A case study of selective impairment of the central executive component of working memory after a focal frontal lobe...

RC is a 36-year-old man who sustained a closed head injury with bilateral frontal lobe hypometabolism in 1978. In 1994, after a lobectomy of a large part of the left frontal lobe, he presented no behavioral disruption and normal performances on most of intelligence, long-term memory, and executive tests. However, he showed deficits in tasks that implicate short-term storage (i.e., span tasks). These deficits in working memory were explored with regard to Baddeley's model using computerized tasks. On these tasks RC showed normal functioning of the articulatory loops and dysfunction of the central executive component in dual tasks. These results confirm those reported in another single case study by Van Der Linden, Coyette, and Seron (1992) and indicate that dual-task performance may assess one separable feature of executive functions.