Midbrain-hypothalamic interrelationships in the control of aggressive behavior

Previous studies have suggested an involvement of the midbrain ventral tegmental area in the biting attack upon a rat elicited by electrical stimulation of the lateral hypothalamus in cats. In order assess further the relationship between these two regions, 12 cats were implanted with attack-eliciting electrodes in both the lateral hypothalamus and the midbrain ventral tegmental area. Following a lesion of the midbrain attack site, attack previously elicited from hypothalamic electrodes ipsilateral to the lesion was eliminated or significantly reduced in frequency. The attack elicited from electrodes in the hypothalamus contralateral to the lesion was unaffected. Midbrain lesions made at sites from which attack was never elicited had no effect on hypothalamically elicited attack. The midbrain lesion in some cases eliminated only certain components of the total attack pattern; for example, the approach of a cat to the rat frequently remained present while the bite was absent. Additionally, it was found that the attack elicited from rostral hypothalamic electrodes was disrupted to a greater degree by a single midbrain lesion than the attack elicited from more caudal hypothalamic electrodes. These finding are discussed in terms of the neural system mediating this form of aggressive behavior in cats.     

Mood,Anxiety, and Substance‐Use Disorders and Suicide Risk in a Military Population Cohort

There are meager prospective data from nonclinical samples on the link between anxiety disorders and suicide or the extent to which the association varies over time. We examined these issues in a cohort of 309,861 U.S. Air Force service members, with 227 suicides over follow‐up. Mental disorder diagnoses including anxiety, mood, and substance‐use disorders (SUD) were based on treatment encounters. Risk for suicide associated with anxiety disorders were lower compared with mood disorders and similar to SUD. Moreover, the associations between mood and anxiety disorders with suicide were greatest within a year of treatment presentation.     

Age-related enhancement of a protein synthesis-dependent late phase of LTP induced by low frequency paired-pulse stimulation in hippocampus

Protein synthesis-dependent late phase of LTP (L-LTP) is typically induced by repeated high-frequency stimulation (HFS). This form of L-LTP is reduced in the aged animal and is positively correlated with age-related memory loss. Here we report a novel form of protein synthesis-dependent late phase of LTP in the CA1 region of hippocampus induced by a brief 1-Hz paired-pulse stimulation (PP-1 Hz, 1 min). In contrast to L-LTP induced by HFS, the late phase of PP-1 Hz LTP does not exist in young adult animals. Rather, it emerges and becomes enhanced in an age-related way. Thus, in 1.5- to 2-mo-old mice, a brief PP-1 Hz stimulation induces only a short lasting LTP, decaying to baseline in about 90 min. By contrast, PP-1 Hz stimulation induces an enduring and protein synthesis dependent LTP in 12- to 18-mo-old mice. The PP-1 Hz-induced L-LTP is dependent on NMDA receptor activation, requires voltage-dependent calcium channels, and is modulated by dopamine D1/D5 receptors. Because memory ability declines with aging, the age-related enhancement of L-LTP induced by PP-1 Hz stimulation indicates that this form of L-LTP appears to be inversely correlated with memory ability.     

Middle childhood and adolescent contextual and personal predictors of adult educational and occupational outcomes: a mediational model in two countries

The authors examined the prediction of occupational attainment by age 40 from contextual and personal variables assessed during childhood and adolescence in 2 participant samples: (a) the Columbia County Longitudinal Study, a study of 856 third graders in a semirural county in New York State that began in 1960, and (b) the Jyv?skyl? Longitudinal Study of Personality and Social Development, a study of 369 eight-year-olds in Jyv?skyl?, Finland, that began in 1968. Both samples were followed up during adolescence and early and middle adulthood. Structural modeling analyses revealed that in both countries, for both genders, children's age 8 cognitive-academic functioning and their parents' occupational status had independent positive long-term effects on the children's adult occupational attainment, even after other childhood and adolescent personal variables were controlled for. Further, childhood and adolescent aggressive behavior negatively affected educational status in early adulthood, which in turn predicted lower occupational status in middle adulthood.     

