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Biomedical subjects

C B Cave

Publications and source records attributed to C B Cave.

7 recordsLinked to original sources
PubMed1992

Intact verbal and nonverbal short-term memory following damage to the human hippocampus.

Short-term memory was assessed in two groups of amnesic patients. Six patients had confirmed or suspected damage to the hippocampal formation, and six patients had diencephalic damage as a result of alcoholic Korsakoff's syndrome. Verbal short-term memory was evaluated with seven separate administrations of the standard digit span test in order to obtain a precise measure of short-term memory. Nonverbal short-term memory was evaluated with four tests that assessed apprehension, retention, and the ability to manipulate nonverbal material--all within the span of immediate memory. One of these four tests assessed short-term memory for spatial location. Patients with damage to the hippocampal formation had a digit span equivalent to that of control subjects and also performed normally on the four tests of nonverbal short-term memory. The patients with Korsakoff's syndrome had a marginally low digit span and performed poorly on three of the four nonverbal tasks, a finding consistent with the deficits in attention and visuospatial processing previously described for this patient group. These deficits are likely due to the frontal lobe atrophy typically associated with Korsakoff's syndrome, rather than to diencephalic damage. The results support the view that short-term (immediate) memory, including short-term spatial memory, is independent of the hippocampus.

Aged↗
PubMed1992

Intact and long-lasting repetition priming in amnesia.

In 2 experiments, we evaluated the ability of amnesic patients to exhibit long-lasting perceptual priming after a single exposure to pictures. Ss named pictures as quickly as possible on a single occasion, and later named the same pictures mixed with new pictures. In Experiment 1, amnesic patients exhibited fully intact priming effects lasting at least 7 days. In Experiment 2, the priming effect for both groups was shown to depend on both highly specific visual information and on less visual, more conceptual information. In contrast, recognition memory was severely impaired in the patients, as assessed by both accuracy and response time. The results provide the first report of a long-lasting priming effect in amnesic patients, based on a single encounter, which occurs as strongly in the patients as in normal Ss. Together with other recent findings, the results suggest that long-lasting priming and recognition memory depend on separate brain systems.

Adult↗
PubMed1991

Equivalent impairment of spatial and nonspatial memory following damage to the human hippocampus.

The hippocampus has sometimes been proposed to function as a cognitive map, a memory system that stores information about allocentric space. Work with experimental animals and memory-impaired patients has raised difficulties with this view by showing that the hippocampus is not performing an exclusively spatial function. However, the possibility has remained that the hippocampus plays a special role in spatial memory or a disproportionately large role in spatial memory compared to other kinds of memory. This study compared spatial and nonspatial memory in amnesic patients with lesions of the hippocampal formation or diencephalon. Subjects studied an array of 16 toy objects and were subsequently tested for object recall, object recognition, and memory for the location of the objects. Control subjects were tested after long retention intervals in order to equate their object memory performance with that of the patients. The main finding was that, when the performance of amnesic patients on the object memory tests was matched to the object memory performance of control subjects, spatial memory performance of the amnesic patients also matched the spatial memory performance of the control subjects. The results were the same for the two groups of patients. These findings suggest that the hippocampus is not especially involved in spatial memory. Spatial memory is simply one instance of a broader category of memory that requires the hippocampus. While cognitive mapping in its most abstract sense may describe hippocampal function, our results support alternative formulation, suggesting that the hippocampus is necessary for the rapid acquisition of relational, configural, or declarative (as opposed to purely spatial) information.

Adult↗
PubMed1989

Evidence for two types of spatial representations: hemispheric specialization for categorical and coordinate relations.

Analyses of human object recognition abilities led to the hypothesis that 2 kinds of spatial relation representations are used in human vision. Evidence for the distinction between abstract categorical spatial relation representations and specific coordinate spatial relation representations was provided in 4 experiments. These results indicate that Ss make categorical judgments--on/off, left/right, and above/below--faster when stimuli are initially presented to the left cerebral hemisphere, whereas they make evaluations of distance--in relation to 2 mm, 3 mm, or 1 in. (2.54 cm)--faster when stimuli are initially presented to the right cerebral hemisphere. In addition, there was evidence that categorical representations developed with practice.

Adult↗