Global switch cost as an index for concussion assessment: reliability and stability

Area of Science:

• Neuroscience
• Sports Medicine
• Human Performance

Background:

• Current concussion assessments often evaluate cognitive and physical functions separately.
• There is a need for integrated testing methods to better reflect real-world demands on athletes.
• Dual-task (DT) methodologies offer a potential avenue for more comprehensive concussion evaluation.

Purpose of the Study:

• To determine the stability and sensitivity of a dual-task (DT) methodology for assessing concussion effects in athletes.
• To evaluate the reliability of global switch cost indices under single-task and DT conditions.
• To assess the sensitivity of global switch costs to cognitive-physical interference.

Main Methods:

• Fifty-nine healthy adults completed auditory switch tasks of varying lengths (30, 40, 60 items) at three time points over seven months.
• Participants performed switch tasks concurrently with a modified Harvard Step Test during later sessions to simulate dual-task conditions.
• Global switch cost indices and percentage error were calculated to measure cognitive performance and interference.

Main Results:

• Stability reliability for the switch tasks was high (0.64 to 0.84) across different test lengths.
• A significant main effect for condition (single task vs. DT) was found for both global switch costs and percentage error (P < 0.0001).
• The magnitude of interference effects under DT conditions was consistent across the tested task lengths.

Conclusions:

• The global switch cost index derived from DT conditions demonstrates good stability reliability, suggesting clinical utility.
• The DT paradigm provides a sensitive measure of cognitive-physical interference, reflecting more realistic scenarios than isolated testing.
• This DT methodology may enhance concussion management by aiding return-to-play decisions.