Attention deficit disorder and hyperactivity--changes in hypothalamic function in hyperactive children: a new model

This presentation proposes a dynamic integrative model for understanding attention deficit disorder and hyperactivity. The proposed model-the lapses model-is based on principles found in control systems. It suggests the existence of a compensatory system employed by the organism in order to correct its internal overload and homeostatic disturbances resulting from a hypothalamic dysfunction. The restoration of internal homeostasis requires resources needed for the interaction with the environment. Allocation of such resources results in lowered control ability to the point of total loss of contact with the environment. Thus, the compensatory system influences the data-processing ability and determines the cognitive style. The limitation of resources directed to coping with the surrounding environment, already creates a disturbance at the input level. This results in continuity-loss and data-loss due to the temporary saturation and oscillations in the arousal level. When balance is regained, the arousal level comes back to the optimal range, until such time when accumulated load will again cause a disturbance. The cycle repeats itself at varying intervals. The model relates to the interaction between three behavioral levels: biochemical-hormonal, physiological and cognitive-communicative.