Showing papers on "Orientation column published in 1969"

Anatomical Demonstration of Columns in the Monkey Striate Cortex

Abstract: Anatomical investigation of the monkey striate cortex supports the physiological concept that the cortex is subdivided vertically into columnar aggregates of cells. Here the shape and size of two independent and overlapping column systems are described.

Visual receptive fields of striate cortex neurons in awake monkeys.

Abstract: THE EXPERIMENTS of Lettvin and colleagues (25) and Hubel and Wiesel (19) have indicated that a neuron in the vertebrate visual system is sensitive to particular characteristics of the visual stimulus. These characteristics have been referred to as the “trigger features” of the stimulus (3) and include such factors as size, shape, orientation, color, and rate and direction of movement; the area of the visual field over which the stimulus is effective is referred to as the receptive field of the neuron (17). Receptive-field characteristics of visual system neurons have subsequently been determined in a wide range of animals (for references see 7, 16). In addition, Hubel and Wiesel (19-24, 30) have shown that there are changes in the characteristics of the stimulus needed to activate a neuron at successively higher levels of the visual system. In both cats and monkeys they observed a progressive change in the predominant type of receptive field from the circular receptive fields of retinal ganglion and lateral geniculate cells, through the elongated receptive fields of the simplest cortical cells, to the more complex fields of other cortical neurons. This understanding of the visual system has been derived entirely from experiments in which the animal was paralyzed and frequently also anesthetized. Such procedures have been designed to eliminate all eye movements, particularly the small eye movements of physiological nystagmus that are characteristic of normal vision (1). The purpose of the present experiments was to determine whether receptive fields of striate cortex neurons in the awake, behaving animal are similar to those in the anesthetized,

Visual Receptive Fields of Neurons in Inferotemporal Cortex of the Monkey

Abstract: Neurons in inferotemporal cortex (area TE) of the monkey had visual receptive fields which were very large (greater than 10 by 10 degrees) and almost always included the fovea. Some extended well into both halves of the visual field, while others were confined to the ipsilateral or contralateral side. These neurons were differentially sensitive to several of the following dimensions of the stimulus: size and shape, color, orientation, and direction of movement.

Visual Receptive Fields of Cells in a Cortical Area remote from the Striate Cortex in the Cat

Abstract: SEVERAL workers1–4 have reported that responses evoked either by light flash or by shock applied to the optic nerve can be recorded from a region of the suprasylvian gyrus (SSG) of the cat. These responses are similar in latency and waveform to those evoked from the primary visual area. Recent studies using the Nauta method have shown that degeneration appears in the medial wall of the suprasylvian sulcus after lesions in various parts of the visual pathway, including the lateral geniculate nucleus (LGN) (ref. 5), striate and peristriate cortex6,7. The band of degeneration is separated from visual area III by a degeneration-free zone along the apex of the suprasylvian gyrus. The experiments reported here were designed to analyse the specificity of response to visual stimuli of single neurones in the medial wall of the suprasylvian sulcus.

Inhibitory and subliminal excitatory contributions from the non-dominant eye to the receptive field of binocularly-activated neurons in the striate cortex of the cat

Abstract: INHIBITORY AND SUBLIMINAL EXCITATORY CONTRIBUTIONS FROM THE NON-DOMINANT EYE TO THE RECEPTIVE FIELD OF BINOCULARLY-ACTIVATED NEURONS IN THE STRIATE CORTEX OF THE CAT