Response Time Inconsistency Research Articles

Aging-related changes in the association between negative affect and response time inconsistency in older adulthood

Negative affect (NA) and positive affect (PA) are established modifiable psychosocial correlates of cognitive health and have demonstrated capacity for meaningful within-person fluctuations based on person–environment interactions, age, and measurement approach. Previous research has shown NA is associated with increased response time inconsistency (RTI), an early performance-based indicator of cognitive health and aging. It is unclear, however, whether PA is associated with RTI and whether affect-RTI associations exist within persons over time or change as individuals get older. We utilized data from a measurement burst study (Cognition, Health, and Aging Project) to explore within- and between-person associations between affect and RTI in community-dwelling older adults (N = 111, M = 80.04 years, SD = 6.30). Affect and RTI were assessed on 6 days over a 2-week period, every 6 months for 2 years. Results revealed a significant association between NA-low arousal and RTI within persons over time. RTI was higher on sessions when NA-low arousal was higher than usual (b = .21, 95% CI [0.08, 0.35], p < .01). This association decreased in magnitude over time (b = −.09, 95% CI [−0.14, −0.03], p < .001), ultimately resulting in increased NA-low arousal being associated with decreased RTI 2 years later (b = −.14, 95% CI [−0.27, −0.01], p < .05). No PA-RTI associations emerged. The results suggest efforts focused on maximizing resource allocation and personalizing cognitive health efforts should consider for whom and when mitigating NA may be maximally beneficial to daily cognition, whereas additional work is needed to determine influences from PA.

Longitudinal changes in response time mean and inconsistency exhibit predictive dissociations for risk of cognitive impairment.

Although mean response time (RT) is a commonly used indicator of cognitive function, trial-to-trial variability (RT inconsistency [RTI]) represents a dissociable dimension of performance arguably more sensitive for characterizing cognitive status. The present study explores whether (a) RT mean or inconsistency reflects a more dispositional characteristic of an individual, particularly with increased cognitive impairment; (b) RT mean and inconsistency exhibit comparable patterns of change across a 4-year period; and (c) these rates of change differentially predict cognitive status. A sample of 304 adults (64-92 years) at baseline completed a choice RT task weekly for 4-5 weeks, repeating this protocol and a basic neuropsychological assessment annually for 4 years. Three cognitive status subgroups were identified at baseline and Year 4: healthy controls (HCs), as well as cognitively impaired-not-demented (CIND) status based upon single (CIND-S) and multiple (CIND-M) domains. RTI was disproportionately stable among cognitively compromised individuals at baseline, suggesting that increased RTI is a dispositional characteristic reflecting underlying changes in psychological process or neurological function. Notably, 4-year trajectories of change for RT mean versus RTI were dissociable; whereas the HC and CIND-S groups exhibited faster mean RTs over time, CIND-M individuals exhibited significant RTI increases. Multinomial logistic regressions demonstrated that greater RTI at baseline (OR = 2.58, p < .01) and steeper 4-year increases (OR = 4.40, p < .01) were linked to increased likelihood of CIND-M classification at Year 4, independent of age, education, chronic health conditions, and mean RT. RT mean and RTI confer distinct sources of information about cognitive function and status. Overall, RTI holds promise as an early indicator of normal and pathological cognitive aging. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Daily Stress Processes as Contributors to and Targets for Promoting Cognitive Health in Later Life.

The aim of this study was to test the hypothesis that daily stress processes, including exposure and emotional reactivity to daily stressors, are associated with response time inconsistency (RTI), an indicator of processing efficiency and cognitive health. Furthermore, we considered daily stress-cognitive health associations at the level of individual differences and within-persons over time. Participants were 111 older adults (mean = 80 years, range = 66-95 years) enrolled in a measurement burst study where assessments of response time-based cognitive performance, stressful experiences, and affect were administered on each of 6 days for a 2-week period. This protocol was repeated every 6 months for 2.5 years. Multilevel modeling was used to examine frequency of stressor exposure, nonstressor affect, and affect reactivity to daily stressors as individual difference and time-varying predictors of RTI. Between-persons, higher levels of nonstressor negative affect (b = 0.41, 95% confidence interval [CI] = -0.01 to 0.83, p = .055) and negative affect reactivity (b = 0.80, 95% CI = 0.18 to 1.42, p = .012) were associated with greater RTI. Within-persons over time, higher levels of negative affect (b = 0.20, 95% CI = 0.06 to 0.34, p = .006) and negative affect reactivity (b = 0.13, 95% CI = 0.02 to 0.24, p = .018) were associated with increased RTI among the oldest portion of the sample, whereas higher levels of positive affect (b = -0.11, 95% CI = -0.21 to -0.02, p = .019) were associated with reduced RTI. Negative affect reactions to daily stressors are associated with compromised RTI both between and within-persons. Findings suggest that emotional reactions to daily stressors contribute to compromise older adults' cognitive health, whereas increased positive affect may be beneficial.

