A Functional Neuroimaging Study on the Sensitivity of Decision Making and Mental Workload to Hypoxia

Introduction. Hypoxia, a state of oxygen deprivation, is common in respiratory diseases and brain injuries. It also affects healthy individuals exposed to extreme operating environments, such as high altitude or low barometric pressure situations. While impairments in cognitive processing and novelty detection have been investigated, there is a lack of observations on its influence on decision making and psychomotor workload, and about the neural networks involved in these functions.

Our study investigated the neurofunctional preparatory processes for a single/double choice button press during four different cue-target visuospatial attentional orienting tasks based on Posner's Attention Network Test and the effects of hypoxia on these processes.

Methods. Healthy participants underwent two experimental sessions in which they breathed either ambient air or 12.5% oxygen-reduced air while performing the four cueing tasks. EEG was recorded from 128 scalp sites and event-related potentials (ERPs), intracerebral sources and behavioural responses (RTs) were computed.

Results. Both the amplitude of pre-target ADAN and LDAP ERP components and post-target RTs were lower for the single choice condition. Moreover, hypoxia had detrimental effects on decision making during valid attentional orienting conditions. Activations in the right anterior cingulate cortex, left superior parietal lobule and dorsolateral prefrontal gyri were enhanced under hypoxia for the double-choice decision task.

Conclusions. Our findings indicate that preparatory processes for a single- or double-choice are associated with the activation of different brain networks more strongly active in the more demanding condition. Overall, hypoxia compromised decision making efficiency. Impaired decision-making erodes accountability, raising ethical concerns about individual responsibility.