The proposed research represents an articulated effort in order to fully understand the neuronal underpinnings of visual selective attention, the cognitive function allowing individuals to cope with the huge amount of information which continuously reaches their senses, through selection, suppression and weighing of specific pieces of information. The ultimate goal of the project is to uncover the brain mechanisms that control which objects in the environment are preferentially processed at any given time, due to the combined influence of factors pertaining to the intrinsic nature and saliency of visual stimuli and factors pertaining to the current cognitive state and goals of the individual. The research will develop along three original lines aimed at:
WP1- Unveiling the influence of stimulus type on contrast coding and attentional modulation, along with their temporal dynamics;
WP2- Revealing the relative (and independent) impact of spatially-directed attention and task-relevance in determining modulation of neuronal activity in the primate visual cortex;
WP3- Uncovering the distinct neuronal basis of distractor suppression (the mechanism to resist distraction).
The research will be conducted by implementing a series of carefully designed electrophysiological studies in the behaving macaque monkey. The general approach will be that of measuring the spiking activity of single V4d and V6a neurons, as well as local field potentials, in conditions where spatial attention will be deployed either inside or outside the receptive field of the recorded neurons to discriminate visual stimuli of different type (WP1). In different experiments, task requirements will be manipulated to mainly engage selection or suppression processes (WP3) and in order to vary the task relevance of specific stimuli (WP2). None of these issues has been addressed in previous neurophysiological studies, thus the project holds great promise for advancing the field considerably