RESUMO
The first two decades of cognitive neuroimaging research have provided a constant increase of the knowledge about the neural organization of cognitive processes. Many cognitive functions (e.g.working memory) can now be associated with particular neural structures, and ongoing research promises to clarify this picture further, providing a new mapping between cognitive and neural function. The main goal of this paper is to outline conceptual issues that are particularly important in the context of imaging changes in neural function through recovery process. This review focuses primarily on studies made in stroke and traumatic brain injury patients, but most of the issues raised here are also relevant to studies using other acquired brain damages. Finally, we summarize a set of methodological issues related to functional neuroimaging that are relevant for the study of neural plasticity and recovery after rehabilitation.
Assuntos
Dano Encefálico Crônico/fisiopatologia , Encéfalo/fisiopatologia , Transtornos Cognitivos/fisiopatologia , Diagnóstico por Imagem , Plasticidade Neuronal/fisiologia , Dano Encefálico Crônico/diagnóstico , Dano Encefálico Crônico/reabilitação , Lesão Encefálica Crônica/diagnóstico , Lesão Encefálica Crônica/fisiopatologia , Lesão Encefálica Crônica/reabilitação , Mapeamento Encefálico , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/reabilitação , Humanos , Testes Neuropsicológicos , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Reabilitação do Acidente Vascular CerebralRESUMO
Attention is a basic cognitive function and a prerequisite for other cognitive processes and is frequently impaired after traumatic brain injury. In the present study, 29 severe traumatic brain injury patients and 30 control subjects completed a battery of three neuropsychological tests of attention (WCST, TMT, Stroop). The aim was to clarify the attentional mechanisms underlying tests performance and to explore the types of attentional impairment after severe traumatic brain injury. Significant differences were found between the control and clinical groups in almost all measures. However, some of these differences disappeared when the speed of information processing was controlled using covariance analysis. In addition, a factor analysis revealed a four-factor solution explaining 89.6% of the variance in the data, i.e. cognitive flexibility, speed of processing, interference and working memory. This result supports the view of at least four different subprocesses of attentional control underlie test performance and allows one to differentiate between high- and low-level processes. The implications for neuropsychological assessment and rehabilitation are discussed.
