title: fMRI of verbal and nonverbal memory processes in healthy and epileptogenic medial temporal lobes.
abstract: Material-specific memory impairments are a well-established consequence of unilateral medial temporal lobe damage. We used fMRI to investigate encoding and recognition of verbal and nonverbal stimuli using adaptations of tasks used successfully in clinical evaluations of patients with temporal lobe epilepsy (TLE). We studied two patient groups, one with left TLE and one with right TLE, and one group of healthy subjects. Results from the healthy subjects indicated that initial and delayed recognition trials of the verbal task activated the left medial temporal lobe, and the same tasks of the nonverbal task activated the right, confirming the sensitivity to laterality of our clinical tasks. Patients tended to use the opposite hippocampus, but often the parahippocampal gyrus on the same side, compared to the healthy subjects. Since our patients and the healthy groups performed similarly on the memory tasks, we conclude that the patients' activation patterns represent an effective adaptation to the presence of an unhealthy hippocampus.
authors.affiliation: Montreal Neurological Institute, 3801 University St, Montreal, Canada QC H3A 2B4. bankss2@ccf.org
authors.forename: Sarah Jane
authors.initials: SJ
authors.lastname: Banks
authors.forename: Viviane
authors.initials: V
authors.lastname: Sziklas
authors.forename: Devin J
authors.initials: DJ
authors.lastname: Sodums
authors.forename: Marilyn
authors.initials: M
authors.lastname: Jones-Gotman
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000150:complications* / Q000473:pathology*; D001931:Brain Mapping; D004833:Epilepsy, Temporal Lobe / Q000209:etiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D013702:Temporal Lobe / Q000098:blood supply* / Q000473:pathology; D014706:Verbal Learning / Q000502:physiology*
chemical_list: D010100:Oxygen