Representation of anatomical constraints in motor imagery: mental rotation of a body segment

Classically, the mental rotation paradigm has shown that when subjects are asked to judge whether objects that differ in orientation are spatially congruent, reaction times increase with angular discrepancy, although some reports have shown that this is not always the case. Would similar results be obtained with realistic figures of body segments? In this work, the mental rotation of a hand attached to its forearm and arm in anatomically possible and impossible starting positions is compared with the mental rotation of a hammer. The main results show that reaction times increase monotonically with the angle of discrepancy for both stimuli and that the speed of rotation is higher for anatomically possible orientations in the case of the hand. Thus, mental rotation of body segments follows the same empirical rules as objects of another nature, and biomechanical constraints imposed to the motility of these segments can be considered as attributes of the mental representation.     

Selective deficit of motor imagery as tapped by a left-right decision of visually presented hands

This paper presents the case of MT, a patient suffering from apraxia with left-hemisphere damage who showed a selective deficit in mentally rotating images of hands whereas he was still able to mentally rotate other visual stimuli. The deficit was particularly evident when MT was asked to decide which hand (left or right) was represented in a picture. suggested that in order to carry out this task, participants would mentally rotate a representation of their own body part until it aligns with the stimulus and it does appear that MT's ability to mentally simulate movements is impaired. In contrast, he was able to mentally rotate other forms of bi- and three-dimensional stimuli. Our findings are also consistent with proposal that there are at least two ways in which objects can be mentally rotated, one that recruits processes devoted to motor preparation (e.g., hands), and another that does not.     

ERP evidence for the time course of graphic, phonological, and semantic information in Chinese meaning and pronunciation decisions

Two words that varied in their relationship were presented sequentially to Chinese readers who made meaning and pronunciation decisions. In the meaning task, they decided whether the words had the same meaning. In the pronunciation task, they decided whether the words had the same pronunciation. In both tasks, the word pairs represented 1 of 4 relationships: graphically similar, homophonic, semantically related, or unrelated. Event related potentials (ERP) recordings made from the onset of the 2nd word suggested a temporal unfolding of graphic, phonological, and semantic effects. Specifically, graphically-related pairs produced a smaller P200 in the pronunciation task and a smaller N400 in the meaning task. Homophones produced reduced N400 component with bilateral sources in the meaning task.     

Developments in long-term explicit memory late in the first year of life: behavioral and electrophysiological indices

Coincident with developments in the temporal-cortical explicit memory network, long-term recall abilities are newly emergent late in the first year of human life. We recorded event-related potentials (ERPs) in 9-month-olds as an index of the integrity of the neural substrate underlying a task thought to reflect explicit memory, namely, deferred imitation. ERP measures of recognition memory 1 week after unique laboratory experiences predicted whether and how much infants recalled of the experiences 1 month later. The findings further imply that memory storage and consolidation processes are a major source of variability in long-term recall memory late in the first year of life.     

The neuroendocrinology of posttraumatic stress disorder: new directions

Studies of the hypothalamic-pituitary-adrenal (HPA) axis in persons with posttraumatic stress disorder (PTSD) have produced variable findings. This review focuses on the factors likely to have affected the outcome of these studies, including population characteristics and experimental design. Also discussed is a possible role for the adrenal neurosteroid dehydroepiandrosterone (DHEA) as a mediator of HPA axis adaptation to extreme stress and the psychiatric symptoms associated with PTSD. The antiglucocorticoid properties of DHEA may contribute to an upregulation of HPA axis responses as well as mitigate possible deleterious effects of high cortisol levels on the brain in some PTSD subpopulations. The neuromodulatory effects of DHEA and its metabolite DHEAS at gamma-aminobutyric acid and N-methyl-D-aspartate receptors in the brain may contribute to psychiatric symptoms associated with PTSD. The possible importance of other neurohormone systems in modulating HPA axis and symptom responses to traumatic stress is also discussed. Understanding the complex interactions of these stress-responsive neurosteroid and peptide systems may help explain the variability in patterns of HPA axis adaptation, brain changes, and psychiatric symptoms observed in PTSD and lead to better targeting of preventive and therapeutic interventions.     

