Figure

Recognition memory and perceptual identification of Korsakoff patients and non-amnesic alcoholics; delayed conditions only. Data from Cermak et al. (1985).

lesions have impaired mirror-tracing performance (e.g., Sanes, Dimitrov, & Hallett, 1990). Gabrieli (1998, pp. 98-99) put forward a hypothesis to account for the findings: "Closed-loop skill learning, which involves continuous external, visual feedback about errors in movements, depends upon the cerebellum. In contrast, open-loop skill learning, which involves the planning of movements and delayed feedback about errors, depends upon the basal ganglia."

The involvement of the basal ganglia and the cerebellum in sensori-motor skill learning has also been shown in brain-scanning studies. PET studies have shown that serial reaction time skill learning and other tasks involving the learning of specific manual sequences produce increased activation in the basal ganglia (e.g., Hazeltine, Grafton, & Ivry, 1997). The notion that cerebellar activity reflects error correction is supported by the finding that cerebellar activity decreased in line with a decrease in errors on a perceptual-motor task (Friston et al., 1996).

The main perceptual skill learning task studied with amnesic patients is reading mirror-reversed script, in which what is being read can only be seen reflected in a mirror. In these studies, we can distinguish between general improvement in speed of reading produced by practice and more specific improvement produced by re-reading the same groups of words or sentences. Cohen and Squire (1980) reported general and specific improvement in reading mirror-reversed script in amnesics, and there was evidence of improvement even after a delay of three months. Martone et al. (1984) also obtained evidence of general and specific improvement in amnesics. However, although the general practice effect was as great in amnesics as in normals, the specific practice effect was not. It may be that normals (but not amnesics) are able to use speed-reading strategies to facilitate reading of repeated groups of words.

The brain areas involved in mirror reading were studied by Poldrack et al. (1996) in a study using functional magnetic resonance imaging (fMRI). Initially, there was much activity in right parietal cortex. However, with practice, this activity decreased, and there was increasing activity in left inferior occipito-temporal cortex. According to Gabrieli (1998, p. 99), "These shifts in activity may represent a change in reliance upon visuo-spatial decoding of mirror-reversed words in unskilled performance to more direct reading in skilled performance."

Beat The Battle With The Bottle

Beat The Battle With The Bottle

Alcoholism is something that can't be formed in easy terms. Alcoholism as a whole refers to the circumstance whereby there's an obsession in man to keep ingesting beverages with alcohol content which is injurious to health. The circumstance of alcoholism doesn't let the person addicted have any command over ingestion despite being cognizant of the damaging consequences ensuing from it.

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