MSU Fund Number: 360016 192700
Awarded Amount: $25,499.00

Principal Investigator: Dr. Gary Bradshaw

Objectives:
Our long-term objectives are to illuminate the nature of the human lexicon, in particular at the lemma level, to explore the mechanisms underlying the Stroop effect, and to investigate the adequacy of contemporary models of cognition. To accomplish these admittedly ambitious objectives, we plan to develop variants on the Stroop task that employ auditory-only and visual-only stimuli, adapt the use of these variants for an fMRI setting, run non-fMRI studies to validate our new variations on Stroop, and run approximately 40 participants on these tasks with fMRI imaging. The variants of the Stroop task that we will first explore utilize a Stroop-like effect that has been shown in the auditory modality for lateralized words. Stroop-like interference can be shown when subjects perform a lateral judgment task (report whether the stimulus appears on the left, in the center, or on the right), and the stimuli are conflicting words (right is heard in the left ear). We have developed a visual task that employs the same basic features (the word right appears on the left-hand side of a visual display). By measuring the magnitude of the auditory and visual interference effect, we will explore whether a single common representation is used, or multiple, modality-specific representations are used. One characteristic of the Stroop effect makes it an ideal candidate for this type of research: Stroop effects are among the most reliable effects known to psychology (Macleod, 1992). Test-retest reliability is high, so that we can select participants for inclusion in our fMRI study in order to achieve a broad range of interference values, then re-test them in the fMRI without fear of contamination from the earlier test administration.