The fragile nature of the speech-perception deficit in dyslexia: natural vs synthetic speech

A number of studies reported that developmental dyslexics are impaired in speech perception, especially for speech signals consisting of rapid auditory transitions. These studies mostly made use of a categorical-perception task with synthetic-speech samples. In this study, we show that deficits in the perception of synthetic speech do not generalise to the perception of more naturally sounding speech, even if the same experimental paradigm is used. This contrasts with the assumption that dyslexics are impaired in the perception of rapid auditory transitions.     

Temperament and its implications for neuroimaging of anxiety disorders

We review the attributes of inhibited and uninhibited infant temperaments, and their developmental trajectories into early adulthood. Inborn individual differences in infants' propensity to respond to novel people and objects are associated with persistent differences in the responsivity of the amygdala to novelty, as measured with functional magnetic resonance imaging, after more than 20 years of development. Because an inhibited temperament is a risk factor for developing later psychiatric disorders, particularly generalized social anxiety disorder, temperamental differences are confounds in neuroimaging and genetic studies. Longitudinal studies are a unique tool for understanding the developmental and temperamental risk factors for psychiatric disorder.     

Habit reversal versus supportive psychotherapy in Tourette's disorder: a randomized controlled trial and predictors of treatment response

Tourette syndrome (TS) is characterized by chronic motor and vocal tics. Habit reversal therapy (HR) is a behavioral treatment for tics which has received recent empirical support. The present study compared the efficacy of HRT in reducing tics, improving life-satisfaction and psychosocial functioning in comparison with supportive psychotherapy (SP) in outpatients with TS. In addition, we investigated whether impairments in response inhibition in patients with TS predict response to HR treatment which specifically aims to inhibit tics. Thirty adult outpatients with DSM-IV TS were randomized to 14 individual sessions of HR (n = 15); or SP (n = 15). HR but not SP reduced tic severity over the course of the treatment. Both groups improved in life-satisfaction and psychosocial functioning during active treatment. Reductions in tic severity (HR) and improvements in life-satisfaction and psychosocial functioning (HR and SP) remained stable at the 6-month follow-up. The extent of pre-treatment response inhibition impairment in the HR group predicted reductions in tic-severity from pre- to post-treatment. Our results suggest that HR has specific tic-reducing effects although SP is effective in improving life-satisfaction and psychosocial functioning. Assessments of response inhibition may be of value for predicting treatment response to HR.     

Knowledge partitioning in categorization: Boundary conditions

Knowledge partitioning refers to the notion that knowledge can be held in independent and nonoverlapping parcels. Partitioned knowledge may cause people to make contradictory decisions for identical problems in different circumstances. We report two experiments that explored the boundary conditions of knowledge partitioning in categorization. The studies examined whether or not people would partition their knowledge (1) when categorization rules were or were not verbalizable and (2) when the to-be-categorized stimuli comprised perceptually separable or integral dimensions. When learning difficulty was controlled, partitioning occurred across all combinations of verbalizability and integrality/separability, underscoring the generality of knowledge partitioning. Partitioning was absent only when the task was rapidly learned and people reached a high level of proficiency, suggesting that task difficulty plays a critical role in the emergence of partitioned knowledge.     

The role of perceptual integration in the recognition of assimilated word forms

We investigated how spoken words are recognized when they have been altered by phonological assimilation. Previous research has shown that there is a process of perceptual compensation for phonological assimilations. Three recently formulated proposals regarding the mechanisms for compensation for assimilation make different predictions with regard to the level at which compensation is supposed to occur as well as regarding the role of specific language experience. In the present study, Hungarian words and nonwords, in which a viable and an unviable liquid assimilation was applied, were presented to Hungarian and Dutch listeners in an identification task and a discrimination task. Results indicate that viably changed forms are difficult to distinguish from canonical forms independent of experience with the assimilation rule applied in the utterances. This reveals that auditory processing contributes to perceptual compensation for assimilation, while language experience has only a minor role to play when identification is required.     

Drug testing,drug treatment,and marijuana use: a fairness perspective

The authors conducted a random statewide telephone survey of 1,484 individuals to study the relationship between marijuana use (in terms of participants' history of marijuana use) and reactions to drug testing and to study 2 hypothetical drug-treatment policies. Job safety sensitivity was related to perceived fairness of drug testing for the participant's job, and more recent marijuana use was associated with more negative reactions. Safety sensitivity was related to perceived fairness of drug treatment. Organizations with voluntary treatment were more attractive than ones with monitored treatment. Marijuana use interacted with drug treatment policy type in predicting reactions to drug treatment. Results suggest that organizations should consider job and employee characteristics when developing a drug treatment policy.     

Seeing stereoscopic depth from disparity between kinetic edges

Traditionally, it is assumed that stereovision operates only on the positional difference (disparity) between luminance-defined features in the images in the left and the right eye. Here, I show that stereoscopic depth can be seen from disparity between edges created by relative motion of texture elements, and between edges created by correlated flicker of stationary texture elements. Luminance-based stereopsis was impossible since the texture was binocularly uncorrelated. Positional disparity of the centre of revolving patterns was not an efficient depth cue. Stereopsis from the stimuli presented here was possible even without binocular overlap of textured areas. The results provide evidence that positional disparity of kinetic edges, defined by correlated flicker or motion contrast alone, can be used as matching features to recover stereoscopic depth.     

Benefit System Effects on Employees’ Benefit Knowledge,Use, and Organizational Commitment

We identified four attributes of benefit systems thought to influence employee attitudes and behavior: employee participation, system quality, communication quality, and benefit importance. Survey data from 974 employees of a Fortune 500 energy industry firm supported a partially mediated model in which these benefit system features exerted both indirect and direct effects on benefit knowledge and use, as well as on affective and continuance commitment. However, the findings differed across benefit system features and across types of benefits. Specifically, improving organizational communications about benefits appears more useful than increasing employee participation or improving benefit system service quality.     

Hyperthermia impairs retrieval of an overtrained spatial task in the Morris water maze

Fifteen rats were trained to learn the location of a spatially fixed platform hidden in a Morris water maze (40 +/- 2 degrees C). Then retention of the spatial task was assessed immediately after raising core body temperature (Tc) to 42 or 40 degrees C or stabilizing at 37 degrees C (the normothermic control). The hyperthermic treatment order was counterbalanced according to a Latin-square design. Hyperthermia at 42 degrees C Tc significantly impaired spatial performance. Hyperthermic animals were cooled to normothermia (Tc = 37 degrees C) and spatial performance was tested again approximately 30 min later. Cooling resulted in a complete recovery of spatial performance. These results demonstrate that hyperthermia-induced amnesia can be obtained on an overtrained spatial-mapping strategy and cooling to normothermia initiates recovery of spatial performance.