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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 the bias in mean response difference in the difference map analysis. The histogram shows a significant bias in mean response difference left and right of the cRF, so that the mean response difference is more positive on the left than on the right (mean 0.6 Hz ± 0.2 Hz SEM, gray triangle, P = 0.013, n = 58 surround cells), corresponding to weaker surround inhibition on the unattended side and stronger surround inhibition on the attended side. Both monkeys analyzed separately show the same trend (monkey D [green]: mean 0.6 Hz ± 0.3 Hz, P = 0.092, n = 34; monkey T [red]: mean 0.6 Hz ± 0.3 Hz, P = 0.067, n = 24).
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fig5: Distribution of the bias in mean response difference in the difference map analysis. The histogram shows a significant bias in mean response difference left and right of the cRF, so that the mean response difference is more positive on the left than on the right (mean 0.6 Hz ± 0.2 Hz SEM, gray triangle, P = 0.013, n = 58 surround cells), corresponding to weaker surround inhibition on the unattended side and stronger surround inhibition on the attended side. Both monkeys analyzed separately show the same trend (monkey D [green]: mean 0.6 Hz ± 0.3 Hz, P = 0.092, n = 34; monkey T [red]: mean 0.6 Hz ± 0.3 Hz, P = 0.067, n = 24).

Mentions: Figure 2B and D shows the difference maps for the 2 example neurons. “Attention left” has been subtracted from “attention right”; the cRF outlines and attention targets of both conditions are marked in black and white, respectively. For both cells, the shift of the center is clearly visible from the 2 bumps overlapping these regions. In cell 164 (D), there is an additional scaling of the receptive field between both conditions with responses being higher with “attention left,” therefore all difference values are below zero. For both cells, the difference map is more positive on the left than on the right of the central region, consistent with a true shift of the inhibitory surround. Figure 5 shows the distribution of differences in means left and right across the same 58 surround cells that were included in the volume shift analysis: The average difference is 0.6 Hz (±0.2 Hz) and is significant across cells (P = 0.013).


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

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

Distribution of the bias in mean response difference in the difference map analysis. The histogram shows a significant bias in mean response difference left and right of the cRF, so that the mean response difference is more positive on the left than on the right (mean 0.6 Hz ± 0.2 Hz SEM, gray triangle, P = 0.013, n = 58 surround cells), corresponding to weaker surround inhibition on the unattended side and stronger surround inhibition on the attended side. Both monkeys analyzed separately show the same trend (monkey D [green]: mean 0.6 Hz ± 0.3 Hz, P = 0.092, n = 34; monkey T [red]: mean 0.6 Hz ± 0.3 Hz, P = 0.067, n = 24).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig5: Distribution of the bias in mean response difference in the difference map analysis. The histogram shows a significant bias in mean response difference left and right of the cRF, so that the mean response difference is more positive on the left than on the right (mean 0.6 Hz ± 0.2 Hz SEM, gray triangle, P = 0.013, n = 58 surround cells), corresponding to weaker surround inhibition on the unattended side and stronger surround inhibition on the attended side. Both monkeys analyzed separately show the same trend (monkey D [green]: mean 0.6 Hz ± 0.3 Hz, P = 0.092, n = 34; monkey T [red]: mean 0.6 Hz ± 0.3 Hz, P = 0.067, n = 24).
Mentions: Figure 2B and D shows the difference maps for the 2 example neurons. “Attention left” has been subtracted from “attention right”; the cRF outlines and attention targets of both conditions are marked in black and white, respectively. For both cells, the shift of the center is clearly visible from the 2 bumps overlapping these regions. In cell 164 (D), there is an additional scaling of the receptive field between both conditions with responses being higher with “attention left,” therefore all difference values are below zero. For both cells, the difference map is more positive on the left than on the right of the central region, consistent with a true shift of the inhibitory surround. Figure 5 shows the distribution of differences in means left and right across the same 58 surround cells that were included in the volume shift analysis: The average difference is 0.6 Hz (±0.2 Hz) and is significant across cells (P = 0.013).

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