On the evidence for a 'pure' binocular process in human vision

Area of Science:

• Neuroscience
• Vision Science
• Computational Neuroscience

Background:

• Wolfe (1986) proposed a model of human binocular vision.
• This model assumes two distinct classes of binocular neurons: AND gates and OR gates.
• These neuron types are hypothesized to process visual information through separate channels.

Purpose of the Study:

• To critically assess the evidence supporting Wolfe's (1986) assumption of functionally distinct AND and OR gate neuron populations.
• To evaluate the psychophysical data related to AND and OR channels in human vision.
• To determine if current data supports the existence of separate channels as proposed by Wolfe.

Main Methods:

• Review of neurophysiological findings in cat and monkey cortex regarding binocular neuron types.
• Critical analysis of psychophysical studies investigating AND and OR channels in human visual perception.
• Examination of alternative interpretations for existing experimental data.

Main Results:

• Both AND and OR type binocular neurons have been described in animal models (cat and monkey cortex).
• However, there is no evidence that these neuron types form functionally separate populations in the cortex.
• Psychophysical evidence for a distinct AND channel in human vision is subject to alternative explanations.

Conclusions:

• The available neurophysiological and psychophysical data do not support the existence of separate AND and OR channels in human binocular vision as proposed by Wolfe (1986).
• Alternative interpretations can account for data previously cited in favor of distinct channels.
• The model of functionally separate AND and OR gate neuron populations requires re-evaluation.