The Association Between Health and Cognitive Performance in a Population-Based Study of Older Adults: The Charlotte County Healthy Aging Study (CCHAS)

In the present study, the relationship between self-reports and objective measures of health status and measures of cognitive performance was examined. Participants consisted of 437 persons (M =72.91 years) from the Charlotte County Healthy Aging Study, a population-based sample of older adults. Cognitive performance was assessed by tests of episodic memory, perceptual speed, and attention. Health status was indexed by subjective ratings, self-reports, and objective measures. The health measures accounted for significant variance on both the Trailmaking A and B tests, accounting for a modest amount of variance (4.4% and 1.1%, respectively). The health measures were not significantly associated with performance on the measures of attention or episodic memory. The results suggest that health status is associated with processing speed to a greater degree than higher order cognitive processes.     

On the automatic evaluation of social exemplars

The present article focuses on the automatic evaluation of exemplars whose category membership has been learned in the past. Studies 1 and 2 confirmed the hypothesis that once an exemplar has been encoded as a member of a given group, at a later encounter the evaluation associated with the group will be unintentionally retrieved from memory, even when no perceptual cue indicates the exemplar's category membership. Study 3 extended the results to the domain of in-group/out-group differentiation. In addition. Studies 4 and 5 confirmed the hypothesis that stored evaluations can be retrieved and affect responses even when the semantic information on which the evaluations were originally based is no longer available for retrieval. Finally, Study 6 investigated spontaneous approach-avoidance behavior tendencies. Overall, results demonstrate the pervasive effects of person-based representations, and they are discussed in terms of recent models of person perception and out-group discrimination.     

The role of input and output modality pairings in dual-task performance: evidence for content-dependent central interference

Recent debate regarding dual-task performance has focused on whether costs result from limitations in central capacity, and whether central operations can be performed in parallel. While these questions are controversial, the dominant models of dual-task performance share the assumption that central operations are generic--that is, their interactions are independent of stimulus and response modalities. To examine these issues, we conducted a series of dual-task experiments with different input and output modality pairings. One condition combined a visual-manual task with an auditory-vocal task, and the other condition reversed the input-output pairings, combining a visual-vocal task with an auditory-manual task. Input/output modality pairings proved to be a key factor; throughout practice, dual-task costs were generally more than twice as large with visual-vocal/auditory-manual tasks than with the opposite arrangement of modalities (Experiments 1 and 2). These differences could be explained neither by competition for peripheral resources nor by differences in single-task response times (Experiment 3). Moreover, the persistent dual-task costs did not appear to stem from a central bottleneck. Contrary to the dominant models of dual-task performance, we propose that central interference between tasks depends not just on the duration of central operations, nor just strategic adaptation, but also on the content of those operations. Implications for structural and strategic accounts of dual-task interference are discussed.     

Simultaneous dual-task performance reveals parallel response selection after practice

E. H. Schumacher, T. L. Seymour, J. M. Glass, D. E. Kieras, and D. E. Meyer (2001) reported that dual-task costs are minimal when participants are practiced and give the 2 tasks equal emphasis. The present research examined whether such findings are compatible with the operation of an efficient response selection bottleneck. Participants trained until they were able to perform both tasks simultaneously without interference. Novel stimulus pairs produced no reaction time costs, arguing against the development of compound stimulus-response associations (Experiment 1). Manipulating the relative onsets (Experiments 2 and 4) and durations (Experiments 3 and 4) of response selection processes did not lead to dual-task costs. The results indicate that the 2 tasks did not share a bottleneck after practice.     

Development of a new spatial test

The development of a new colored spatial test is described. Some psychometric characteristics of this new test are presented from a correlational study, and some suggestions about its incorporation into research are offered.     

Measurement and interpretation of situational and dispositional attributions

Four problems with the measurement of situational and dispositional causality are reviewed. These are: the assumption that dispositional and situational causality are inversely linked; the diversity of the causes considered within the situational and dispositional categories; the difficulties of differentiating between causes internal and external to the actor; and the low convergent validity of various closed-ended attribution measures. A study reaffirms the lack of convergence among closed-ended measures and between closed and open-ended measures as well. In a second study, subjects' ratings of closed-ended attributions are taken as indicators that a freely chosen to not freely chosen dimension may better represent subjects' attributional thought than the internal/external dimension does. Open-ended data from the convergence study are recoded using this scheme and achieve significantly better convergence with closed-ended data. The implications of this redefinition for solving the various measurement problems are discussed.     

Children's embedded figures test: an examination of item difficulty in grades K-4

Indices of item difficulty for both the Tent and the House series of the Children's Embedded Figures Test are reported from a sample of 240 children in grades K-4. Results indicate that the failure rule should be re-considered and the test shortened.     

Delayed alternation in the pigeon

Pigeons were studied in a delayed-response task requiring alternation of key pecks on two response keys. Blackouts of from 1 to 10 sec intervened between successive choices on the two keys.

The following results were obtained: (1) Birds performed at well above chance accuracy on all the delays tested. Accuracy was generally lowest at 1- and 10-sec delays. (2) Overt postural orientations during the delay interval appeared to mediate accurate key-pecking behavior. (3) The shape of the delay vs. accuracy function was discussed in terms of the possibly confounding influences of (a) stimulus “trace” variables, and (b) aversive effects of the time outs produced by incorrect responding.