Browsing by Author "Kola, Aino"

Background. Aphasia is a deficit of language and cognition caused by brain damage. Rehabilitation is based on reactivating and reorganizing the nervous system – or learning things anew. Learning is based on many factors, that would require more thorough examination to best allocate and plan rehabilitation. The impact of reaction speed on the ability to learn novel words has not yet been studied in aphasic patients, although inter- and intraindividual variability in their reaction times clearly exists. Some aphasic patients have also been associated with a behavioral pattern called speed-accuracy trade-off, a pattern where a person balances between acting fast or accurately. This has led to overly cautious or overly hasty responding in some aphasic patients, which potentially could influence the learning ability. Objectives. The purpose of this study is to examine reaction times and response accuracy and their possible relationship in a novel word learning task in aphasic patients and healthy controls. Special interest is placed on the occurrence of speed-accuracy trade-offs, or overly cautious or fast responding related to response accuracy outcome. Additionally, it is being examined if intrapersonal variability in reaction times predicts novel word learning ability. Methods. The participants of this study consist of 10 aphasic patients in subacute stage and 21 healthy age-matched controls. This study was executed as a part of “Opi sanoja” research project, in which novel word learning ability was studied through a computer-based word learning task. The purpose of the task was to learn six pseudo-words associated with a picture. The pictures were shown in pairs, of which the examinee was told to choose the right one according to seen and heard pseudo-word and earlier received feedback. Reaction speed was measured by reaction times recorded by the word learning task. Reaction times were compared with response accuracy in and between the study groups. Results and conclusions. Aligned with previous studies, aphasic patients learned novel words worse than the controls, although great interindividual variability was noted. The reaction times of aphasic patients were significantly slower, but again interindividual variability was large in the group. Reaction speed correlated with novel word learning in the control group, but not significantly in the aphasic group. Intraindividual reaction time variability was notable in both groups, being twice as large in the aphasic group. Broader intraindividual variability correlated with weaker novel word learning ability in the control group. The speed-accuracy trade-off pattern occurred in two aphasic patients: one with overly cautious and one with overly hasty response behavior. According to this study, examining reaction times and possibly speed-accuracy trade-offs with, for example, a specific learning test would help to recognize the patients with maladaptive timing patterns. This would benefit the patient, as optimizing the speed-accuracy trade-offs has been studied to improve item naming, the effect even being transferred to connected speech. The relationship of speed-accuracy trade-offs with novel word learning requires further studying, taking into consideration factors behind reaction times and word learning ability.