Report of Panel V: Perceptual Processes
|Panel Chair:||D. Regan|
|Panel Members:|| T. Allison|
Regan: We can begin with the data base. We shall discuss types of ERPs that seem to have something to do with perception (though we have not been able to find a clear and consistent distinction between perception and cognition). I shall discuss visual ERPs; Truett Allison will comment on somatic sensation; and, following that, Lynn Cooper and Steve Palmer will discuss cognition and perception.
The ERPs associated with perception discussed in Chapter 11 do not require the conscious processing of information, whereas cognitive EP components are associated with conscious information processing. One problem in cognitive ERP experiments is possible contamination with perceptual ERP components. The other side of this coin is that if you have an experiment involving a perceptual aspect and a cognitive aspect, then evoked potentials might help you to distinguish the two brain activities. If you factor this element out of a cognitive experiment, you might then be able to see what is processed at a lower level and what you must attribute to cognition.
To take another example, Wheatstone ( 1838) described the stereoviewer. Looking through it at a stereo pair of drawings or photographs, you saw the scene in three-dimensional depth. Wheatstone then optically reversed the right and left eyes. The two eyes' retinal images were virtually as before, but the depth was reversed. If he looked at a cube, he saw the cube in reversed depth. When he looked at something familiar like a coin, he saw the embossing recessed. But when he looked through a window, the result was different be