Effects of Age and Task Load on Drivers’ Response Accuracy and Reaction Time When Responding to Traffic Lights

International audienceDue to population aging, elderly drivers represent an increasing proportion of car drivers. Yet, how aging alters sensorimotor functions and impacts driving safety remains poorly understood. This paper aimed at assessing to which extent elderly drivers are sensitive to various task loads and how this affects the reaction time (RT) in a driving context. Old and middle-aged people completed RT tasks which reproduced cognitive demands encountered while driving. Participants had to detect and respond to traffic lights or traffic light arrows as quickly as possible, under three experimental conditions of incremental difficulty. In both groups, we hypothesized that decision-making would be impacted by the number of cues to be processed. The first test was a simple measure of RT. The second and third tests were choice RT tasks requiring the processing of 3 and 5 cues, respectively. Responses were collected within a 2 s time-window. Otherwise, the trial was considered a no-response. In both groups, the data revealed that RT, error rate (incorrect answers), and no-response rate increased along with task difficulty. However, the middle-aged group outperformed the elderly group. The RT difference between the two groups increased drastically along with task difficulty. In the third test, the rate of no-response suggested that elderly drivers needed more than 2 s to process complex information and respond accurately. Both prolonged RT and increased no-response rate, especially for difficult tasks, might attest an impairment of cognitive abilities in relation to aging. Accordingly, casual driving conditions for young drivers may be particularly complex and stressful for elderly people who should thus be informed about the effects of normal aging upon driving

KINEMATIC SYMMETRY IN ROWING: COMPARISON OF FIXED STRETCHER VERSUS FREE-FLOATING ERGOMETER

The purpose of this study was to examine kinematic symmetry of lower and upper limbs when using two kinds of rowing ergometers. Fifteen high-level rowers performed two 15stroke tests at a race rate on two different Rowperfect rowing ergometers. One was fitted up with a fixed stretcher mechanism and the other with a free-floating stretcher mechanism. The tests were carried out in a randomised order. Flexion/extension angles were computed from trajectories of twenty-two markers collected by a motion analysis system. A functional data framework was realised to compare right versus left side angle function curves. These angle curves were validated by bibliographic data. High levels of symmetry were observed for angles of the lower and upper limbs regardless of the mechanism rowed. Shoulder and hip angles for the fixed and the free-floating conditions respectively, were the only exceptions in this regard. The rower's symmetry pointed out by this work allows one-side kinematical analysis of flexion/extension angles

Testing multiple pathways for impacts of the non-native Black-headed Weaver Ploceus melanocephalus on native birds in Iberia in the early phase of invasion

Not all non-native species have strong negative impacts on native species. It is desirable to assess whether a non-native species will have a negative impact at an early stage in the invasion process, when management options such as eradication are still available. Although it may be difficult to detect early impacts of non-native species, it is necessary to ensure that management decisions can be based on case-specific scientific evidence. We assess the impacts of a non-native bird, the Black-headed Weaver Ploceus melanocephalus, at an early stage in its invasion of the Iberian Peninsula. To do this we identify potential pathways by which competition for shared resources by Black-headed Weavers could lead to population declines in two ecologically similar native species, and generate hypotheses to test for evidence of competition along these pathways. Black-headed Weavers could potentially impact native species by displacing them from nesting habitat, or by reducing habitat quality. We found no evidence for either potential competition pathway, suggesting that Black-headed Weavers do not currently compete with the two native species. However, it is possible that mechanisms that currently allow coexistence may not operate once Black-headed Weavers reach higher population densities or different habitats

The Alestle - Vol. 58 No. 52 - 04/11/2006

Vol. 58 No. 5

Modelling response time in a mental rotation task by gender, physical activity, and task features - Supplementary information

Mental rotation (MR) is a spatial skill considered to be a key-component of intellectual ability. Studies have suggested that the response time (RT) in a MR task (MRt) might be influenced, with possible gender differences, by the practice of a physical activity (PA) and depending on the plane, direction, degrees of the MR and the frame of reference to perform it. The present study aimed at examining the respective influences of all these variables on the RT by developing a linear mixed-effect model from the RTs varying according to the MR plane, direction, degrees and frame of reference. The MRt was performed by 96 males and females, all undergraduate students, distributed in three groups (sedentary subjects, artistic gymnasts, and futsal players). The results showed that only gender had a main effect (faster log RT in males), probably task-dependent. The other variables interacted among them showing that: (a) the log RT may be influenced by rotations experienced during PA, in particular during the locomotion on a horizontal ground and (b) such influence mainly depends on the compatibility of the physical rotations experienced with the plane and the degrees of the MRt

The effect of improvisational music therapy on the treatment of depression: protocol for a randomised controlled trial

Background. Music therapy is frequently offered to individuals suffering from depression. Despite the lack of research into the effects of music therapy on this population, anecdotal evidence suggests that the results are rather promising. The aim of this study is to examine whether improvisational, psychodynamically orientated music therapy in an individual setting helps reduce symptoms of depression and improve other health-related outcomes. In particular, attention will be given to mediator agents, such as musical expression and interaction in the sessions, as well as to the explanatory potential of EEG recordings in investigating emotion related music perception of individuals with depression. Methods. 85 adults (18–50 years of age) with depression (ICD-10: F 32 or F33) will be randomly assigned to an experimental or a control condition. All participants will receive standard care, but the experimental group will be offered biweekly sessions of improvisational music therapy over a period of 3 months. A blind assessor will measure outcomes before testing, after 3 months, and after 6 months. Discussion. This study aims to fill a gap in knowledge as to whether active (improvisational) music therapy applied to people with depression improves their condition. For the first time in this context, the mediating processes, such as changes in musical expression and interaction during the course of therapy, will be objectively investigated, and it is expected that the results will provide new insights into these processes. Furthermore, the findings are expected to reveal whether music related emotional experiences, as measured by EEG, can be utilized in assessing a depressive client's improvement in the therapy. The size and the comprehensiveness of the study are sufficient for generalizing its findings to clinical practice as well as to further music therapy research. Trial registration. ISRCTN84185937peerReviewe

Social facilitation of laughter and smiles in Preschool children

Surprisingly little is known about the social dimensions of laughter in preschool children. We studied children's responses to amusing video clips in the presence or absence of peers. The sample consisted of 9 boys and 11 girls aged 31-49 months (M 39.8, SD 4.2) who watched three cartoons under three different conditions: individually, in pairs, or in groups of 6 or 8. The social viewing conditions showed significantly higher numbers of laughs and smiles than the individual viewing condition. On average children laughed eight times as much in company as on their own and smiled almost three times as much. No differences were found between pairs and groups, and no association was found between subjective funniness ratings and group size. This suggests that the presence of even a single social partner can change behavior in response to humorous material. It supports the idea that laughter and smiles are primarily flexible social signals rather than reflexive responses to humor