TY - JOUR
T1 - Apolipoprotein E and category fluency
T2 - Evidence for reduced semantic access in healthy normal controls at risk for developing Alzheimer's disease
AU - Rosen, Virginia M.
AU - Sunderland, Trey
AU - Levy, James
AU - Harwell, Angela
AU - McGee, Lori
AU - Hammond, Christopher
AU - Bhupali, Deepa
AU - Putnam, Karen
AU - Bergeson, Judy
AU - Lefkowitz, Charlene
PY - 2005
Y1 - 2005
N2 - Two groups of non-demented individuals, who differed on genetic risk for Alzheimer's disease (AD) based on their apolipoprotein E (APOE) genotype, were tested on a category fluency task. Twenty ε4 carriers and twenty ε4 non-carriers were tape recorded while saying animal names for ten minutes. Five measures were examined: total names generated; total clusters; mean cluster size; mean within-cluster retrieval time; and mean between-cluster retrieval time. Groups were matched on age and education and scored as normal on a battery of psychometric tests. The ε4 carriers generated significantly fewer names and clusters, and took significantly longer to access clusters, when compared to the ε4 non-carriers. No group differences were found for cluster size or within-cluster retrieval times. We previously reported [Rosen, V. M., Bergeson, J. L., Putnam, K., Harwell, A., Sunderland, T. (2002). Working memory and apolipoprotein E: What's the connection? Neuropsychologia 40, 2226-2233] that the ε4 carriers in the present study scored significantly lower than the ε4 non-carriers on a measure of working memory/attentional capacity [Operation Span Task, see Turner, M. L., Engle, R. W. (1989). Is working memory capacity task dependent? Journal of Memory and Language 28, 127-154]. In the present study, a significant negative relationship found between span performance and between-cluster retrieval times suggested that reduced attentional capacity may have negatively impacted semantic access for the ε4 carriers. Finally, we found significant relationships between a Trail Making Test [Reitan, R. M. (1992). Trail Making Test, manual for administration and scoring. Tucson, AZ: Reitan Neuropsychology Laboratory] "switch" measure (Form B-Form A) and three of the five fluency measures. The findings suggested that the ε4 carrier's reduced attentional capacity may have interfered with their covertly shifting attention among subcategories in the fluency task, resulting in fewer names and clusters generated and longer times to access clusters.
AB - Two groups of non-demented individuals, who differed on genetic risk for Alzheimer's disease (AD) based on their apolipoprotein E (APOE) genotype, were tested on a category fluency task. Twenty ε4 carriers and twenty ε4 non-carriers were tape recorded while saying animal names for ten minutes. Five measures were examined: total names generated; total clusters; mean cluster size; mean within-cluster retrieval time; and mean between-cluster retrieval time. Groups were matched on age and education and scored as normal on a battery of psychometric tests. The ε4 carriers generated significantly fewer names and clusters, and took significantly longer to access clusters, when compared to the ε4 non-carriers. No group differences were found for cluster size or within-cluster retrieval times. We previously reported [Rosen, V. M., Bergeson, J. L., Putnam, K., Harwell, A., Sunderland, T. (2002). Working memory and apolipoprotein E: What's the connection? Neuropsychologia 40, 2226-2233] that the ε4 carriers in the present study scored significantly lower than the ε4 non-carriers on a measure of working memory/attentional capacity [Operation Span Task, see Turner, M. L., Engle, R. W. (1989). Is working memory capacity task dependent? Journal of Memory and Language 28, 127-154]. In the present study, a significant negative relationship found between span performance and between-cluster retrieval times suggested that reduced attentional capacity may have negatively impacted semantic access for the ε4 carriers. Finally, we found significant relationships between a Trail Making Test [Reitan, R. M. (1992). Trail Making Test, manual for administration and scoring. Tucson, AZ: Reitan Neuropsychology Laboratory] "switch" measure (Form B-Form A) and three of the five fluency measures. The findings suggested that the ε4 carrier's reduced attentional capacity may have interfered with their covertly shifting attention among subcategories in the fluency task, resulting in fewer names and clusters generated and longer times to access clusters.
KW - APOE
KW - Attention
KW - Retrieval
KW - Switching
KW - Working memory
UR - http://www.scopus.com/inward/record.url?scp=13844277058&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=13844277058&partnerID=8YFLogxK
U2 - 10.1016/j.neuropsychologia.2004.06.022
DO - 10.1016/j.neuropsychologia.2004.06.022
M3 - Article
C2 - 15716154
AN - SCOPUS:13844277058
SN - 0028-3932
VL - 43
SP - 647
EP - 658
JO - Neuropsychologia
JF - Neuropsychologia
IS - 4
ER -