Showing papers in "Journal of Neurophysiology in 1957"

Modality and topographic properties of single neurons of cat's somatic sensory cortex.

Abstract: THE PRESENT PAPER describes some observations upon the modality and topographical attributes of single neurons of the first somatic sensory area of the cat’s cerebral cortex, the analogue of the cortex of the postcentral gyrus in the primate brain. These data, together with others upon the response latencies of the cells of different layers of the cortex to peripheral stimuli, support an hypothesis of the functional organization of this cortical area. This is that the neurons which lie in narrow vertical columns, or cylinders, extending from layer II through layer VI make up an elementary unit of organization, for they are activated by stimulation of the same single class of peripheral receptors, from almost identical peripheral receptive fields, at latencies ers. It is early These which are not significantly different for the cells of the various layemphasized that this pattern of organization obtains only for the repetitiv neurons ‘e responses may be rela of ted cortical in quite neurons different to brief peripheral stimuli. organization patterns when analyzed in terms of later discharges. A report of these experiments was made to the American Physiological Society in September, 1955 (10, 17).

Effects of small frontal lesions on delayed alternation in monkeys.

Abstract: THIS EXPERIME~ attempti to detie the ~ cortical lesion which wiU 4 disrupt a monkey’s performance on a dekyed-mpo= type of problem. If such a cortid focus can be preckly located, data from neuroanatomy and electrophysiology relating this cortid area to other cerebral structures might then be used to suggest the larger cerebral network, and, hence, the neural mechanism, which mediates this c~ of problem-solving behavior. Of more immediate concern, neural mechanism aheady proposed codd be more accurately evaluatid against the touchstone provided by a description of the cortical focus. A series of studies by ~bram and his associates (13, 15, 16, 18) has demonstrated that the cortical area foca~y concerned in delayed-response types of functions must be bited at least to the lateral surface of the frontal lobes anterior to the arcuate sticus. The purpose of the present experiment is to determine whether restits obtained by Blum (1) implying an even more timited focus-namely, the mid-lateral cortex—cotid be substantiated. Subjects. Ten immature Mac@a mulati (Rksus) monkeys, without previo~ training, were used as subjecti. Apwaratus. AU animak were trained in a Wisconsin General-Testing Apparatus. The essential features of the apparatus are: an enclosure divided into two sections-an animal chamber and a section for the testing tray; a sfiding panel which can be lowered between the two sections to conceal the ($ testing tray from the animal during the baiting and delay periods; a oneway-vision screen which conceak the experimenter when the shding panel ! is raised.