[Overview and assessment of cognitive function in interpreting postoperative cognitive dysfunction].

The most important point for evaluation of the post-operative cognitive dysfunction is that we understand "cognitive function". First we described the definition of the "cognitive function" and second, outlined each function (dysfunction) and introduced the main assessment methods from the view point of neuropsychology. Cognitive function (dysfunction) described in this paper includes consciousness (confusional state, disturbance of consciousness), generalized attention (disorder of generalized attention), memory (amnesia), orientation (disorientation), executive function (dysexecutive syndrome), social cognition (social cognitive impairment), language (aphasia), cognition (agnosia), behavior (apraxia), directed attention (unilateral spatial neglect), and construction (constructional disorder).