{"content":[{"text":"338","bbox":{"left":0.15289,"top":0.054779,"width":0.026507000000000003,"height":0.016625999999999995}},{"text":"John Joseph Downes and Others","bbox":{"left":0.407089,"top":0.056051,"width":0.23611,"height":0.015218000000000002}},{"text":"of recognition memory and very few studies have used a recognition version of \n the Brown-Peterson task (Butters and Cermak, 1974). \n The Brown-Peterson and Huppert and Piercy tasks differ in two other \n important ways. One major difference is the time course over which they \n typically assess forgetting. The Brown-Peterson task has assessed memory over \n short delays of a matter of seconds usually starting with a delay of zero seconds. \n By contrast, the Huppert and Piercy task has assessed memory from a delay of \n 10 minutes onwards. Thus, the two tasks have been considered to be assessing \n forgetting rate from short-term memory (STM) and long-term memory (LTM) \n respectively. \n The second difference is related to the initial delay at which memory is \n tested. When the initial delay is greater than a few seconds the baseline memory \n performance against which forgetting is measured differs between amnesic and \n control groups and this causes problems in interpreting rate of forgetting data \n (Mayes, 1986). To overcome this problem Huppert and Piercy (1978) ensured \n that amnesics’ and controls’ recognition performance was matched at the \n shortest delay by allowing amnesic patients longer exposures to target items \n during the study phase. As Huppert and Piercy were interested in the rate \n at which information was forgotten from LTM, the performance of the amnesic \n and control subjects was matched at ten minutes, a delay at which STM was \n thought to be no longer contributing to performance. Although this choice of \n initial delay is arbitrary, most subsequent studies have also used ten minutes as \n the shortest delay. In contrast, the tasks developed by Brown (1958) and \n Peterson and Peterson (1959) did not require a matching manipulation as both \n subject groups performed equally (at ceiling) on the initial delay of zero \n seconds. \n The results regarding the forgetting rate of amnesic patients which have been \n obtained using these tasks are not clear cut. There have been conflicting findings \n concerning forgetting rate of subjects with medial temporal lobe and \n diencephalic damage on the Huppert and Piercy task. A number of research \n groups have reported abnormally fast forgetting by amnesic patients with \n damage to medial temporal lobe structures, but not by patients with damage to \n midline diencephalic structures (Huppert and Piercy, 1978; Huppert and Piercy, \n 1979; Squire, 1981). However, at least one study failed to show abnormally fast \n forgetting for either medial temporal lobe or diencephalic amnesics (e.g., McKee \n and Squire, 1992). Also, Freed, Corkin and Cohen (1987) reported normal rate \n of forgetting by patient HM and patients with Alzheimer’s disease, the \n neuropathology of which includes damage to medial temporal lobe structures, \n have also been reported to exhibit normal rates of forgetting over periods of \n three days (Freed, Corkin, Growden et al., 1989) and of one week (Kopelman, \n 1985). \n There is also controversy concerning rate of forgetting of amnesic patients on \n the Brown-Peterson task. The pattern that has emerged is that patients with \n amnesia resulting from medial temporal lobe damage perform at near normal \n levels (e.g., Butters, 1984), whereas Korsakoff patients, with presumed \n diencephalic damage, are impaired (e.g., Starr and Phillips, 1970). However. \n after reviewing this work, Kopelman (1992) concluded that no study had","bbox":{"left":0.15289,"top":0.084824,"width":0.745594,"height":0.816638}}],"images_bbox":[],"images_bbox_not_text_overlap":[]}