Poster Session 06 Program Schedule
02/15/2024
04:00 pm - 05:15 pm
Room: Majestic Complex (Posters 61-120)
Poster Session 06: Aging | MCI | Neurodegenerative Disease - PART 2
Final Abstract #97
Enhancing Memory Using Enactment in Stroke Patients: Assessing the Role of Semantic Integration and Cognitive Planning
Yadurshana Sivashankar, University of Waterloo, Waterloo, Canada
Brady Roberts, University of Chicago, Chicago, United States
Myra Fernandes, University of Waterloo, Waterloo, Canada
Category: Memory Functions/Amnesia
Keyword 1: movement
Keyword 2: stroke
Keyword 3: planning
Objective:
Previous research has suggested that performing an action depicting the meaning of a target word (known as ‘enactment’) benefits later memory retrieval, relative to reading. Some studies have proposed that enactment confers a memory benefit by allowing for multimodal encoding of the target word through the integration of verbal and motoric representations; a process thought to be localized within the parietal lobe. Others have instead suggested that cognitive planning preceding the execution of an action (likely requiring frontal lobe-based processes) is the critical factor boosting memory. Here, we looked for evidence to support the involvement of brain areas responsible for the memory benefit conferred by enactment. In doing so, we make inferences about the neural mechanism underlying this mnemonic effect.
Participants and Methods:
We assessed memory retrieval performance (free-recall of words) following enactment or reading at encoding (trial-types intermixed) in participants who sustained a focal stroke to either parietal (n = 6), or frontal (n = 11) regions of the brain, and in age-matched healthy controls (n = 20). On enactment trials, participants were instructed to encode words by performing a related physical action depicting the to-be-remembered word. On silent reading trials, participants were asked to encode the word by reading it, without moving their lips or body. We also administered an Apraxia screening tool (Tulia) as an indirect assessment of integration (of verbal commands and corresponding actions), and the Tower of London, Category Fluency task, and Digit Span as measures of cognitive planning.
Results:
As predicted, enactment led to higher recall performance, compared to silent reading, in all three groups. However, the magnitude of the enactment benefit was the greatest in frontal patients (d = 1.14) followed by healthy controls (d = 0.67), and was the least in parietal patients (d = 0.22). Of note, we found a main effect of Group, such that overall recall (collapsed across encoding condition) was significantly poorer in frontal patients compared to healthy controls, even after controlling for age and education; this was not true of parietal patients. We also found that output on the Category Fluency task correlated positively with recall performance, after partializing out the variance accounted by Group.
Conclusions:
The posterior parietal lobe plays a central role in linking verbal and motoric representations that are semantically related. Damage to this region may limit multimodal encoding of enacted words, and the subsequent memory benefit that this process is thought to confer. Overall poorer memory performance in frontal patients, relative to healthy controls, might be indicative of a retrieval difficulty in the former group because of their impaired executive functioning. The significant positive relation observed between our assessment of planning (category fluency) and overall recall lends further support to this claim. These findings inform models of the neural basis of the enactment benefit to memory. They also suggest there are limitations to mnemonic benefits for parietal patients, when integration of multimodal information is required.
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