Developmental changes in attentional skills: the effect of irrelevant variations on encoding and response selection

The present experiments examine how irrelevant variations within a stimulus set interfere with performance in a selective attention task. Second graders, fifth graders, and adults were administered a discrete trial version of a selective attention task in which they were required to search for an object that matched the prime on the targeted dimension. The stimuli in the first experiment were constructed from spatially integrated dimensions whereas the second experiment used spatially separated dimensions. The results indicated that while the spatially separated dimensions were perceived independently by all age groups, developmental differences in perceived structure were evident with the spatially integrated dimensions. Problems associated with response selection were a major source of interference with both types of stimuli, but the severity of the interference varied with the age of the perceiver and the nature of the stimuli. The developmental implications of these findings were considered.     

Validity and clinical scale comparisons between the MMPI and MMPI-2 with psychiatric inpatients.

This study was designed to investigate the comparability of the original MMPI (1950) and the MMPI-2 (1989) with a psychiatric patient population. 34 male and 3 female patients, shortly after admission to one of two acute psychiatry units, completed the old and revised versions of the MMPI. Paired t tests indicated but scant differences for raw scores, while many more differences were found among T scores for validity, clinical, and supplemental scales. Analyses, however, showed all scales on the two forms to be highly correlated. Analysis of the high-point and two-point codes across the two administrations also showed relative stability, although the proportion of Scales 2 (Depression) and 8 (Schizophrenia) decreased, while those for Scales 6 (Paranoia) and 7 (Psychasthenia) increased markedly in the MMPI-2 protocols. Examination of each version's discriminability among mood- and thought-disordered subsamples suggested that the MMPI provides slightly better delineation between diagnostic classes. Discriminant function analyses showed that there were essentially no differences between the two forms in the accurate classification of clinical and nonclinical groups. The findings reported here provide support for the MMPI-2; despite modification, the newer form retains the advantages of the original MMPI. Differences found here may be unique to psychiatric patients and their patterns of MMPI/MMPI-2 equivalence and may not generalize to other special populations.     

Do recognizable figures enjoy an advantage in binocular rivalry?

Five experiments examined whether recognizable stimuli predominate in binocular rivalry. It was found that a face predominated more than did a pattern equated for spatial frequency, luminance, and contrast; an objective reaction time procedure confirmed predominance of the face. The face was still liable to fragmentation as stimulus size increased. Observers tracked exclusive dominance of a picture of a camouflaged figure (a Dalmatian dog) prior to and then following discovery of the figure's presence; control observers received the same protocol with a scrambled version of the dog stimulus. Compared with control results, predominance of the dog picture was higher even before observers knew of the camouflaged figure. Inversion of the dog figure reduced its predominance. Binocular rivalry is sensitive to object-related, configural properties of a stimulus.     

The gestural repertoire and its evolution over the second year

The entire repertoire of communicative gestures was documented in a longitudinal, observational study of 10 infants, whose combined ages covered the range from 9 to 22 months. Early in the second year, giving as a request to do something with the object increased, while emotive gestures decreased. Later in the second year, pointing gestures increased, while protest gestures tended to decrease. Combining gestures with vocalization tended to increase only for protest gestures later in the second year. Eye contact showed a small but continuous increase in coordination with gestures over the second year, particularly with comment, request, and emotive gestures. These findings indicate an increasing use of the parent as an agent and of the informative function in non-verbal communication during this period of transition to verbal communication.     

The development of selective attention: holistic perception versus resource allocation

In two experiments, a speeded sorting task was administered to children. In each sorting, the child was instructed to sort a deck of cards according to values on one dimension while the values of a second irrelevant dimension were held constant, were correlated, or were varied orthogonally. Experiment 1 evaluated developmental changes in perceived structure as compared with such changes in the control of attention. Different groups of kindergarten, 2d-, and 5th-grade children performed the task with spatially integrated vs spatially separated dimensions. The results indicate that with spatially integrated dimensions there is a trend from holistic to featural perception and an increase in attentional control with increasing age. Spatially separate dimensions are perceived dimensionally at all ages, but show a trend in attentional development. In Experiment 2, the spatially integrated dimensions of Experiment 1 were made separable by portraying different targets within a configuration in different colors. The theoretical implications of the results are discussed.     

Adjustment to hemodialysis treatment through behavioral controls

The present study was conducted to examine the hypothesis that compliant chronically ill patients, typically described as adjusted, reinforce more positive social environments using behavioral controls than noncompliant patients, typically described as maladjusted. Specifically, it is hypothesized that diet-compliant chronic hemodialysis patients emit significnatly more active involvement-in-treatment behaviors and more social behaviors than diet-noncompliant chronic hemodialysis patients. Subjects, who ranged in age from 30 to 77 years, were outpatients at a kidney center. Behavioral observations were conducted to assess the occurrence or frequency of (1) four involvement-in-treatment behaviors that are routinely taught to all patients and (2) two social behaviors, which were patient verbalizations and smiles. The results showed that compliant patients emitted significantly more involvement-in-treatment behaviors and smiles than noncompliant patients. Results support the proposed control framework that compliant, in contrast to non-compliant, chronically ill patients have recourse through positive behavioral controls when adjusting to the stresses of illness. It was proposed that through these controls, compliant patients reinforce positive environments rather than simply respond to life circumstances as given.     

Drug-behavior interaction history: modification of the effects of morphine on punished behavior.

Squirrel monkeys were trained to respond under a multiple fixed-interval, fixed-interval schedule in which the first response after 5 min terminated a visual stimulus in the presence of which electric shocks could occur. During one component of the schedule, correlated with one color of stimulus lights, every 30th response also produced electric shock; responding was suppressed during this component to approximately 10 to 12% of that occurring in the alternate component in which responding was not punished. In contrast to previous research, morphine (0.03 to 1.0 mg/kg) increased punished responding. Unpunished responding, however, was either not affected or decreased at doses of morphine that increased punished responding. Increases in rate of punished responding also occurred when the single-schedule punishment condition was studied alone in these animals. Subsequent experimentation, which systematically analyzed the development of the rate-enhancing effects of morphine on punished responding, involved the study of drug effects in additional monkeys trained initially under a single-schedule punishment condition. The effects of morphine on punished responding were studied before, after, and then during exposure to the multiple schedule that included a component in which responding was not punished. Increases in response rate with morphine did not occur until it was administered during exposure to the multiple schedule that included a component in which responding was not punished. As with the other monkeys, once the rate increases in punished responding occurred under the multiple schedule, these effects of morphine persisted, even when the multiple schedule was removed.(ABSTRACT TRUNCATED AT 250 WORDS)