Biomedical subjects

Christian Collet

Publications and source records attributed to Christian Collet.

9 recordsLinked to original sources

PubMed2006

Relationship between spatial abilities, mental rotation and functional anatomy learning.

This study investigated the relationship between visuo-spatial representation, mental rotation (MR) and functional anatomy examination results. A total of 184 students completed the Group Embedded Figures Test (GEFT), Mental Rotation Test (MRT) and Gordon Test of Visual Imagery Control. The time spent on personal assignment was also considered. Men were found to score better than women on both GEFT and MRT, but the gender effect was limited to the interaction with MRT ability in the anatomy learning process. Significant correlations were found between visuo-spatial, MR abilities, and anatomy examination results. Data resulting from the best students' analyzes underscore the effect of high MR ability which may be considered reliable predictor of success in learning anatomy. The use of specific tests during learning sessions may facilitate the acquisition of anatomical knowledge.

Adolescent↗

PubMed2005

Contribution from neurophysiological and psychological methods to the study of motor imagery.

This paper reviews studies on neurophysiological and behavioral methods used to evaluate motor imagery accuracy. These methods can be used when performed in the field and are based on recordings of peripheral indices such as autonomic nervous system or electromyographic activities, mental chronometry and psychological tests. Providing physiological signs that correlate to these types of mental processes may be considered an objective approach for motor imagery analysis. However, although autonomic nervous system activity recording has been shown to match motor imagery in real time, to evaluate its accuracy qualitatively and the individual ability to form mental images, the relationship between physiological responses and mental processes remains an inference. Moreover, electromyographic recordings may be associated with postural control data, but due to inconsistent results, they remain insufficient to solely evaluate motor imagery accuracy. Other techniques traditionally used in psychology and cognitive psychology are questionnaires, "debriefing" with subjects and mental chronometry. Although such methods lead to interesting results, there remains an important part of subjectivity as subjects perform an auto-evaluation of motor imagery accuracy. Similarly, mental chronometry gives information on the ability to preserve temporal organization of movement but does not allow the evaluation of the vividness of mental images. Thus, several methods should be combined to analyze motor imagery accuracy in greater detail. Neurophysiological recordings cannot therefore be considered an alternative but rather a complementary technique to behavioral and psychological methods. The advantages and inconvenient of each technique and the hypotheses that could be tested are discussed.

Animals↗

PubMed2005

Effect of a fatiguing protocol on motor imagery accuracy.

This study was devised to evaluate the influence of muscle fatigue on athletes' ability to perform motor imagery. Performance impairment is a consequence of fatigue, but alterations on perception and mental activity may also occur. To test whether peripheral fatigue affects mental processes, ten sports students imagined three consecutive countermovement jumps before and after a fatiguing protocol, through repetition of upright movements, at 70% of maximal voluntary contraction, until exhaustion. Autonomic nervous system responses and imagined movement durations were considered the dependent variables. Actual duration was systematically overestimated during both visual and kinesthetic imagery, but motor imagery duration and autonomic responses were similar without and under fatigue. Results suggest that muscle fatigue, unlike fatigue induced by prolonged exercise, does not elicit mental fatigue and therefore does not alter motor imagery accuracy.

Adult↗

PubMed2005

Stroop color-word test, arousal, electrodermal activity and performance in a critical driving situation.

The aim of this experiment was to study drivers' performance when confronted with a critical crash avoidance situation. Subjects were asked to cover three laps of a private circuit (4 min per lap), respecting speed limits. During the last lap, an inflated dummy car, placed at an intersection, was pulled onto the traffic lane. The synchronization signal releasing the obstacle was triggered to make the braking distance too short, thus requiring subjects to brake and turn the driving wheel simultaneously. Before driving, subjects completed the Stroop color-word test. Skin conductance (SC) was recorded continuously, before and during driving. Subjects who performed the least well also performed the least well to Stroop test. The SC level showed that subjects avoiding the obstacle were more aroused than those who crashed into the dummy car. Performance to Stroop test and physiological arousal were thus shown to be determining factors in management of a critical driving situation.

Adult↗

PubMed2005

Observation of action and autonomic nervous system responses.

Observing somebody performing an action has been shown to elicit neuronal activity in the premotor cortex. This paper investigated physiological effect of observing an effortful action at the peripheral level. As Autonomic Nervous System responses reflect central nervous system processes such as movement planning and programming, it was expected that observing an action would elicit a pattern of ANS responses matching those recorded during actual movement. 12 male subjects, ages 23 to 28 years (M = 25.5, SD = 1.9), were selected as they were experienced in weight lifting. They were asked to observe a squat movement followed by returning to the upright position under 3 different conditions: (i) observation of actual movement performed by somebody else, (ii) observation of a video of the subject himself (first-person video), and (iii) observation of a video of somebody else performing the same movement (third-person video). Moreover, each movement was observed when performed at 50% and 90% of each participant's personal best mark (% of the highest weight which could be lifted). Three ANS parameters were continuously recorded: skin resistance, temperature and heart rate. ANS responses varied as a function of movement intensity: autonomic responses recorded during movement observation at 90% were significantly higher and longer than those recorded during movement observation at 50%. Thus, autonomic responses were linked to the amount of observed effort. Conversely, no difference was found among the three conditions of observation. ANS responses from observation of actual movement were shown to resemble those recorded under the two conditions of video observation.

