Short answer

For assessments requiring rapid cognitive processing and reaction, ensure the testing environment minimizes mental fatigue or that fatigue is accounted for in the analysis. For purely physical assessments, mental state may be less of a concern.

Field: Human Factors
Source: Medicine & Science in Sports & Exercise (2020)
Method: Experimental Crossover Design
Sample: 14 participants
Evidence: Strong effect

Mental fatigue significantly degrades performance on neurocognitive functional tests that require rapid decision-making and visual processing, while leaving traditional physical performance tests largely unaffected. This human factors research insight is drawn from a 2020 study published in Medicine & Science in Sports & Exercise. Using Experimental crossover design with 14 participants, researchers explored how this design variable affects real-world outcomes. The key design takeaway: For assessments requiring rapid cognitive processing and reaction, ensure the testing environment minimizes mental fatigue or that fatigue is accounted for in the analysis. For purely physical assessments, mental state may be less of a concern.

Study

Human FactorsHigh ImpactStrong effect

Mental Fatigue Impairs Neurocognitive Functional Performance, Not Traditional Metrics

Medicine & Science in Sports & Exercise · 2020

Key Findings

01Mental fatigue was successfully induced, as evidenced by subjective reports and task performance.
02Traditional functional performance tests (single-leg hop, countermovement jump, Y-balance test) were not significantly affected by mental fatigue.
03The neurocognitive reactive balance test showed a significant decrease in accuracy under conditions of mental fatigue.

Application

Design takeaway

How to apply

When designing a user experience that involves performance monitoring, consider whether the task is primarily physical or cognitive. If cognitive, implement strategies to mitigate fatigue or select metrics less susceptible to it.

Project actions

01When designing a product that measures performance, think about whether the user might be mentally tired. For example, a driving simulator might need to account for this.
02If you're creating a test for a product, consider if it's testing physical skill or quick thinking. Mental fatigue will affect quick thinking more.

Method & Evidence

AimTo investigate the impact of induced mental fatigue on both traditional and neurocognitive functional performance tests in healthy adults.

MethodExperimental Crossover Design

ProcedureParticipants underwent two conditions in a randomized order: one inducing mental fatigue via a demanding cognitive task (Stroop test) and a control condition involving a passive task (watching a documentary). Both traditional physical performance tests (e.g., hop, jump, balance) and a neurocognitive test (reactive balance test) were administered before and after each condition. Mental fatigue levels were also assessed.

Sample14 participants

ContextSports Science and Human Performance Assessment

Variables

IVMental fatigue (induced vs. control)

DVPerformance on traditional FPTs (distance, height, balance score) and neurocognitive FPT (RBT accuracy, reaction time)

CVParticipant characteristics (age, height, weight), type of traditional FPTs, type of neurocognitive FPT, duration of tasks, environmental conditions

Strengths & Limitations

Strengths

+Use of a randomized crossover design helps control for individual differences.
+Successful induction of mental fatigue was confirmed through multiple measures.

Limitations

The induced mental fatigue might not perfectly represent real-world fatigue. The sample size is relatively small.

Reliability & validity

The use of established tests like the Stroop and Eriksen-Flanker tasks, along with subjective VAS, enhances the validity of mental fatigue induction. The crossover design improves internal validity by controlling for participant variability. Reliability of the FPTs themselves would depend on their inherent test-retest reliability.

Think critically

How might the duration and intensity of the mental fatigue task influence the observed effects on different types of performance tests?

Design Principles

"Cognitive load significantly influences the validity of neurocognitive performance metrics."

This finding is crucial for designers and researchers developing performance assessment tools. It highlights the importance of considering the cognitive load of a test, as mental fatigue can introduce confounding variables that disproportionately impact certain types of assessments, particularly those involving reactive or decision-making elements.

What This Means for Your Design

Being mentally tired makes you worse at tests that need you to think fast and react, but it doesn't really affect your ability to do physical things like jumping.

How to use in your project

1.Reference this study when discussing how mental fatigue might affect the results of a performance test you are designing or evaluating for your project.

Add to My Project

Quick Cite

Paragraph starter

Research indicates that mental fatigue can significantly impair performance on neurocognitive functional tests, specifically affecting accuracy in tasks requiring rapid visual processing and decision-making, while traditional physical performance metrics remain largely unaffected. This suggests that when evaluating user performance, the cognitive demands of the task are a critical factor to consider, as fatigue may disproportionately influence outcomes in cognitively intensive scenarios.

Source

Medicine & Science in Sports & Exercise

Does Mental Fatigue Negatively Affect Outcomes of Functional Performance Tests?

journal · 2020

View source

Questions About This Research

What does the research say about mental fatigue impairs neurocognitive functional performance, not traditional metrics?: For assessments requiring rapid cognitive processing and reaction, ensure the testing environment minimizes mental fatigue or that fatigue is accounted for in the analysis. For purely physical assessments, mental state may be less of a concern. Evidence: Medicine & Science in Sports & Exercise (2020).
Why does "Mental Fatigue Impairs Neurocognitive Functional Performance, Not Traditional Metrics" matter for design?: This finding is crucial for designers and researchers developing performance assessment tools. It highlights the importance of considering the cognitive load of a test, as mental fatigue can introduce confounding variables that disproportionately impact certain types of assessments, particularly those involving reactive or decision-making elements.
How can designers apply this research?: For assessments requiring rapid cognitive processing and reaction, ensure the testing environment minimizes mental fatigue or that fatigue is accounted for in the analysis. For purely physical assessments, mental state may be less of a concern.
What were the main findings?: Mental fatigue was successfully induced, as evidenced by subjective reports and task performance.. Traditional functional performance tests (single-leg hop, countermovement jump, Y-balance test) were not significantly affected by mental fatigue.. The neurocognitive reactive balance test showed a significant decrease in accuracy under conditions of mental fatigue.
What research method was used?: Experimental Crossover Design with 14 participants.
How strong is the evidence?: Evidence strength is rated Strong effect, based on a 2020 journal from Medicine & Science in Sports & Exercise.
What should I do differently in my next project?: When designing a user experience that involves performance monitoring, consider whether the task is primarily physical or cognitive. If cognitive, implement strategies to mitigate fatigue or select metrics less susceptible to it.
What are the limitations?: The study focused on a specific type of mental fatigue induction and a limited set of neurocognitive tests. The generalizability to other populations or different fatigue-inducing activities may vary.