Deficit of preparatory attention in frontotemporal dementia

We studied preparatory attention in patients suffering from frontotemporal dementia in the beginning stages of the disease, using an experimental test developed by LaBerge, Auclair, and Siéroff (2000). In this experimental test, a distracter can appear while subjects have to prepare to respond to a simple target. The probability that a distracter can appear in a trial is varied across three blocks. Normal controls show an increase of response times to targets (slope) as a function of the distracter probability, preparatory attention to the target is reduced by the increase of the distracter probability. Patients suffering from frontotemporal dementia show a slope of response times which is more than twice as large as the slope obtained by their matched controls. Such an abnormal increase of response times to targets is interpreted as a deficit in preparatory attention. Patients also show more omissions than controls. We suggest that this deficit in preparatory attention is related to the frontal lesion presented by the patients and can result in higher distractibility, a symptom frequently encountered in these patients.     

Development and preliminary validation of the physiological hyperarousal scale for children

Considerable empirical support exists for the positive affect and negative affect components of the tripartite model of anxiety and depression proposed by L. A. Clark and D. Watson (1991); however, less attention has been paid to the physiological hyperarousal component of the model. The development of the Physiological Hyperarousal Scale for Children (PH-C; J. Laurent, S. J. Catanzaro, & T. E. Joiner Jr., 1995) is described. The psychometric properties of items are examined using students in Grades 6-12 (N = 398). Initial scale validation includes a joint factor analysis with the Positive and Negative Affect Scale for Children (PANAS-C; J. Laurent et al., 1999; J. Laurent, K. Potter, & S. J. Catanzaro, 1994). The relationship between the PH-C and existing measures that tap related constructs is examined. Together, the PH-C and PANAS-C provide a means to assess tripartite model constructs useful in differentiating anxiety and depression.     

Can animation compensate for temporal processing difficulties in deaf people?

This article addresses the issue of animation as an aid for temporal processing difficulties in deaf people learning the Highway Code. A decision-making task involving static or animated road situations was performed by 21 deaf and 24 hearing participants. They were confronted with four types of driving situations (overtaking, negotiating roundabouts, highways, and intersections) and had to decide whether or not to proceed. Participants were presented with two different formats (static vs. animated) and two levels of difficulty (simple vs. complex). Results showed that deaf participants had poorer performances in the static condition than hearing participants. Performance was better in the animated condition than in the static condition, especially in deaf participants. The benefits of animation were greater in complex situations for all participants. Decisions made on dynamic road situations were facilitated by the presence of spatiotemporal dimensions. These proved helpful to deaf candidates who have difficulties in this particular area.     

On-line versus memory-based orientations and self-report validity

A partial replication of a study by Nisbett and Bellows (1977) to which a memorization condition was added showed that subjects did not have introspective access to the determinants of their judgments, but did so only in the impression-formation condition. In the memorization condition, the subjects' self-reports matched the observed experimental effects. An analysis of the results showed that this was probably because the subjects' judgments in the latter condition were based on causal theories. ©1997 John Wiley & Sons, Ltd.     

A Test of the Links between Family Interference with Work, Job Enrichment and Leader–Member Exchange

Nous avons testé l'hypothèse selon laquelle le degré d'interférence entre la vie familiale et le travail (FIW) chez des sujets "suiveurs" varie en fonction de la qualité de la relation leader-suiveur dans le monde du travail (Qualité LMX) et de leur niveau de valorisation du travail. La relation entre ce niveau et la qualité LMX a aussi étéévaluée. Si le FIW, en accord avec les résultats relatifs à la théorie de l'échange social, est lié négativement, et à la qualité LMX, et au niveau de valorisation du travail des suiveurs, ce dernier est corrélé positivement à la qualité LMX conformément aux prédictions principales de la théorie LMX. Cependant, bien que le FIW se rapporte directement au niveau de valorisation du travail, nous avons pu montrer qu'il est lié indirectement à la qualité LMX par le truchement du niveau de valorisation du travail.
We tested whether followers' frequency of family interference with work (FIW) relates to the quality of the leader–follower work relationship (LMX quality), and to followers' reported level of job enrichment. We also tested the relationship between followers' job enrichment and LMX quality. We found that that FIW relates negatively to LMX quality and to job enrichment, supporting arguments based on social exchange theory, and that followers' job enrichment relates positively to LMX quality, supporting one of the key predictions of LMX theory. We also found that while FIW relates directly to job enrichment, it relates only indirectly to LMX quality through job enrichment.     

