Acute neuropsychological consequences of coronary artery bypass surgery

This study examines a series of coronary artery bypass patients (CABS) for neuropsychological and regional cerebral blood flow (RCBF) changes at 8 days and 8 weeks post surgery. Seventy-three percent were found to have moderate or severe neuropsychological deficits at 8 days post operation and 37% at 8 weeks post surgery. A comparison group of major vascular and thoracic surgery patients was also found to have a significant proportion of neuropsychological deficit following surgery. The RCBF assessments indicated a significant drop in mean RCBF at 8 days post surgery in the coronary artery bypass group which did not persist to 8 weeks. The comparison group showed no changes in RCBF following surgery. The findings suggest different patterns of recovery and origins of the neuropsychological deficit in the two groups and emphasize the need for appropriate control groups in studies examining the cortical effects of extracorporeal circulation. In addition, the project received generous support from the special trustees of the Middlesex Hospital.     

The influence of cue unreliability on judgment in a multiple cue probability learning task

The effect of cue reliability was tested in a two-cue multiple-cue probability learning (MCPL) task. Subjects were 42 undergraduates. The cue validities were.78 and.37. Unreliability in a cue was defined as variability in multiple observations of that cue on a given trial. That variability was provided by adding random errors to the true value of the cue. One group was given consistent cues (i.e., the more valid cue was the more reliable cue), one group was given inconsistent cues, and the control group was given true scores. Cue reliability did not affect subjects' consistency or achievement, but did interact with the presence of outcome feedback. The subjective weights showed that subjects thought they weighted the more reliable cue more heavily regardless of the cue validities or their actual cue weightings. There were wide individual differences in performance, illustrating the need for an idiographic-statistical approach in studying decision making.     

Effect of artificial voice feedback delay in typing and its implications for the blind user

We examined the effect of voice-feedback delay on learning to type nonsense strings on a reduced computer terminal keyboard. The results suggest that long delays (1,642 msec) affect learning of the keyboard before mastery, whereas shorter delays (841 msec) do not. With mastery, subjects learn to ignore the disruptive effects of long feedback delays. Feedback delay may nevertheless be an important human-factors issue for blind consumers who are learning to type with a voice-based system, and for hardware and software designers of systems for the blind and visually impaired.     

Can substantive theorizing really save us from ourselves? A skeptical commentary on Wicker's proposal

This commentary concurs in Wicker's call for more attention to substantive theorizing, but attempts to place that strategic approach within a broader conceptual and methodological context. It presents a perspective that is somewhat more skeptical than Wicker's as to the ultimate potential of research in our field. Specifically, the commentary discusses five themes that Wicker raises in support of the importance and potential value of substantive theorizing, looking at the dark side of each of them as well as at the potential gains. The commentary thus tries to give an appropriate balance of attention to both the limitations and the advantages of substantive theorizing.     

An investigation of body part as object (BPO) responses in normal and brain-damaged adults

A test of simple pantomime was administered to three groups of adults and comparisons were made across groups of the incidence of subjects who exhibited body part as object (BPO) responses and of the mean frequency of occurrence of BPO in each group. The three groups were left-hemisphere-damaged aphasics (N = 28), right-hemisphere-damaged (N = 24), and normal controls (N = 28). The results indicated no significant differences among groups on the BPO measures. Also, to test the strength of association between the frequency of occurrence of BPO and measures of limb apraxia and severity of aphasia for the left-hemisphere-damaged aphasic group, correlation coefficients were obtained. The correlations were low and nonsignificant. The results of this investigation do not support the common clinical assumption that the occurrence of BPO during the performance of simple pantomimes is pathognomic for left-hemisphere pathology or associated with limb apraxia.     

Simulating second-guessing in on-line probability learning

Formal processes (especially metacognitive or control processes) involved in complex human problem solving are examined in a game-playing situation with one person pitted against a microcomputer algorithm. In particular, the strategy of second-guessing is simulated in real-time in an attempt to outwit the person in a binary prediction paradigm. Aspects of success and failure are suggested. A working implementation in BASIC for a TRS-80 Level II is provided.     

Reduction in clinical assessment time using computer algorithms

A new mathematical procedure (BIDALGO) is suggested for application to the psychological testing field. BIDALGO, similar to past adaptive testing methods, is compared both with MMPI short-form efforts and applications in the educational testing literature. A comparison is also made between linear regression models used in past efforts and the Bayesian decision models used in BIDALGO. The requirements for an MMPI application are delineated, emphasizing branching procedures for specific scales and difficulties expected in achieving code-type congruence. Work in progress of applying BIDALGO to the depression scale and the full MMPI is also described.     

Reliability issues in the penile assessment of incarcerants

Although there has been increased reliance upon the direct physiological measurement of penile tumescence in the assessment of sexual deviations, the reliability of these measures has never been empirically validated. This investigation evaluates the reliability of the rape index as a technique in differentiating rapists from nonrapists. Eighteen individuals incarcerated on non-sexual-related offenses were presented visual and audio stimuli depicting mutually consenting intercourse, rape, and aggression. These stimuli were presented under two instructional sets: (1) enchance arousal and (2) suppress arousal. Reliability indices for the rape index were computed among various conditions of modality presentation, instructional set, and test-retest conditions. The overall reliability of the rape index was found to be low. The implications of these results upon the assessment and classification of offenders is discussed.