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Biomedical subjects

N E Kroll

Publications and source records attributed to N E Kroll.

6 recordsLinked to original sources
PubMed1992

Semantic memory: complexity or connectivity?

The complexity hypothesis predicts that concept-feature verification times should be directly related to the number of features associated with a concept (the fan effect). Conversely, the connectivity hypothesis predicts that for interconnected semantic relationships, this verification time should be inversely related to the number of closely associated features (the reversed fan effect). In the present experiments, although the time required for episodic recognition memory decisions tended to be directly related to the number of features associated with a concept, semantic verification times were inversely related to the complexity of the concept. In addition, the concept's complexity was at least as good a predictor of performance in semantic tasks as was the strength of association between the concept and feature. Both of these results are interpreted in terms of the connectivity hypothesis.

Adult↗
PubMed1978

Interference with short-term visual memory produced by concurrent central processing.

Double-letter memory and test stimuli were used in two experiments on a speek comparison task. Faster decision times were found when memory and test stimuli were physically identical than when they were the same in name only. This finding was true even with retention intervals as long as 12 sec and even when difficult tasks filled the retention intervals. However, the decision-time advantage of physically identical comparisons was greatest when the interval was not filled with a task likely to interfere with rehearsals. High verbal subjects had a smaller advantage for the physically identical comparisons than did low verbal subjects but were affected in the same way as low verbal subjects in terms of which conditions raised the overall correct comparison times, raised the error rates, and reduced the advantage of physically identical comparisons.

Attention↗
PubMed1976

Autonomic responses to shock-associated words in a nonattended message: a failure to replicate.

Names of cities were shock associated and then embedded in material presented to the nonattended channel in a dichotic listening and shadowing situation. Despite earlier claims of differential responding to city names in the absence of awareness, no such differential responding was found. A test for conditioning following the dichotic listening task found that the subjects had been conditioned. Postexperimental interviews found that the subjects were aware of the city-shock contingency and had expected to be shocked during the dichotic listening task. Comparisons are made with other studies of galvanic skin responses to unattended words.

Association↗
PubMed1975

Rehearsal of visual and auditory stimuli while shadowing.

Memory trigrams were presented by one of three methods: visual-concurrent (all three letters appeared simultaneously), visual-successive, and auditory-successive. During the 12-sec retention interval, subjects shadowed and reported their rehearsals and mnemonic associations via switches. On trials without associations, recall performance was interpreted as support for the hypothesis that the form of rehearsal is related to presentation modality. However, the frequency and temporal patterning of the rehearsals over the retention interval were virtually identical for all three presentation conditions, suggesting that the "control processes" were relatively independent of both method of presentation and modality of rehearsal. Most importantly, these data in combination with earlier data suggest that the efficiency of each rehearsal was also independent of those same factors, in each case quite comparable to that of a concurrent visual stimulus.

Association↗
PubMed1975

Enduring visual memory despite forced verbal rehearsal.

The ability to decide rapidly that two visual stimuli are nominally the same when they are also visually the same (the Posner effect) was examined for stimuli of increasing visual complexity (Experiment 1) and when a greater variety of visual differences between the two stimuli was employed (Experiment 2). When the two stimuli each consisted of a pair of letters or when to single-letter stimuli sometimes differed in both case and style, the Posner effect occurred even though subjects made overt verbal rehearsals of the first stimulus. The results suggest that losses of the Posner effect found under simpler circumstances are not attributable to a switch from visual to exclusively verbal coding.

Adult↗