Related Experiment Video
Updated: Apr 25, 2026

Development of a Gaze-Contingent Display Framework Designed for Perceptual and Oculomotor Research with Simulated Central Vision Loss
Published on: April 11, 2025
Top-down inputs enhance orientation selectivity in neurons of the primary visual cortex during perceptual learning
Samat Moldakarimov1, Maxim Bazhenov2, Terrence J Sejnowski3
1Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, California, United States of America; The Institute for Neural Computation, University of California, San Diego, La Jolla, California, United States of America.
Abstract:
Perceptual learning has been used to probe the mechanisms of cortical plasticity in the adult brain. Feedback projections are ubiquitous in the cortex, but little is known about their role in cortical plasticity. Here we explore the hypothesis that learning visual orientation discrimination involves learning-dependent plasticity of top-down feedback inputs from higher cortical areas, serving a different function from plasticity due to changes in recurrent connections within a cortical area. In a Hodgkin-Huxley-based spiking neural network model of visual cortex, we show that modulation of feedback inputs to V1 from higher cortical areas results in shunting inhibition in V1 neurons, which changes the response properties of V1 neurons. The orientation selectivity of V1 neurons is enhanced without changing orientation preference, preserving the topographic organizations in V1. These results provide new insights to the mechanisms of plasticity in the adult brain, reconciling apparently inconsistent experiments and providing a new hypothesis for a functional role of the feedback connections.
More Related Videos
Related Concept Videos
Vision
Motor and Sensory Areas of the Cortex
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex....
Visual System
Once through the pupil, the light passes through the lens, a...
Perception
Bottom-up processing begins at the sensory level, where receptors detect external environmental stimuli. These could include the tactile sensation of...
Parallel Processing
Anatomy of the Eyeball

