Brain areas sensitive to coherent visual motion

Detection of coherent motion versus noise is widely used as a measure of global visual-motion processing. To localise the human brain mechanisms involved in this performance, functional magnetic resonance imaging (fMRI) was used to compare brain activation during viewing of coherently moving random dots with that during viewing spatially and temporally comparable dynamic noise. Rates of reversal of coherent motion and coherent-motion velocities (5 versus 20 deg s-1) were also compared. Differences in local activation between conditions were analysed by statistical parametric mapping. Greater activation by coherent motion compared to noise was found in V5 and putative V3A, but not in V1. In addition there were foci of activation on the occipital ventral surface, the intraparietal sulcus, and superior temporal sulcus. Thus, coherent-motion information has distinctive effects in a number of extrastriate visual brain areas. The rate of motion reversal showed only weak effects in motion-sensitive areas. V1 was better activated by noise than by coherent motion, possibly reflecting activation of neurons with a wider range of motion selectivities. This activation was at a more anterior location in the comparison of noise with the faster velocity, suggesting that 20 deg s-1 is beyond the velocity range of the V1 representation of central visual field. These results support the use of motion-coherence tests for extrastriate as opposed to V1 function. However, sensitivity to motion coherence is not confined to V5, and may extend beyond the classically defined dorsal stream.     

Sequence skill learning in persons who stutter: implications for cortico-striato-thalamo-cortical dysfunction

The basal ganglia and cortico-striato-thalamo-cortical connections are known to play a critical role in sequence skill learning and increasing automaticity over practice. The current paper reviews four studies comparing the sequence skill learning and the transition to automaticity of persons who stutter (PWS) and fluent speakers (PNS) over practice. Studies One and Two found PWS to have poor finger tap sequencing skill and nonsense syllable sequencing skill after practice, and on retention and transfer tests relative to PNS. Studies Three and Four found PWS to be significantly less accurate and/or significantly slower after practice on dual tasks requiring concurrent sequencing and colour recognition over practice relative to PNS. Evidence of PWS’ deficits in sequence skill learning and automaticity development support the hypothesis that dysfunction in cortico-striato-thalamo-cortical connections may be one etiological component in the development and maintenance of stuttering.

Educational objectives: As a result of this activity, the reader will: (1) be able to articulate the research regarding the basal ganglia system relating to sequence skill learning; (2) be able to summarize the research on stuttering with indications of sequence skill learning deficits; and (3) be able to discuss basal ganglia mechanisms with relevance for theory of stuttering.     

The Predictive Utility of Narcissism among Childrenand Adolescents: Evidence for a Distinction betweenAdaptive and Maladaptive Narcissism

We examined the predictive utility of narcissism among a community sample of children and adolescents (N=98) longitudinally. Analyses focused on the differential utility between maladaptive and adaptive narcissism for predicting later delinquency. Maladaptive narcissism significantly predicted self-reported delinquency at one-, two-, and three-year follow-ups. This pattern held even when considering other intrapersonal risk factors for conduct problems (i.e., callous-unemotional traits, impulsivity), parenting practices, and when controlling for earlier conduct problems. In addition, adaptive narcissism was predictive of delinquency in the absence of positive parenting practices, with maladaptive narcissism being particularly predictive of delinquency in the presence of negative parenting. The implications for understanding delinquency in terms of the social and motivational characteristics that are the hallmark of maladaptive narcissism are discussed.     

Neuropsychological Deficits in Childhood Epilepsy Syndromes

Seizure disorders are relatively common in childhood, and the International League Against Epilepsy (ILAE) provides a hierarchical classification system to define seizure types. At the final level of classification, specific epilepsy syndromes are defined that represent a complex of signs and symptoms unique to an epilepsy condition. The present review discusses the issues related to several of these epilepsy syndromes in childhood, including those classified as generalized idiopathic epilepsies (e.g., childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy), focal epilepsies (benign rolandic epilepsy, occipital epilepsy, temporal lobe epilepsy, frontal lobe epilepsy) and the "epileptic encephalopathies," including Dravet's Syndrome, West Syndrome, Lennox-Gastaut Syndrome, Myoclonic Astatic Epilepsy, and Landau-Kleffner Syndrome. For each syndrome, the epidemiology, clinical manifestations, treatments, and neuropsychological findings are discussed.     

