Pgj. Ganzevles et Ma. Haenen, A PRELIMINARY-STUDY OF EXTERNALLY AND SELF-ORDERED TASK-PERFORMANCE IN SCHIZOPHRENIA, Schizophrenia research, 16(1), 1995, pp. 67-71
Frontal lobe dysfunctions are assumed to be involved in the cognitive
problems of schizophrenia. The inability to plan or organize behavior,
however, may be the result of an inability to process information (i.
e., attention disorder) as well as of an incapacity of information pro
cessing (i.e., overstimulation). Wiegersma et al. (1990) described imp
aired performance in frontal lobe patients on self-ordered tasks (Rand
omization Span and Sequential Pointing span) but intact performance on
externally ordered tasks (Digit Span and Missing Item scan). These fo
ur tasks were used in the present study in which ten schizophrenic pat
ients and ten matched controls participated. The schizophrenic patient
s exhibited significant impairments in the self-ordered as well as in
the externally ordered tasks. It was concluded that the impairment of
schizophrenic patients may be caused by overstimulation rather than by
attention disorders.