| Title: |
Selective activation around the left occipito-temporal sulcus for words relative to pictures: Individual variability or false positives? |
| Authors: |
Wright, ND; Mechelli, A; Noppeney, U; Veltman, DJ; Rombouts, SARB; Glensman, J; Haynes, JD; Price, CJ |
| Source: |
HUM BRAIN MAPP , 29 (8) 986 - 1000. (2008) |
| Publisher Information: |
WILEY-LISS |
| Publication Year: |
2008 |
| Subject Terms: |
fMRI; reading; object recognition; selectivity; occipitotemporal cortex; fusiform; magnetic field strength; LEFT FUSIFORM GYRUS; FORM AREA; SPECIALIZATION; LANGUAGE; CORTEX; ALEXIA; LEVEL; PURE; psy |
| Description: |
We used high-resolution fMRI to investigate claims that learning to read results in greater left occipito-temporal (OT) activation for written words relative to pictures of objects. In the first experiment, 9/16 subjects performing a one-back task showed activation in >= 1 left OT voxel for words relative to pictures (P = 1 left OT voxel for words relative to pictures. However, at this low statistical threshold false positives need to be excluded. The semantic decision paradigm was therefore repeated, within subject, in two different scanners (1.5 and 3T). Both scanners consistently localised left OT activation for words relative to fixation and pictures relative to words, but there were no consistent effects for words relative to pictures. Finally, in a third experiment, we minimised the voxel size (1.5 X 1.5 X 1.5 mm(3)) and demonstrated a striking concordance between the voxels activated for words and pictures, irrespective of task (naming vs. one-back) or script (English vs. Hebrew). In summary, although we detected differential activation for words relative to pictures, these effects: (i) do not withstand statistical rigour; (ii) do not replicate within or between subjects; and (iii) are observed in voxels that also respond to pictures of objects. Our findings have implications for the role of left OT activation during reading. More generally, they show that studies using low statistical thresholds in single subject analyses should correct the statistical threshold for the number of comparisons made or replicate effects within subject. Hum Brain Mapp 2008. (C) 2007 Wiley-Liss, Inc. |
| Document Type: |
article in journal/newspaper |
| Language: |
unknown |
| Relation: |
http://discovery.ucl.ac.uk/132646/ |
| Availability: |
http://discovery.ucl.ac.uk/132646/ |
| Rights: |
undefined |
| Accession Number: |
edsbas.85CDFB6E |
| Database: |
BASE |