Motor sequence learning in children with recovered and persistent developmental stuttering: preliminary findings

PurposePrevious studies have associated developmental stuttering with difficulty learning new motor skills. We investigated non-speech motor sequence learning in children with persistent developmental stuttering (CWS), children who have recovered from developmental stuttering (CRS) and typically developing controls (CON).MethodsOver the course of two days, participants completed the Multi-Finger Sequencing Task, consisting of repeated trials of a10-element sequence, interspersed with trials of random sequences of the same length. We evaluated motor sequence learning using accuracy and response synchrony, a timing measure for evaluation of sequencing timing. We examined error types as well as recognition and recall of the repeated sequences.ResultsCWS demonstrated lower performance accuracy than CON and CRS on the first day of the finger tapping experiment but improved to the performance level of CON and CRS on the second day. Response synchrony showed no overall difference among CWS, CRS and CON.Learning scores of repeated sequences did not differ from learning scores of random sequences in CWS, CRS and CON. CON and CRS demonstrated an adaptive strategy to response errors, whereas CWS maintained a high percentage of corrected errors for both days.ConclusionsOur study examined non-speech sequence learning across CWS, CRS and CON. Our preliminary findings support the idea that developmental stuttering is not associated with sequence learning per se but rather with general fine motor performance difficulties.     

Investigating behavior inhibition in obsessive-compulsive disorder: Evidence from eye movements

We investigated the role of inhibition failure in Obsessive Compulsive Disorder (OCD) through an eye tracking experiment. Twenty-five subjects with OCD were recruited, as well as 25 with Generalized Anxiety Disorder (GAD) and 25 healthy controls. A 3 (group: OCD group, GAD group and control group) × 2 (target eccentricity: far and near) × 2 (saccade task: prosaccade and antisaccade) mixed design was used, with all participants completing two sets of tasks involving both prosaccade (eye movement towards a target) and antisaccade (eye movement away from a target). The main outcome was the eye movement index, including the saccade latency (the time interval from the onset of the target screen to the first saccade) and the error rate of saccade direction. The antisaccade latency and antisaccade error rates for OCDs were much higher than those for GADs and healthy controls. OCDs had longer latency and error rates for antisaccades than for prosaccades, and for far-eccentricity rather than near-eccentricity stimuli. These results suggest that OCDs experience difficulty with behavior inhibition, and that they have higher visual sensitivity to peripheral stimuli. In particular, they show greatest difficulty in inhibiting behavior directed towards peripheral stimuli.     

Effects of serotonin receptor agonists and antagonists on offensive aggression in mice

The effects of serotonin receptor agonists 5-methoxytryptamine and quipazine, and antagonist mianserin on resident-intruder offensive aggression were investigated. Both agonists reduced aggression. The fact that 5-methoxytryptamine preferentially binds to 5-HT-1 receptors strongly suggest that the decreased aggression with S-methoxytryptamine was related to stimulation of an inhibitory 5-HT-1 receptor. It is also suggested that the reduction in aggression with quipazine was related to quipazine's preferential binding to the 5-HT-1 receptor. The 5-HT-2 receptor antagonist mianserin reduced aggression suggesting that 5-HT-2 receptor blockade is inhibitory for aggression. Thus, two serotonin classes of receptors may be differentially involved in offensive aggression.     

Meaning Selection and the Subcortex: Evidence of Reduced Lexical Ambiguity Repetition Effects Following Subcortical Lesions

Recent research indicates that individuals with nonthalamic subcortical (NS) lesions can experience difficulties processing lexical ambiguities in a variety of contexts. This study examined how prior processing of a lexical ambiguity influences subsequent meaning activation in 10 individuals with NS lesions and 10 matched healthy controls. Subjects made speeded lexical decisions on related or unrelated targets following homophone primes. Homophones were repeated with different targets biasing the same or different meanings on the second presentation. The effects of prime-target relatedness, interstimulus interval (200 or 1250 ms), and same vs. different meaning repetition were examined. Both the patient and control groups showed priming when the same homophone meaning was biased on repetition. When a different meaning was biased on the second presentation, no priming was evident in the controls, while facilitation remained present for the NS group, consistent with aberrant meaning selection and deactivation processes. These findings are discussed in terms of age and task-related repetition effects and current conceptions of frontal–subcortical involvement in cognition.David Copland is supported by the Australian Research Council     

