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A study was performed to examine the utility of an ERP-based irrelevant probe technique for the assessment of variations in mental workload. Ten highly trained Navy radar operators performed a simulated radar-monitoring task which varied in the density and type of targets to be detected and identified. This task was performed in the presence of a series of(More)
Extracellular microelectrode recordings from 148 single cells in the pretectum of the hooded rat were classified according to their temporal response properties to light stimulation of their retinal receptive fields. Fifty-six cells were classified as tonic-on cells, 22 cells were classified as tonic-off cells, and 53 cells were classified as phasic cells.(More)
We measured the pupillary light reflex (PLR) in 5 pigmented, Long Evans rats (under urethan sedation) in three conditions: direct stimulation, consensual stimulation, and a control condition designed to measure the effects of stray light. The average constriction (maximal amplitude) produced by a ganzfeld stimulus delivering 1.6 log quanta absorbed per rod(More)
The effects of retinal degeneration on the sensitivity of the retina were studied in the Royal College of Surgeons (RCS) rat by measuring the light reflex of the pupil in response to ganzfeld (full field) flashes. Light reflex thresholds were measured for animals from 32 to 683 days of age, and an age-related decrease in sensitivity of 5.2 log units(More)
We examined the attentional sensitivity of the frequency-change mismatch negativity (MMN). Subjects listened to a binaural mixture of a narrative and a series of tone bursts that included 1200-Hz standards and two deviants (1000 and 1400 Hz). In the attend-tones condition, subjects responded to one deviant and ignored the narrative. In the attend-words(More)
Hereditary retinal degeneration in the Royal College of Surgeons (RCS) strain of rat has been shown to produce extensive loss of photoreceptors and a corresponding decline of the electroretinogram, ganglion cell sensitivity, and the sensitivity of the pupillary light reflex. The behaviorally measured thresholds of RCS rats, on the other hand, are reported(More)
We evaluated event-related potentials (ERP) as indices of performance in three visual display-monitoring tasks: (a) signal detection, (b) running memory and (c) computation. Using factor analysis, we developed a global measure of performance (PFI) for each task. Task-relevant and irrelevant-probe stimuli elicited ERPs, which included components P1, N1, P2,(More)
To improve the measurement and differentiation of normal and abnormal brain function we are developing new methods to decompose multichannel (electroencephalogram) EEG into elemental components or " atoms. " We estimate EEG atoms using multiway analysis, specifically parallel factor analysis or PARAFAC for modeling. Activation sequences of EEG atoms can(More)
Eight eyes of adult cats were injected with different doses of kainic acid (KA) and examined following survival times of either 5 or 12 days. At a survival time of 12 days, a dose of 76 nmol produced an 18% loss of ganglion cells in the center of the area centralis (AC), 70% loss at a location 2 mm from the AC, and 95% loss at a location 6 mm from the AC.(More)
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