Traumatic Brain Injury, Aging and Reaction Time

Abstract

ABSTRACT:The effects of traumatic brain injury (TBI) and aging were compared on tests of simple and complex reaction time (RT). Simple RT was not significantly affected by aging or TBI. TBI patients, however, tended to be slower on Simple RT tasks, and had a larger standard deviation. Individuals over age 60 and patients of any age with TBI demonstrated slower RT with choice RT tests. In addition, both groups (those over 60 and TBI patients) were less able than other groups to inhibit the processing of redundant information. For the TBI patients, this occurred primarily on reassessment. These results suggest that the deficit in both aging and TBI is not only a generalized neuronal slowing but a more specific impairment in attentional control processes, exhibited as a deficit in focused attention. RESUME: Lesion cerebrate traumatique, vieillissement et temps de reaction Nous avons compare les effets de lesions cerfibrales traumatiques (LCT) et du vieillissement par des epreuves du temps de reaction (TR) simple et complexe. Le TR simple n'etait pas affecte de facon significative par le vieillissement ou par une LCT. Cependant, les patients avec LCT avaient tendance a etre plus lents dans les epreuves de TR simple et avaient un ecart type plus considerable. Les individus au-dessus de 60 ans ainsi que les patients de tous ages avec LCT manifestaient un TR plus lent dans certaines epreuves TR. De plus, les deux groupes (les individus de plus de 60 ans et les patients) etaient moins aptes que les autres groupes a inhiber le traitement d'informations redondantes. Dans le cas des patients avec LCT, ceci survenait surtout lors de la devaluation. Ces resultats suggerent que le deficit dans le vieillissement et la LCT n'est pas seulement un ralentissement neuronal generalise, mais aussi une alteration plus specifique du processus de controle de I'attention, manifeste par un deficit de l'attention focalisee.Can. J. Neurol. Sci. 1989; 16:161-167 Aging and traumatic brain injury (TBI) appear to have some similar effects on complex information processing. With advancing age there is a behavioral slowing, the degree of slowing being a function of task complexity.1 " 3 TBI also causes slowing of reaction time (RT).4 " 6 The slowing varies with task complexity and complex choice RT best reflects the severity of TBI 7 -". Gronwall, 12 describing the performance of patients with mild head injury, suggested that "these difficulties are similar to those a 65-year man would have if suddenly confronted with the work schedule he had coped with at 25" (p. 372).There appear to be at least broad similarities between aging and TBI in their effect on the brain. Severe TBI results in widespread brain damage;13 -14 aging also causes diffuse loss of neurons.15 -16 Both aging and TBI may cause focal frontal lobe dysfunction. The frontal lobes are particularly sensitive to damage by the inertial effects of TBI.1317 " 20 Neuropsychological tests 21 " 23 and blood flow studies 24 both suggest frontal lobe dysfunction with increasing age, althoug...

Functional and neurobiological similarities of aging in monkeys and humans

“…For example, the target appeared in the same location on each trial, the target was present for a stable period of time within a block of trials, and as many trials as was necessary to achieve the individual fastest reaction time possible was provided. Our findings parallel reports that simple reaction time is not increased with age in people when task parameters are kept stable (Gottsdanker, 1982;Stuss et al, 1989;Light, 1990). Additional evidence that impairments in reaction time may not be observed under all testing conditions in aged monkeys comes from a recent investigation in which response latencies were not slower in aged monkeys compared to young monkeys in learning hierarchial relationships (Rapp et al, in press).…”

“…Complexity of stimulus display and required movements to the stimulus can influence the degree of age-related motor slowing. For example, simple reaction time in which a single movement is made at the appearance of a target can be maintained into old age (Gottsdanker, 1982;Welford, 1982;Stuss et al, 1989;Spirduso & MacRae, 1990). However, age-related differences in reaction time increase as stimulus discriminations and choices increase (Welford, 1982;Light & Spirduso, 1990).…”

Closed head injury-related information processing deficits: An event-related potential analysis

“…Closed head trauma also leads to pronounced and enduring cognitive impairments, most notably in attention (Arciniegas et al, 1999;Binder et al, 1997;Gronwall, 1987;Mangels et al, 2002;Posner, 1987;Shum et al, 1990;Spikman et al, 1996;Stuss et al, 1986;van Zomeren, 1981), memory (Arcia and Gualtieri, 1993;Baddeley et al, 1987;De Renzi et al, 1995;Dikmen et al, 1986;Grossi et al, 1998;Laiacona et al, 1993;Levin et al, 1987;Markowitsch et al, 1993;Richardson, 1990;Rousseaux et al, 1984;Watt et al, 1999), and the speed of information processing (Ferraro, 1996;Grö n, 1996;Heinze et al, 1992;Ponsford and Kinsella, 1992;Spikman et al, 1996;van Zomeren, 1981). Many head-injury survivors are unable to concentrate, are easily distracted, fatigue quickly, and their memory -in terms of storage of new information and retrieval of old information -is poor.…”

Comparing temporal order judgments and choice reaction time tasks as indices of exogenous spatial cuing

“…Another consideration comes from the examination of clinical populations. Individuals with hemiparesis due to stroke or brain injury may not be able to execute a manual response with the dominant preferred hand and may be excessively slow even with an unaffected hand (e.g., Stuss et al, 1998). Aging and other neurological disorders can also affect overall speed of responding, e.g., individuals with Parkinson's disease (Daum and Quinn, 1991), major depression (Pardo et al, 2006); healthy aging (Salthouse, 1991).…”