Describe the concept of receptive fields and the functions of simple and complex cells.

Question

What will be an ideal response?

Answer 1

A receptive field refers to the area from which cells receive their information or input. For example, each ganglion cell receives input from a particular area of the retina. Thus, ganglion cells that have an almost one-to-one communication with cone receptors have receptive fields in the fovea. The receptive fields are small, meaning that the cells receive information from only a small area. The ganglion cells that communicate with the rods have larger receptive fields since they receive information from many rods. In color processing, each ganglion cell's receptive field is made up of a group of receptors arranged in a concentric circle. With this type of arrangement, light has opposing effects on receptors that make up the center of the circle versus receptors that make up the surrounding area of the circle.
Once this information received by the ganglion cells is sent to the cortex, it is first processed in the primary visual area by simple and complex cells. The receptive fields of these cells are arranged differently - they are arranged side by side rather than in a circle, what allow for sensitivities to bars of light rather than to spots of light. Each group of simple cells responds best to a line or an edge that is at a specific orientation and at a specific place on the retina. Each group of complex cells responds in the same way as simple cells with the addition of responding to a line or an edge that moves in a particular direction.