Ageing effects on the attention demands of walking

Attention demands of walking were determined in six male and six female young adults (mean 26.3 yr) and 12 gender-matched healthy, active older adults (mean 71.1 yr) using a dual task procedure with a reaction time (RT) secondary task. In three conditions an auditory stimulus, a visual stimulus and both stimuli (auditory/visual) were presented. Relative to no-walking baselines, increased RT was found in all conditions revealing an attentional cost of normal walking. When participants traversed the laboratory walkway and also positioned one of their feet within a target area on the ground, attention demands were greater than in unconstrained walking. In the targeting task, RTs to the visual stimulus were longer than for the auditory stimulus due to the interference associated with viewing both the stimulus monitor and the foot-target. Older participants' RTs in the visual and auditory/visual conditions, but not in the auditory condition, were significantly longer than for the young group in both walking tasks but RTs for young and older adults were not different in no-walking baseline trials. Inspection of mean RT functions at time intervals following gait initiation (0-3000 ms from the first step) suggested a fluctuating attentional cost of walking with increased demands associated with contingencies requiring step length regulation. The findings have applied significance in demonstrating the possibility of increased falls and pedestrian accident risk in older individuals in dual task situations such as road crossing.     

Effects of approach velocity and foot-target characteristics on the visual regulation of step length.

Two questions emerge from the literature concerning the perceptual-motor processes underlying the visual regulation of step length. The first concerns the effects of velocity on the onset of visual control (VCO), when visual regulation of step length begins during goal-directed locomotion. The second concerns the effects of different obstacles such as a target or raised surface on step length regulation. In two separate experiments, participants (Experiment 1 & 2: n=12, 6 female, 6 male) walked, jogged, or sprinted towards an obstacle along a 10 m walkway, consisting of two marker-strips with alternating black and white 0.50 m markings. Each experiment consisted of three targeting or obstacle tasks with the requirement to both negotiate and continue moving (run-through) through the target. Five trials were conducted for each task and approach speed, with trials block randomised between the six participants of each gender. One 50 Hz video camera panned and filmed each trial from an elevated position, adjacent to the walkway. Video footage was digitized to deduce the gait characteristics. Results for the targeting tasks indicate a linear relationship between approach velocity and accuracy of final foot placement (r=0.89). When foot placement was highly constrained by the obstacle step length shortened during the entire approach. VCO was found to occur at an earlier tau-margin for lower approach velocities for both experiments, indicating that the optical variable 'tau' is affected by approach velocity. A three-phase kinematic profile was found for all tasks, except for the take-off board condition when sprinting. Further research is needed to determine whether this velocity affect on VCO is due to 'whole-body' approach velocity or whether it is a function of the differences between gait modes.     

The level and nature of autistic intelligence

Autistics are presumed to be characterized by cognitive impairment, and their cognitive strengths (e.g., in Block Design performance) are frequently interpreted as low-level by-products of high-level deficits, not as direct manifestations of intelligence. Recent attempts to identify the neuroanatomical and neurofunctional signature of autism have been positioned on this universal, but untested, assumption. We therefore assessed a broad sample of 38 autistic children on the preeminent test of fluid intelligence, Raven's Progressive Matrices. Their scores were, on average, 30 percentile points, and in some cases more than 70 percentile points, higher than their scores on the Wechsler scales of intelligence. Typically developing control children showed no such discrepancy, and a similar contrast was observed when a sample of autistic adults was compared with a sample of nonautistic adults. We conclude that intelligence has been underestimated in autistics.     

Word frequency and predictability effects in reading French: An evaluation of the E-Z Reader model

French readers' eye movements were monitored as they read a passage of text. Initial global analyses of word frequency, accounting for the majority of fixations in the text, revealed a good fit between the observed data and the simulated data from the E-Z Reader 7 model of eye movement control. However, the model did not perform as well on simulations of contextual predictability effects. A subset of 20 controlled words from the passage were used to examine the combined effects of frequency and predictability. Results from the observed data showed main effects of frequency and predictability but no interaction. With certain modifications, the E-Z Reader 7 model was able to adequately simulate the pattern of data. Although the E-Z Reader model successfully accounted for the present data, we believe that further modifications will be necessary in order to better account for data in the literature.     

Auditory local bias and reduced global interference in autism

Processing local elements of hierarchical patterns at a superior level and independently from an intact global influence is a well-established characteristic of autistic visual perception. However, whether this confirmed finding has an equivalent in the auditory modality is still unknown. To fill this gap, 18 autistics and 18 typical participants completed a melodic decision task where global and local level information can be congruent or incongruent. While focusing either on the global (melody) or local level (group of notes) of hierarchical auditory stimuli, participants have to decide whether the focused level is rising or falling. Autistics showed intact global processing, a superior performance when processing local elements and a reduced global-to-local interference compared to typical participants. These results are the first to demonstrate that autistic processing of auditory hierarchical stimuli closely parallels processing of visual hierarchical stimuli. When analyzing complex auditory information, autistic participants present a local bias and a more autonomous local processing, but not to the detriment of global processing.