Dual Tasking Influences Cough Sensorimotor Outcomes in Healthy Young Adults

Purpose: Reflex cough is an essential airway protective mechanism that often occurs in the context of divided attention. The effect of divided attention on measures of reflexive cough airflow and sensitivity remains unknown. We present findings from a study testing the effects of divided attention (via a dual-task paradigm) on measures of reflex cough in healthy young adults. Method: Volunteers (N = 20, age = 20-40 years) underwent 4 blocks of capsaicin-induced cough challenges. Within each block, capsaicin ranging from 0 to 200 [micro]M was presented in a randomized order. Two blocks consisted of cough testing only (single task). During the other 2 blocks, participants counted tones while simultaneously undergoing cough testing (dual task). Measures of cough motor response, self-reported urge-to-cough, cough frequency, and cough airflow were collected. Results: Participants coughed more in the single-task condition compared to the dual-task condition (p = 0.001). Participants' urge-to-cough ratings were lower in the dual-task condition (x¯ = 2, "slight") compared to the single-task condition (x¯ = 3, "moderate"; p = 0.007). Participants' cough reflex sensitivity thresholds were significantly increased in the dual-task condition (p = 0.002). Cough peak expiratory flow rates did not change between the 2 conditions (p = 0.34). Conclusions: Somatosensation of tussive stimuli changes during dual tasking. Abnormal cortical resource allocation may be a mechanism involved in silent aspiration.