What Does the Activation in the Visual Cortex Reflect?
We have found higher activation during the recognition memory tasks compared with the phonological control. During the former, subjects had to relate to the semantic content of the words in order to judge whether the presented word is old or new, while during the latter, they were directed to focus on phonological components of the words. Thus, the differences in activation level might be a result of semantic components per se. As was reported by Burton et al. (2003), higher activation in the occipital cortex of blind is found when subjects are required to focus on the semantic content of words compared with the requirement to relate to the words’ phonological content. This is also in agreement with a recent study showing that applying repetitive TMS pulses to the occipital pole of blind subjects results in an increase in the number of semantic errors (but not in sighted peers) while phonological errors are very rare (Amedi et al., 2004). However, we think that such a description expla
