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Biomedical subjects

G Musen

Publications and source records attributed to G Musen.

10 recordsLinked to original sources

Attentional requirements for object-location priming.

The purpose of the present experiments was to investigate whether a verbal and a spatial secondary task would disrupt priming for object-location associations. Symbols were placed one at a time in one of nine locations in a rectangle. Implicit memory was tested with a reaction time (RT) task. All symbols were placed in the same location of the rectangle across 10 trial blocks; then, all their locations were changed. Responses were made on the numeric keypad, which corresponded to the spatial locations used in the rectangle. A decrease in RTs across the first 10 trial blocks followed by an increase in RTs when the symbols changed locations would indicate priming for the associations. The results were that implicit memory for object-location associations was obtained under single-, but not under dual-task conditions. We have interpreted the results in terms of a working memory model that posits that implicit memory will suffer when cognitive resources are limited.

Adult↗

Implicit memory for nonverbal associations.

A color-naming priming task was used to examine implicit memory for new nonverbal associations. Implicit memory was observed for associations between words and colors and between abstract shapes and colors. The authors also asked whether nonverbal association priming might occur more readily than verbal association priming. Colored compound nonwords were used as stimuli, and participants were asked to attend either to the 2 syllables of the compound nonword or to the compound nonword and the color in which it was printed. The authors found that the association formed depended on which attributes of the stimuli were attended to and were not more readily formed for nonverbal material. The results demonstrate that tasks that encourage unitization between the elements to be associated facilitate associative priming.

Adolescent↗

Implicit learning of color-word associations using a Stroop paradigm.

Our experiments asked whether implicit learning occurs for novel nonverbal associations. We presented subjects with color names printed in incongruent colors; subjects were asked to name the color in which the word was printed. In Experiment 1, each of 7 color words were associated with the same incongruent color across 6 blocks of trials, and then the color-word associations were abruptly changed. Both control subjects and patients with amnesia reduced their color-naming times across the first 6 trial blocks, and naming times increased when the color-word associations were changed. In Experiment 2, similar results were obtained when neutral words were associated with colors. In Experiment 3, we found that naming times were not disrupted when an irrelevant dimension (typecase) was changed. Finally, in Experiment 4, we found that the effect persisted across a 5-min delay. These studies provide evidence that implicit learning occurs for nonverbal associations and is independent of the brain structures damaged in amnesia.

Aged↗

Nonverbal priming in amnesia.

In this experiment, we examined whether a group of well-characterized amnesic patients would exhibit normal priming for novel nonverbal materials after a single exposure. Both amnesic patients and normal control subjects studied line figures and were then given a priming test in which they were asked to reproduce both old (studied) and new (unstudied) figures after a brief exposure. The measure of priming was the number of old patterns drawn correctly relative to the number of new patterns drawn correctly. Both subject groups reproduced more old patterns than new patterns, and the effect was similar in the two groups. In contrast, amnesic patients were significantly impaired on a recognition memory test for the items that had been presented. This study contributes to recent evidence that implicit memory can support the rapid acquisition of novel verbal and nonverbal information. Perceptual priming for such material is independent of the structures damaged in amnesia.

Aged↗

Effects of verbal labeling and exposure duration on implicit memory for visual patterns.

The present study investigated the role of verbal labeling and exposure duration in implicit memory for novel visual patterns. Encoding condition was varied in Experiment 1. Two encoding conditions discouraged verbal labeling and a third required it. In Experiment 2, exposure duration was manipulated to determine whether a new memory representation could be formed after a single 1-s exposure. The results suggest that verbal labeling is not necessary to support priming. Type of encoding did not affect implicit memory, but had a pronounced effect on explicit memory. Furthermore, a single 1-s exposure was sufficient to support priming, and priming was not further enhanced by longer stimulus exposures. In contrast, recognition performance was enhanced by a longer stimulus duration. Thus, priming effects with these novel figures are likely to be supported by newly acquired representations rather than by preexisting memory representations.

Humans↗

Normal acquisition of novel verbal information in amnesia.

Amnesic patients (n = 9) and normal subjects (n = 12) read lists of unique words, repeated words, unique nonwords, and repeated nonwords as quickly as possible. In the first experiment both groups of subjects read the lists of repeated items faster than the lists of unique items and improved at the same rate within each list. In the second experiment, subjects read four new lists of items and then reread the same four lists after a 10-min delay. The results replicated the findings from the first experiment and demonstrated in addition that the facilitated reading speed persisted across the delay. These results show that the acquisition of novel verbal information can be supported by nondeclarative (implicit) memory. It is suggested that facilitated reading speed for words and nonwords reflects changes in early-stage perceptual systems and that these changes occur independently of the brain structures damaged in amnesia.

Aged↗

Implicit and explicit memory for visual patterns.

The article reports an investigation of implicit and explicit memory for novel, visual patterns. Implicit memory was assessed by a speeded perception task, and explicit memory by a four-alternative, forced-choice recognition task. Tests were given either immediately after testing or 7 days later. The results suggest that a single exposure of a novel, nonverbal stimulus is sufficient to establish a representation in memory that is capable of supporting long-lived perceptual priming. In contrast, recognition memory showed significant loss over the same delay. Performance measures in the two tasks showed stochastic independence on the first trial after a single exposure to each pattern. Finally, a specific occurrence of a previously studied item could be retrieved from explicit memory but did not affect the accuracy of perception in the implicit memory test. The results extend the domain of experimental dissociations between explicit and implicit memory to include novel, nonverbal stimuli.

Consciousness↗

Intact text-specific reading skill in amnesia.

Amnesic patients were studied to determine whether the acquisition and retention of item-specific skills can be supported by nondeclarative (implicit) memory. In Experiment 1, subjects read 2 different passages 3 times in succession. Reading speed improved at a similar rate in both amnesic patients and normal subjects and was specific to the text that was read. In Experiment 2, amnesic patients and normal subjects read a passage 3 successive times and then reread the same passage after a 0-s, 10-min, 2-hr, or 1-day delay. In both groups, facilitation persisted for at least 10 min and disappeared within 2 hr. It is suggested that facilitated reading speed depends importantly on both semantic and perceptual information and that such information can be supported by nondeclarative memory.

Aged↗