Sex differences in the incidence and sonographic characteristics of antipredator ultrasonic cries in the laboratory rat (Rattus norvegicus).

Long-Evans rats (Rattus norvegicus; ns = 10 males and 10 females) in a burrow system responded to a cat in the open area by retreating to a burrow and emitting ultrasounds of 18-27 kHz. Females made more frequent ultrasonic cries, with longer durations of ultrasounds. In a 2nd study (ns = 19 males and 19 females), sonographic analyses confirmed the more frequent vocalizations of females and indicated that the sound pulses of females were reliably shorter in duration and of higher base frequency than those of males. Also, females emitted more pulses per pulse train with shorter within-train interpulse intervals. Six basic pulse forms were determined, and males emitted more (70%) pulses with negatively accelerated descending frequencies than females (25%). The findings indicate that female rats show qualitatively different antipredator vocalizations than do males and add to previous findings of higher levels of female antipredator defensiveness.     

Correlation between Changes in Stress-Induced Corticosterone Secretion and GR mRNA Levels

The current study was conducted to determine the potential relationship between stress-induced corticosterone secretion and corticosteroid receptor mRNA levels after 5 days of intermittent stress. In particular, we were interested in the rate at which animals terminate a stress response, and how this termination may be altered by repeated stress. Adult male Sprague-Dawley rats were subjected to either 5 days of restraint stress or 5 days of an unpredictable stress paradigm. Restraint-stress induced corticosterone secretion was measured on Days 1 and 5 in both groups, and animals were killed on Day 6. Glucocorticoid receptor (GR), and mineralocorticoid (MR) mRNA levels were determined using in-situ hybridization techniques. Five days of restraint stress caused an habituation of the plasma corticosterone response to stress measured 60 and 90 min post-stress initiation; this pattern of corticosterone secretion was not observed in the animals subjected to unpredictable stress. Five days of either stress paradigm did not alter MR mRNA levels measured within the hippocampus or GR mRNA levels within the hippocampus or the medial parvocellular division of the paraventricular nucleus of the hypothalamus (mpPVN). However, an individual's GR mRNA levels measured within the CA1/2 region of the hippocampus and the mpPVN were significantly correlated with the degree of habituation of the corticosterone response to stress measured on Day 5. This suggests that an increase in the rate of termination of the stress response and levels of GR within the hippocampus and mpPVN may be functionally related.     

Action and emotion in everyday life

This study of naturally occurring behaviour employed a "beeper technique" to investigate the actions carried out by 152 subjects in eight different groups, viz. adult students, employed students who were also parents, unemployed, art students, doctoral students, alcoholics, retired people and a control group. Actions were sampled for seven subsequent days, five times per day between 8 a.m. and 10 p.m. at randomly selected occasions. Each action was rated on a number of variables, shortly after it was sampled (median delay approximately 10 min). Some of the findings were: Time allocation corresponded well with national estimates. Being under situational control was highly aversive. Instrumental and consummatory orientations correlated positively. The background variables were, on the whole, only rather weakly related to action ratings, but it was found that women and retired persons tended to report a higher level of well-being.     

A comparison of 13-year-old boys with attention deficit and/or reading disorder on neuropsychological measures

This study compared 13 year-old-boys with attention deficit disorder (ADD) and/or reading disability (RD), and controls with neither disorder on a battery of verbal and nonverbal neuropsychological measures. The aim was to examine whether ADD was associated with a qualitatively distinct pattern of deficits compared with RD. None of the measures differentiated the boys with ADD-only from the controls; the only deficit associated with ADD was slightly lower IQ. RD, on the other hand, was associated with deficits in memory and verbal skills.The Dunedin Multidisciplinary Health and Development Research Unit is supported by the Medical Research Council of New Zealand and involves several Departments of the University of Otago. Much of the data are gathered by voluntary workers from the Dunedin community.The authors are indebted to the many people who contributions make this ongoing study possible. We wish to acknowledge the advice and help of Dr. P. A. Silva, director of the Dunedin Unit, in preparing this report.     

The structure and correlates of self-reported symptoms in 11-year-old children

Self-reports of DSM-III symptomatology were obtained from 792 11-year-old children using the Diagnostic Interview Schedule for Children (DISC). We report results concerning 13 subscales derived from the DISC. Factor-analysis of the subscales suggested a broad distinction between externalizing and internalizing disorder for boys' self-report. For girls, two separate internalizing factors representing anxiety and depression emerged. We also found sex differences in correlates of self-reported disorder. Finally, we examined agreement between child and parent and teacher reports. Overall, agreement was relatively low, although somewhat higher for child-parent than for child-teacher.The Dunedin Multidisciplinary Health and Development Research Unit is supported by the Medical Research Council of New Zealand and the Departments of Education and Health, and involves several departments of the University of Otago. Much of the data are gathered by voluntary workers from the Dunedin community. The authors are indebted to the many people whose contributions make this ongoing study possible.     

THE FACILITATIVE EFFECTS OF INCIDENTAL TEACHING ON PREPOSITION USE BY AUTISTIC CHILDREN

In a comparison of incidental teaching and traditional training procedures, three language-delayed autistic children were taught expressive use of prepositions to describe the location of preferred edibles and toys. Traditional highly structured training and incidental teaching procedures were used in a classroom setting, and generalization was assessed during free-play sessions. Results clearly indicate that incidental teaching promoted greater generalization and more spontaneous use of prepositions. These findings have important implications for language programming and teacher training, suggesting that incidental teaching should be included as a standard component of language development curricula for autistic and other developmentally delayed children.     

Does the Conners' Continuous Performance Test Aid in ADHD Diagnosis?

The performance of clinic-referred children aged 6–11 (N = 100) was examined using the Conners' Continuous Performance Test (CPT) and measures of auditory attention (Auditory Continuous Performance Test; ACPT), phonological awareness, visual processing speed, and visual-motor competence. The Conners' CPT overall index was unrelated to measures of visual processing speed or visual-motor competence. Although the Conners' CPT converged with the ACPT, the latter demonstrated age and order effects. Significant variance in Conners' CPT parameters was predicted by phonological awareness measures, suggesting that Reading Disordered (RD) children could be false positives on the Conners' CPT. The Conners' CPT overall index, phonological awareness, and visual-motor measures were submitted to a 2×2 MANCOVA (ADHD vs. RD, covarying for age and socieoeconomic status): a main effect for RD status was found. Children with ADHD did not have higher Conners' CPT scores than did clinical controls; however, children with Reading Disorders did. Phonological measures distinguished RD children from ADHD children and other clinical controls. ADHD children who failed the Conners' CPT were rated by teachers as more hyperactive. Despite the strengths of the Conners' CPT, its utility for differential diagnosis of ADHD is questioned.