Predictors of online information seeking by international students when disaster strikes their countries.

This study explores factors influencing international students' likelihood of using the Internet to seek disaster-related information should a disaster affect their countries. A cross-sectional survey was conducted in two universities in America between August 1 and September 30, 2005. Two hundred twenty-nine (n = 229) students completed the self-administered questionnaires. ANOVA analyses found that respondents' Internet self-efficacy had no significant impact on their intentions to seek disaster-related information on the Internet. However, respondents' Internet dependency and attitude toward seeking information online were found to have a significant effect on such intentions.     

Anxious attachment and psychological distress in cardiac rehabilitation patients

This study investigated the relevance of anxious attachment to the differentiation of psychologically distressed and non-psychologically distressed cardiac patients. Attachment is a biologically based behavioral system in which proximity to a special other is sought or maintained to achieve a sense of safety and security. Anxious attachment, as the name denotes, fails to achieve the function of attachment in the sense of individuals having little or no confidence in the availability of their attachment figures. Empirically, three scales (feared loss of the attachment figure, proximity seeking and separation protest) capture the features of anxious attachment as elaborated by Bowlby. These scales were administered to 178 cardiac rehabilitation patients drawn from the cardiac rehabilitation program of the Calgary General Hospital. The results indicate that feared loss and proximity seeking differentiated psychologically distressed from non-psychologically distressed patients. The implications of this finding for the understanding of psychologically distressed cardiac patients are discussed.     

Ability to generate mental images in students of art

To evaluate the ability to generate mental images and its relations to artistic training, 44 undergraduates were presented with a list of selected fragments from 40 characters in the Roman alphabet. Subjects provided those letters suggested by the fragments for as many items as possible within a 90-second interval. It was hypothesized that students who had received college training in studio art would be able to produce a greater number of candidate images than students not trained in art, resulting in more correct answers and higher scores. Results confirmed the hypothesis. Trained subjects completed significantly more of the letters on the image-generation task than did those not trained in art (p=.0001). This suggests that superior ability to generate images is associated with artistic training. Further, these results imply that, to the degree to which artistic training reflects ability, image generation may also be related to artistic ability.     

Vocal frequency and person perception: Effects of perceptual salience and nonverbal sensitivity

Previous research has demonstrated that changes in vocal frequency (pitch) influence judgments made about a speaker, although there is some question as to the relative importance of frequency to message content in person perception. Moreover, these studies have failed to examine the possible joint effect of frequency and individual differences in nonverbal sensitivity on person perception. The purpose of the present investigation was to examine the independent and joint effects of vocal frequency, perceptual salience, and nonverbal sensitivity (assessed by the Profile of Nonverbal Sensitivity) on person perception. Participants were assigned to one of nine experimental conditions and were asked to rate two male and two female speakers on seven unipolar adjective scales. The nine conditions were produced by factorially combining three levels each of salience (content, voice, control) and vocal frequency (decreased, increased, unmanipulated). The results of hierarchical multiple regression analyses indicated that variations in frequency did influence evaluative judgments of the speakers (competent, honest, persuasive), but that the magnitude of the influence varied as a function of the participants' levels of nonverbal sensitivity. The analyses, however, yielded no significant effects for participants' affective judgments, nor any significant effects involving perceptual salience.     

Tooth color: effects on judgments of attractiveness and age

Tooth whitening has become a very popular procedure. Advertisements for whitening products imply that whiter teeth are more attractive than yellower teeth. We tested this idea empirically by manipulating the tooth color of pictures of male and female targets. Participants' ratings of attractiveness were not influenced by tooth color. Exp. 2 yielded a negative correlation between attractiveness and age ratings: targets judged to be older were rated as less attractive. Unless whiter teeth help in some other way, e.g., improved self-esteem or confidence, it seems that tooth whitening procedures or products are not associated with increased attractiveness to others.