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Attention reshapes center-surround receptive field structure in macaque cortical area MT.

Anton-Erxleben K, Stephan VM, Treue S - Cereb. Cortex (2009)

Bottom Line: Furthermore, cRF size is changed as a function of relative distance to the attentional focus: attention inside the cRF shrinks it, whereas directing attention next to the cRF expands it.In addition, we find systematic changes in surround inhibition and cRF amplitude.This nonmultiplicative push-pull modulation of the receptive field's center-surround structure optimizes processing at and near the attentional focus to strengthen the representation of the attended stimulus while reducing influences from distractors.

View Article: PubMed Central - PubMed

Affiliation: Cognitive Neuroscience Laboratory, German Primate Center, Göttingen, Germany. kantonerxleben@dpz.gwdg.de

ABSTRACT
Directing spatial attention to a location inside the classical receptive field (cRF) of a neuron in macaque medial temporal area (MT) shifts the center of the cRF toward the attended location. Here we investigate the influence of spatial attention on the profile of the inhibitory surround present in many MT neurons. Two monkeys attended to the fixation point or to 1 of 2 random dot patterns (RDPs) placed inside or next to the cRF, whereas a third RDP (the probe) was briefly presented in quick succession across the cRF and surround. The probe presentation responses were used to compute a map of the excitatory receptive field and its inhibitory surround. Attention systematically reshapes the receptive field profile, independently shifting both center and surround toward the attended location. Furthermore, cRF size is changed as a function of relative distance to the attentional focus: attention inside the cRF shrinks it, whereas directing attention next to the cRF expands it. In addition, we find systematic changes in surround inhibition and cRF amplitude. This nonmultiplicative push-pull modulation of the receptive field's center-surround structure optimizes processing at and near the attentional focus to strengthen the representation of the attended stimulus while reducing influences from distractors.

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Distribution of center and surround shifts relative to the cRF diameter. (A) The histogram shows a significant shift of the cRF center toward the attended stimulus by 10.1% (±1% SEM, P < 0.0005, n = 100) of the cRF diameter (monkey D [green]: 8.7%, ± 1.2%, P < 0.0005, n = 58; monkey T [red]: 12.1%, ± 1.5%, P < 0.0005, n = 42). (B) The histogram shows a significant shift of the surround toward the attended stimulus by 20.2% (±7.7% SEM, P = 0.022, n = 45 cells in the surround centroid analysis) of the cRF diameter (monkey D: not significant, P = 0.182, n = 26; monkey T: 22.3%, ± 9.4%, P = 0.043, n = 19). Triangles mark the mean shift magnitudes (gray: overall, green: monkey D, red: monkey T).
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fig3: Distribution of center and surround shifts relative to the cRF diameter. (A) The histogram shows a significant shift of the cRF center toward the attended stimulus by 10.1% (±1% SEM, P < 0.0005, n = 100) of the cRF diameter (monkey D [green]: 8.7%, ± 1.2%, P < 0.0005, n = 58; monkey T [red]: 12.1%, ± 1.5%, P < 0.0005, n = 42). (B) The histogram shows a significant shift of the surround toward the attended stimulus by 20.2% (±7.7% SEM, P = 0.022, n = 45 cells in the surround centroid analysis) of the cRF diameter (monkey D: not significant, P = 0.182, n = 26; monkey T: 22.3%, ± 9.4%, P = 0.043, n = 19). Triangles mark the mean shift magnitudes (gray: overall, green: monkey D, red: monkey T).

Mentions: Figure 3A shows the distribution of normalized center shifts: On average, the receptive field center shifts by 10.1% (±1%) of its diameter toward the attended stimulus. This shift is highly significant (P < 0.0005) across cells. The average absolute magnitude of the center shift is 0.9° (±0.1°); and the average center shift normalized to the distance between the targets (the “attentional shift,” i.e., the shift of spatial attention between the conditions) is 13.8% (±1.2%).


