1 Department of Experimental and Clinical Psychology, Barrow Hospital, Barrow Gurney, near Bristol
2 The Queen Alexandra Military Hospital, Millbank, London, S.W.1
3 Royal Victoria Hospital, Netley, near Southampton
The experiment reported was the first of three investigations of the relationship between sedation threshold and autonomic lability. The blood pressure response to cold water was examined in 32 neurotic and 13 normal subjects, on whom measures of sedation threshold and Archimedes spiral after-effect were also obtained. By partialling out the relationship between prestress level and post-stress change, consistently positive correlations were found between sedation threshold and blood pressure rise, although only in the case of one measure of the diastolic response was this significant. The spiral after-effect correlated significantly and positively with the pre-stress blood pressure level, which, in turn, showed a near-zero correlation with sedation threshold. These results were considered sufficiently encouraging for further investigations to be carried out, using more adequate measures of autonomic function. They were also held to support the view that it is necessary to hypothesize two sources of arousal to account for some of the postulates of Eysenck's theory of personality.