Functionally activated brain imaging (O-15 PET and fMRI) in the study of learning and memory after traumatic brain injury.

Advances in functional imaging technology and cognitive neuropsychology have resulted in paradigms in which participants can perform cognitive tasks during functional image acquisition. We will discuss the application of two approaches (oxygen-15 positron emission tomography and functional magnetic resonance imaging) that have recently been used to examine components of learning and memory following traumatic brain injury (TBI). Activated functional brain imaging findings that we will discuss may suggest possible functional reallocation and reorganization of brain substrates involved in verbal learning and memory following brain injury. The findings also are clearly in line with other research that indicates a prominent role for the frontal lobes in learning and memory functioning, and support the concept of distributed neural networks for memory-related functions, cognitive load, and the potential for examining brain re-organization after injury.