This article discusses recent data from functional magnetic
resonance imaging (FMRI) studies of language. Although preliminary,
these data suggest activation of the left prefrontal cortex across a
variety of tasks, with less activation of posterior cortical areas
known to play a role in language. Potential sources of error in
functional imaging studies related to task subtraction techniques are
briefly discussed. The semantic decision task used by the author and
colleagues, which produces left lateralized activation of both
prefrontal and temporoparietal areas, is presented in detail, and the
activation pattern observed in these studies is discussed in the
context of converging neuropsychological and positron emission
tomography data. It is argued that superior temporal responses evoked
by listening to speech represent sensory rather than language
processes. The data bring into question the classical disconnection
model of transcortical aphasia and confirm the participation of left
prefrontal areas in comprehension. FMRI shows promise as an
alternative to the intracarotid amobarbital test for language
dominance.