Banbury Center Workshop Series Main Page

Neurocomputational Strategies: From Synapses to Behavior (1998)
Functional Organization of the Thalamus and Cortex and their Interactions (1999)
Toward Animal Models of Attention and Consciousness (2000)
Persistent Neural Activity (2000)
Can a Machine Be Conscious? (2001)
Communication in Brain Systems (2004)
Neurobiology of Decision-Making (2005)
Computational Approaches to Cortical Functions (2006)
New Frontiers in Studies of Nonconscious Processing (2007)
Theoretical and Experimental Approaches to Auditory and Visual Attention (2008)

TOWARD ANIMAL MODELS OF ATTENTION AND CONSCIOUSNESS

Abstract

Attention increases sensitivity of V4 neurons.
Reynolds JH, Pasternak T, Desimone R

When attention is directed to a location in the visual field, sensitivity to stimuli at that location is increased. At the neuronal level, this could arise either through a multiplicative increase in firing rate or through an increase in the effective strength of the stimulus. To test conflicting predictions of these alternative models, we recorded responses of V4 neurons to stimuli across a range of luminance contrasts and measured the change in response when monkeys attended to them in order to discriminate a target stimulus from non-targets. Attention caused greater increases in response at low contrast than at high contrast, consistent with an increase in effective stimulus strength. On average, attention increased the effective contrast of the attended stimulus by a factor of 1.51, an increase of 51% of its physical contrast.