Review
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World J Radiol. Apr 28, 2014; 6(4): 93-105
Published online Apr 28, 2014. doi: 10.4329/wjr.v6.i4.93
FMRI contributions to addressing autobiographical memory impairment in temporal lobe pathology
Ekaterina J Denkova, Liliann Manning
Ekaterina J Denkova, Liliann Manning, Department of Psychology, University of Strasbourg, 67000 Strasbourg, France
Liliann Manning, Cognitive Neuropsychology and Physiopathology of Schizophrenia, INSERM U1114, 67000 Strasbourg, France
Author contributions: Denkova EJ and Manning L contributed to this review equally.
Correspondence to: Dr. Ekaterina J Denkova, Department of Psychology, University of Strasbourg, 12 rue Goethe, 67000 Strasbourg, France. ekaterina.denkova@yahoo.ca
Telephone: +33-3-68851927 Fax: +33-3-68851947
Received: December 17, 2013
Revised: February 20, 2014
Accepted: March 13, 2014
Published online: April 28, 2014
Abstract

Episodic autobiographical memory (AM) allows one, through the recollection of sensory-perceptual details, thoughts and feelings, to become aware of an event as belonging to one’s own past as well as being able to project into one’s future. Because AM provides a sense of self-continuity, contributes to the integrity of the self, and helps predicting future experiences, any deficit of AM may have debilitating consequences for everyday life functioning. Understanding AM failure and the underlying neural mechanisms has the potential to shed light on brain reorganization mechanisms and engagement of compensatory processes. Functional magnetic resonance imaging (fMRI) provides the most promising imaging method to tackle these issues. We reviewed evidence from the few studies that used fMRI to investigate the functionality of the residual tissue, the neural reorganization and compensatory mechanisms in patients with neurological conditions due to impaired medial temporal lobe. Overall, these studies highlight the importance of the left hippocampus, which when atrophied and not functional leads to AM deficits but its residual functionality may support relatively normal AM recollection. When damaged hippocampal tissue is not functional, other brain regions (e.g., the medial prefrontal cortex) may be involved to compensate impairment, but they appear generally ineffective to support detailed episodic recollection.

Keywords: Functional magnetic resonance imaging, Autobiographical memory, Amnesia, Medial temporal lobe, Memory deficit, Reorganization

Core tip: Functional magnetic resonance imaging investigations of patients with impaired autobiographical memory (AM) can greatly contribute to further our understanding of brain reorganization mechanisms and engagement of compensatory processes after damage to the medial temporal lobe. These investigations are reviewed here. Overall, they highlight the importance of the left hippocampus, which when atrophied and not functional leads to deficits in AM but its residual functionality may support relatively normal AM recollection. When damaged hippocampal tissue is not functional, other brain regions (e.g., the medial prefrontal cortex) may be involved to compensate impairment, but they appear generally ineffective to support detailed recollection.