Dissociative states and chaotic patterns of electrodermal activity during associative experiment

Abstract

A dynamic concept of schizophrenia linked to the theory of dissociated complexes was experimentally demonstrated by Jung in "The Psychology of the Dementia Praecox". According to him, during schizophrenia the psyche is split-off into a plurality of autonomous complexes and the whole personality is pathologically disintegrated. This pathological disinte-gration is frequently observed in schizophrenic associations that display "chaotic randomness". The "chaotic random-ness" does not mean a true randomness because schizophrenic associations are not without underlying order and causali-ty. An important aspect of schizophrenic dissociation is an extreme subjective sensitivity. These two signs of schizoph-renic associations are analogical to known characteristics of chaotic nonlinear dynamical systems. The hypothesis tested in the present study is that neural chaos, calculated from electrodermal activity (EDA), during rest and word-association process is more prominent in schizophrenic patients compared to healthy controls. To test the hypothesis we have meas-ured EDA during the experiment performed in 25 schizophrenic patients and 21 healthy control subjects. Results of non-linear and statistical analysis indicate that the neural chaos characterized by positive largest Lyapunov exponents during rest and the word-association process is significantly higher in the schizophrenic patients. These data suggest that pseu-do-randomness of schizophrenic associations and increased sensitivity related to dissociative states might be linked to the chaotic neural dynamics.