Executive Functions in relation to Autonomic Control: An Overview of Neuropsychological Evaluation Methods

Executive functions are a set of cognitive processes essential for cognitive control and coordination, enabling the achievement of objectives. These functions include mental exploration of ideas, reasoning, logical conclusion drawing, discipline, decision making, thoughtful consideration before action, tackling unforeseen challenges, resisting temptations, and maintaining focus. Numerous neuropsychological tests assess executive functions in relation to different autonomic control pathways that regulate involuntary physiological processes.

The complexity of the autonomic nervous system and the challenges in measuring it alongside cognitive assessments are significant. Issues such as subject movement, environmental changes, and time-consuming protocols further complicate this measurement. There is a notable lack of research on suitable neuropsychological tests for assessing executive functions across diverse autonomic regulatory states. This paper reviews the most frequently used neuropsychological instruments in this context, aiming to guide the research community towards optimal tasks and administration protocols for concurrent autonomic nervous system measurement.

The diversity of current executive function tests presents both opportunities and challenges. Some tests are better suited for simultaneous neurophysiological measurements due to their design, duration, and cognitive load, while others may interfere with or be influenced by such monitoring. This variability can lead to inconsistencies in findings and complicate result interpretation and comparison across studies of brain disorders. A significant drawback of using different tasks is the difficulty in comparing outcomes and conducting meta-analyses.

Standardizing a smaller selection of tasks with consistent protocols would enhance research reliability, facilitate robust comparisons, and improve the overall quality of meta-analyses. To achieve this standardization, it is essential to first survey and describe the current landscape of executive function assessments in conjunction with autonomic nervous system measurements.

Objective

This paper aims to comprehensively analyze current instruments utilized in the assessment of executive functions, elucidating their advantages, limitations, and implications for future standardization initiatives. By systematically examining the most prevalent tools for evaluating executive functions in conjunction with autonomic nervous system measurements within clinical and experimental research settings, this review seeks to provide valuable insights for enhancing methodological consistency and advancing research in this area.

Methods

We searched for articles published using the PubMed database with the following terms: (neuropsychological test OR neuropsychological evaluation OR neuropsychological measure*) AND (executive functions OR EF OR executive function) AND (autonomic OR ANS OR parasympathetic OR PNS OR vagal OR “heart rate variability” OR HRV OR sympathetic OR HPA OR electrodermal OR RSA)

Only the healthy population was chosen. There was no language restriction.

Results

62 articles fulfilled all the inclusion criteria. The 5 neuropsychological tests most frequently used to evaluate executive functions in relation to autonomic regulation were:

Trail Making Test (TMT) B

The n-back Task including 2-back Task

Wisconsin Card Sorting Test

Stroop Test and its variants

Wechsler Adult Intelligence Scale (WAIS)-Working Memory Composite

The domains of executive functions most frequently assessed are: cognitive flexibility, working memory, and inhibitory control/selective attention.

Conclusion

These findings offer valuable insights for future research directions and the development of standardized assessment protocols for executive functions, tailored to diverse socio-demographic profiles.