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Biomedical subjects

N S Walker

Publications and source records attributed to N S Walker.

5 recordsLinked to original sources
PubMed1994

An integrated clinical computer system: implications for a medical information services department.

The hybrid record--both paper and electronic--is a cumbersome byproduct of the evolution to the computer-based patient record. Nancy Walker describes how William Beaumont Hospital managed its information services with this mixed media record. Her article provides practical solutions for health information managers including downtime procedures, report distribution plans, release of information steps, and audit procedures for maintaining confidentiality.

Computer Security↗
PubMed1982

Non-linear temporal summation by simple cells in cat striate cortex demonstrated by failure of superposition.

Simple cells in area 17 of the anaesthetized, paralysed cat were stimulated with stationary sinusoidal gratings whose contrast was temporally modulated in different ways. The response to a temporal waveform which was the sum of two sinusoids (1.25 Hz and 7.75 Hz) was compared with the response elicited by each component when presented alone. The responses to the high temporal frequency in the compound stimulus were relatively enhanced by the addition of the low temporal frequency; those to the low frequency were relatively depressed.

Animals↗
PubMed1980

Non-linearities of temporal summation in neurones in area 17 of the cat.

Sinusoidal temporal modulation of the contrast of sinusoidal gratings has been used to provide one description of the temporal properties of neurones in area 17 of the cat's visual cortex. Concurrently, the waveforms of the neurones' responses to 2 s flashes of identical gratings were examined. In most neurones, the response to the long flash was much more transient than would be expected from the shape of the temporal-frequency tuning curve. Temporal summation in cortical neurones is non-linear.

Animals↗
PubMed1977

An analysis of motor coordination components for various localization tasks.

Localization abilities of subjects in three perceptual-motor tasks were considered before and after an exposure to a visual distortion. During this distortion the subject observed his hand ballistically point to an invisible but audible target while either receiving or not receiving knowledge of results (KR) concerning pointing accuracy. Also, subjects either received a 1- or a 4-sec rest period between each of 30 exposure ballistic pointing actions. The pre- and postexposure tasks involved the ability of a subject to accurately point to an occluded and stationary auditory target, to point to the straight-ahead position in space, and to indicate when a moving, auditory target was perceived as being in the straight-ahead position. For these tasks, the pre- vs. postexposure localization difference scores are referred to as the negative aftereffect, the proprioceptive shift, and the auditory shift, respectively. Wilkinson's (1971) two-component additive model (negative aftereffect = proprioceptive shift plus auditory shift) held when KR was given regardless of amount of rest between exposure pointing responses. With a 4-sec rest and no KR, the relationship between coordination components was nonadditive (negative aftereffect greater than proprioceptive shift plus auditory shift).

Journal Article↗