Regional cerebral blood flow response to recognition memory versus semantic classification tasks

Two randomly assigned groups, N = 7 each, of neurologically normal patients were composed. One group, RM, had regional cerebral blood flow measurements during a recognition memory probe test; the other group, SC, had rCBF measurements during a semantic classification task, using the same stimulus and response features as the RM task. Thus, the groups differed only in the cognitive instruction they were executing. The RM group showed a significantly lower change from resting baseline to activation, in mean left hemisphere initial slope index, than did the SC group. The RM group, but not the SC group, showed a significant inverse correlation between occipital flow and accuracy of memory performance as indicated by d′. Correlations between age and hemispheric initial slope index, and between homologous left and right hemisphere sites, were also described. The results are considered to support an anatomical basis for the distinction between episodic and semantic memory and to suggest that occipital flow may diminish with accurate memory performance because of an upstream demand of blood in the medial temporal lobes.     

The effect of set size on hemifield asymmetries in letter recognition

Single letters were presented tachistoscopically in the left or right hemifield to right-handed observers. Superior recognition of letters on the right was found for letters chosen from subsets containing four items, but no differences were found when any letter, or any symmetrical letter, could appear. In a second experiment, the right hemifield advantage was found under conditions requiring the subject to determine the subset only when the subset chosen was appropriate. Results were discussed in terms of the adequacy of language-based explanations of hemifield asymmetries in letter recognition.     

Formal assessment of problem-solving and planning processes in preschool children

While much is known about adult problem-solving, the materials, analyses, and theoretical issues from the adult literature rarely make contact with the tasks typically used to investigate children's thinking. This paper examines the behavior of 4-, 5-, and 6-year-old children attempting to solve a novel variant of the Tower of Hanoi task. Problems varied in difficulty (one to seven moves for the minimum path solution) and in goal type: tower (all objects on one peg) or flat (all pegs occupied). For each problem, children gave verbal statements of their complete solution plan. The Plan Analysis examined performance as a function of goal type and age. Better performance was observed for tower ending problems, and among older children. The Error Analysis revealed that specific error propensities were related to both age and goal type. The Strategic Analysis compared the first move profiles of 6-year-olds to those of several plausible move selection models, and a high degree of correspondence was obtained between specific models and individual children. Young children appear to have rudimentary forms of many of the problem-solving processes previously identified in adults, but they may differ in encoding and representational processes.     

Measurement of sexual arousal in several paraphilias: The effects of stimulus modality,instructional set and stimulus content on the objective

The effects of instructional set (become aroused or suppress arousal), stimulus modality (videotape, audiotape, slides, free fantasy) and stimulus content (paraphilic or non-paraphilic) on sexual arousal, as measured by penile plethysmograph, of six different groups of paraphilics, pedophiles, rapists, exhibitionists, homosexuals, sado-masochists and fetishists, were determined. The results showed significant main effects of instructional set and of stimulus modality (videotape was clearly more arousing) as well as several complex interactions of diagnostic group with the other independent variables.     

Design and implementation of a microcomputer-based adaptive testing system

Adaptive testing is a relatively new form of test administration in which a test is tailored to the individual taking it by choosing items most informative about that person. Methods for determining which items are most appropriate take on a variety of forms, some requiring extensive computation, and almost all requiring administration by a computer. The increasing availability of inexpensive microcomputer systems has made adaptive testing possible when access to larger computer systems is impractical. To make implementation of a variety of adaptive testing methods feasible on a microcomputer, a system efficient from both the examinee’s and the test constructor’s perspectives is necessary. This paper begins by briefly outlining the strategies of adaptive testing developed to date and showing how, structurally, they can be grouped into three general categories. Considerations in design of a test-specification subsystem are then discussed as they relate to this categorization. Finally, a specific implementation of a subsystem for use under the CP/M microcomputer operating system is described. Techniques used to make the extensive computations required by adaptive testing feasible on a microcomputer are presented.     

Developing a laboratory course using PASCAL on the Apple II

Several resources are available to the person seeking to develop a laboratory course that utilizes microprocessors. Several roles for such equipment are envisioned, and some of the issues regarding types of equipment and programming languages are addressed.     

Subjective contours can facilitate performance in a reaction-time task

Subjective contours were compared with objective contours in their ability to facilitate performance in speeded tasks that required judging the position of a dot or the slope of a line segment relative to the contour. Subjective contours were found to reduce both reaction times and error rates for dot localization but not for the more difficult slope discrimination task. These results add to the growing body of evidence suggesting that subjective contours have functional properties similar to those of objective contours.     

Exercise, changes in aerobic capacity, and changes in self-perceptions: An experimental investigation

Subjects in an exercise training condition participated in a 10-week aerobic exercise class, whereas subjects in waiting-list control and independent control conditions did not. The results indicated that subjects in the training condition evidenced reliably greater improvements in physical fitness (aerobic capacity) and reported reliably greater improvements in their abilities and confidence in both the physical area (e.g., ability to run distances) and nonphysical area (e.g., frustration tolerance) than did subjects in the control conditions. On the other hand, improvements in physical fitness were not related to reported improvements in abilities and confidence. These findings are of interest because they indicate that some of the important personal changes that are associated with physical fitness training are not due to changes in fitness, but appear to be due to other factors (e.g., group participation and expectancies).