Cognitive conflict in a syllable identification task causes transient activation of speech perception area

It has previously been shown that task performance and frontal cortical activation increase after cognitive conflict. This has been argued to support a model of attention where the level of conflict automatically adjusts the amount of cognitive control applied. Conceivably, conflict could also modulate lower-level processing pathways, which would be evident as trial-to-trial changes in domain specific activation. The present fMRI experiment used a syllable identification task where conflict is manipulated by presenting recently ignored syllables. Results showed that on trials following a high conflict trial, activation increased primarily in the planum temporale region of the left temporal cortex, an area believed to be involved in syllable discrimination. The experiment thus showed a transient, domain specific attention effect that was modulated on a trial-to-trial basis. We argue that this indicates a self-regulating system where increased levels of conflict directs resources in order to improve performance.

► We applied a syllable discrimination task that varied the degree of cognitive conflict. ► fMRI activation increased in perceptual areas following high conflict trials. ► This indicates that processing resources are automatically directed according to task demands. ► This may indicate a self-regulating attentional mechanism applied to language stimuli.