Interplay between cognitive conditions and individual traits in voluntary apnea

Apnea is employed to enhance performance in diving and other sports due to its specific physiological correlates. Its duration can be enhanced through training and the use of specific cognitive strategies and can be influenced by individual traits. Hypnotizability could be one of them, being associated with interoceptive sensibility and imagery abilities. The study investigates whether these traits affect apnea duration during imagery of normal breathing (motor imagery, a cognitively incongruent condition) and while focusing attention on apnea sensations (internally focused attention, a cognitively congruent condition) in participants with different hypnotizability scores. Hypnotizability was assessed in healthy participants -as low-medium (med-lows, N = 16) and medium-to-high hypnotizables (med-highs, N = 17)-, according to the Stanford Hypnotic Susceptibility Scale: Form A. They completed the Multidimensional Assessment of Interoceptive Awareness and the Movement Imagery Questionnaire-3 to assess interoceptive sensibility and trait imagery abilities and performed three apnea trials of internally focused attention and motor imagery in counterbalanced order. Heart rate and skin conductance were monitored. The vividness and ease of motor imagery and internally focused attention tasks were reported. Apnea duration increased across trials independently of the cognitive condition and hypnotizability. Heart rate increased during motor imagery more than during internally focused attention, skin conductance decreased quasi-significantly during both tasks in both groups. Imagery abilities and interoceptive sensibility masked hypnotizability-related differences in the tasks' subjective experience, heart rate, and increase in apnea duration across trials. Thus, hypnotizability, imagery abilities, and interoceptive sensibility jointly contribute to increase apnea duration across trials and to the associated experience and autonomic responses.