Biomedical subjects

Emilio Ferrer

Publications and source records attributed to Emilio Ferrer.

5 recordsLinked to original sources

PubMed2005

Multivariate modeling of age and retest in longitudinal studies of cognitive abilities.

Longitudinal multivariate mixed models were used to examine the correlates of change between memory and processing speed and the contribution of age and retest to such change correlates. Various age- and occasion-mixed models were fitted to 2 longitudinal data sets of adult individuals (N>1,200). For both data sets, the results indicated that the correlation between the age slopes of memory and processing speed decreased when retest effects were included in the model. If retest effects existed in the data but were not modeled, the correlation between the age slopes was positively biased. The authors suggest that although the changes in memory and processing speed may be correlated over time, age alone does not capture such a covariation.

Age Factors↗

PubMed2004

Estimating retest effects in longitudinal assessments of cognitive functioning in adults between 18 and 60 years of age.

Several analyses were conducted on data from samples of adults between 18 and 58 years of age who completed the same cognitive tests after an interval ranging from less than 1 week to 35 years. Because the retest interval varied across individuals, it was possible to determine the length of time needed before the gains associated with a retest decreased to 0 and to obtain simultaneous estimates of the magnitude of effects associated with increased age and a prior assessment. The results indicated that for adults within this age range, 7 or more years were needed before positive retest effects were no longer detectable. Age effects in longitudinal comparisons could be interpreted in terms of large positive effects associated with a prior assessment and negative effects associated with age that were comparable in magnitude to those observed in cross-sectional comparisons.

Adolescent↗

PubMed2004

An experimental analysis of dynamic hypotheses about cognitive abilities and achievement from childhood to early adulthood.

This study examined the dynamics of cognitive abilities and academic achievement from childhood to early adulthood. Predictions about time-dependent "coupling" relations between cognition and achievement based on R. B. Cattell's (1971, 1987) investment hypothesis were evaluated using linear dynamic models applied to longitudinal data (N=672). Contrary to Cattell's hypothesis, a first set of findings indicated that fluid and crystallized abilities, as defined by the Woodcock-Johnson Psycho-Educational Battery-Revised (WJ-R; R. W. Woodcock & M. B. Johnson, 1989-1990), were not dynamically coupled with each other over time. A second set of findings provided support for the original predictions and indicated that fluid ability was a leading indicator of changes in achievement measures (i.e., quantitative ability and general academic knowledge). The findings of this study suggest that the dynamics of cognitive abilities and academic achievement follow a more complex pattern than that specified by Cattell's investment hypothesis.

Adolescent↗

PubMed2004

Modeling age and retest processes in longitudinal studies of cognitive abilities.

Mixed effects models were used to examine the separate effects associated with age and retest on changes in various cognitive abilities. Individuals (N > 800) ranging in age from 40 to 70 years at the 1st measurement occasion were assessed with measures of memory, spatial abilities, and speed on 4 occasions. All cognitive abilities showed decline associated with increased age and improvement across the 4 measurement occasions. The age-related effects were similar across variables, but the practice effects were largest for memory and smallest for speed. When retest effects were not included in the models, the age-related effects were underestimated, with the magnitude of bias depending on the size of the ignored retest effects. It is suggested that both age and retest should be modeled simultaneously when analyzing longitudinal data because part of the change across occasions may be attributable to practice or reactive effects.

Adult↗

PubMed2003

Modeling affective processes in dyadic relations via dynamic factor analysis.

An intraindividual variability design, including application of dynamic factor models, was used to examine the affective processes of a husband-wife dyad over 182 consecutive days. Structural equation analyses indicated differences in the affective structure between the husband and the wife, and these differences were characterized in terms of their factorial configuration and temporal organization. Examination of the dyad's affective dynamics revealed unidirectional (i.e., from the husband to the wife) interpersonal influences with a defined structure over time.

Adult↗