Associations Between Control Beliefs and Response Time Inconsistency in Older Adults Vary as a Function of Attentional Task Demands.

Control beliefs are established correlates of cognitive aging. Despite recent demonstrations that response time inconsistency (RTI) represents a proxy for cognitive processing efficiency, few investigations have explored links between RTI and psychosocial correlates. We examined associations among RTI and control beliefs (perceived competence and locus of control) for two choice-response time (RT) tasks varying in their attentional demands. Control beliefs and RTI were measured weekly for 5 weeks in a sample of 304 community-dwelling older adults (Mage = 74.11 years, SD = 6.05, range = 64-92, 68.58% female). Multilevel models revealed that for the attentionally demanding task, reporting higher perceived competence than usual was associated with lower RTI for relatively younger participants and greater RTI for relatively older participants. For the less attentionally demanding task, reporting higher perceived competence than usual was associated with lower RTI for relatively older participants. Links between locus of control and RTI were comparatively scant. Our findings suggest that control beliefs may have adaptive and maladaptive influences on RTI, depending on dimension of control beliefs, individual differences in level of control beliefs and age, as well as attentional task demands. Both for whom and when control beliefs can be leveraged to optimize cognitive aging are discussed.

The influence of social support and perceived stress on response time inconsistency

ABSTRACTObjectives: Lack of social support and high levels of stress represent potentially modifiable risk factors for cognitive aging. In this study we examined the relationships between these two risk factors and response time inconsistency (RTI), or trial-to-trial variability in choice response time tasks. RTI is an early indicator of declining cognitive health, and examining the influence of modifiable psychosocial risk factors on RTI is important for understanding and promoting cognitive health during adulthood and old age.Methods: Using data from a community sample study (n = 317; Mage = 49, range = 19–83), we examined the effects of social support, including size of network and satisfaction with support, global perceived stress, and their interactions on RTI.Results: Neither size of network nor satisfaction with support was associated with RTI independent of perceived stress. Stress was positively associated with increased RTI on all tasks, independent of social support. Perceived stress did not interact with either dimension of social support to predict RTI, and perceived stress effects were invariant across age and sex.Conclusion: Perceived stress, but not social support, may be a unique and modifiable risk factor for normal and pathological cognitive aging. Discussion focuses on the importance of perceived stress and its impact on RTI in supporting cognitive health in adulthood and old age.

A Comprehensive Comparison of Quantifications of Intraindividual Variability in Response Times: A Measurement Burst Approach.

To formally identify and contrast the most commonly-employed quantifications of response time inconsistency (RTI) and elucidate their utility for understanding within-person (WP) and between-person (BP) variation in cognitive function with increasing age. Using two measurement burst studies of cognitive aging, we systematically identified and computed five RTI quantifications from select disciplines to examine: (a) correlations among RTI quantifications; (b) the distribution of BP and WP variation in RTI; and (c) the comparability of RTI quantifications for predicting attention switching. Comparable patterns were observed across studies. There was significant variation in RTI BP as well as WP across sessions and bursts. Correlations among RTI quantifications were generally strong and positive both WP and BP, except for the coefficient of variation. Independent prediction models indicated that slower mean response time (RT) and greater RTI were associated with slower attention switching both WP and BP. For selecting simultaneous prediction models, collinearity resulted in inflated standard errors and unstable model estimates. RTI reflects a novel dimension of performance that is a robust and theoretically informative predictor of BP and WP variation in cognitive function. Among the plenitude of RTI quantifications, not all are interchangeable, nor of comparable predictive utility.

PSYCHOSOCIAL STRESS AND RESPONSE TIME INCONSISTENCY IN OLD AGE: A MEASUREMENT BURST APPROACH

Psychosocial stress has been identified as an important modifiable risk factor for normal and pathological cognitive aging. Evidence exists showing psychosocial stress predicting poorer performance across multiple cognitive domains (e.g., working memory), with limited research considering stress effects on response time inconsistency (RTI). Using data from a measurement burst design, 111 older adults (Mage=80, Range=66–95) completed a processing speed task on 6 occasions over a 14-day period, repeating this protocol every 6 months for 2.5 years. Participants also completed measures of daily and perceived stress. Results from multilevel models revealed that individual differences in emotional (affect) and psychosomatic (pain) reactions to daily stressors and global perceptions of stress were associated with greater RTI (ps<.001). Additionally, these associations increased with age (p<.01). Discussion will focus on the importance of different dimensions of psychosocial stress for understanding cognitive aging, and the utility of measurement burst designs for examining stress-RTI links.

