Tuesday, September 16, 2014

The right theory of mirror neuron function. Guess who said it.

A quote on mirror neuron function.  I think it is spot on, as discussed in The Myth of Mirror Neurons.  Who said it? (It wasn't me.)

One of the fundamental functions of the premotor cortex is that of retrieving appropriate motor acts in response to sensory stimuli. Evidence has been provided that action retrieval can occur in response to two-dimensional patterns, color, and size and shape of three-dimensional objects. The present data indicate that in addition to these physical factors, retrieval can also occur in response to the meaning of the gestures made by other individuals. If one considers the rich social interactions within a monkey group, the understanding by a monkey of actions performed by other monkeys must be a very important factor in determining action selection. Thus, the capacity of inferior premotor neurons to select actions according to gesture meanings fits well in the conceptual framework of current theory on the functions of premotor cortex and expands it to include movement selection related to interpersonal relations.

10 comments:

Greg Hickok said...

Quote is from the very first report on the discovery of mirror neurons by the Parma group. It is the first paragraph of the discussion.

di Pellegrino, G., Fadiga, L., Fogassi, L., Gallese, V., & Rizzolatti, G. (1992). Understanding motor events: a neurophysiological study. Experimental Brain Research, 91(1), 176-180.

tim faber said...

Hi Greg,

Doesn't this still leave room for the simulation-understanding hypothesis? We simulate perceived gestures to understand them in order to select an appropriate response. The only difference is that the outcome of the actor doesn't need to be imitative but rather more functional/ interactive behavior (what indeed makes way more sense).
Got the book last week, like it a lot!
Cheers
tim

Greg Hickok said...

Sure it leaves room. But what's the evidence for the additional assumption that the system is the basis also for action understanding? There is no direct evidence in the monkey and the human data provides strong evidence against the claim. The simple, elegant hypothesis regarding mirror neuron function initially proposed by Rizzolatti and colleagues is all we need to understand mirror neuron function.

tim faber said...

For them I guess it would be deficits in understanding for people not able to perform the perceived action but in your book you make a good case against this. With regards to the function this makes a lot of sense, I like the related argument given in Newman-Norlund, van Schie, van Zuijeln, & Bekkering (2007)
http://www.ncbi.nlm.nih.gov/pubmed/17529986

Greg Hickok said...

Interesting result in Newman-Norlund et al. I wasn't aware of this paper. It probably has little to do with mirror neurons though as the right IFG activation is typical in so-called "stopping" experiments: work on the neural basis of inhibiting a planned action. See the work of Adam Aron on this topic.

tim faber said...

I see, I'll check it out! More generally I like the notion that a functional account of MNS could be as effective in explaining imitative as well as complementary actions in response to perceived gestures (or even more so for the latter).

Greg Hickok said...

Right. In which case it's not a "mirror system" but a broad sensory-motor integration system that can take input of a variety of sorts (object shape/size/location, actions, sounds, somato stimulation) and map them onto various motor plans as appropriate, only some of which will be mirror-like.

tim faber said...

Right! So they/we/somebody should perhaps provide a novel term as not to restrict this system to explaining mirror-like processes. Maybe the notion of self-other distinction can help in setting boundaries where mirror vs different sensorimotor coordinations come into play
(e.g., http://www.sciencedirect.com/science/article/pii/S0960982206019154)

Greg Hickok said...

I don't think self-other has anything to do with it. It's just sensory-motor control. What gets fed into the motor control circuit and selected for action is a function of other mechanisms. We "mirror" people (i.e., the chameleon effect) not because our motor system is capable of mirroring--after all so is the macaques' and they don't do it like we do!--but because some other system "feeds" the info into the motor system. Pure "motor resonance" is pathological: echophenomena.

tim faber said...

I see, the qoute is about action-selection/ control, it's the understanding part which is the problem. I think pure motor resonance would not even make sense if the function of the premotor cortex is to select appropriate actions towards perceived actions by others.