Functional Neuroimaging of Phonological Processing: Effects of Cognitive Load

A number of recent neuroimaging studies have found that regions of prefrontal cortex are active during phonological tasks. Overlapping regions of prefrontal cortex have also been reported as activated during studies of working memory. These findings have raised questions about the extent to which this activation is due to overlapping cognitive processes required to perform these tasks. Results from functional MRI studies that vary load on components of working memory will be presented. These studies explore how systematic variations in speech vs. nonspeech stimuli, lexical status, task, and modality of stimulus presentation can shed light on these questions. The results will be discussed in terms of implications for the framework developed by Hickok and Poeppel (2004) for language-brain relations.