401 Broca’s Area: Rethinking Classical Concepts From a Neuroscience Perspective Martha S. Burns, PhD, 1 and Jill Fahy, MA 2 1 Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois; 2 Department of Communication Disorders & Sciences, Eastern Illinois University, Charleston, Illinois Just about one and one-half centuries ago, Paul Broca identified the posterior third left frontal convolution of the human brain as a critical area for speech production. Although years of cerebrovascular accident localization studies partially confirmed Broca’s claim, recent years have seen a clarification and expansion of the role Broca’s area plays in serial processing of language and speech as well as a probable role in nonlinguistic processing. This article will review some of the more recent anatomical and physiological research, including lesion studies, imaging research, and interoperative electrocortical stimulation studies. The article will summarize the research on the role of the human inferior frontal gyrus in lexical, phonologic, and grammatical production, the so-called “mirror mechanism” and other aspects of cognitive processing and motor execution. Key words: aphasia, Broca, executive function, motor cortex, neuroplasticity, prefrontal cortex D r. Gerald Canter, the teacher to whom this edition of Topics in Stroke Rehabilitation is dedicated, always began his aphasia lectures in the 1970s with historical reference to 2 neurological pioneers, Paul Broca and Carl Wernicke. It is a testimony to the foresight of these scientists, and to that of Dr. Canter, that their ideas are being studied and debated a century and a half after their initial publication. This article summarizes some of the new research on the region now referred to as Broca’s area. In tribute to Dr. Canter, it begins by borrowing from the historical account that he customarily used in his first lecture. Background If one considers a scientific revolution as representing a radical change in thought and behavior, one might view Paul Broca, a mid- 19th century anthropologist and anatomist, as a true revolutionary. The seminal event that led to current views of language organization within the brain can be attributed to Broca 1 in his 1861 presentation at the Anthropological Society of Paris. That any scientist is still discussing this paper almost 150 years later in a scientific journal speaks to the importance of that presentation. At that meeting, Broca presented neurological and behavioral data from which he localized “articulate language” to the posterior left third frontal convolution of the cerebrum. His now famous presentation of the autopsy results of Leborgne, whose speech had been reduced to a single recurrent utterance despite what Broca asserted was otherwise generally intact mental capacity, led him to propose a new diagnostic term, aphemia, to describe the loss of speech associated with damage to this region. The posterior left third frontal convolution has since become commonly referred to as Broca’s area. The aphemia Broca described in this patient and a later patient, Lelong, has been referred to as Broca’s aphasia for many decades. But Broca’s contribution to the understanding of aphasia represents a small portion of the research that has followed his initial paper. A cursory PubMed search uncovered 50 or more journal articles that have been published on Broca’s area in the last few years. This diverse research archive speaks to the pivotal role this brain region appears to hold within the neuroscience community for understanding not only aphasia but also human communication and human cognition. Indeed, over the past 149 years, researchers in diverse fields such as medicine, speech-language pathology, cognitive psychology, linguistics, anthropology, and developmental neuroscience have intently studied this small and quite variable region of the human brain Top Stroke Rehabil 2010;17(6):401–410 © 2010 Thomas Land Publishers, Inc. www.thomasland.com doi: 10.1310/tsr1706-401