Complex cell
Encyclopedia
Complex cells can be found in the primary visual cortex (V1)
, the secondary visual cortex (V2), and Brodmann area 19
(V3) .
Like a simple cell
, a complex cell will respond primarily to oriented edges and gratings, however it has a degree of spatial invariance. This means that its receptive field cannot be mapped into fixed excitatory and inhibitory zones. Rather, it will respond to patterns of light in a certain orientation within a large receptive field
, regardless of the exact location. Some complex cells respond optimally only to movement in a certain direction.
These cells were discovered by Torsten Wiesel
and David Hubel in the early 1960s . They refrained from reporting on the complex cells in (Hubel 1959) because they did not feel that they understood them well enough at the time . In they reported that complex cells were intermixed with simple cells and when excitatory and inhibitory regions could be established the summation and mutual antagonism properties didn't hold.
The difference between the receptive fields and the characteristics of simple and complex cells is the hierarchical convergent nature of visual processing. Complex cells receive inputs from a number of simple cells. Their receptive field is therefore a summation and integration of the receptive fields of many input simple cells .
Visual cortex
The visual cortex of the brain is the part of the cerebral cortex responsible for processing visual information. It is located in the occipital lobe, in the back of the brain....
, the secondary visual cortex (V2), and Brodmann area 19
Brodmann area 19
-Human:Brodmann area 19, or BA19, is part of the occipital lobe cortex in the human brain. Along with area 18, it comprises the extrastriate cortex...
(V3) .
Like a simple cell
Simple cell
A simple cell in the primary visual cortex is a cell that responds primarily to oriented edges and gratings . These cells were discovered by Torsten Wiesel and David Hubel in the late 1950s ....
, a complex cell will respond primarily to oriented edges and gratings, however it has a degree of spatial invariance. This means that its receptive field cannot be mapped into fixed excitatory and inhibitory zones. Rather, it will respond to patterns of light in a certain orientation within a large receptive field
Receptive field
The receptive field of a sensory neuron is a region of space in which the presence of a stimulus will alter the firing of that neuron. Receptive fields have been identified for neurons of the auditory system, the somatosensory system, and the visual system....
, regardless of the exact location. Some complex cells respond optimally only to movement in a certain direction.
These cells were discovered by Torsten Wiesel
Torsten Wiesel
Torsten Nils Wiesel was a Swedish co-recipient with David H. Hubel of the 1981 Nobel Prize in Physiology or Medicine, for their discoveries concerning information processing in the visual system; the prize was shared with Roger W...
and David Hubel in the early 1960s . They refrained from reporting on the complex cells in (Hubel 1959) because they did not feel that they understood them well enough at the time . In they reported that complex cells were intermixed with simple cells and when excitatory and inhibitory regions could be established the summation and mutual antagonism properties didn't hold.
The difference between the receptive fields and the characteristics of simple and complex cells is the hierarchical convergent nature of visual processing. Complex cells receive inputs from a number of simple cells. Their receptive field is therefore a summation and integration of the receptive fields of many input simple cells .