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Abstract
We manipulated categorical typicality and the presence of conflicting information as participants categorized multifeatured artificial animals. In Experiment 1, rule-irrelevant features were correlated with particular categories during training. In the test phase, participants applied a one-dimensional rule to stimuli with rule-irrelevant features that were category-congruent, category-incongruent, or novel. Category-incongruent and novel features delayed RT and P3 latency, but had no effect on the N2. Experiment 2 used a two-dimensional rule to create conflict between rule-relevant features. Conflict resulted in prolonged RTs and larger amplitudes of a prefrontal positive component, but had no impact on the N2. Stimuli with novel features did elicit a larger N2 than those with frequent features. These results suggest limitations on the generality of the N2's sensitivity to conflicting information while confirming its sensitivity to attended visual novelty.
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Braverman ER, Chen TJH, Prihoda TJ, Sonntag W, Meshkin B, Downs BW, Mengucci JF, Blum SH, Notaro A, Arcuri V, Varshavskiy M, Blum K. Plasma growth hormones, P300 event-related potential and test of variables of attention (TOVA) are important neuroendocrinological predictors of early cognitive decline in a clinical setting: evidence supported by structural equation modeling (SEM) parameter estimates. Age (Dordr) 2007; 29:55-67. [PMID: 19424831 PMCID: PMC2267660 DOI: 10.1007/s11357-007-9030-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2006] [Revised: 02/13/2007] [Accepted: 02/26/2007] [Indexed: 05/27/2023]
Abstract
A review of the literature in both animals and humans reveals that changes in sex hormone have often been associated with changes in behavioral and mental abilities. Previously published research from our laboratory, and others, provides strong evidence that P300 (latency) event-related potential (ERP), a marker of neuronal processing speed, is an accurate predictor of early memory impairment in both males and females across a wide age range. It is our hypothesis, given the vast literature on the subject, that coupling growth hormones (insulin-like growth factor-I, (IGF-I) and insulin-like growth factor binding protein 3 (IGF-BP3)), P300 event-related potential and test of variables of attention (TOVA) are important neuroendocrinological predictors of early cognitive decline in a clinical setting. To support this hypothesis, we utilized structural equation modeling (SEM) parameter estimates to determine the relationship between aging and memory, as mediated by growth hormone (GH) levels (indirectly measured through the insulin-like growth factor system), P300 latency and TOVA, putative neurocognitive predictors tested in this study. An SEM was developed hypothesizing a causal directive path, leading from age to memory, mediated by IGF-1 and IGF-BP3, P300 latency (speed), and TOVA decrements. An increase in age was accompanied by a decrease in IGF-1 and IGF-BP3, an increase in P300 latency, a prolongation in TOVA response time, and a decrease in memory functioning. Moreover, independent of age, decreases in IGF-1 and IGF-BP3, were accompanied by increases in P300 latency, and were accompanied by increases in TOVA response time. Finally, increases in P300 latency were accompanied by decreased memory function, both directly and indirectly through mediation of TOVA response time. In summary, this is the first report utilizing SEM to reveal the finding that aging affects memory function negatively through mediation of decreased IGF-1 and IGF-BP3, and increased P300 latency (delayed attention and processing speed).
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Affiliation(s)
| | - Thomas J. H. Chen
- Chang Jung Christian University, Taiwan, People’s Republic of China
- Changhua Christian Hospital, Changhua, Taiwan People’s Republic of China
| | - Thomas J. Prihoda
- Department of Pathology, University Of Texas Health Science Center, San Antonio, Texas USA
| | - William Sonntag
- Department of Physiology & Pharmacology, Wake Forest University School Of Medicine, Winston-Salem, North Carolina USA
| | - Brian Meshkin
- Department of Molecular Nutrition & Nutrigenomics, Salugen, Inc., San Diego, California USA
| | - B. William Downs
- Natural Products Division & Research, Allied Nutraceutical Research, Lederach, Pennsylvania USA
| | - Julie F. Mengucci
- Department of Psychoneurogenetics, Synaptamine, Inc., San Antonio, Texas USA
| | - Seth H. Blum
- Department of Psychoneurogenetics, Synaptamine, Inc., San Antonio, Texas USA
| | - Alison Notaro
- PATH Research Foundation, New York, NY USA
- Cleveland Clinic, Toronto, Ontario Canada
| | | | | | - Kenneth Blum
- PATH Research Foundation, New York, NY USA
- Department of Physiology & Pharmacology, Wake Forest University School Of Medicine, Winston-Salem, North Carolina USA
- Department of Molecular Nutrition & Nutrigenomics, Salugen, Inc., San Diego, California USA
- Department of Psychoneurogenetics, Synaptamine, Inc., San Antonio, Texas USA
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