Faculty Bibliography

This study demonstrates that overtraining in temporal discrimination modifies temporal stimulus control in a bisection task and produces habitual responding, as evidenced through insensitivity to food devaluation. Rats were trained or overtrained in a 2- versus 8-sec temporal discrimination task, with each duration associated with a lever (left or right) and food (grain or sucrose). Overtraining produced a leftward shift in the bisection point. Devaluation treatment induced a differential loss of responding depending on stimulus duration (short versus long) and the level of training (training versus overtraining). The relationships between timing behavior and habitual behavior are discussed.

Huntington disease (HD) is an autosomal dominantly inherited, progressive neurodegenerative disorder which is accompanied by executive dysfunctions and emotional alteration. The aim of the present study was to assess the impact of emotion/stress on on-going highly demanding cognitive tasks, i.e., temporal processing, as a function of age in BACHD rats (a "full length" model of HD). Middle-aged (4-6 months) and old (10-12 months) rats were first trained on a 2 vs. 8-s temporal discrimination task, and then exposed to a series of bisection tests under normal and stressful (10 mild unpredictable foot-shocks) conditions. The animals were then trained on a peak interval task, in which reinforced fixed-interval (FI) 30-s trials were randomly intermixed with non-reinforced probe trials. After training, the effect of stress upon time perception was again assessed. Sensitivity to foot-shocks was also assessed independently. The results show effects of both age and genotype, with largely greater effects in old BACHD animals. The older BACHD animals had impaired learning in both tasks, but reached equivalent levels of performance as WT animals at the end of training in the temporal discrimination task, while remaining impaired in the peak interval task. Whereas sensitivity to foot-shock did not differ between BACHD and WT rats, delivery of foot-shocks during the test sessions had a disruptive impact on temporal behavior in WT animals, an effect which increased with age. In contrast, BACHD rats, independent of age, did not show any significant disruption under stress. In conclusion, BACHD rats showed a disruption in temporal learning in late symptomatic animals. Age-related modification in stress-induced impairment of temporal control of behavior was also observed, an effect which was greatly reduced in BACHD animals, thus confirming previous results suggesting reduced emotional reactivity in HD animals. The results suggest a staggered onset in cognitive and emotional alterations in HD, with emotional alteration being the earliest, possibly related to different time courses of degeneration in cortico-striatal and amygdala circuits.

The purpose of this article is to determine the risk of schizophrenia in offspring of women exposed to x-ray radiation during pregnancy. The risk of schizophrenia was evaluated using cohort data collected in The Jerusalem Perinatal Study. The cohort of 92,408 births from 1964 to 1976 was linked to Israel's National Psychiatric Registry of all individuals hospitalized for psychiatric conditions. Cross-tabulations were analyzed for development of schizophrenia in offspring of mothers who were exposed to an x-ray procedure during the first four months of pregnancy. Relative risks (RRs) were estimated using proportional hazards models, adjusted for male sex, paternal age, family psychiatric history, and social class. The adjusted RRs for schizophrenia spectrum associated with maternal x-rays in months 3 and 4 were, respectively, 2.97 (0.94-9.35) and 1.23 (0.39-3.87). Among 80 cases with narrowly defined schizophrenia (ICD-10 = F20) maternal x-rays in months 3 and 4 were associated, respectively, with adjusted RRs of 3.08 (0.75-12.6, based on 2 cases), and 2.04 (0.64-6.46, 3 cases). Offspring of mothers exposed to x-ray radiation during the third and fourth months of pregnancy may have an increased risk of developing schizophrenia. (PsycInfo Database Record (c) 2020 APA, all rights reserved)

PURPOSE OF REVIEW:This review summarizes the recent literature examining nonsuicidal self-injury (NSSI) in adolescents, with a particular focus on how primary care pediatricians (PCPs) might assess and intervene as a common first point of contact. This NSSI review is timely and relevant, given the prevalence rates among adolescents, as well as its link to suicidal behaviors. RECENT FINDINGS:NSSI is most prevalent among adolescents, with lifetime prevalence rates between 17 and 60%. With evidence that the most common age of onset is between 12 and 14 years, evaluating NSSI is a challenging yet necessary aspect of a comprehensive adolescent medical examination. The function of NSSI behaviors may have implications for effective treatment and should be included in assessment. The majority of research has indicated that NSSI serves an emotion regulation function, in that the behavior results in a decrease in intensity of adverse emotional states in the absence of more effective coping strategies. SUMMARY:Considering the prevalence of self-injury among adolescents, the likelihood that PCPs will encounter NSSI in their practice is quite high. Given that more than 50% of youth do not receive needed mental health services, it is critical that PCPs assess for NSSI and intervene accordingly.