Modulation of activity in temporal cortex during generation of inner speech.
Monitoring one's thoughts (in the verbal modality) is thought to be critically dependent on the interaction between areas that generate and perceive inner speech in the frontal and temporal cortex, respectively. We used functional magnetic resonance imaging (fMRI) to examine the relationship between activity in these areas while the rate of inner speech generation was varied experimentally. The faster rate was associated with activation in the left inferior frontal gyrus, the right pre- and postcentral gyri and both superior temporal gyri. Thus, temporal cortical activation was associated with increasing the rate of covert articulation, in the absence of external auditory input, suggesting that there is effective fronto-temporal connectivity. Furthermore, this may provide support for the existence of feed forward models, which suggest that activity in regions responsible for verbal perception is modulated by activity in areas that generate inner speech.
Institute of Psychiatry, GKT School of Medicine and Dentistry, De Crespigny Park, London, United Kingdom. s.shergill@iop.kcl.ac.uk
Sukhwinder S
SS
Shergill
Michael J
MJ
Brammer
Rimmei
R
Fukuda
Ed
E
Bullmore
Edson
E
Amaro
Robin M
RM
Murray
Philip K
PK
McGuire
D000328:Adult; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology*; D005625:Frontal Lobe / Q000502:physiology*; D006212:Hallucinations / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D013067:Speech Perception / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*