|Reference code: ||PT/FB/BL-2004-016.06|
|Location: ||Arquivo PCA - Pasta 24/2004|
|Dissociable memory impairments after selective bilateral fornix damage|
|Publication year: ||2007|
The fornix is the major efferent pathway connecting the hippocampus with the diencephalon and the frontal lobe and it is regarded as a key link in the memory circuit comprising these structures. It remains a topic of debate whether this circuit supports a unique episodic memory system that can be dissociated from other memory systems. The objective of our study was to test the hypothesis of dissociable memory impairments following fornix damage.
PARTICIPANTS AND METHODS:
We have comprehensively investigated memory performance in a patient, J. T., with selective bilateral fornix damage resulting from neurosurgical cyst removal through a transcallosal approach. Standard neuropsychological assessment of all cognitive functions was performed approximately one year after surgery. Further assessment aimed at clarifying the memory impairments of the patient included a large number of both standard and experimental tests of recall and recognition memory, spatial memory and procedural memory.
Standard neuropsychological tests revealed severe impairment in episodic memory recall, with relatively intact recognition memory, while all other cognitive functions were normal. The long-term episodic memory deficits were confirmed in all subsequent tests, while patient J.T. consistently showed normal recognition memory in the Warrington Recognition Memory Test (RMT) for faces, a Delayed Matching-to-Sample (DMS) test and a Visual Paired Comparison (VPC) test. Moreover, patient J.T. was severely impaired in an Object - Relocation spatial memory test, when involving object to location binding but not so for positions only memory conditions. Normal perceptual-motor skill learning was observed in two standard tasks, mirror tracing and rotary pursuit.
In summary, our results support the hypothesis that the fornix is part of a memory circuit essential for recollection and recall but not familiarity processes. Our study further demonstrates spatial memory impairments and preserved procedural memory after fornix damage.
|Accessibility: ||Document does not exist in file|
|Secondary author(s): |
|Cavaco, S., Almeida, I., Van Asselen, M., Massano, J., Cunha, C., Machado, E., Santana, I., Castelo-Branco, M.|
|Document type: |
|Number of reproductions: |
|Figueiredo, P., Cavaco, S., Almeida, I., Van Asselen, M., Massano, J., Cunha, C., Machado, E., Santana, I., & Castelo-Branco, M. (2007). Dissociable memory impairments after selective bilateral fornix damage. Journal of the International Neuropsychological Society, 13(Suppl. 2), S45. doi: 10.1017/S1355617707071408|
|Indexed document: ||Yes|
|Keywords: ||Psychophysiology / Memory / Fornix damage|
Dissociable memory impairments after selective bilateral fornix damage