Combining steady-state visual evoked potentials and f MRI to localize brain activity during selective attention
✍ Scribed by Steven A. Hillyard; Hermann Hinrichs; Claus Tempelmann; Stephen T. Morgan; Jonathan C. Hansen; Henning Scheich; Hans-Jochen Heinze
- Book ID
- 101232732
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 116 KB
- Volume
- 5
- Category
- Article
- ISSN
- 1065-9471
No coin nor oath required. For personal study only.
✦ Synopsis
Brain activity was studied with fMRI and steady-state visual evoked potentials (SSVEPs) in separate sessions as subjects attended to letter sequences in either the right or left visual field. The two letter sequences were superimposed on small square backgrounds that flickered at 8.6 and 12.0 Hz, respectively, and elicited SSVEPs at the flicker frequencies. The amplitude of the frequency-coded SSVEP elicited by either of the flickering backgrounds was enlarged when attention was focused upon the letter sequence at the same location. Source analysis of the SSVEP waveforms localized the attentional modulation to ventral and lateral extrastriate visual cortex, which corresponded to zones of activation observed with fMRI.