AUTHOR=Liebenthal Einat , Desai Rutvik H. , Humphries Colin , Sabri Merav , Desai Anjali 

TITLE=The functional organization of the left STS: a large scale meta-analysis of PET and fMRI studies of healthy adults

JOURNAL=Frontiers in Neuroscience

VOLUME=8

YEAR=2014

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2014.00289

DOI=10.3389/fnins.2014.00289

ISSN=1662-453X

ABSTRACT=<p>The superior temporal sulcus (STS) in the left hemisphere is functionally diverse, with sub-areas implicated in both linguistic and non-linguistic functions. However, the number and boundaries of distinct functional regions remain to be determined. Here, we present new evidence, from meta-analysis of a large number of positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) studies, of different functional specificity in the left STS supporting a division of its middle to terminal extent into at least three functional areas. The middle portion of the left STS stem (<italic>f</italic>mSTS) is highly specialized for speech perception and the processing of language material. The posterior portion of the left STS stem (<italic>f</italic>pSTS) is highly versatile and involved in multiple functions supporting semantic memory and associative thinking. The <italic>f</italic>pSTS responds to both language and non-language stimuli but the sensitivity to non-language material is greater. The horizontal portion of the left STS stem and terminal ascending branches (<italic>f</italic>tSTS) display intermediate functional specificity, with the anterior-dorsal ascending branch (<italic>f</italic>atSTS) supporting executive functions and motor planning and showing greater sensitivity to language material, and the horizontal stem and posterior-ventral ascending branch (<italic>f</italic>ptSTS) supporting primarily semantic processing and displaying greater sensitivity to non-language material. We suggest that the high functional specificity of the left <italic>f</italic>mSTS for speech is an important means by which the human brain achieves exquisite affinity and efficiency for native speech perception. In contrast, the extreme multi-functionality of the left <italic>f</italic>pSTS reflects the role of this area as a cortical hub for semantic processing and the extraction of meaning from multiple sources of information. Finally, in the left <italic>f</italic>tSTS, further functional differentiation between the dorsal and ventral aspect is warranted.</p>