UCL Centre for Developmental Cognitive Neuroscience seminar - Dr Rachael Elward
Research Associate, Cognitive Neuroscience and Neuropsychiatry, UCL GOS Institute of Child Health
Wednesday 11th October 4 pm
Leolin Price Lecture Theatre, Lower Ground Floor, UCL GOS Institute of Child Health, 30 Guilford Street, London WC1N 1EH
Title: Context Memory Effects in Developmental Amnesia
Abstract: Recollection involves bringing back to mind a prior event, including the sights and sounds associated with that experience. Patients with developmental amnesia (DA) have hippocampal damage and show a deficit in recollection such that they are not able to recall unique experiences, yet are able to generalise across multiple similar events. It is possible that some contextual information is retrieved in DA at a level which is insufficient to support recall, but sufficient for a decontextualized representation of the event. Using functional MRI it is possible to investigate whether the patterns of brain activity indicate that some contextual information is retrieved in DA, even in circumstances where memory performance is very poor. We investigated context reinstatement in 4 patients with DA and 20 controls in a memory test where words and pictures were pared together. In the MRI scanner, participants were asked to recall the type of image that was previously paired with each word. Behaviourally, all controls performed above chance, whereas patients could not typically remember the pictures that were associated with each word. fMRI data in the controls showed the typical pattern of context reinstatement effects, such that words that were previously paired with scenes were associated with greater activity in the parahippocampal and retrosplenial cortices than words paired with images that were not scenes. Interestingly, patients also showed scene reinstatement effects, but these were localised in the visual cortex, and not the regions that are typically associated with scene processing. For both groups, scene reinstatement effects were not present in a control task where the picture was not relevant. This suggests that cortical reinstatement is dependent on the retrieval goal, even in amnesic patients. These data indicate that patients with developmental amnesia are able to reinstate aspects of their prior experience (i.e. visual context) in a strategically directed way, but that this reinstatement is qualitatively different from that of controls and is insufficient to support context-dependent memory responses. We conclude that limited subthreshold context memory processes occur in DA, despite the profound impairment in recollection.
All welcome to attend