The classification of violence risk

The Classification of Violence Risk (COVR) is an interactive software program designed to estimate the risk that a person hospitalized for mental disorder will be violent to others. The software leads the evaluator through a chart review and a brief interview with the patient. At the end of this interview, the software generates a report that contains a statistically valid estimate of the patient's violence risk-ranging from a 1% to a 76% likelihood of violence-including the confidence interval for that estimate, and a list of the risk factors that the program took into account to produce the estimate. In this article, the development of the COVR software is described and several issues that arise in its administration are discussed.     

Are members of low status groups perceived as bad, or badly off? Egalitarian negative associations and automatic prejudice

Three studies explored the hypothesis that implicit measures of prejudice can tap negative, yet egalitarian associations. In Study 1, automatically associating African Americans with oppression predicted greater automatic prejudice. In Studies 2 and 3, classically conditioning associations between the novel group Noffians and words like oppressed, maltreated, and victimized led to greater automatic prejudice against Noffians. Results suggest that White Americans’ negative automatic associations with African Americans may partly result from associating members of low status groups with unfair circumstances. Because automatic associations predict prejudiced behaviors, the burden of proof is on those wishing to argue that egalitarian negative associations complicate the assessment of automatic attitudes rather than contribute to prejudiced responses. Discussion focuses on the implications of egalitarian negative associations for the theory and measurement of automatic prejudice.     

Temporal Parts and Timeless Parthood

What is a temporal part? Most accounts explain it in terms of timeless parthood: a thing's having a part without temporal qualification. Some find this hard to understand, and thus find the view that persisting things have temporal parts—four‐dimensionalism—unintelligible. T. Sider offers to help by defining temporal parthood in terms of a thing's having a part at a time. I argue that no such account can capture the notion of a temporal part that figures in orthodox four‐dimensionalism: temporal parts must be timeless parts. This enables us to state four‐dimensionalism more clearly.     

Dishabituation in Aplysia can involve either reversal of habituation or superimposed sensitization

Dishabituation has been thought to be due either to reversal of the process of habituation or to a second process equivalent to sensitization superimposed on habituation. One way to address this question is by testing whether dishabituation and sensitization can be dissociated. Previous studies using this approach in Aplysia have come to different conclusions about the nature of dishabituation, perhaps because those studies differed in many respects, including (1) whether they also observed transient behavioral inhibition, and (2) whether they used test stimuli that activated the LE siphon sensory neurons or as yet unidentified sensory neurons. To attempt to resolve the apparent contradictions between the previous studies, we have explored the importance of these two factors by performing a parametric study of dishabituation and sensitization of gill withdrawal in a simplified preparation that does not exhibit transient behavioral inhibition, using two different test stimuli that are known to activate the LE (Touch) or unidentified (Not Touch) sensory neurons. We find that dishabituation and sensitization in this preparation have similar time courses and generally similar functions of shock intensity. However, under one condition, with the Not Touch stimulus 2.5 min after the shock, dishabituation has a reverse effect of shock intensity. Additional analyses suggest that dishabituation with the Not Touch stimulus 2.5 min after the shock is due to reversal of habituation, whereas 12.5 min after the shock, dishabituation is due to superimposed sensitization. These results thus suggest that dishabituation may involve either process in the same preparation, and begin to define the conditions that favor one or the other.     

Boys will be boys: a pre‐line‐up gameplay has beneficial effects on boys' but not girls' identification performance

Fifty children, aged between 4 and 7 years, underwent a sequential photo line‐up procedure in order to identify a man they had met the previous day. Half of the participants engaged in a pre‐procedure gameplay with the female interviewer. It was hypothesised that the game would stimulate rapport building and would ultimately result in an increased performance during the line‐up procedure. The beneficial effect was indeed observed, but only for the male participants. This finding suggests that gameplay may be a fruitful strategy to decrease child witness discomfort and to increase participation. Copyright © 2006 John Wiley & Sons, Ltd.