Stuttering and sensory gating: a study of acoustic startle prepulse inhibition

It was hypothesized that stuttering may be related to impaired sensory gating, leading to overflow of superfluous disturbing auditory feedback and breakdown of the speech sequence. This hypothesis was tested using the acoustic startle prepulse inhibition (PPI) paradigm. A group of 22 adults with developmental stuttering were compared with controls regarding the degree of PPI. No significant differences were found between the stuttering adults and the control group; the groups showed similar means and distribution. Likewise, no relation between the degree of PPI and the effect of altered auditory feedback on stuttering was found. In summary, the results of the study indicate that there is no relation between stuttering and PPI.     

Latent Inhibition Depends on Inhibitory Attentional Learning to the Preexposed Stimulus: Evidence from Visual Search and Rule-Learning Tasks

Latent inhibition (LI) refers to findings of poorer learning with stimuli preexposed as irrelevant, compared to novel stimuli. In order to investigate the role of attention in traditional LI, two experiments with human subjects were conducted. Experiment 1 used a simplified visual-search design. As in previous studies, but now with a simpler design, there was a LI-like effect, thereby supporting the position that attentional learning to irrelevantly preexposed stimuli is reduced. Experiment 2 introduced conditions that were designed to exclude a potential contribution of novel popout to the visual-search LI-like effect. It was shown that the effect could be observed independently of contributions from novel popout. In addition, when participants were divided into good and poor attentional learners on the basis of visual-search LI scores, traditional rule-learning LI was established in good attentional learners, whereas it was absent in poor attentional learners. Together, these results indicate that visual-search procedures can be used to provide a measure for LI, and, as such, they support attention-based explanations of traditional LI.     

儿童2～4岁抑制性发展类型与陌生同伴交往特征关系的实验研究

该研究通过对儿童2～4岁的抑制性发展类型与他们同陌生同伴交往特征的关系研究发现(1)在陌生情境中,稳定极端抑制儿童与陌生同伴的游戏活动的社交复杂程度是最低的.从非抑制发展到抑制的儿童在陌生情境中与稳定极端抑制的儿童没有明显差异.(2)从抑制发展到非抑制的儿童在陌生情境中的单独-被动行为是最多的;他们在介绍生日的同伴活动中的主动性是最好的;他们进行的社会性装扮游戏也是最多的.(3)稳定极端非抑制的儿童在陌生情境中与陌生同伴交往的社交复杂程度最高,他们进行的活动类型和活动频次最多,但他们可能有一些外显行为问题.     

Responsiveness to Threat and Incentive in Bipolar Disorder: Relations of the BIS/BAS Scales with Symptoms

Over the past 10 years, theorists have suggested that bipolar disorder symptoms result from increases and decreases in the activity of the Behavioral Activation or Facilitation System (BAS or BFS) and the Behavioral Inhibition System (BIS). These neurobehavioral systems are thought to determine the intensity of affective and behavioral responses to incentives and threats. This study examined cross-sectional and prospective associations of self-reported BIS and BAS with mania and depression in a sample of 59 individuals diagnosed with Bipolar I disorder. Depression was tied to BIS, pointing to the importance of sensitivity to threats in depression. However, links between BIS and depression appeared state-dependent. BAS subscales did not correlate with manic symptoms in a state-dependent manner; however, BAS (total scale and reward responsiveness subscale) predicted relative intensification of manic symptoms over time. Thus, evidence suggests that BAS sensitivity may constitute a vulnerability to mania among persons diagnosed with bipolar disorder. Discussion focuses on the integrative potential of the BIS/BAS constructs for linking psychosocial and biological research on bipolar disorder.     

小学学习成绩优生与差生有意遗忘中抑制能力的发展研究

有意遗忘是一种探讨个体抑制能力发展的新的记忆研究的实验范式。本研究以单字为实验材料,被试为小学二、四、六年级共90名学生,每个年级的学生按学习成绩好和差分别选取15人。实验结果为:1、小学生有意遗忘中的认知抑制能力是发展的;2、小学生有意遗忘中的认知抑制能力具有明显的个体差异,各年级小学生中学习成绩好的学生抑制能力强,学习成绩差的学生抑制能力弱。