Attentional modulation of visual responses by flexible input gain

Area of Science:

• Neuroscience
• Computational Neuroscience
• Visual Perception

Background:

• Sensory cortex responses are modulated by external stimuli and internal states like attention.
• The precise mechanisms of integrating sensory and behavioral signals, particularly attention, remain unclear.
• Previous studies often examined sensory interactions or attention in isolation.

Purpose of the Study:

• To model the effects of a center-surround organization of attentional modulation on sensory integration.
• To explore how attention selectively facilitates and suppresses neuronal inputs based on behavioral relevance.
• To reconcile disparate findings in the neurophysiological literature on attentional effects.

Main Methods:

• Developed a computational model incorporating center-surround attentional modulation within existing receptive field models.
• Systematically varied location, orientation, and spatial attention in simulations.
• Compared model predictions with behavioral and neurophysiological data.

Main Results:

• The model accurately reproduced behavioral observations of spatial attention, including suppressive surrounds.
• Incorporating center-surround modulation explained phenomena like receptive field shifts and preferential modulation of low-contrast stimuli.
• Model results align with feature-based attention models and functional imaging findings.

Conclusions:

• Spatial attention employs a flexible gain mechanism with center-surround properties across the visual system.
• This mechanism explains diverse attentional effects observed in neurophysiology and functional imaging.
• Attention likely utilizes a common, adaptable gain control strategy throughout visual processing.