Attention reshapes center-surround receptive field structure in macaque cortical area MT.

Anton-Erxleben K, Stephan VM, Treue S - Cereb. Cortex (2009)

Distribution of center and surround shifts relative to the cRF diameter. (A) The histogram shows a significant shift of the cRF center toward the attended stimulus by 10.1% (±1% SEM, P < 0.0005, n = 100) of the cRF diameter (monkey D [green]: 8.7%, ± 1.2%, P < 0.0005, n = 58; monkey T [red]: 12.1%, ± 1.5%, P < 0.0005, n = 42). (B) The histogram shows a significant shift of the surround toward the attended stimulus by 20.2% (±7.7% SEM, P = 0.022, n = 45 cells in the surround centroid analysis) of the cRF diameter (monkey D: not significant, P = 0.182, n = 26; monkey T: 22.3%, ± 9.4%, P = 0.043, n = 19). Triangles mark the mean shift magnitudes (gray: overall, green: monkey D, red: monkey T).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2742598&req=5

fig3: Distribution of center and surround shifts relative to the cRF diameter. (A) The histogram shows a significant shift of the cRF center toward the attended stimulus by 10.1% (±1% SEM, P < 0.0005, n = 100) of the cRF diameter (monkey D [green]: 8.7%, ± 1.2%, P < 0.0005, n = 58; monkey T [red]: 12.1%, ± 1.5%, P < 0.0005, n = 42). (B) The histogram shows a significant shift of the surround toward the attended stimulus by 20.2% (±7.7% SEM, P = 0.022, n = 45 cells in the surround centroid analysis) of the cRF diameter (monkey D: not significant, P = 0.182, n = 26; monkey T: 22.3%, ± 9.4%, P = 0.043, n = 19). Triangles mark the mean shift magnitudes (gray: overall, green: monkey D, red: monkey T).
Mentions: Figure 3A shows the distribution of normalized center shifts: On average, the receptive field center shifts by 10.1% (±1%) of its diameter toward the attended stimulus. This shift is highly significant (P < 0.0005) across cells. The average absolute magnitude of the center shift is 0.9° (±0.1°); and the average center shift normalized to the distance between the targets (the “attentional shift,” i.e., the shift of spatial attention between the conditions) is 13.8% (±1.2%).

Bottom Line: Furthermore, cRF size is changed as a function of relative distance to the attentional focus: attention inside the cRF shrinks it, whereas directing attention next to the cRF expands it.In addition, we find systematic changes in surround inhibition and cRF amplitude.This nonmultiplicative push-pull modulation of the receptive field's center-surround structure optimizes processing at and near the attentional focus to strengthen the representation of the attended stimulus while reducing influences from distractors.

View Article: PubMed Central - PubMed

Affiliation: Cognitive Neuroscience Laboratory, German Primate Center, Göttingen, Germany. kantonerxleben@dpz.gwdg.de

ABSTRACT
Directing spatial attention to a location inside the classical receptive field (cRF) of a neuron in macaque medial temporal area (MT) shifts the center of the cRF toward the attended location. Here we investigate the influence of spatial attention on the profile of the inhibitory surround present in many MT neurons. Two monkeys attended to the fixation point or to 1 of 2 random dot patterns (RDPs) placed inside or next to the cRF, whereas a third RDP (the probe) was briefly presented in quick succession across the cRF and surround. The probe presentation responses were used to compute a map of the excitatory receptive field and its inhibitory surround. Attention systematically reshapes the receptive field profile, independently shifting both center and surround toward the attended location. Furthermore, cRF size is changed as a function of relative distance to the attentional focus: attention inside the cRF shrinks it, whereas directing attention next to the cRF expands it. In addition, we find systematic changes in surround inhibition and cRF amplitude. This nonmultiplicative push-pull modulation of the receptive field's center-surround structure optimizes processing at and near the attentional focus to strengthen the representation of the attended stimulus while reducing influences from distractors.

Show MeSH