CEREBRAL BLOOD FLOW AND STATE OF SOME COGNITIVE FUNCTIONS IN HEALTHY HUMAN SUBJECTS FOLLOWING 520-DAY ISOLATION

Six male volunteers at the age of 27 to 39 years were participants in an investigation of cerebral circulation and cognitive functions in a 520-d isolation study. Transcranial doppler ultrasonography was used for continuous recording the mean linear blood flow velocity in medial cerebral arteries (MCAs) at rest, during voluntary maximal breath-holding (hypercapnia), and cognitive tests. After the long-term isolation, both MCAs retained a statistically significant increase of the standard deviation of blood flow velocity relative to the values at rest. This finding reflects changes in amplitude of blood flow fluctuations in response to physiological and cognitive tests. Cognitive functions and mean blood flow velocity in both MCAs were not affects by long-term isolation.