Robert Porter

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1. Recordings were made of the natural discharges of neurons in the supplementary motor area (SMA) of conscious monkeys trained to perform stereotyped motor task, pulling a horizontal lever, with either hand. 2. Of the total population of cells, 80% showed modulation of their activity during particular movements of either limb. Many cells had a similar(More)
The relative numbers and locations of neurons projecting to the "forelimb" region of the precentral motor cortex were studied in three monkeys by using the retrograde transport of horseradish peroxidase. Within the forelimb area of the motor cortex itself, there are extensive and profuse interconnections. However, regions within this area receive afferents(More)
1. Corticocortical synaptic influences on pyramidal neurones in the precentral motor cortex of monkeys were examined using intracellular recordings. Corticocortical afferents from the postarcuate premotor area and the somatic sensory cortical areas were activated by bifocal stimulation of the cortical surface. Neurones that were found to respond(More)
The cells of origin of the corticostriatal projection have been identified in squirrel monkeys by the use of the retrograde horseradish peroxidase method. In the subfields of the somatic sensory, motor, parietal and frontal areas of the cortex, cells projecting to the ipsilateral striatum are relatively sparsely distributed and form a group of small- to(More)
To investigate climatic, spatial, temporal, and environmental patterns associated with hantavirus pulmonary syndrome (HPS) cases in the Four Corners region, we collected exposure site data for HPS cases that occurred in 1993 to 1995. Cases clustered seasonally and temporally by biome type and geographic location, and exposure sites were most often found in(More)
1. Group Ia EPSPs were recorded from lumbosacral motoneurones in anaesthetized cats after almost complete section of the relevant dorsal roots. The EPSPs were usually of small amplitude (median value of 230 muV) and an averaging device was used to improve the definition of their time course.2. From a total of over 500 averaged EPSPs a smaller number (342)(More)
The optimal features with which to discriminate between regions and, thus, segment an image often differ depending on the nature of the image. Many real images are made up of both smooth and textured regions and are best segmented using different features in different areas. A scheme that automatically selects the optimal features for each pixel using(More)