An ERP study of the temporal course of the Stroop color-word interference effect.

Published

Journal Article

The electrophysiological correlates of the Stroop color-word interference effect were studied in eight healthy subjects using high-density Event-Related Potentials (ERPs). Three response modalities were compared: Overt Verbal, Covert Verbal, and Manual. Both Overt Verbal and Manual versions of the Stroop yielded robust Stroop color-word interference as indexed by longer RT for incongruent than congruent color words. The Incongruent vs Congruent ERP difference wave presented two effects. A first effect was a medial dorsal negativity between 350-500 ms post-stimulus (peak at 410 ms). This effect had a significantly different scalp distribution in the Verbal and Manual Stroop versions, with an anterior-medial focus for overt or covert speech, and a broader medial-dorsal distribution for the manual task. Dipole source analysis suggested two independent generators in anterior cingulate cortex. Later on in time, a prolonged positivity developed between 500-800 ms post-stimulus over left superior temporo-parietal scalp. This effect was present for all the three response modalities. A possible interpretation of these results is that Stroop color-word interference first activates anterior cingulate cortex (350-500 ms post-stimulus), followed by activation of the left temporo-parietal cortex, possibly related to the need of additional processing of word meaning.

Full Text

Duke Authors

Cited Authors

  • Liotti, M; Woldorff, MG; Perez, R; Mayberg, HS

Published Date

  • January 2000

Published In

Volume / Issue

  • 38 / 5

Start / End Page

  • 701 - 711

PubMed ID

  • 10689046

Pubmed Central ID

  • 10689046

Electronic International Standard Serial Number (EISSN)

  • 1873-3514

International Standard Serial Number (ISSN)

  • 0028-3932

Digital Object Identifier (DOI)

  • 10.1016/s0028-3932(99)00106-2

Language

  • eng