How do Patients With Amnesia Acquire New Knowledge?

New Semantic Learning in Patients With Selective Brain Lesions in Temporal Regions: a Behavioural and MRI Study

THE STUDY AIMS to constitute the largest group of patients with major memory impairment resulting from various etiology and specific lesions of the medial temporal lobe (MTL) and use a combined psychometric and neuroimaging approach to study the factors allowing these patients to successfully learn new semantic information.

The preservation of learning abilities is an essential aspect in the implementation of cognitive rehabilitation programs for patients with an amnesic syndrome. Particularly disabled on a daily basis, these patients have significant difficulties in coping with the demands of work and family life. Data from previous case studies attest to the ability of these patients to rely on preserved cognitive systems to learn new semantic information. However, the procedures for the acquisition of new information are sometimes long, not optimal and the clinical factors, that can influence it, are poorly identified. In addition, the brain networks necessary for such learning are still debated. In order to better understand the cognitive mechanisms and brain networks that underlie the ability to learn new semantic information, the research aims to study a group of patients with major memory impairment following medial temporal lobe lesions of various etiologies (non-degenerative). The study will use a combined psychometric and neuroimaging approach to identify the factors that enable these patients to successfully learn new semantic information.

Inclusion Criteria:

• Patients aged between 18 and 70 years
• Living in France since less than 20 years, being able to understand the French language, and have basic cultural knowledge as evaluated in classical clinical consultation
• Written agreement to participate in the study
• Intellectual capacities compatible with the cognitive tasks and signing of consent
• Affiliation to the French social security system
• For patients: bilateral brain lesion of the medial temporal lobe or the extended hippocampal system

Exclusion Criteria:

• Subjects under the age of 18 or over 70
• Contraindications for MRI (examples: wearers of a pacemaker or cardiac defibrillator, implanted equipment activated by an electrical, magnetic or mechanical system, wearers of haemostatic clips for intracerebral aneurysms or carotid arteries, wearers of orthopedic implants, claustrophobic)
• Refusal to be informed of an anomaly detected during the MRI