Attention deficiency and car driving

  Contact person

Nathalie BEDOIN

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Scientific framework and objectives

Numerous causes of attention dysfunctions exist and could impair car driving competency. Some populations are particularly likely to present attention dysfunctions, such as people subjected to addictions, users of some pharmaceutical drugs, persons having pathologies liable to result in attention disorders. Among the causes, new information and communication technologies and driving aids put the driver in a dual task situation, which implies a division of his/her attention. In a first study, we focus on the evolution of attention deficiencies in brain injured patients who wish to drive a car again. Our aim was to gather epidemiological and experimental data to provide the most relevant clues about visual spatial attention abilities. We are alsoinvolved in a second study where differences between young adults’ and seniors’ attentional abilities are assessed. We participate in a large grant-aided programme of research (PREDIT Go4), which is concerned with this issue. The objective of the project is to gather French competences in order to study the effects of driver attention dysfunctions on vehicle driving and consequences on potential occurrence of accidents. Making use of similar and/or complementary methods and research tools between the various partners of the project should make it possible to compare the several specific research actions and provide useful data to grade the respective risks associated to each dysfunction. We conducted a longitudinal study with 11 brain injured young adults and a group of control subjects, using neuropsychological tests to assess their processing speed, vigilance, distractibility, sustained, divided and focused attention, inhibitory processes, mental flexibility, categorisation and planning capacities, inferences. Subjects were examined three times (immediately after the post-traumatic amnesia, when coming out of the rehabilitation centre, and one year after this coming out), in order to assess the dynamic of their cognitive recovery. Additionally, we elaborated a new attentional test, STHIDEL, to investigate the ability to focus attention on the global aspect of a complex visual scene while inhibiting irrelevant details and the ability to focus on details to the detriment of the global form. The overall neuropsychological assessment is used to provide an advice about the opportunity to drive a car again. This advice is compared with another advice provided from a road test in a cameras-equipped car. Additionally, a method to investigate visual exploration strategies, based on ocular-motor data, was finalized. Regarding, the second programme of research, we are involved in a study about visual attentional processes required to deal with left turning at an intersection. An epidemiological study assesses what manoeuvres have been made just before a car crash, from the close examination of BAAC (bulletins of road accidents involving physical injury). Every accident involving physical injury in France (1 102 486 crashes) has been assessed between 1996 and 2005. At the moment, we are designing experiments to investigate age and lack of attention effects on the ability to build a representation of the situation and on decision making in left-turn situations. We use the change blindness experimental paradigm (Rensink, 1997), and a modified version of the flickers technique (Caird, 2005). Ninety-six intersection photographs are manipulated so that one object (pedestrian, vehicle, road sign) in the scene would change when flickering, with or without a distractive task. Subjects had to detect changes, and to make a decision about left turning. The main hypothesis is that older drivers have more difficulties than younger to detect changes in a rapidly changing and dynamic environment, such as a busy intersection. Additionally, visual, visual attention tests are used and oculomotor data are recorded. The results from the neuropsychological battery showed significant improvement of the patients’ cognitive abilities at the third test stage, except regarding attentional abilities (especially when inhibition or motor components are involved). However, it was observed that the cognitive processes involved in categorisation and planning are preserved. At the first test stage, the data from the new test STHIDEL confirmed the well-known response time slowing associated with brain injury. In the second and third test stages only some patients had shorter response times, but patients who presented with impulsivity at the first stage provided less speed and more accurate responses at the third stage. Additionally, 7 out of 12 patients indicated a perceptive bias to the local level, which was not necessarily associated with an attentional bias to the local level. This result confirmed the dissociation between perceptive and attentional aspects in complex visual scene processing. Taken together, the data suggest the relevance of a test that dissociates perceptual and attentional deficits for global/local information processing in brain-injured drivers. Neuropsychological advices provided about car driving opportunity, based on STHIDEL and the other neuropsychological tests, were consistent with their driving abilities assessed in the road test. On the contrary, the patients who were recommended to pursue driving training before driving alone again experienced difficulties in visual exploration, visual control and anticipation in the road test, although they were generally unaware of these disabilities. The tests that we used appeared to be related to the driving field tests data. According to the first results obtained in the second study confirmed the increase in the number of fatal accidents with age. The most dramatic increase concerned left-turning situations at intersections. We are currently conducting two experiments with the change blindness paradigm. The first results show that the errors rates for change detection and decision making are in accordance with literature. The distractive task has no effect, neither on change detection nor on decision making in young adults, whereas it seems to have a negative effect in old participants. An interesting result is observed in few cases: some participants made correct decisions in the absence of change detection.

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  Financial support

• PREDIT Go4
  Attention dysfunctions and car driving (P.I. Laurence Paire-Ficout, INRETS)
  Ministère chargé de la recherche, des transports, de l’environnement et de l’industrie, ADEME, OSEO et ANR
  2005-2008
• PREDIT 3
  Cognitive efficiency in brain injured patients and car driving again (P.I. Claude Marin-Lamellet, INRETS)
  Ministère chargé de la recherche, des transports, de l’environnement et de l'industrie, ADEME, ANVAR et Région Rhône-Alpes
  2004-2006

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  Publications

• Marin-Lamellet, C., Bedoin, N., Kerleroux, J., Lafont, S., 2005, "Efficience cognitive des traumatisés crâniens et conduite automobile", actes de 20ème Congrès de la Société Française de Médecine Physique et de Réadaptation (SOFMER), Dijon, France, 2005, October