MOSCOW (Itar-Tass): During prolonged orbital flights space crews lose some skills of tackling logical problems, a preliminary study has said.

"The results of examinations held on board the International Space State last year indicate certain problems with reproducing adaptive biocontrol skills in dealing with logical problems and tasks, something not observed in handling spatial tasks," the experiment's chief, Tatyana Yershova said.

The preliminary conclusions made by scientists at the Russian Academy of Sciences' Institute of Medical and Biological Problems were presented at the 34th international academic conference on astronautics this week.

Yershova recalled that all tasks and problems ISS crews are expected to deal with fall within two categories - spatial ones (maneuvering, docking, extra-vehicular activity), and logical ones (examination of the station's condition, maintenance and repairs of ISS systems and others).

For evaluating the crews' psychological aptitude for doing certain jobs, researchers probed into the ability to retain adaptive biocontrol skills using the bioelectric activity of the brain.

"At the beginning of the experiment we record a sample encephalogram, and then we turn the computer game on, imitating this or that type of activity. Then there follows a ten-minute test training session, and finally, a computer game simulating the other type of activity is switched on," Yershova said.