Analysis of individual variability among older adults on the Stroop Color Word Interference Test

Evaluating the effects of episodic and semantic memory induction procedures on divergent thinking in younger and older adults

Evidence suggesting that episodic specificity induction improves divergent thinking performance in younger and older adults has been taken as indicative of the role of declarative memory processes in creativity. A series of studies were carried out to verify the specificity of such findings by investigating the effects of several novel episodic and semantic memory induction procedures on a widely employed measure of divergent creative thinking (the Alternate Uses Task), in comparison to a control induction and a no-induction baseline in both younger and older adults. There was no clear evidence for a specific role played by the induction of episodic or semantic memory processes in facilitating creative thinking across the three experiments, and the effects of the induction procedures (episodic, semantic and control) on divergent thinking were not comparable across age groups. On the other hand, higher levels of creativity were generally associated with older adults (60-80 years). In Experiments 2 and 3, older adults generated a greater number of responses (fluency), more unique responses (average originality, peak originality, creativity ratings) and more varied responses (flexibility) than younger adults (18-30 years). The findings are discussed in relation to the specificity of declarative memory operations and their impact on creative thinking, especially within the context of healthy ageing.

Factors affecting ambulatory status and survival of patients 90 years and older with hip fractures

This study was done to assess the long-term functional outcome of very elderly patients with hip fractures, to determine whether bone mineral density and prevalent vertebral fractures could affect mortality and ambulatory status, and to examine which patient characteristics reported in the literature are predictive of patient mortality and ambulatory status. Seventy-four patients 90 years and older with hip fractures were analyzed and followed up for at least 4 years or until death. The mean age of the patients was 92.8 years and all were treated surgically. Walking ability before injury was better than at discharge; walking ability decreased during the first year after discharge, but thereafter reached a plateau. The predictors of survival were the preoperative American Society of Anesthesiologists score, walking ability, fracture type, type of surgery, and the number of prevalent vertebral fractures on admission. Dementia and the number of prevalent vertebral fractures were predictors of the recovery of walking ability. Type of surgery and fracture type are collinear variables, and because it is difficult to separate the effects of one versus the other, additional well-designed, randomized studies on the effect of the type of surgery and fracture type on outcome are needed.

LEVEL OF EVIDENCE

Prognostic study, Level II-1 (retrospective study). See the Guidelines for Authors for a complete description of levels of evidence.

Color-Word Stroop test performance across the adult life span

In the Color-Word Stroop test (CWST), the basic task is to name the ink color of rows of XXXs, and performance in this condition is compared with performance in naming the ink-color of color words under conditions where word meanings and ink colors mismatch or are incongruent (e.g., the word red printed in green ink). The present study investigated whether Stroop test interference, defined as the cost associated with ink-color naming in the incongruous stimulus condition versus in the basic color-naming condition, provides positive evidence for a kind of processing qualitatively different than that which is required for color naming or for word reading. Does the pattern of age-related differences in Stroop interference force the conclusion that the incongruous condition taps a qualitatively different kind of processing than that required for color naming or for word reading? We gave the CWST to 310 healthy adults. Their performance in each condition of the test replicates and extends previous findings. Structural equation modeling of the data showed a significant, direct link between age and performance in the latent factor associated with the incongruent condition. However, this direct link with age produced a relatively small increase in the model's fit; it amounted to only a .024 increase in the proportion of variance explained in the incongruent condition. In light of this small direct influence due to age, the most parsimonious explanation of our findings is that age effects in Stroop interference are due to age-related slowing (which is also indexed by color naming and by word reading) primarily; the findings do not provide evidence for a qualitatively different kind of processing that declines with age.

Effect of test duration on age-related differences in Stroop interference

The effect of test duration on age-related differences in Stroop interference was assessed in a large cross-sectional study involving 429 healthy subjects in four age groups (25-35 years, 40-50 years, 55-65 years, 70-80 years). The results show a clear effect of test duration on Stroop interference. The Stroop Color Word Test was run in two parts. The young group performed the first part relatively rapidly but became slower in the second part, whereas the old group showed the reverse effect. The two middle-aged groups did not show differences between the first and second parts of the test. The results are interpreted in terms of a deficit in response inhibition by a controlled processing strategy. A psychological interpretation of the study findings in terms of increased cautiousness appears less probable. The first part of the test, that is, an abridged version of the test, may prove superior to the regular version for both clinical and research purposes.

Color- and picture-word Stroop tests: performance changes in old age

The Stroop test comes in different variations, but all of them index performance on a basic task, like color or picture naming, when it is carried out by itself versus when it is performed in the presence of conflicting or incongruent stimuli. The present study examined the hypothesis that Stroop interference--the cost of performing one task in the presence of another--is a general as opposed to a test-specific index of cognitive flexibility. A second goal was to examine changes in Stroop test performance in old age. A group of 129 healthy older adults (> or = 65 years of age) were assessed on the color- and picture-word Stroop test, as well as on a battery of neuropsychological tests. Subjects' performance on each card of both Stroop tests, and various derived (differences and ratios) scores, were used to prepare age-group norms. The use of the norms is illustrated with findings from previous studies. Regression analyses showed age-changes in several aspects of Stroop test performance. Hierarchical multiple regression analyses, and causal modeling showed an age effect on Stroop interference only on the picture-word test but not on the color-word test. Exploratory factor analysis of the Stroop data and the neuropsychological test data revealed different factor loadings for the color- and picture-word test. The combined findings suggest that the color- and picture-word Stroop test measure different cognitive functions, at least in old age.