Changes in step variability of new walkers with typical development and with Down syndrome

Models of human gait are based on adult locomotion. C. E. Bauby and A. D. Kuo (2000) proposed that adults rely on passive mechanisms at the spinal level to control motion in the anteroposterior direction and rely on direct monitoring of postural control in the lateral direction. The authors' purpose in this study was to determine if that model applies to control at the onset of walking in typically developing toddlers (n = 9) and in toddlers with Down syndrome (n = 6). Their longitudinal data suggested that toddlers control gait in a distinctly different manner than adults do. An adult pattern of control emerges with experience. In addition, the effect of experience on the emergence of that pattern is magnified by task-specific early intervention. The present data support the emergence and discovery of efficient patterns of control in this fundamental human behavior.     

Semantic inhibition of return is the exception rather than the rule

Inhibition of return (IOR) has recently been reported for lexical/semantic categories (see, e.g., Fuentes, Vivas, & Humphreys, 1999). The present research examines the impact on semantic IOR of three components: item repetition, item heterogeneity, and spatial variability. Experiments 1 and 2 indicate that lexical/semantic IOR occurs only after extensive repetition. Experiment 2 also shows that semantic IOR is independent of spatial variability. Experiments 3 through 5 show facilitatory rather than inhibitory effects when the item pool is heterogeneous. The results support an episodic account of semantic IOR, according to which inhibitory effects accumulate with massive repetition of homogeneous items.     

Disfluency data of German preschool children who stutter and comparison children

This study compared the disfluencies of German-speaking preschool children who stutter (CWS, N = 24) with those produced by age- and sex-matched comparison children who do not stutter (CWNS, N = 24). In accordance with Yairi and Ambrose's [Yairi, E., & Ambrose, N. (1992). A longitudinal study of stuttering in children: A preliminary report. Journal of Speech and Hearing Research, 35, 755-760] guidelines the CWS group had a narrow age range (2-5 years) and were seen close to the reported time of their stuttering onset (average of 8 months). Furthermore, over 95% of the CWS group had not received any type of speech therapy intervention. Consistent with previous findings for English-speaking preschool children, 'stuttering-like' disfluencies (prolongations, blocks, part- and one-syllable word repetitions) were significantly more frequent in CWS (mean = 9.2%) than in CWNS (mean = 1.2%), whereas no significant group differences occurred with respect to 'normal' disfluencies. The number of iterations in stuttering-like disfluencies was also significantly higher in CWS (mean = 1.28 iterations) than in CWNS (mean = 1.09 iterations). In contrast to previous findings, a sub-group of children who have been stuttering for a shorter time (1-5 months) did not differ from a sub-group who had stuttered for a longer period (8-22 months). EDUCATIONAL OBJECTIVES: The reader will be able to: (1) describe how German-speaking preschool children who stutter and who do not stutter display stuttering-like and normal disfluencies including number of iterations; (2) explain how powerful classification measures for the diagnosis of stuttering are for German-speaking preschool children; (3) discuss how disfluency patterns of native English- and German-speaking children close to onset of stuttering differ.     

Examination stress as an ecological inducer of cortisol and psychological responses to stress in undergraduate students

The purpose of the present study was to investigate basic methodological issues related to the usage of an examination stress protocol in studies of psychoneuroendocrinology. In the present study, 57 undergraduate students served as participants. All subjects provided salivary samples and completed psychological inventories during a low examination stress period and again during a high examination stress period. Salivary samples were analyzed for cortisol. Three major findings were observed. First, the examination stress protocol proved to be an effective trigger of elevations in both psychological measures of stress and in cortisol levels. Second, sex differences were observed in cortisol levels, such that males showed an elevation in cortisol during the high examination stress session whereas females did not. Finally, no significant correlations were observed between elevations in psychological measures of stress and elevations in cortisol levels. These findings suggest that the examination stress protocol used in the present study effectively elevated both psychological stress and cortisol levels. Furthermore, these findings suggest that there are biological differences in how males and females respond to stress. Finally, no evidence was found to suggest a relationship between psychological and hormonal levels of stress. Together, these findings suggest the need to better define and consider the implications of both the specific measures of stress being used and individual differences in the subject samples in psychoendocrine studies.     

Die logik der unbestimmtheiten und paradoxien

Ohne Zusammenfassung     

Dealing With Complexity Differently: From Interaction-Dominant Dynamics to Theoretical Plurality

We describe how the work of Guy Van Orden has been deeply influential in a variety of ways and focus on 2 important features: measurement and context. The centrality of these variables in understanding how psychological regularities emerge in our investigative contexts, and evolve into theories, recommends a different way of dealing with complexity. We argue that the Van Orden approach has, as one possible consequence, a plural approach to psychological phenomena. We end by describing what this means for cognitive science.     

The effect of mindfulness meditation on time perception

Research has increasingly focussed on the benefits of meditation in everyday life and performance. Mindfulness in particular improves attention, working memory capacity, and reading comprehension. Given its emphasis on moment-to-moment awareness, we hypothesised that mindfulness meditation would alter time perception. Using a within-subjects design, participants carried out a temporal bisection task, where several probe durations are compared to “short” and “long” standards. Following this, participants either listened to an audiobook or a meditation that focussed on the movement of breath in the body. Finally, participants completed the temporal bisection task for a second time. The control group showed no change after the listening task. However, meditation led to a relative overestimation of durations. Within an internal clock framework, a change in attentional resources can produce longer perceived durations. This meditative effect has wider implications for the use of mindfulness as an everyday practice and a basis for clinical treatment.