Response Plasticity in Primary Visual Cortex and its Role in Vision and Visuomotor Behavior: Bottom-up and Top-down Influences

Abstract

Neurons in the primary visual cortex (V1) have been traditionally considered to respond exclusively and steadily to the physical properties of visual stimuli presented within their receptive fields. Indeed, since V1 neurons are mainly involved in processing elementary features of visual stimuli such as orientation or direction of motion, they were long believed to possess stable or unchanging properties. However, another view has emerged in the past 15 years. According to this view, V1 responses are strongly influenced by the history of visual stimulation. Such response changes can be driven by properties of previously viewed visual stimuli (bottom up changes), or by aspects of internal state, including an internal representation of previous stimuli (top-down changes). In effect, the temporal content of visual stimulation results in short term experience-dependent plasticity in local as well as distributed cortical circuits, and these changes are manifest as changes in neuronal responses, visual perception and visuomotor behavior. In this review, we describe our recent findings demonstrating rapid plasticity of responses in V1 neurons resulting from time-dependent bottom-up and top-down influences.

Indexing terms:

• Cortical processing
• networks
• internal representation
• vision
• dynamics
• plasticity

Additional information

Notes on contributors

Valentin Dragoi

Valentin Dragoi is a McDonnell-Pew postdoctoral fellow in the Department of Brain and Cognitive Sciences at the Massachusetts Institute of Technology. He received his BS in Computer Science at the Polytechnic Institute of lasi, Romania (1989). He f studied neural modeling and image processing as a Research Fellow at the Institute for Computer Science in lasi. (1990–92) and received his PhD in Experimental Psychology from Duke University in 1997. His research interests include neural coding in visual cortex, learning and adaptive behavior, and computational neuroscience.

Jitendra Sharma

Jitendra Sharma is a Research Scientist in the Department of Brain and Cognitive Sciences at the Massachusetts Institute of Technology. He served as a Senior Scientist at the Center for Biomedical Engineering, Indian Institute of Technology, and the All India Institute of Medical Sciences, New Delhi. He completed his PhD in Biomedical Engineering at the Indian Institute of Technology, Delhi (1988). Dr Sharma is the recipient of Fogarty and Markey Foundation fellowships. Before joining MIT he was a Joint Director at the Department of Electronics, Government of India, where he guided programs on technology development for mass health care and the design of indigenous linac for cancer therapy. Dr Sharma studies cortical plasticity and adaptive changes in local and distributed cortical networks and their consequence on vision and visuomotor behavior.