Chapter 20: Stimulus selectivity and its postnatal development in the cat's suprasylvian visual cortex

This chapter deals with the stimulus selectivity and its postnatal development in the cat's suprasylvian visual cortex. In the cat, the lateral suprasylvian cortex around the suprasylvian sulcus is visually responsive and subdivided into six regions on the basis of their topographical organization. The areas in the medial (PMLS) and lateral banks (PLLS) of the middle suprasylvian sulcus display a complicated pattern of afferent connectivity. Neurons in the lateral suprasylvian cortex respond well to moving stimuli and are usually direction selective. The chapter uses drifting and contrast-modulated gratings, as well as conventional projected stimuli, to examine the selectivity of cells in both PMLS and PLLS of adult cats and also to study the postnatal development of PMLS. The spatial properties of cells in PMLS are shifted to lower spatial frequencies than those of striate neurons, implying that the subunits underlying the receptive fields are larger.