Attention enhances stimulus representations in macaque visual cortex without affecting their signal-to-noise level.
The magnitude of the attentional modulation of neuronal responses in visual cortex varies with stimulus contrast. Whether the strength of these attentional influences is similarly dependent on other stimulus properties is unknown. Here we report the effect of spatial attention on responses in the medial-temporal area (MT) of macaque visual cortex to moving random dots pattern of various motion coherences, i.e. signal-to-noise ratios. Our data show that allocating spatial attention causes a gain change in MT neurons. The magnitude of this attentional modulation is independent of the attended stimulus' motion coherence, creating a multiplicative scaling of the neuron's coherence-response function. This is consistent with the characteristics of gain models of attentional modulation and suggests that attention strengthens the neuronal representation of behaviorally relevant visual stimuli relative to unattended stimuli, but without affecting their signal-to-noise ratios.
Neuroscience and Neuroengineering Research Laboratory, Biomedical Engineering Department, School of Electrical Engineering, Iran University of Science &Technology (IUST), Narmak, Tehran, Iran.|Cognitive Neuroscience Laboratory, German Primate Center, Goettingen, Germany.|School of Cognitive Sciences (SCS), Institute for Research in Fundamental Sciences (IPM), Niavaran, Tehran, Iran.
Mohammad Reza
MR
Daliri
Cognitive Neuroscience Laboratory, German Primate Center, Goettingen, Germany.|Visual Cognition Laboratory, University of Fribourg, Fribourg, Switzerland.
Vladislav
V
Kozyrev
Cognitive Neuroscience Laboratory, German Primate Center, Goettingen, Germany.|Faculty for Biology and Psychology, Goettingen University, Goettingen, Germany.
Stefan
S
Treue
D000818:Animals; D001288:Attention; D008251:Macaca; D008297:Male; D009474:Neurons / Q000502:physiology; D059629:Signal-To-Noise Ratio; D013028:Space Perception; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*; D014796:Visual Perception