The Push-Turn-Taptap task outperforms measures of executive functioning in predicting declines in functionality: evidence-based approach to test validation.

Performance on the Push-Turn-Taptap (PTT) task has been shown to be a strong predictor of concurrent everyday functioning. This study utilized a prospective, longitudinal design to evaluate the PTT task for predicting future performance on a behavioral assessment of everyday functioning. The PTT task was compared to other measures of executive functioning as well as general cognition in terms of administration time and ability to identify participants who evidenced functional decline. A total of 50 community-dwelling older adults (ages 58-87) completed the PTT task, Mattis Dementia Rating Scale, Geriatric Depression Scale, Behavioral Dyscontrol Scale, Delis-Kaplan Executive Function System, and Timed Instrumental Activities of Daily Living. Baseline PTT performance (a) was highly correlated with an objective measure of everyday functioning after approximately one year (r = -.497, p < .001), (b) was associated with changes in follow-up functioning, F(3, 46) = 3.15, p = .03, (c) was a better predictor of future functional status than a longer battery of EF, and (d) reliably identified individuals with the greatest magnitude of functional decline. The PTT tasks may provide a particularly advantageous method of predicting future changes in everyday functioning in older adults.

Executive functioning, motor programming, and functional independence: accounting for variance, people, and time.

Assessing functional independence is an important part of making diagnostic decisions and treatment recommendations but is often complicated by the limitations of self-report and behavioral measures. Alternatively, it may be worthwhile to investigate neurocognitive correlates of incipient functional declines including using tests of executive functioning (EF) and motor programming (MP). The current study examined an electronic MP task and pitted it against other assessment instruments to evaluate its relative utility in assessing both EF and functional independence. Participants were 72 community-dwelling older adults. Results of this study showed that the MP task was correlated with other measures of EF, an efficient and reliable predictor of functionality, useful for identifying at-risk patients, and comparable to a longer battery in terms of sensitivity and specificity.

Practice effect and beyond: reaction to novelty as an independent predictor of cognitive decline among older adults.

Practice Effects (PE) have been gaining interest as an early marker of pathological cognitive decline among older adults, with cognitively compromised individuals exhibiting diminished or absent PE, presumably due to reduced ability to learn. However, the opposite pattern has also been observed, with MCI participants showing larger PEs than controls. In this prospective cohort study, we examined the possibility that individuals with incipient cognitive decline may be more "thrown" by task novelty, which may inflate PE due to diminished performance during the first exposure to the task. We assessed Novelty Effect (NE) and Learning (LRN) on a motor task in 50 community-dwelling independent older adults who expressed a concern about their cognition. Results showed that larger NE was associated with greater cognitive decline 17 months later, reliably classifying participants into decliners and nondecliners. LRN did not independently explain any variance in future cognitive change, but moderated the relationship between NE and decline and correlated with the level of cognition at baseline and follow-up. These findings highlight the differing contributions of NE and LRN to PE, and demonstrate that NE may be sensitive to depletion of cognitive reserve among individuals who are on the verge of exhibiting a reliable cognitive decline.

Instrumental activities of daily living among community-dwelling older adults: discrepancies between self-report and performance are mediated by cognitive reserve.

The ability to engage in instrumental activities of daily living (IADLs) is known to rely on cognitive abilities, primarily executive functioning and memory. There is also evidence that good self-awareness, which facilitates the use of compensatory strategies, may prolong functionality and delay the diagnosis of dementia. However, little is known about the mechanisms that mediate self-awareness among healthy elderly. The present study examined the correlates of discrepancies between self-report and performance-based measures of IADLs in a sample of 75 community-dwelling elderly. The results indicate that even among independently living individuals, there is still variability in functionality (i.e., 35% of the sample made IADL performance errors) and self-awareness (i.e., 38% of the sample demonstrated a discrepancy between IADL self-report and performances). Better awareness of IADL weaknesses was associated with higher levels of cognitive reserve but, unexpectedly, lower levels of executive abilities. Additionally, consistent with prior research, better IADL performances were associated with better cognition.

Instrumental activities of daily living among community-dwelling older adults: personality associations with self-report, performance, and awareness of functional difficulties.

Self-reports of the ability to engage in instrumental activities of daily living (IADLs) among older adults are known to be related to personality traits. However, self-reports are sometimes discrepant with performance-based IADL assessments, and little is known about personality associations with objective functionality or with poor insight about functional deficits. This study examined the NEO Personality Inventory-Revised profiles associated with (a) self-report of functional problems, (b) functional errors evidenced on performance-based IADL assessment, and (c) discrepancies between self-report and performance. Participants were 65 community-dwelling individuals ranging in age from 60 to 87 years. The results showed that self-report of IADL problems are associated with higher neuroticism and lower conscientiousness, actual IADL difficulties with higher neuroticism and lower agreeableness and openness to experience, underreporting of problems with higher conscientiousness, and overreporting of problems with higher extraversion and neuroticism. These relationships were partly mediated by age, education, and cognitive status. When unique personality associations with self-report and performance were examined, neuroticism and agreeableness, respectively, emerged as the strongest predictors.

Understanding design fluency: motor and executive contributions.

Design Fluency (DF) is typically assumed to assess planning, cognitive flexibility, and fluency in generation of visual patterns, above and beyond contributions from motor speed (Delis, Kaplan, & Kramer, 2001; Ruff, 1998). The present study examined these assumptions, as little construct validation research has been done in the past. Sixty one community-dwelling elderly participants were administered the DF, Trail Making, and Letter Fluency tests from the Delis-Kaplan Executive Function System (D-KEFS), as well as electronically administered measures of motor planning and motor sequence fluency. Hierarchical regressions were used to parse out unique variance contributions to DF performance. The results showed that generation of novel designs (i.e., the first two trials on the D-KEFS DF) relied primarily on motor planning, the ability to generate novel motor actions, and, to a lesser extent, speed of drawing with a writing implement. In contrast, generation of unique designs while switching (i.e., the third trial on the D-KEFS DF) relied primarily on visual scanning and perhaps visual-attentional resources. These findings highlight the wisdom of interpreting the switching trial of the D-KEFS DF separately. Interestingly, cognitive flexibility did not contribute to performance on any of the three D-KEFS DF trials.

Evaluating the role of motor regulation in figural fluency: partialing variance in the Ruff Figural fluency test.

Figural fluency is often thought to assess the ability to "think fluently and flexibly in the visual-spatial mode" (Ruff, 1988). However, the contribution of motor regulation to the performance of this task has not been previously examined. The goal of this study was to evaluate the potential relationship between motor sequence fluency (without a visual-spatial component) and figural fluency. A total of 55 participants (ages 18 to 68 years) were administered (a) the Ruff Figural Fluency Task (RFFT), (b) the Trail Making Test Part B (TMT-B), which overlaps with the RFFT in visual tracking and graphomotor demands, (c) an electronically administered Motor Sequence Fluency Test (MSFT), which overlaps with the RFFT in generation of novel hand movements in the absence of visual stimuli, and (d) a Complex Motor Programming Task. Hierarchical regression analyses were used to determine whether complex motor programming uniquely contributes to RFFT performance above and beyond the processes that are traditionally assumed to be required, as well as to determine whether the ability to generate novel motor sequences uniquely contributes to RFFT performance. Age and education were also added to the regression models in order to determine the contribution of demographic variables to the current findings. Results indicated that age, specific components of motor programming, and nonvisual motor generative fluency represent the most prominent predictors of RFFT performance. Consequently, the role of motor regulation and motor flexibility may in fact be more important for RFFT performance than previously thought, whereas visual-spatial processing may play a lesser role.