Processing speed has a significant effect on both letter and category fluency in older adults, while IQ does not¶
Claim · All claims
Evidence · 1 study · associationalr2·q3
Currency · newest study 2011 · not yet checked against its sources · not reviewed by a person
Subclaims¶
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q3 i? In ANCOVA models, processing speed significantly affected both fluency measures, but the effect of full-scale IQ (NART) was not significant for either fluency measure. → Safa A. Elgamal 2011
Evidence¶
Safa A. Elgamal 2011¶
Safa A. Elgamal, MBBCh, PhD, Eric A. Roy, PhD, Michael T. Sharratt, PhD. (2011). Age and Verbal Fluency: The Mediating Effect of Speed of Processing. Canadian Geriatrics Journal, Volume 14, Issue 3. https://doi.org/10.5770/cgj.v14i3.17
q3 · i? · associational · r2
Univariate ANCOVAs on letter and category fluency controlling for NART and the processing speed composite; Table 4 reports effect of speed p < .001 (letter) and p = .002 (category), with NART effects non-significant (p = .09 and p = .25). The MANCOVA confirmed "the effect of speed was significant (p = .001)" while IQ remained insignificant (p = .24).
"The two models showed that processing speed had a significant effect on both fluency measures; however, the effect of IQ was not significant (Table 4)."
Discussion¶
Related Claims¶
- Young adults outperform older adults on category fluency and processing speed, while older adults outperform young adults on premorbid IQ (NART) — related
- Category fluency declines with age and remains significantly impaired after controlling for processing speed and IQ — related
- Curve estimation shows linear decline in processing speed after age 30, quadratic trajectories for category fluency and IQ, and no age change in letter fluency — related
- Letter fluency shows no age-group difference in ANOVA, but older adults outperform young adults once processing speed and IQ are controlled — reports the opposite
- Age correlates negatively with processing speed and category fluency and positively with IQ, but not with letter fluency — related
- Decline in letter fluency beyond normal age expectations warrants further evaluation for neurological or mental disorder — related
Page metadata
| Field | Value |
|---|---|
type |
claim |
id |
processing-speed-significant-covariate-both-fluencies |
title |
Processing speed has a significant effect on both letter and category fluency in older adults, while IQ does not |
description |
Processing speed has a significant effect on both letter and category fluency in older adults, while IQ does not |
status |
review |
evidence_strength |
moderate |
newest_evidence |
2011 |
generated |
by process:wiki-ingest on 2026-10-17 |
trust |
unverified — no one has confirmed this page's content |
sources |
1 — safa-a-elgamal-2011 |
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