Genetic influences on the overlap between low IQ and antisocial behavior in young children

The well-documented relation between the phenotypes of low IQ and childhood antisocial behavior could be explained by either common genetic influences or environmental influences. These competing explanations were examined through use of the Environmental Risk Longitudinal Twin Study 1994-1995 cohort (Moffitt & the E-Risk Study Team, 2002) of 1,116 twin pairs and their families. Children's IQ was assessed via individual testing at age 5 years. Mothers and teachers reported on children's antisocial behavior at ages 5 and 7 years. Low IQ was related to antisocial behavior at age 5 years and predicted relatively higher antisocial behavior scores at age 7 years when antisocial behavior at age 5 years was controlled. This association was significantly stronger among boys than among girls. Genetic influences common to both phenotypes explained 100% of the low IQ-antisocial behavior relation in boys. Findings suggest that specific candidate genes and neurobiological processes should be tested in relation to both phenotypes.     

Violent self-harm in schizophrenia

Patients with schizophrenia have a substantial lifetime suicide risk, especially by violent means. Little published work exists on self-harm (SH) in this population. The goal of this study was to examine whether patients with schizophrenia were also more likely to self-harm in a violent manner. A retrospective analysis performed on method, motive, and suicidal intent in patients with schizophrenia (n = 50) and adjustment reaction (n = 138) who presented with SH over a 3-year period found that there was no significant difference between the two groups in terms of violence of method or suicidal intent. Presence of positive symptoms of schizophrenia was not significantly associated with use of a violent method. This study suggests that the expected pattern of violent SH in schizophrenia is inaccurate and for the majority the acts are of a similar nature to those seen in adjustment reactions.     

Taste-aroma interactions in a ternary system: a model of fruitiness perception in sucrose/acid solutions

Cross-modal interactions between aroma, sweetness, and acidity were studied. A series of samples was presented to trained panelists who assessed strawberry flavor intensity using magnitude estimation with a reference modulus. The delivery of aroma stimuli from the different solutions was measured by monitoring exhaled breath using atmospheric pressure chemical ionization-mass spectrometry to determine whether there were any physicochemical effects on volatile release; no significant differences were noted. Three-dimensional predictive models were built to describe perceived strawberry flavor intensity as a function of concentrations of sucrose, acid, and volatiles. Analysis of the data identified two groups of panelists with different responses: For Group 1, increasing sucrose and/or acid levels also increased the perceived flavor intensity. For Group 2, changing sucrose concentrations had little effect, but increasing acid and/or volatile levels did. The results show different effects of organic and inorganic acids on perception, as well as clear interactions between the modalities of taste (sugar and acid) and aroma. The clustering of panelists' responses suggests that this phenomenon may depend on prior associations between the fruity flavor and the tastants.     

Time perception and word recognition: an elaboration of the time-criterion account

Past research suggests that a time criterion guides responding in speeded word recognition tasks. The time-criterion account has been challenged, however, because it incorrectly predicts equivalent latencies for stimuli of differing difficulty when those stimuli are presented in the same trial block. By requiring participants to perform a lexical decision or naming task but to respond only once they had estimated that 1 sec had elapsed, we investigated the idea that stimulus difficulty effects in response latency might be at least partially due to time perception processes. Consistent with this idea, the participants produced shorter estimates of 1-sec intervals when processing easier stimuli (i.e., time seemed to pass faster when easier stimuli were processed). The implication is that understanding speeded word recognition performance will require looking beyond processes involved in acquiring information about the presented stimulus and examining more general response processes.     

Oppositional defiant disorder toward adults and oppositional defiant disorder toward peers: initial evidence for two separate constructs

Confirmatory factor analysis of 25 items on the Child and Adolescent Disruptive Behavior Inventory (CADBI, Version 2.3; G. L. Burns, T. K. Taylor, & J. C. Rusby, 2001) was conducted on teacher ratings of 824 kindergarten children and replicated on 534 children. Model fit was improved when correcting for 2 method effects: (a) adjacent items and (b) identical behaviors (e.g., argues with adults, argues with peers). The results show that the 25 items loaded on 3 distinct but correlated factors: Hyperactivity, Oppositional to Adults, and Oppositional to Peers. These more refined constructs from the CADBI may be useful for practitioners in identifying children who are at risk and for helping define appropriate contexts in which to intervene. The CADBI and analytic procedures also may contribute to future psychoeducational research on the development of problem behavior.     

