1 Garrard, P. & Forsyth, R. (2010). Abnormal discourse in semantic dementia: a data-driven approach. Neurocase, 16, 520-528. Notes: Structural and content-related deficits occur in connected discourse of patients with semantic dementia (SD). We used principal components analysis (PCA) to characterise the sources of variation in word usage during picture description by controls and SD patients. ...