Cognitively-Impaired-Not-Demented Status Moderates the Time-Varying Association between Finger Tapping Inconsistency and Executive Performance.

Response time inconsistency (RTI) in cognitive performance predicts deleterious health outcomes in late-life; however, RTI estimates are often confounded by additional influences (e.g., individual differences in learning). Finger tapping is a basic sensorimotor measure largely independent of higher-order cognition that may circumvent such confounds of RTI estimates. We examined the within-person coupling of finger-tapping mean and RTI on working memory, and the moderation of these associations by cognitive status. A total of 262 older adults were recruited and classified as controls, cognitively-impaired-not-demented (CIND) unstable or CIND stable. Participants completed finger-tapping and working-memory tasks during multiple weekly assessments, repeated annually for 4 years. Within-person coupling estimates from multilevel models indicated that on occasions when RTI was greater, working-memory response latency was slower for the CIND-stable, but not for the CIND-unstable or control individuals. The finger-tapping task shows potential for minimizing confounds on RTI estimates, and for yielding RTI estimates sensitive to central nervous system function and cognitive status.

Staying on Task: Age-Related Changes in the Relationship Between Executive Functioning and Response Time Consistency.

Little is known about the relationship of executive functioning with age-related increases in response time (RT) distribution indices (intraindividual standard deviation [ISD], and ex-Gaussian parameters mu, sigma, tau). The goals of this study were to (a) replicate findings of age-related changes in response time distribution indices during an engaging touch-screen RT task and (b) investigate age-related changes in the relationship between executive functioning and RT distribution indices. Healthy adults (24 young [aged 18-30], 24 young-old [aged 65-74], and 24 old-old [aged 75-85]) completed a touch-screen attention task and a battery of neuropsychological tests. The relationships between RT performance and executive functions were examined with structural equation modeling (SEM). ISD, mu, and tau, but not sigma, increased with age. SEM revealed tau as the most salient RT index associated with neuropsychological measures of executive functioning. Further analysis demonstrated that correlations between tau and a weighted executive function composite were significant only in the old-old group. Our results replicate findings of greater RT inconsistency in older adults and reveal that executive functioning is related to tau in adults aged 75-85. These results support literature identifying tau as a marker of cognitive control, which deteriorates in old age.

Intraindividual variability is related to cognitive change in older adults: Evidence for within-person coupling.

In this study, the authors addressed the longitudinal nature of intraindividual variability over 3 years. A sample of 304 community-dwelling older adults, initially between the ages of 64 and 92 years, completed 4 waves of annual testing on a battery of accuracy- and latency-based tests covering a wide range of cognitive complexity. Increases in response-time inconsistency on moderately and highly complex tasks were associated with increasing age, but there were significant individual differences in change across the entire sample. The time-varying covariation between cognition and inconsistency was significant across the 1-year intervals and remained stable across both time and age. On occasions when intraindividual variability was high, participants' cognitive performance was correspondingly low. The strength of the coupling relationship was greater for more fluid cognitive domains such as memory, reasoning, and processing speed than for more crystallized domains such as verbal ability. Variability based on moderately and highly complex tasks provided the strongest prediction. These results suggest that intraindividual variability is highly sensitive to even subtle changes in cognitive ability.

Sustained attention deficits in manic and euthymic patients with bipolar disorder

Sustained attention deficits are proposed to be both state and trait indicators of bipolar disorder. The nature of these deficits and their association with medication and symptoms is not clear yet. The aim of this study was to investigate the impairments in various components of sustained attention task in euthymic and manic patients and was to investigate the relationship between the deficits in the manic state and medication effects. The performances of 37 manic patients, 34 euthymic patients with bipolar disorder and 34 control subjects on eight scores from Conners' CPT II, reflecting three different dimensions of sustained attention were compared. Similar to some recent findings, euthymic patients had decreased target sensitivity (omission errors) and response time inconsistency. The increased false responding (commission errors), perseveration and vigilance deficits were prominent in the manic patients. These state dependent impairments could not be explained by the impact of medication. In contrast, the exacerbation of seemingly trait-related impairments in the manic state can be at least partly explained by the impact of pharmacological therapy.