Attention-dependent physiological correlates in sleep deprived healthy humans

Distinct cognitive functions are based on specific brain networks, but they are also affected by workload. The workload is a common factor affecting cognitive functioning that, by activating the Central Autonomic Network, modulates heart rate peripheral correlates of cognitive functioning. Based on these premises, we expected that the peripheral patterns associated with different attentional systems would have common (workload-related) and specific (task-dependent) components. To disentangling the components, a profile of peripheral physiological correlates of cognitive functioning was derived by studying healthy volunteers while performing different cognitive tasks during baseline and post-sleep deprivation conditions. Post-sleep deprivation condition was introduced to increase workload during tasks, allowing the investigation of the same participant at different levels of workload in different conditions. We performed, in each condition, physiological recordings of heart pulse, facial temperature and head movements during tasks assessing attentional networks efficiency (ANT - Attentional Network Task; CCT - Continuous Compensatory Tracker). We assessed perceived workload after the execution of these tasks. Physiological correlates of cognitive performance were identified by associating changes of task indices with the corresponding changes in physiological measures from baseline to post-sleep deprivation condition. Correlation analyses were performed after correction for the between-conditions workload changes: indeed, mental and physical demands of perceived workload increased after sleep deprivation. We found that alerting/vigilance has specific physiological correlates as indicated by the negative correlation between changes in ANT-alerting score and changes in amplitude of head movements and the positive one between changes in CCT-visuomotor speed indexing alertness and changes in facial temperature.