tag:blogger.com,1999:blog-9048879464910781933.post6316131859268346676..comments2023-10-12T00:25:24.119-07:00Comments on Talking Brains: Mirror neurons in humans revealed by fMRI adaptationGreg Hickokhttp://www.blogger.com/profile/16656473495682901613noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-9048879464910781933.post-20841689786491175332009-01-19T08:03:00.000-08:002009-01-19T08:03:00.000-08:00Mirror neurons may be incredibly difficult to pinp...Mirror neurons may be incredibly difficult to pinpoint specifically. There are several areas of the brain that they are thought to, or have been known to exist. However if the theory that epigenetics and neuroplasticity has a major role to play in development is correct, then it may be purely a random assignment of totipotent cells. <BR/><BR/>For example in the study by Neville & Lawson (1987) people who were born deaf had adapted the primary audio area of their brains so that instead of being redundant, the region became specialised in vision (particularly peripheral). This evidence of brain plasticity has been supported in pathological reports of young (and some older) stroke victims, and even more convincingly in contraversial rewiring ferrits experiments (Surr et al 2000). <BR/><BR/>If this is the case that the brain areas only develop and specialise as a result of the information being pumped into each region, then mirror neurons may be incredibly unreliable in location, which would explain why the exact location in which they reside remains ambiguous.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9048879464910781933.post-75673030450378877362008-11-14T10:15:00.000-08:002008-11-14T10:15:00.000-08:00Since that post links to here, it seemed only fair...Since that post links to here, it seemed only fair that this post should <A HREF="http://cognitionandculture.net/index.php?option=com_content&view=article&id=223:do-we-have-mirror-neurons-at-all&catid=9:neuro-dash&Itemid=34" REL="nofollow">link to there</A>:<BR/><BR/><I>" in a piece published in Current Biology based on data published in the Journal of Neurosciences, I. Dinstein suggested that [mirror neurons] can hardly be found in humans, and J. Neurosciences editors seem to concur."</I>mrGhttps://www.blogger.com/profile/00582052332934960204noreply@blogger.comtag:blogger.com,1999:blog-9048879464910781933.post-12957908224432313272008-11-05T11:43:00.000-08:002008-11-05T11:43:00.000-08:00Good point Tom, I hadn't thought that part of thei...Good point Tom, I hadn't thought that part of their argument through. Seems there are several funky things about the study. Having played with adaption effects in fMRI though, if there is one thing I've learned, it is that these effects are extremely finicky and not very strong. Adaptation could be occurring in other areas (IFG for example) and in other conditions, but weren't detected in this study. At the same time, if these effects are really that weak, I wonder how meaningful they are.Greg Hickokhttps://www.blogger.com/profile/16656473495682901613noreply@blogger.comtag:blogger.com,1999:blog-9048879464910781933.post-67194756456141728912008-11-05T09:22:00.000-08:002008-11-05T09:22:00.000-08:00Interesting paper. fMRI is perfect for these adapt...Interesting paper. fMRI is perfect for these adaptation/priming type of paradigms. The one thing about these results that worries me is the lack of an adaptation effect for the 'Observe/Execute' task. In the paper, the authors argue that this is because the SMG is a 'motor planning area' therefore any adaptation effects in this condition are 'offset' by increases in activation resulting from the covert motor planning that occurs during the 'Observe' part of the task when subjects know they will shortly be performing an action. To support this, they point to a table in the supplementary material that shows higher activation in 'motor preparation areas' (SMA, PMd, CMA)during the 'Observe' part of the 'Observe-Execute' condition relative to the 'Execute-Observe' condition (collapsed across the Novel/Repeated dimension. I don't find this a particularly convincing argument. Firstly because, weirdly, data from the right SMG is not shown on this graph, so we have no idea exactly what was happening there during observation. Secondly, even if the SMG is involved in motor planning, any planning related increases during the 'Observe' period should be common to both the Novel and Repeated 'Execute' stimuli - i.e. an adaptation effect should still be visible in the contrast of interest (Novel vs Repeated for Observe/Execute), if this is really a 'mirror' area.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9048879464910781933.post-64358471717376160132008-11-05T07:35:00.000-08:002008-11-05T07:35:00.000-08:00This smells fishy to me. In fact, the very notion ...This smells fishy to me. In fact, the very notion of the 'mirror system' or 'mirror neurons' has no meaning to me. I think what's needed now is a clear computational statement about the functional properties of neurons encoding sensory, motor and sensory-motor information within a well-defined behavioral context.The Vladhttps://www.blogger.com/profile/04915516119500937892noreply@blogger.comtag:blogger.com,1999:blog-9048879464910781933.post-16352640342344246392008-11-04T16:05:00.000-08:002008-11-04T16:05:00.000-08:00Very cool result if it holds. Interesting, though,...Very cool result if it holds. Interesting, though, how the adaptation effect observed was not in the anterior intraparietal sulcus (aIPS) where a host of previous studies had reported mirror neuron activity, as Trevor et al. note. I just wish these pesky little critters would decide where they are so we can test their language properties.Anonymousnoreply@blogger.com