Functional imaging correlates of environmentally induced memory changes

Environmentally induced stress may lead to a phenomenon termed ‘mnestic block syndrome’. The memory changes primarily affect the patient's autobiography by either blocking the retrieval of old memories, or by impairing the formation of new memories. We studied patients with either form of amnesia neuropsychologically and with functional imaging methods. We obtained a right temporo-frontal hypometabolism in patients with psychogenic amnesia, restricted to their autobiography. We conclude that environmentally induced brain changes are due to the action of stress hormones leading to a block of memory-related information flow in the brain which can persist over decades.