Receptive Fields

Receptive Fields

1. each cell in the visual system has a receptive field, an area in visual space that excites or inhibits it. Is the point in space from which light strikes the cell.

   • Lateral inhibition- the reduction of activity in one neuron by activity in neighbouring neurons.
   • Simple cell- fixed excitatory and inhibitory zones.
     • The more light shines in the excitatory zone, the more the cell responds
     • The more light shines in the inhibitory zone, the less the cell responds
   • Complex cell- do not respond to the exact location of a stimulus. Responds to a pattern of light in a particular orientation only where within its large receptive field.
   • Inferior temporal cortex- respond to identifiable objects and respond accordingly to what the viewer perceives. Not what it is physically.
     • Fusiform gyrus- area in the ITC for recognising faces
   • Middle Temporal Cortex- activated by motion. Receives input from the magnocellular paths and detects overall patterns.
     • Damage can result in motion blindness. Can see objects, but not in which direction or if they are moving.
   • Feature detectors- responses indicate the presence of particular features. Respond strongly to bar or edge shaped patterns.