Development of demographic norms for four new WAIS-III/WMS-III indexes

Following the publication of the third edition Wechsler scales (i.e., WAIS-III and WMS-III), demographically corrected norms were made available in the form of a computerized scoring program (i.e., WAIS-III/WMS-III/WIAT-II Scoring Assistant). These norms correct for age, gender, ethnicity, and education. Since then, four new indexes have been developed: the WAIS-III General Ability Index, the WMS-III Delayed Memory Index, and the two alternate Immediate and Delayed Memory Indexes. The purpose of this study was to develop demographically corrected norms for the four new indexes using the standardization sample and education oversample from the WAIS-III and WMS-III. These norms were developed using the same methodology as the demographically corrected norms made available in the WAIS-III/WMS-III/WIAT-II Scoring Assistant.     

Cognitive-behavioral therapy of insomnia: A clinical case series study of patients with co-morbid disorders and using hypnotic medications

Cognitive-behavioral therapy for insomnia (CBTi) has demonstrated considerable efficacy within randomized clinical trials and case-series designs. This case-series study in a community sleep medicine clinic assessed the effectiveness of an eight-session CBTi protocol chronic insomnia patients who were allowed to continue their use of hypnotics (intent-to-treat n = 48), administered by a clinical psychology doctoral student receiving training and supervision in CBTi by a behavioral sleep medicine certified clinician. Outcome measures included daily sleep diaries, self-report measures on insomnia severity, dysfunctional beliefs and attitudes about sleep, daytime sleepiness, as well as medication usage. Patients showed significant improvements in sleep onset latency, wake time after sleep onset, sleep efficiency, insomnia severity, and dysfunctional sleep beliefs from pre- to post-treatment. No changes were seen in daytime sleepiness - patients were not excessively sleepy either before or after treatment. Use of sleep medication declined significantly from 87.5% pre-treatment to 54% post-treatment, despite no active efforts to encourage patients to withdraw. Results demonstrate that a CBTi conducted in a community sleep medicine clinic with patients not required to discontinue sleep-related medications can have similar effects as therapy delivered among those not on medication.     

Suicide schemas in non-affective psychosis: An empirical investigation

Suicide is the leading cause of premature death among individuals experiencing psychosis. The risk of suicide is proposed to increase with a greater potential for activation of suicide related schemas. Empirical representations of suicide schemas were compared between individuals experiencing non-affective psychosis, with and without a history of suicidal behaviour. Employing a cross-sectional between-groups comparison design, 84 participants, previously diagnosed with a non-affective psychotic disorder, were recruited from community mental health services. Participants completed a demographic questionnaire and clinical measures of psychopathology. To assess participants’ suicide schemas, a series of direct and indirect cognitive tasks were designed and administered. Pathfinder analysis enabled the construction of empirically derived representations of the groups’ suicide schemas based on responses to the cognitive tasks. The suicide group achieved significantly greater scores on measures of anxiety, depression, hopelessness and suicidality than the non-suicide group, but not on measures indicative of the severity of psychosis. The suicide schema for the suicide group was more elaborate and extensive than for the non-suicide group, even when clinical measures were taken into account. Clinical and theoretical implications are discussed.     

Response acquisition and fixed-ratio escalation based on interresponse times in rats

The effectiveness of a fixed‐ratio (FR) escalation procedure, developed by Pinkston and Branch (2004) and based on interresponse times (IRTs), was assessed during lever‐press acquisition. Forty‐nine experimentally naïve adult male Long Evans rats were deprived of food for 24 hr prior to an extended acquisition session. Before the start of the session, three food pellets were placed in the magazine. Otherwise, no magazine training, shaping, nor autoshaping procedure was employed. The first 20 presses each resulted in the delivery of a 45‐mg food pellet. Then, the FR increased (2, 4, 8, 11, 16, 20, 25, 30) when each IRT in the ratio was less than 2 s during three consecutive ratios. Sessions lasted 13 hr or until 500 pellets were earned. On average, rats reached a terminal ratio of 11 (mean) or 16 (median) during the first session. Seven rats reached the maximum value of FR 30 and only one rat did not acquire the response. In most rats, a break‐and‐run pattern of responding characteristic of FR schedules began to develop in this acquisition session. Subsequently, the ratio‐escalation procedure continued during daily 2‐hr sessions. In these sessions, the starting ratio requirement was set at the terminal ratio reached in the previous session. Using this procedure, over half (26) of the rats reached the FR 30 requirement by the fourth session. These data demonstrate that a ratio‐escalation procedure based on IRTs provides a time‐efficient way of establishing ratio responding.