The assessment of sequential response organization in schizophrenic and control subjects.

1. A novel analysis is introduced for the sequential organization of behavioral elements derived from the ergodic theory of nonlinear dynamical systems and statistical mechanics of physical systems. 2. This analysis yields the fluctuation spectrum of local dynamical entropies, S (h), which quantifies the contributions of subsequences with different degrees of association between elements to the overall observed behavior. In addition, q-dependent order parameter functions assess the relationship between the degree of association between consecutive behavioral elements and qualitative aspects of the subsequences. 3. A binary choice task paradigm is used to extract thought-contingent responses in order to determine the organization of sequences of behavioral actions. 4. A group a schizophrenic patients and controls was tested with a binary choice task paradigm to determine the sequential organization of their responses. 5. The results indicate that the overall response sequences of both schizophrenics and controls are non-random. In addition, clear differences in qualitative aspects between response subsequences with different degrees of association are revealed. Finally, significant fluctuations within individual subjects were found between highly predictable and highly unpredictable response subsequences. 6. These results are discussed with respect to dysregulations in behavioral organization that could not be assessed previously and may provide new insights into the behavioral effects of the underlying dysregulated neural circuitry.