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Further Implications of Mundy-Castle's Correlations Between EEG and Wechsler-Bellevue Variables EEG

Saunders, David R.
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Report Number:
ETS Research Bulletin
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Subject/Key Words:
Society for the Investigation of Human Ecology, Age Differences, Electroencephalograph (EEG), Employment Level, Factor Structure, Intelligence, Wechsler Bellevue Intelligence Scale


Factor analysis is re-applied, using relatively more rigorous methods, to a 15 x 15 correlation matrix reported by Mundy-Castle and containing 11 Wechsler-Bellevue subtest variables, 2 EEG variables, age and occupational level, for a sample of 34 employees of the South African National Institute for Personnel Research. Six common factors were extracted and subjected to orthogonal rotation in search of meaningful simple structure. Two age-related factors were found and respectively identified as "Experience" and "Deterioration." (Factors I and II.) Within the residual four-space, the vectors for alpha Frequency in the EEG and Digit Span performance in the W-B were found to be comparable. (Factor III.) This result is discussed in relation to the excitability cycle hypothesis, primary vs. secondary function, and externalization vs. internalization. The vector for alpha Index was found to have a near perfect communality in the residual three-space, and is interpreted as measuring (inversely) strength of "Conditioned Attentiveness." (Factor IV.) Picture Completion in the W-B is judged to depend partially on this factor. It is suggested that a proper interpretation for common factors, when there have not been enough variables to preclude the existence of specific factors, is in terms of dynamic mechanisms presumptive of a cause-effect relationship between loaded variables, rather than in terms of hypothetical underlying variables. Factors I, IV, and V can be used to illustrate this principle.

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