tag:blogger.com,1999:blog-9048879464910781933.post5533368162261029159..comments2023-10-12T00:25:24.119-07:00Comments on Talking Brains: Internal forward models -- New insight or just hype?Greg Hickokhttp://www.blogger.com/profile/16656473495682901613noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-9048879464910781933.post-74594032985068449352010-10-09T12:40:04.985-07:002010-10-09T12:40:04.985-07:00Great entry. Personally, I think that the evidence...Great entry. Personally, I think that the evidence (to date) for motor-system instantiated internal forward models being a necessary component of speech perception is unconvincing.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9048879464910781933.post-90767983331432796012010-10-07T19:11:42.429-07:002010-10-07T19:11:42.429-07:00Hi,
The nice thing about forward models is that t...Hi,<br /><br />The nice thing about forward models is that they are probably the primary source of information to drive movements. The motor system adjusts the motor commands only when the actual and predicted sensory consequences of the movement differs. Therefore, it is nothing like using sensory input to drive the behavior. Sensory input are only there to signal when the output of the forward model was wrong.<br /><br />I think that there is plenty of evidence to support the cerebellum as the locus of forward models (TMS: Miall et al. 2007 PLOS biology; patients: Smith et al. JNP 2005 or Criscimagna-Hemminger et al. 2010). Even for internal models of moving objects have been found in the cerebellum (Cerminara et al. J Physiol 2009).<br /><br />I have to say that I'm very skeptical about the PPC as site for forward models. The study by the team of Richard Andersen (in PNAS)is far from convincing. The task they used does not discard the possibility that the observed neural activity is not driven by very short-term prediction of the moving cursor rather than prediction of the hand movements.<br /><br />The real question is if you are able to predict someone else's movement or intention, have you built a forward model of that person? Would such forward model be located in the cerebellum as well? <br /><br />JJ<br /><br />PS: I enjoyed reading your piece in JOCN about the problems of the mirror neuron theoryAnonymousnoreply@blogger.com