Biomedical subjects

C Worley

Publications and source records attributed to C Worley.

4 recordsLinked to original sources

PubMed2000

Vector subtraction implemented neurally: a neurocomputational model of some sequential cognitive and conscious processes.

Although great progress in neuroanatomy and physiology has occurred lately, we still cannot go directly to those levels to discover the neural mechanisms of higher cognition and consciousness. But we can use neurocomputational methods based on these details to push this project forward. Here we describe vector subtraction as an operation that computes sequential paths through high-dimensional vector spaces. Vector-space interpretations of network activity patterns are a fruitful resource in recent computational neuroscience. Vector subtraction also appears to be implemented neurally in primate frontal eye field activity, which computes dimensions of saccadic eye movements. We use this apparent neural implementation as a model and construct from it a general neurocomputational account of an important type of sequential cognitive and conscious process. We defend the biological plausibility of all components of the general model and show that it yields testable anatomical and physiological predictions. We close by suggesting some interesting consequences for consciousness if our model characterizes correctly the neural mechanisms producing a common type of episode in our conscious streams.

Cognition↗

PubMed1995

This looks like malignant hyperthermia!

Based on the content of this article, the reader should be able to (1) describe the symptoms of malignant hyperthermia (MH); (2) describe the use of dantrolene in the treatment of MH; (3) explain the history of the Malignant Hyperthermia Association of the United States; (4) list the recommended contents of an MH emergency cart; and (5) explain how to plan a mock MH crisis drill.

Dantrolene↗

PubMed1993

Disruption caused by the house officer's bleep: a simple solution.

For a 'control' week, all bleep calls a surgical house officer received were charted without the nurses' knowledge and graded according to an arbitrary scale of usefulness. Also recorded were time of day, the person bleeping and whether the house officer was involved in patient care. A system was then tried in a later 'test' week, whereby only the nurse in charge would bleep the house officer and a board was placed on the house officer's own two wards where tasks could be written. Again all calls were recorded. This led to a decrease in inappropriate bleep calls from the nurses (58 per cent falling to 15 per cent p < 0.01) and a fall in numbers of nurses' bleep calls by two-thirds before 5 pm (p < 0.01). There was also a decrease in the number of bleeps when the house officer was directly involved in patient care (46 per cent falling to 28 per cent). The nurses in charge were agreeable to the changes. The entire study was repeated by another house officer with similar results. There has been little research on the disruption caused by the bleep and we believe that by this simple policy the house officers' day can be disrupted far less.

Medical Staff, Hospital↗

PubMedDate not supplied

A functional hypothesis for LGN-V1-TRN connectivities suggested by computer simulation.

We employ computer simulation to investigate the function of neural circuitries between thalamic sensory relay nuclei, primary sensory cortices, and the thalamic reticular nucleus (TRN). Computational similarities exist between these circuits and the architecture of a simple artificial neural network. We impose processing parameters on this network architecture in keeping with anatomical and physiological details of the mammalian geniculo-cortical visual pathway, and then run the simulation on a task involving multiple simultaneous inputs from the simulated visual field. After two to three loops through the simulation, activity in cortical and thalamic units whose receptive fields include the stronger stimulus remains constant, while activity in other cortical and thalamic units activated by weaker stimuli declines toward resting values. These results suggest that the modeled neural circuitry functions to "prime" selective attentional mechanisms further up the visual streams toward specific portions of the total visual stimulus. Besides extending existing models and evidence about the function of these neural circuits, our results also provide physiologists with predicted activity profiles of thalamic and cortical elements of the modeled neural system for a task not yet studied experimentally.

Animals↗