European isolation and confinement study. Attention during isolation and confinement.

The aim of this study was to examine the effect of isolation and confinement on selective attention. The experiments were carried out on six specially selected male subjects. The subjects were isolated in a hyperbaric chamber complex at a low overpressure for a period of 28 days. Distribution of attention between two tasks, visual search and orientation of attention to symbolic and automatic cues were studied. The results showed that 4 weeks of isolation and confinement do not significantly modify visual search and the capacity to execute two tasks simultaneously. In the double task experiment there was a clear improvement of performance during isolation and the post-isolation period. However, the development of a remarkably large difference between subjects was found. Orientation of attention to automatic cues gave results comparable to those obtained under normal conditions. Valid trials (stimulus flash and cue in same box) were faster than both neutral (cue in all boxes) and invalid trials (stimulus flash and cue in different boxes). Orientation of attention to symbolic cues also produced this effect. However, the "meridian effect" (increased reaction time when the stimulus is in the opposite half of the visual field as cue), which is constantly observed under normal conditions, was absent during isolation. The absence of the meridian effect is interpreted as a change in the subject's strategy to allocate attention. It is proposed that the absence of the meridian effect indicates an initial deficit of attentional capacities during isolation and confinement.