Executive functions are a cognitive apparatus that controls and manages cognitive processes. proposed a model on executive functioning of attentional control that specifies how thought and action schemata become activated or suppressed for routine and non-routine circumstances. Schemas, or scripts, specify an individual's series of actions or thoughts under the influence of environmental conditions. Every stimulus condition turns on the activation of a response or schema. The initiation of appropriate schema under routine, well-learned situations is monitored by which laterally inhibits competing schemas for the control of cognitive apparatus. Under unique, non-routine procedures the supervisory attentional system (SAS) controls schema activation. The SAS is an executive monitoring syste