Abstract Details

Title Age-Related Differences in Cognitive and Neural Activity in Target Processing

Topic Behavioral Neurology

Presentation(s) P07 - (-)

Poster/Presentation
Number 156

Objective

Background BACKGROUND: In young adults, research using grand average ERPs has identified a posteriorly-distributed P3b component, interpreted as an index of categorization/memory updating, and an anteriorly-distributed P3a component, interpreted as an index of orienting/executive control. One of the most common observations in the ERP literature is that the P3b component becomes more anteriorly distributed as a function of age. Does this finding represent an age-related shift in the neural processors that mediate categorization/updating, or is it a reflection of overlapping components that index different cognitive operations?

Design/Methods DESIGN/METHODS: ERPs were measured in 12 young and 15 old well-matched adults during a task in which they responded to designated target letters. Temporospatial principal component analysis (PCA) was used to investigate the spatial distribution of the P3b.

Results RESULTS: Consistent with reports in the literature, grand average ERPs suggested that old subjects generated a more anteriorly-distributed target P3b that encompassed a larger portion of the scalp. However, temporospatial PCA revealed two spatially distinct factors: an anterior P3a and a centro-posterior P3b. For the old subjects, the P3a and P3b did not differ in amplitude. For the young subjects, the P3b was substantially larger than the P3a.

Conclusions CONCLUSIONS: PCA revealed that rather than having a more widely/frontally distributed target P3b, older subjects had a large P3a and P3b overlapping during the same temporal interval. Although the age-related increase in P3a amplitude could reflect a failure of old subjects to habituate an orienting response to targets, we hypothesize that it is due to their increased reliance on executive control operations that provide extra scaffolding for carrying out the categorization process.

Authors/Disclosures
Kirk R. Daffner, MD, FAAN (Brigham & Women's Hospital - Harvard Medical School) PRESENTER	The institution of Dr. Daffner has received research support from Azheimer's Association. The institution of Dr. Daffner has received research support from FUJIFILM.
Brittany Alperin (Brigham and Women's Hospital)	No disclosure on file
	No disclosure on file
Tatyana Zhuravleva	No disclosure on file
	No disclosure on file
David M. Greer, MD, FAAN (Boston University School of Medicine)	Dr. Greer has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Thieme, Inc. Dr. Greer has received personal compensation in the range of $5,000-$9,999 for serving as an Expert Witness for multiple. Dr. Greer has received publishing royalties from a publication relating to health care. Dr. Greer has received publishing royalties from a publication relating to health care. Dr. Greer has received publishing royalties from a publication relating to health care. Dr. Greer has a non-compensated relationship as a Treasurer-Elect with American Neurological Association that is relevant to AAN interests or activities. Dr. Greer has a non-compensated relationship as a President with Neurocritical Care Society that is relevant to AAN interests or activities.
David M. Greer, MD, FAAN (Boston University School of Medicine)	Dr. Greer has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Thieme, Inc. Dr. Greer has received personal compensation in the range of $5,000-$9,999 for serving as an Expert Witness for multiple. Dr. Greer has received publishing royalties from a publication relating to health care. Dr. Greer has received publishing royalties from a publication relating to health care. Dr. Greer has received publishing royalties from a publication relating to health care. Dr. Greer has a non-compensated relationship as a Treasurer-Elect with American Neurological Association that is relevant to AAN interests or activities. Dr. Greer has a non-compensated relationship as a President with Neurocritical Care Society that is relevant to AAN interests or activities.
Dorene M. Rentz, PsyD (Brigham and Women's Hospital)	Dr. Rentz has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Digital Cognition Technologies. Dr. Rentz has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Neurotrack.
Gary W. Small, MD (UCLA Semel Institute)	No disclosure on file

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