Receptive Fields and Orientation Selectivity of SimpleCells in Visual Cortex

Abstract

We present a three-layer feedforward visual pathway model consisting of retina, LGN and cortex for development of orientation selectivity in layer 4 simple cells. Receptive field (RF) development in the model, is determined by diffusive cooperation and resource limited competition guided axonal growth and retraction in geniculocortical pathway. The simulated cortical RFs resemble experimental RFs. In the feed forward model when only the linear contribution from LGN was considered we obtained a mean hwhh (half width at half the maximum response) of 58°. The mean hwhh improved to 37° when nonlinearity in spiking mechanism was incorporated. The hwhh in the cells improved by another 9° when a push-pull effect was included. The tuning in the simulated cells matches reported tuning in layer 4 simple cells.

Indexing terms:

• Simple cells
• Receptive field
• Orientation tuning
• Iceberg effect
• Push-pull inhibition

Additional information

Notes on contributors

Basabi Bhaumik

Basabi Bhaumik received her PhD and MTech in Electrical Engineering from the Indian Institute of Technology, Kanpur and BE in Electronics and Telecommunication from Jadavpur University, Kolkata. She joined the faculty of Indian Institute of Technology, Delhi in 1980. She is currently a professor in the Department of Electrical Engineering. Her research interests are in the areas of Biological Neural Networks and Analog/Mixed Signal VLSI Design.

Mona Mathur

Mona Mathur was born in New Delhi, in 1971 She received her Bachelor of Engineering in Instrumentation and Control Engineering from the Delhi Institute of Technology, Delhi in 1992. She completed her Masters of Technology in Integrated Electronics and Circuits from the Indian Institute of Technology, New Delhi in 1995. She is currently pursuing her PhD at the Department of Electrical Engineering at the Indian Institute of Technology, New Delhi. Her research interests are in the areas of computational neuroscience and analog VLSI design.