A Reverse Temporal Gradient for Public Events in a Single Case of Semantic Dementia

Abstract

A patient with semantic dementia (DM) was tested on a Public Events Test comprising famous events from three time periods (1989–1991,1992–1994 and 1995–1997). DM was impaired on both recognition and identification of these events compared to two matched control subjects. Furthermore, he showed evidence of a reverse temporal gradient on both components of the test, recognizing more items and producing more detailed information about events from 1995 to 1997 compared to events from the other two time periods. The results from this experiment are congruent with data from other published studies in which patients with semantic dementia show reverse temporal gradients on tests of autobiographical and semantic knowledge.