Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

Observing actions made by others activates the cortical circuits responsible for the planning and execution of those same actions This observation–execution matching system (mirror-neuron system) is thought to play an important role in the understanding of actions made by others In an fMRI experiment, we tested whether this system also becomes active during the processing of action-related sentences Participants listened to sentences describing actions performed with the mouth, the hand, or the leg Abstract sentences of comparable syntactic structure were used as control stimuli The results showed that listening to action-related sentences activates a left fronto-parieto-temporal network that includes the pars opercularis of the inferior frontal gyrus (Broca's area), those sectors of the premotor cortex where the actions described are motorically coded, as well as the inferior parietal lobule, the intraparietal sulcus, and the posterior middle temporal gyrus These data provide the first direct evidence that listening to sentences that describe actions engages the visuomotor circuits which subserve action execution and observation

Listening to Action-related Sentences Activates Fronto-parietal Motor Circuits

Evidence from functional magnetic resonance imaging of crossmodal binding in the human heteromodal cortex.

Listening to Action-related Sentences Activates Fronto-parietal Motor Circuits J. Cogn. Neurosci. 2005 17: 273-281

http://recherche.ircam.fr/pcm/pressnitzer/P2web/AnneLise/vanatteveldt.pdf

Integration of letters and speech sounds in the human brain.

Regional cerebral blood flow (rCBF) PET scans were used to study the physiological bases of lipreading, a natural skill of extracting language from mouth movements, which contributes to speech perception in everyday life. Viewing connected mouth movements that could not be lexically identified and that evoke perception of isolated speech sounds (nonlexical lipreading) was associated with bilateral activation of the auditory association cortex around Wernicke's area, of left dorsal premotor cortex, and left opercular-premotor division of the left inferior frontal gyrus (Broca's area). The supplementary motor area was active as well. These areas have all been implicated in phonological processing, speech and mouth motor planning, and execution. In addition, nonlexical lipreading also differentially activated visual motion areas. Lexical access through lipreading was associated with a similar pattern of activation and with additional foci in ventral- and dorsolateral prefrontal cortex bilaterally and in left inferior parietal cortex. Linear regression analysis of cerebral blood flow and proficiency for lexical lipreading further clarified the role of these areas in gaining access to language through lipreading. The results suggest cortical activation circuits for lipreading from action representations that may differentiate lexical access from nonlexical processes.

S. Sensolo

Papers

A functional-anatomical model for lipreading.

Ventral prefrontal areas specialised for lip-reading: A PET activation study