Schizophrenia is characterized not only by a number of clinical symptom but also by board cognitive impairment deficiency in a few elementary functions may underlie impairment in various neuropsychologic domains as well as impede daily-life functioning is woking memory according to baddeley’s model working memory is in charge of the simultaneous manipulation and storage of the information the central executive component of working memory which involves attentional and inhibitory processes enable the manipulation of the information working memory is trus distinct from short-term memory which merely ensures storage an impaired working memory has been established in patient with schizophrenia and proposed as a core deficit underlying a board rang of neurocognitive dysfunctions another possible mechanism is decrease processing speed which has emerged as an important cause of various types of cognitive impairment in these patients slowing is a consistent feature of patient with schizophrenia and affect both the motor and that cognitive speed shares a common factor with the central executive component of working memory.