Adult↗

PubMed2004

Expertise and peripheral autonomic activity during the preparation phase in shooting events.

This study compared effectiveness of the concentration period in two groups of shooters to evaluate the influence of their expertise while concentrating on the target. Marksmen (pistol shooters, 10 men and 5 women) and pentathletes (6 men and 7 women) took part in a shooting competition in keeping with the rules of each event. Participants were then asked to imagine themselves shooting, at the laboratory. Five variables representing the activity of the autonomic nervous system were continuously recorded (skin resistance and potential, skin blood flow, skin temperature, instantaneous heart rate). Autonomic responses recorded during concentration, actual shooting, and mental imagery were compared by calculating the ratios concentration/ shooting and imagery/shooting. The resultant mean ratio was used to characterize each participant. The same autonomic nervous system pattern was observed during concentrating on the target, mental imagery, and actual shooting. However, marksmen showed ratios closer to 1.0 than pentathletes, absolute mean differences being .06 and .3, respectively. Shorter duration and weakest amplitude responses were recorded during the concentration phase in the Pentathlete group, suggesting that they have more difficulty in using mental imagery during competition than marksmen. When subjects performed well, a specific response pattern was observed in the Marksman group, but not in the Pentathlete group, except in skin potential. In both Marksman and Pentathlete groups, a majority of negative skin potential responses were found in the concentration and shooting phases for the best shots.

Adult↗

PubMed2004

Field dependence-independence in complex motor skills.

This study analyzed the relationship between field dependence-independence and complex motor skills. According to the requirements of each sporting activity, subjects' motor system can be mainly controlled through exteroceptive or proprioceptive information. Sport performances require the athlete to disembed himself, other players, or the ball from the background, and decision-making appears to require cognitive restructuring. 26 athletes (13 men and 13 women) involved in acrobatic sports (gymnastics, trampoline, half-pipe snowboard, synchronized 3-m springboard, acrobatic rock, skateboard, and free skating) and 26 athletes (13 men and 13 women) involved in individual racket sports (tennis and table-tennis) completed the Group Embedded Figures Test. Participants (at least 10 years of practice) were from 16 to 35 years of age (M=22.0, SD=3.1). No significant difference among athletes on scores for field dependence-independence was evidenced given this expertise, sex, or age. Significantly higher scores were obtained by athletes in acrobatic sports, indicating that they tended to be predominately more field-independent whereas the lower scores were obtained by tennis and table-tennis players.

Adolescent↗

PubMed2004

Mental workload in air traffic control: an index constructed from field tests.

BACKGROUND: Mental workload assessment is a recurrent issue in air traffic control (ATC). Studies of ATC have used either objective aspects, i.e., numbers and distribution of aircraft, or subjective factors, such as self-imposed performance and stress levels, with mixed results. This is partly due to the difficulty in bringing together comparable data pertaining to both air traffic, with its ever-changing distribution, and judgement or quickly fluctuating psychophysiological variables. METHODS: We propose a method of mental load estimation devised to take into account both objective traffic variables and the additional load imposed by subjective effects, including the seriousness of conflicts and the time-pressure for their resolution. First, we developed a traffic load index (TLI) to identify time boundaries during which additional load may occur. Then we quantified the additional load according to the air traffic situation. RESULTS: TLI was developed from analysis of 25 h of recordings of radar control sessions involving 25 professional air traffic controllers at a major airport. Results were then compared with a simple objective index (number of aircraft) and subjective workload ratings (NASA-TLX test). The whole population (intersubjects analysis) showed a better correlation between the TLI and the self-rated workload than for the number of aircraft alone. Among the controllers who rated more than one level of workload through the TLX-test, 77.8% showed better correlation between TLI and TLX than between N and TLX (intrasubjects analysis). CONCLUSION: Workload estimation should integrate both objective task variables and subjective evaluations associated with them.

Accidents, Aviation↗

PubMedDate not supplied

Assessing workload through physiological measurements in bus drivers using an automated system during docking.

The aim of the experiment was to test the effect of an automated system of bus docking on drivers' mental workload. Reduced workload is thought to be brought about by helping the driver to maneuver, as he or she is required only to monitor proper functioning of the system. However, the true impact of the system on drivers must be studied to guarantee good acceptance and minimal distraction from traffic. Workload was estimated by electrodermal activity recording while drivers tested 5 scenarios involving (or not involving) the docking system. Results showed that docking precision was improved when the system was used. When drivers monitored the functioning of the system, their workload was higher than that observed during manual docking; however, reduced workload was evidenced after a learning process. The docking system was also shown to increase workload in the event of dysfunction, especially when drivers had to take over control. Despite this particular situation, and after habituation, such a system could be integrated into buses to improve safety during boarding and egress.

Automation↗