The effect of knowledge of reversibility on the reversibility of ambiguous figures

The role of knowledge of the reversibility of reversible figures was tested in four experiments. Two ambiguous figures, the vase-face figure and a depth-reversing pyramid-hallway figure were shown to high school students. In the Uninformed condition, subjects were not told that the figures were reversible. A sampling procedure was used in which subjects reported what they perceived at 5-sec intervals. Viewing durations of up to 3 min were used, and approximately half of all subjects did not reverse at all during the uninformed condition, whereas virtually all subjects reversed quickly and frequently once they knew that the figures were reversible. These results are not consistent with neural fatigue models of perceptual reversal.     

THE EFFECTIVENESS OF REINFORCEMENT,RESPONSE COST,AND MIXED PROGRAMS ON CLASSROOM BEHAVIORS1

Six elementary school children served as subjects in an experiment comparing the relative effectiveness of (1) token reinforcement, in which children received tokens for attending and for correct arithmetic performance; (2) response cost, in which children received “free” tokens at the start of a period but lost them for inattention and for arithmetic performance below a specified level; and (3) a combination of both token reinforcement and response cost. During training, the six subjects received all three procedures in counterbalanced sequence. The effects of the three procedures were assessed by a within-subject comparison divided into three phases: (i) baseline, (ii) training, (iii) withdrawal of tokens. Introduction of the three token procedures markedly increased the two dependent measures. However, there were no differences across the procedures in the amount of change produced in either attending behavior or arithmetic performance. During baseline, the subjects averaged 29% attending behavior and 6.4 correct problems. These levels increased to 85% for attending behavior and 11.4 correct problems for arithmetic performance during training. Removal of all token procedures significantly decreased attending behavior (to an average of 65%), but produced a nonsignificant reduction in arithmetic performance (to an average of 7.6 correct problems). There was evidence that this lack of differential effects of the three token procedures was not due to an inability to discriminate among them. Furthermore, the subjects were evenly divided in their preference for the three procedures.     

Regional cerebral glucose metabolism in aphemia: A case report

Local cerebral metabolism was determined in a patient suffering aphemia following cerebral infarction using the 18FDG-PET technique. The syndrome was characterized by profound ictal nonfluency with sparing of other language functions. Speech subsequently improved so that content and grammar were appropriate but mild dysprosody persisted. Conventional CT showed no lesion of the left hemisphere while PET revealed a discrete focus of hypometabolism on the left which partially resolved on serial studies. The metabolic lesion could be localized to the region of the inferior precentral gyrus and the adjacent subcortical space.     

Suicide Ideation in Adolescents Following Inpatient Hospitalization: Examination of Intensity and Lability Over 6 Months

Understanding suicide ideation (SI) in adolescents, especially during the high‐risk time following hospitalization for a suicidal event, is a crucial component of improving risk assessment. Most studies rely on single assessments of SI, despite the potential for SI to vary considerably over time. This study examined how indices of SI intensity (mean values) and lability (mean squared successive difference values) over a 6‐month period predict suicide attempts (SAs) and self‐harm, as well as how they relate to psychosocial risk factors and affective functioning, in a sample of 103 adolescents hospitalized for a SA or significant SI. Across the sample, SI intensity, but not lability, was associated with SAs and nonsuicidal self‐injury at 6‐month follow‐up. SI intensity performed similarly to single time point SI assessments, and its relations were not moderated by SI lability. SI intensity was also associated with borderline personality disorder criteria and a history of sexual abuse. In contrast, SI lability was associated with greater negative affect intensity and lability. These findings suggest that intensity of SI may confer more risk posthospitalization, and provide support for using these statistical methods to capture two distinct parameters of SI.     

Predicting Persistence of Nonsuicidal Self‐Injury in Suicidal Adolescents

Prospective predictors of persistent nonsuicidal self‐injury (NSSI) were examined in adolescents admitted to an inpatient psychiatric unit for suicidal behaviors and followed naturalistically for 6 months. Seventy‐one (77%) participants reported NSSI at baseline, and 40 (56%) persisted at the 6 month follow‐up. Those who endorsed automatic positive reinforcement (APR) as the predominant reason for NSSI were more likely to persist in NSSI. Depression over follow‐up, but not at baseline, also predicted persistence. These results suggest that helping high‐risk adolescents to identify alternative ways of generating emotion(s) to counter the effects of APR that may accompany NSSI should be a high priority treatment target.