Time estimation in patients with right or left medial-temporal lobe resection

Patients with either left or right antero-medial-temporal lobe (MTL) resect ion were investigated as to their ability to reproduce and produce three du rations (5, 14, or 38 s) in three conditions (silence, counting, articulato ry suppression). The results showed that patients with unilateral MTL lesio ns did not differ from controls when they had to encode the duration of a v isual stimulus in order to reproduce it. By contrast, patients with right M TL lesions underestimated all three durations, compared with controls and w ith patients with left MTL resection, when they had to produce durations gi ven in chronometric units. This finding suggests that the right MTL retains long-term representations of the conventional units necessary to the accur ate production of durations. NeuroReport 12:939-942 (C) 2001 Lippincott Wil liams & Wilkins.