Human autonomy and the frontal lobes. Part II: Patient behavior in complex and social situations: the "environmental dependency syndrome".

Imitation and utilization behavior have previously been described in terms of a simple interaction between an examiner and a patient, and were interpreted as an excessive dependence on environmental cues. In this study, patient dependence was observed in complex situations of everyday life. Two patients with focal unilateral frontal lobe lesions were observed while in a doctor's office, a lecture room, a car, and a garden, while visiting an apartment where various activities were possible, and while in a gift shop. The patients' behavior was striking, as though implicit in the environment was an order to respond to the situation in which they found themselves. The term environmental dependency syndrome is proposed for this condition. It implies a disorder in personal autonomy. Individual psychological traits influenced the way in which loss of autonomy was manifested. This study does not offer a physiological model of autonomy, but it does provide clinical and behavioral observations on the loss of autonomy secondary to unilateral lesions of the frontal lobe.