Repressive and defensive coping during fear and anger

In this study, the relationship between repressive and defensive coping styles and somatovisceral responses as well as emotion self-reports were investigated in 2 situational contexts conceived to induce fear and anger. Anxiety (State-Trait Anxiety Inventory; L. Laux, P. Glanzmann, P. Schaffner, and C. D. Spielberger, 1981) x Defensiveness (Marlowe-Crowne Social Desirability Scale; D. P. Crowne and D. Marlowe, 1960) x Emotion (fear, anger) moderated regression analyses revealed that compared with baseline during fear, defensiveness was related to a decrease in heart rate variability. Also during fear, repressive-defensive copers had lower self-reports of negative affect but showed higher behavioral negative affect (m. corrugator reactivity) than other participants. During anger, defensiveness was positively related to both diastolic blood pressure reactivity and m. zygomaticus reactivity. Additional analyses showed that emotional responses of repressive-defensive copers were strongly moderated by the situational context.     

The clinical effectiveness of cognitive behaviour therapy for chronic insomnia: implementation and evaluation of a sleep clinic in general medical practice

Chronic insomnia is a very common clinical condition which may respond well to non-pharmacological treatment. Indeed, the literature supports the efficacy of cognitive behaviour therapy (CBT). However, there has been no substantial study of clinical effectiveness. Since insomniacs typically present in general medical practice this is a crucial gap in the outcome research. This study, therefore, specifically investigated the clinical effectiveness of CBT delivered by Health Visitors (primary care nurses) trained as therapists. One hundred and thirty-nine insomniacs (mean age 51 yr) were randomised to CBT or Self-Monitoring Control (SMC) in a controlled trial. CBT comprised six group sessions (n=4 to 6 patients). After the controlled phase, SMC patients entered deferred treatment (CBT-DEF), allowing both treatment replication and long-term outcome to be investigated for a sizeable, treated sample. Repeated measures ANOVAs demonstrated superiority of CBT over SMC in substantially reducing sleep latency and wakefulness during the night. CBT-DEF replicated similar effects and maintained improvement was observed in both groups one year later. Furthermore, total sleep increased significantly during follow-up and 84% of patients initially using hypnotics remained drug-free. Results suggest that CBT administered by Health Visitors offers a clinically effective treatment for insomnia.     

Inhibiting progesterone metabolism in the hippocampus of rats in behavioral estrus decreases anxiolytic behaviors and enhances exploratory and antinociceptive behaviors

Blocking progesterone’s metabolism to 5α -pregnan-3α -ol-20-one (3α ,5α -THP) with finasteride, a 5α -reductase inhibitor, and effects on anxiolytic, exploratory, and antinociceptive behaviors of rats in behavioral estrus were examined. Rats in behavioral estrus received finasteride systemically (SC), to the hippocampus, or to control implant sites, the nucleus accumbens (NA) or ventral tegmental area (VTA), and were tested in horizontal crossing, open-field, elevated plus-maze, emergence, holeboard, social interaction, tailflick, pawlick, and defensive freezing tasks. Finasteride, SC or intrahippocampally, reduced 3α ,5α -THP in the hippocampus relative to vehicle implants or finasteride to the NA or VTA. Systemic or intrahippocampal finasteride decreased central entries in the open field and open-arm time on the elevated plus-maze and increased freezing in response to shock relative to vehicle. Finasteride to the hippocampus decreased emergence latencies and increased social interaction, pawlick, and tailflick latencies relative to all other groups. Finasteride to the hippocampus of rats in behavioral estrous decreased anxiolysis and enhanced exploration and analgesia. In summary, these data demonstrate that decreases in anxiolytic behavior of behavioral estrous rats can be produced by reductions in 3α ,5α -THP in the hippocampus, which suggest that elevations in 3α ,5α -THP in the hippocampus may give rise to anxiolysis seen during behavioral estrus.     

Evaluation of an MMPI--a short form: implications for adaptive testing

Efforts to develop a viable short form of the MMPI (Hathaway & McKinley, 1943) span more than 50 years, with more recent attempts to significantly shorten the item pool focused on the use of adaptive computerized test administration. In this article, we report some psychometric properties of an MMPI-Adolescent version (MMPI-A; Butcher et al., 1992) short form based on administration of the first 150 items of this test instrument. We report results for both the MMPI-A normative sample of 1,620 adolescents and a clinical sample of 565 adolescents in a variety of treatment settings. We summarize results for the MMPI-A basic scales in terms of Pearson product-moment correlations generated between full administration and short-form administration formats and mean Tscore elevations for the basic scales generated by each approach. In this investigation, we also examined single-scale and 2-point congruences found for the MMPI-A basic clinical scales as derived from standard and short-form administrations. We present the relative strengths and weaknesses of the MMPI-A short form and discuss the findings in terms of implications for attempts to shorten the item pool through the use of computerized adaptive assessment approaches.