Development and Validation of the State-Trait Inventory of Cognitive Fatigue in Community-Dwelling Older Adults

Automatic Cognitive Fatigue Detection Using Wearable fNIRS and Machine Learning

Wearable sensors have increasingly been applied in healthcare to generate data and monitor patients unobtrusively. Their application for Brain-Computer Interfaces (BCI) allows for unobtrusively monitoring one's cognitive state over time. A particular state relevant in multiple domains is cognitive fatigue, which may impact performance and attention, among other capabilities. The monitoring of this state will be applied in real learning settings to detect and advise on effective break periods. In this study, two functional near-infrared spectroscopy (fNIRS) wearable devices were employed to build a BCI to automatically detect the state of cognitive fatigue using machine learning algorithms. An experimental procedure was developed to effectively induce cognitive fatigue that included a close-to-real digital lesson and two standard cognitive tasks: Corsi-Block task and a concentration task. Machine learning models were user-tuned to account for the individual dynamics of each participant, reaching classification accuracy scores of around 70.91 ± 13.67 %. We concluded that, although effective for some subjects, the methodology needs to be individually validated before being applied. Moreover, time on task was not a particularly determining factor for classification, i.e., to induce cognitive fatigue. Further research will include other physiological signals and human-computer interaction variables.

Mental Load and Fatigue Assessment Instruments: A Systematic Review

Mental load and fatigue are important causes of performance decreases and accidents in different activities. However, a robust systematic review, detailing the instruments used to quantify them, is currently lacking. The purpose of this study was to summarize and classify by derivations the validated instruments used to quantify mental load and fatigue. The most representative electronic databases in the scope of this review, PubMed, WOS, Scopus, SPORTDiscus, and PsycINFO (until September 2020) were searched for studies that included instruments to analyze mental load and fatigue. The quality of the selected studies was scored using a quality assessment checklist. A total of 40 papers were included. Most of the papers used subjective scales (75%) to quantify mental load and fatigue, with a small presence of behavioral (n = 5) and objective techniques (n = 5). Less is known about the analysis of mental load and fatigue using a combination of derivations. Despite the high cost and complexity of objective techniques, research that applies these measures is important for further analysis of brain processes in mental load and fatigue. The design of a battery of tests that include the three types of derivations also seems necessary.

Fatigue in community-dwelling older adults: A review of definitions, measures, and related factors

Fatigue is a common age-related symptom among community-dwelling adults aged 65 years and older. Yet, a systematic approach has rarely been applied to review definitions, measures, related factors, and consequences of fatigue in this population. A scoping review was conducted in December 2020 to fill the gap, and 36 articles met the inclusion criteria. Definitions, albeit diverse, included at least one of the following attributes: an early indicator of disablement, subjective, a lack of energy, multidimensional, impaired daily activities, and temporal. A summary of fatigue measures used in this population was provided, including a brief overview, number of items, reliability, and validity. In general, different measures were used with considerable variability in the content. Additionally, most measures had limited information on test-retest reliability and validity. Fatigue-related factors mapped into biological, psychological, social, and behavioral factors. Fatigue consequences were primarily declines in physical and cognitive functions. (100-150 words).

Validation of Perceived Mental Fatigability Using the Pittsburgh Fatigability Scale

OBJECTIVES

Establish reliability, concurrent and convergent validity of the Pittsburgh Fatigability Scale (PFS) Mental subscale.

DESIGN

Cross-sectional.

SETTING

Older adults from two University of Pittsburgh registries, Baltimore Longitudinal Study of Aging (BLSA), and Long Life Family Study (LLFS).

PARTICIPANTS

PFS Mental subscale validation was conducted using three cohorts: (1) Development Sample (N = 664, 59.1% women, age 74.8 ± 6.4 years, PFS Mental scores 10.3 ± 9.1), (2) Validation Sample I-BLSA (N = 430, 51.9% women, age 74.5 ± 8.2 years, PFS Mental scores 9.4 ± 7.9), and (3) Validation Sample II-LLFS (N = 1,917, 54.5% women, age 72.2 ± 9.3 years, PFS Mental scores 7.5 ± 8.2).

MEASUREMENTS

Development Sample, Validation Sample I-BLSA, and Validation Sample II-LLFS participants self-administered the 10-item Pittsburgh Fatigability Scale. Validation Sample II-LLFS completed cognition measures (Trail Making Tests A and B), depressive symptomatology (Center for Epidemiologic Studies-Depression Scale, CES-D), and global fatigue from two CES-D items.

RESULTS

In the Development Sample and Validation Sample I-BLSA, confirmatory factor analysis showed all 10 items loaded on two factors: social and physical activities (fit indices: SRMSR = 0.064, RMSEA = 0.095, CFI = 0.91). PFS Mental scores had strong internal consistency (Cronbach's α = 0.85) and good test-retest reliability (ICC = 0.78). Validation Sample II-LLFS PFS Mental scores demonstrated moderate concurrent and construct validity using Pearson (r) or Spearman (ρ) correlations against measures of cognition (Trail Making Tests A (r = 0.14) and B (r = 0.17) time), depressive symptoms (r = 0.31), and global fatigue (ρ = 0.21). Additionally, the PFS Mental subscale had strong convergent validity, discriminating according to established clinical or cognitive testing cut points, with differences in PFS Mental scores ranging from 3.9 to 7.6 points (all P < .001). All analyses were adjusted for family relatedness, field center, age, sex, and education.

CONCLUSIONS

The validated PFS Mental subscale may be used in clinical and research settings as a sensitive, one-page self-administered tool of perceived mental fatigability in older adults.

Motivation in multiple sclerosis cognitive fatigue: An experimental approach

Introduction: Cognitive fatigue is a common symptom in multiple sclerosis (MS). Recent research has implicated dopaminergic pathways originating in the basal ganglia as neurological correlates of cognitive fatigue in MS. This same system has long been associated with goal-directed behavior and reward-based motivation. While researchers have demonstrated that reward has a reliable impact on performance in tasks of sustained attention in healthy individuals, the effect of reward on fatigue is less clear, as prior research has not adequately controlled for desensitization to reward in a sustained attention task. The primary aims of this study were to examine the effect of reward on attention in MS patients, and to examine the effect of reward on objective cognitive fatigue. Method: The study employed a 3 × 3 repeated measures design to evaluate performance of N = 64 patients with definite MS on a measure of cognitive fatigue across several reward conditions. The study utilized a novel delayed-reward paradigm to better control the measured effect of reward on fatigue. Results: Reward (main effect) displayed a significant effect on overall performance (F = 3.050, p < .05). Reward was also shown to affect fatigue trajectory (Reward × Interval, F = 2.433, p < .05). However, this effect was dependent on the method of reward administration. Conclusions: Study findings support the role of motivation in MS cognitive performance, particularly in objective cognitive fatigue, a behavioral finding that is consistent with current neuropsychological theory. Study findings support the delayed-reward paradigm as an effective method for measuring reward effect on tasks of sustained attention.