In search of closure: subjective contour illusions, Gestalt completion tests, and implications

This study investigates the construct validity of perceptual closure tests (CTs), and isolates a common processing demand from the right-hemisphere. Sixty-seven patients with focal unilateral lesions (34 right side, 33 left side), and 80 control subjects participated. Multivariate analyses indicated that there was substantial age-related variance in all CTs, while sex was variably significant; CTs are not uniform in their discriminating ability, and hence factorially complex; and their specifically right hemisphere-sensitive dimension was subjective contour illusions, and interestingly unrelated to facial discrimination ability. The methodological and theoretical implications are discussed.     

Computer-based interactive video systems

Computer-controlled interactive video instruction provides an instructional technique that overcomes many of the shortcomings of using the computer alone as an instructional device. Students who have used interactive video modules have been shown to better retain the material presented and to enjoy the course more than students not using the video modules.     

Computerphobia

Five studies of over 450 university students presented a comprehensive picture of computer-phobia. Three research and clinically based self-report instruments were developed to measure three nearly independent dimensions of computerphobia-computer anxiety, computer attitudes, and computer cognitions and feelings. Results indicated that older students were more computer anxious, but did not have more negative attitudes, cognitions, or feelings, than did younger students. Women had more negative attitudes than did men. Feminine-identity students showed more anxiety and negative attitudes than did masculine-identity students, regardless of gender. White students had more anxiety and more positive attitudes than did nonwhite students. Computerphobia was related to other anxiety measures (mathematics, state, and trait), but was a separate construct. Experience with computer interaction did not reduce anxiety or improve attitudes. Finally, regardless of academic major, computer-anxious students showed less computer aptitude, literacy, and interest. Implications for treating computerphobia are discussed.     

The Computerphobia Reduction Program: Year 1. Program development and preliminary results

The program development and first-year results of a 3-year U.S. Department of Education Fund for the Improvement of Postsecondary Education (FIPSE) grant are described. The identification of computerphobics and the types of discomfort they experience are defined. A clinically based 5-week model computerphobia reduction and skills-acquisition program is presented. Screening and assessment measures are outlined and three treatment modules—two individual treatments (systematic desensitization and thought stopping) and an information/support group—are described. The first-year results demonstrate significant pretreatment-to-posttreatment change in anxiety, attitudes, cognitions, and feelings. Plans are discussed for further evaluation and program expansion.     

Plucks and bows are not categorically perceived

Letter-like targets (a circle and a square) were presented in one of two fixed and cued visual field locations and were shown alone, flanked by a noise stimulus on the peripheral side (side of target farthest from fixation), on the central side, or on both sides simultaneously. The adjacent target and noise stimulus borders had similar featural properties (both curved or both straight lines) or dissimilar properties (one being a curved line and one a straight line). Each of 10 subjects made a go, no-go response only when his or her designated target appeared in a display. The results showed: (1) single targets were discriminated more accurately and more rapidly than were targets shown simultaneously with noise stimuli, (2) targets having dissimilar border relationships with noise items were discriminated more accurately than were targets having similar border relationships, (3) targets in central-noise displays were discriminated more accurately and rapidly than were targets in peripheral-noise displays, and (4) there was no interaction between border relationships and noise position. The principal result relating to target-noise border featural relationship was consistent with predictions derived from models which place the locus of noise effects at the stage of stimulus feature extraction. Aspects of the results were, however, seen to be consistent with both feature extraction and response competition conceptualizations.     

How much help do repeated presentations give to recognition processes?

A recent experiment by Haber and Hershenson (1965) had shown that in a recognition task one long look at a stimulus was always superior to two or more shorter looks summing to the same total presentation time. In order to explore this more fully and to account for opposite results in a different type of recognition task, as well as in a serial learning task, an improved replication of the earlier study was carried out using very short durations and single letters as stimuli. The same non-reciprocity was found, again strongly favoring duration over repetition as a determinant of clarity of a percept, even though repetition alone was also shown to be a significant independent variable. As a subsidiary finding, an error analysis showed that when a letter was misnamed it was nearly always confused with one that looked like it rather than one that sounded like it. Some discussion was offered as to the role of an auditory information storage in low memory load tasks such as this one, as well as some general implications for information processing analyses of the non-reciprocity of duration and repetition.