,B) and occipitotemporal site 22 here [also site 22 in (A,B) is more like site 3 here]. Crucially, the frontopolar ERPs with a mastoid reference [e.g., P250, N3 in (A,B)] correspond, with the average reference shown here, to the occipitotemporal ERPs (e.g., N250, P3(N3) at site 22 here). This demonstrated a clear link between the present and prior research on the frontocentral N3 complex and its subcomponents, and prior research on the occipitotemporal N250 and Ncl, which were defined using the nose or average reference, as shown here; note scalp distribution shapes with nose and average reference are similar. Like the frontopolar P250/N3 with the mastoid reference (see A,B), here with an average reference, the occipitotemporal N250 and P3(N3) show the impoverished-real-object effect, being more positive for MI than LI real objects but not pseudo objects, and this effect inverts polarity over frontopolar sites to P250 and N3 effects. Further, like the frontopolar P250 and N3 with the mastoid reference (see A,B), here with an average reference, the occipitotemporal N250 and P3(N3) show object type effects, being more positive for pseudo than real objects on LI and MI trials, and these effects invert polarity over frontopolar sites. The whole head ERPs in Figure 4 demonstrate that this polarity inversion of effects occurs between frontal sites toward the midline (3–4, 11–12, 19–20, 29–30) and more lateral occipitotemporal sites with a right hemisphere maximum (22, 32, 34), especially for the N250, consistent with the known right lateralization of the N250 (i.e., N250r).
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Figure 5: ERP effects of impoverishment and object type on the N3 complex. (A,B) Shown are sites of the N3 complex maxima (left frontopolar site 3, right frontocentral site 30, right occipitotemporal site 22). Frontal effects inverted polarity to positivity at occipitotemporal sites, especially on the right (“P3[N3]” maximal at site 22), including an N250; note, a D220 index of task difficulty for decisions also inverted polarity between frontocentral and occipitotemporal sites. (A) N3 effects of impoverishment shown for real objects and pseudo objects. The frontal N3 showed an impoverished-real-object effect, including a frontopolar P250 component: The frontal N3 components were more negative for MI than LI real objects but not pseudo objects; note, the N3 showed no such effect for pseudo objects, but, in contrast, briefly at the peak, the N3 was instead slightly more negative for LI than MI pseudo objects. The occipitotemporal N250 but not later posterior N3 counterparts showed impoverishments effects for real objects. (B) N3 effects of object type shown on LI and MI trials. The N3 complex was larger for real than pseudo objects, and this type effect was larger on LI than MI trials. (C,D) To compare with other publications, the reference was computed using the average of all scalp sites (i.e., “common average reference”), and ERPs were plotted positive up. Shown are left frontopolar site 3 and occipitotemporal site 22. (C) N3 effects of impoverishment shown, for real and pseudo objects. (D) N3 effects of object type shown on LI and MI trials. Here, with the average reference, the effects over occipitotemporal sites become larger than when the bilateral mastoid reference is used instead (see A,B): Notice the similarity of effects between frontopolar site 3 in (A,B) and occipitotemporal site 22 here [also site 22 in (A,B) is more like site 3 here]. Crucially, the frontopolar ERPs with a mastoid reference [e.g., P250, N3 in (A,B)] correspond, with the average reference shown here, to the occipitotemporal ERPs (e.g., N250, P3(N3) at site 22 here). This demonstrated a clear link between the present and prior research on the frontocentral N3 complex and its subcomponents, and prior research on the occipitotemporal N250 and Ncl, which were defined using the nose or average reference, as shown here; note scalp distribution shapes with nose and average reference are similar. Like the frontopolar P250/N3 with the mastoid reference (see A,B), here with an average reference, the occipitotemporal N250 and P3(N3) show the impoverished-real-object effect, being more positive for MI than LI real objects but not pseudo objects, and this effect inverts polarity over frontopolar sites to P250 and N3 effects. Further, like the frontopolar P250 and N3 with the mastoid reference (see A,B), here with an average reference, the occipitotemporal N250 and P3(N3) show object type effects, being more positive for pseudo than real objects on LI and MI trials, and these effects invert polarity over frontopolar sites. The whole head ERPs in Figure 4 demonstrate that this polarity inversion of effects occurs between frontal sites toward the midline (3–4, 11–12, 19–20, 29–30) and more lateral occipitotemporal sites with a right hemisphere maximum (22, 32, 34), especially for the N250, consistent with the known right lateralization of the N250 (i.e., N250r).
Mentions: Focal spatiotemporal results demonstrated that the frontal N3 was more negative for (a) MI than LI stimuli for real objects only (Figures 3, 5A) and (b) pseudo than real objects on LI more than MI trials (Figures 3, 5B). Occipitotemporal counterparts showed the same but with opposite polarity (i.e., more positive). Specifically, the results (Table 3) showed main effects of type were significant the entire time from 200 to 500 ms at frontopolar, frontocentral, and occipitotemporal sites. Main effects of impoverishment were significant at frontopolar sites the entire time, frontocentral sites from 400 to 500 ms, and occipitotemporal sites from 200 to 300 ms. The critical impoverishment by type interactions were significant at frontopolar sites from 300 to 400 ms; note, interactions were marginal at other times frontally and occipitotemporally from 200 to 300 ms. Planned contrasts (Table 3) showed that only real objects had significant impoverishment effects during the entire frontopolar N3 (200 to 500 ms) and later frontocentral N3 (300 to 500 ms); note, this effect was marginal on the occipitotemporal N250 from 200 to 300 ms. Further, type effects were significant, for LI, at all times and N3 sites and, for MI, from 200 to 400 ms at frontopolar sites and all times at occipitotemporal sites; note, for MI, type was marginal at frontocentral sites. With a common average reference, N3 effects split about evenly between frontal and occipitotemporal sites (Figures 4, 5C,D).

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