An economical dispenser to improve control of food reinforcement in the rat

A hopper dispenser designed for the study of food reinforcement in rats is described. By using ordinary rat chow, it significantly reduces the cost of reinforcing rats with food. By preventing stockpiling, it also guarantees control of the accessibility, as well as the presentation of food.     

Modification of the rat's acoustic startle response by antecedent visual stimulation.

Male hooded and albino rats were exposed to a light flash followed at various temporal intervals by a startle-eliciting 117 db. (re 20 muN/m2) burst of white noise. The visual stimulus engendered startle response inhibition (maximally when the lead time was 64-250 msec) as well as startle response latency reduction (maximally when the lead time was 2-8 msec). The temporal functions for the effects of visual stimuli paralleled those previously reported for startle modification by acoustic events. Further study revealed that, given optimal lead times, inhibition is produced reliably by weaker visual stimuli (3 X 10-6 cd-sec/cm2) than latency reduction (3 X 10-4 cd-sec/cm2). This differential sensitivity to visual stimuli is also analogous to previously reported findings for events in the acoustic environment. It reveals that the neural mechanisms that mediate latency reduction and inhibition can be engaged by either acoustic or visual stimulation.     

Reaction time, race, and racism

The claim (Jensen, 1975) that blacks are slower than whites in choice (but not simple) reaction time is examined. It is false. The claim (Jensen, 1985) that Muhammad Ali was shown to have a “very average” reaction time is examined. It is false. The claim (Vernon & Jensen, 1984) that an unpublished technical report showed blacks to be inferior to whites on a relatively content-free mental processing task is examined. It is false. Suggestions are made concerning relevant questions that might be addressed by students of race differences in intelligence.     

Divergent effects of healthy ageing on semantic knowledge and control: Evidence from novel comparisons with semantically impaired patients

Effective use of semantic knowledge requires a set of conceptual representations and control processes which ensure that currently relevant aspects of this knowledge are retrieved and selected. It is well-established that levels of semantic knowledge increase across the lifespan. However, the effects of ageing on semantic control processes have not been assessed. I addressed this issue by comparing the performance profiles of young and older people on a verbal comprehension test. Two sets of variables were used to predict accuracy and RT in each group: (1) the psycholinguistic properties of words probed in each trial and (2) the performance on each trial by two groups of semantically impaired neuropsychological patients. Young people demonstrated poor performance for low-frequency and abstract words, suggesting that they had difficulty processing words with intrinsically weak semantic representations. Indeed, performance in this group was strongly predicted by the performance of patients with semantic dementia, who suffer from degradation of semantic knowledge. In contrast, older adults performed poorly on trials where the target semantic relationship was weak and distractor relationships strong – conditions which require high levels of controlled processing. Their performance was not predicted by the performance of semantic dementia patients, but was predicted by the performance of patients with semantic control deficits. These findings indicate that the effects of ageing on semantic cognition are more complex than has previously been assumed. While older people have larger stores of knowledge than young people, they appear to be less skilled at exercising control over the activation of this knowledge.     

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.     

Chaplains' Engagement with Suicidality among Their Service Users: Findings from the VA/DoD Integrated Mental Health Strategy

Chaplains play an important role in supporting the mental health of current and former military personnel; in this study, the engagement of Department of Veterans Affairs (VA), Army, Navy, and Air Force chaplains with suicidality among their service users were examined. An online survey was used to collect data from 440 VA and 1,723 Department of Defense (DoD) chaplains as part of the VA/DoD Integrated Mental Health Strategy. Differences were noted for demographics, work setting characteristics, encountering suicidality, and self‐perceived preparation for dealing with suicidality. Compared to DoD chaplains, VA chaplains encounter more at‐risk service users, yet feel less prepared for dealing with suicidality.     

Effect of Problem‐Solving Therapy on Depressed Low‐Income Homebound Older Adults' Death/Suicidal Ideation and Hopelessness

Previous study findings of psychotherapy's effect on suicide prevention have been inconsistent. This study reports the results of secondary analyses of outcome data from a short‐term depression treatment on reducing death/suicidal ideation among 158 low‐income homebound adults aged 50+. The treatment, in‐person or telehealth problem‐solving therapy (PST), compared with telephone support call, has been found effective in reducing depressive symptoms and disability among participants. Compared with support call participants, tele‐PST participants, but not in‐person PST participants, exhibited lower ideation ratings across the follow‐up period. Effect sizes at 36 weeks were 0.31 for tele‐PST and 0.17 for in‐person PST. Hopelessness mediated the effect of tele‐PST but not in‐person PST; however, in‐person PST also alleviated hopelessness, which led to lower ideation. Clinical implications of the findings are discussed.