Respiratory Muscle Training and Cognitive Function Exercising at Altitude.

Background: Hiking and trekking often occur at altitudes up to 12,000 ft altitude. The hypoxia-induced hyperventilation at altitude paradoxically reduces arterial CO2 (Paco2). A reduction in Paco2 results in vasoconstriction of the blood vessels of the brain and thus in local hypoxia.

Influence of recruitment and participation bias in neuropsychological research among MS patients.

The potential influence of recruitment context in neuropsychological (NP) research is seldom addressed in the literature. Our experience with a previous large-scale study of MS cognitive impairment led us to speculate that referral questions and motivation bias significantly impact conclusions drawn from NP testing. We re-analyzed data from Benedict et al.