Dissociations between procedural and episodic memory: effects of time and aging

The issue of multiple memory systems is explored. Young and older adults (mean ages = 20 and 71, respectively) named pictures and were tested immediately, 1, 7, or 21 days later. Episodic memory (recognition) for pictures was significantly lower in older relative to young adults and declined systematically across all retention intervals in both age groups. In contrast, procedural memory (repetition priming in picture naming) revealed no reliable age differences. In both age groups, priming declined within the first 24 hr, but unlike recognition, there was no further decrement from 1 to 21 days. There were also within-subject dissociations: The magnitude of priming was equivalent for remembered and forgotten items, and the relation between recognition and priming across intervals was nonmonotic, revealing a reversed association. The findings were interpreted within a multiple-memory-systems framework.     

Preserved organization of semantic attributes in Alzheimer's disease

This study investigated whether Alzheimer's disease (AD) disrupts the basic organization of the semantic attributes of concepts. Young and normal older subjects and AD patients were presented with a target concept followed by a stimulus word and were to decide whether the stimulus was related to the target. On those trials where it was, the stimulus was either a high-, medium-, or low-dominance attribute of the target. The higher the normative dominance, the more important the attribute to concept meaning. In all 3 subject groups, decision time varied as a function of dominance. The higher the dominance, the faster the decision. Attribute dominance affected the performance of AD patients more than that of normal subjects. These results suggest that AD patients retain their knowledge of the relative importance that the different attributes of a concept have for concept meaning.     

Age differences in everyday memory: laboratory analogues of telephone number recall

Three experiments were conducted to examine age differences in memory for telephone numbers by adults ranging from 18 to 85 years of age. In the first 2 studies, using visual simultaneous presentation, age declines in immediate recall were evident on 10-digit numbers, but not on 3-digit numbers. With 7-digit numbers, the youngest group performed significantly better than the oldest (70-85 years) group. In the second study, more marked age declines occurred when subjects had to redial a number after a busy signal. The third experiment replicated the observed aging pattern with auditory sequential presentation. Also, chunked presentation of local telephone numbers resulted in high performance for old and young in sequential recall. The findings were discussed in relation to task processing demands and practical issues related to telephone number recall.     

Information processing,neuropsychological function,and the inherited predisposition to alcoholism

Sons of male alcoholics are at particularly heightened risk for the development of alcoholism. This heightened risk frequently appears in association with increased incidence of conduct disorder or hyperactivity, with deficits in abstract thinking and poor school performance, with abnormalities in cued psychophysiological response, and with increased sensitivity to the putatively stress-response-dampening effects of alcohol intoxication. This risk and its associated features are discussed within the context of a neuropsychological theory, predicated on the notions (1) that deficits in cognitive functions theoretically dependent upon the intact functioning of the prefrontal cortex could underlie manifestation of the idiosyncracies commonly attributed to sons of male alcoholics, and (2) that acute alcohol intoxication could relieve the subjective discomfort associated with the consequences of such deficits.     

Effects of decision strategy and number of openings on employment selection decisions

The purpose of this study was to explore the impact of two factors—decision strategy and the number of openings—on selection decisions. Two hundred graduate and undergraduate students participated in a human resource employment screening simulation. Decision strategy was varied by having candidates evaluate resumes and letters of application for 20 candidates one-at-a-time (sequentially) or all at once (simultaneously). The number of position openings was either one or three. Decision strategy affected the number of candidates accepted, acceptance threshold, and decision time. The number of openings affected selection decisions in the simultaneous but not the sequential context. Implications of these results for selection processes are discussed.     

Evaluation of visual display surfaces by real users early in the design stage

Groups of non-computer scientists were tested to evaluate the potential of an as yet non-existent interactive terminal with a screen diagonal of one meter. A simulated large image terminal provided limited realistic interactions using software developed to give close proximity to the predicted visual effect. Subjective responses from 101 subjects were elicited from a questionnaire designed to evaluate specific aspects of the “terminal” in use. From this data, two types of screen (lenticular and plain) and two types of interaction devices (touch and remote pointer) were analyzed experimentally using a two-way factorial design. Potential end-users provided positive feedback concerning future use of the Large Image Terminal. Building a realistic mock-up revealed screen contaminations which would not have been discovered until a much later stage. Although statistical analysis of screen evaluations was equivocal, the questionnaire was sufficiently penetrating to separate the positive and negative features. This methodology was invaluable in guiding the design process. Copies of the questionnaire may be obtained from the authors at the Heriot-Watt address.