[Processes of logical thought in a case of cerebral vascular lesion]

Reasoning and logical thought processes have traditionally been attributed to frontal lobe function or,on the other hand, have been considered as diffuse functions of the brain. However, there is today evidence enough about the possibility to find dissociations in thought processes, depending on logical structure of the experimental tasks and referring to different areas of the brain, frontal and post rolandic ones.

To study possible dissociations between thought structures corresponding to categorical and relational logic, on one hand, and propositional logic on the other hand.

The case of a brain injured patient with vascular etiology, localized in left frontal parietal cortex, is presented. A specific battery of reasoning tests has been administered.

. A differential performance at some reasoning experimental tasks has been found depending on such logical conceptual structures.

The possibility of establishing dissociations among certain logical thought and intelectual functions depending on localization of possible brain lesion (frontal versus temporal) is discussed.