ABSTRACT
This chapter examines the kernels that express the interactions to obtain a clearer picture of their spatial and temporal limits, and their possible mechanisms. Single-unit extracellular recordings of directional selectivity (DS) cells in the striate cortex of anesthetized cats provided responses to conventional bar and edge stimuli that were used for classifying cells as simple or complex and for assessing DS. Simple cells showed separate regions of response to presentation and removal of a light stimulus, whereas cells of the complex family gave ON and OFF responses to light or dark stimuli. Having classified the random stimuli (RF), the chapter presents a prerecorded video random-bar white-noise stimulus. As possible combinations of dark and light bars could occur in a given frame, the grating included narrow and wide bars of both contrast signs, moving up and down in short sequences at random regions of RF, over a wide range of speeds whose values were limited only by the 16-ms temporal quantization.
