Authors:

Price, C., Wise, R., Watson, J., Patterson, K., Howard, D. & Frackowiak, R.

Reference:

Year of publication:

1994

CBU number:

3179

Abstract:

Brain activity during reading tasks was investigated using positron emission tomography (PET). The aim was to account for differences in the results of two previous studies by systematically varying the type of reading task and the exposure duration of the word stimuli. Both variables strongly influenced patterns of brain activity. There were three types of task - (i) reading aloud, (ii) reading silently and (iii) lexical decision on visually presented words and pseudowords. Reading aloud and reading silently engaged the left middle and superior temporal regions, confirming the important role of these areas in visual word processing. The areas principally engaged during lexical decision were the left inferior and middle frontal cortices and the supplementary motor area: activity in these areas suggests that the subjects were using a phonological strategy to perform the task. There was also a significant effect of exposure duration, with activity being greater for short (150ms) exposure durations than for long (1000ms) exposure durations. We conclude that until we understand how subtle variations in experimental design influence brain activity during reading tasks, the association of specific processing functions with individual anatomical areas activated during reading is premature.