Slowing of visual reaction time in closed head injury patients: Experimental and clinical results using the Hick-paradigm [VISUELLE REAKTIONSZEITVERLANGSAMUNGEN BEI SCHADEL-HIRN-TRAUMA-PATIENTEN: EXPERIMENTELLE UND KLINISCHE ERGEBNISSE ZUM HICK-PARADIGMA]

Abstract

Subjects of the study were a group of patients with neurological/surgical problems (N = 27) and a group of patients with traumatic brain injury (N = 20). Measures of single reaction time and choice reaction time were examined by a hybrid experiment called 'Hick-paradigm'. Data analyses showed that the reliabilities of single reaction time and choice reaction time measures were sufficient. A specific slowing of reaction time could be demonstrated for patients with contusions of the brain and for every experimental condition. Also, reaction time proved to be correlated with post traumatic amnesia, which is an indicator of the severity of traumatic brain injury, and also with intelligence. Further analyses revealed that slowing of reaction time in the traumatic brain injury patients was not confounded with processes of fatigue or practice. Single case evaluations of the data differentiated this result of group-comparisons: both groups of patients seemed to undergo a high degree of fatigue as well as practice effects.