Re: [xmca] Neural basis of tool use

From: Steve Gabosch <sgabosch who-is-at>
Date: Fri Feb 01 2008 - 00:39:59 PST

Thanks for the url, Mike. Mike Cole's comments got me to go back
again and look at the further reading.

"Grasping the Intentions of Others with One’s Own Mirror Neuron
System" by Marco Iacoboni, Giacomo Rizzolatti and others,
reports on an interesting MRI study. I wound up turning my notes on
that article into a post. Pardon its length.

22 subjects were brain scanned on an MRI while watching some movie
clips of a tea setting (teacup, teapot, utensils, plate of food,
cream, sugar, jam) in two different states (ready to consume, and
ready to clean up); in each of these states (or contexts), a person
picked up the cup with two different kinds of grasp (prehensile,
grabbing the cup from the top, and precision, by the handle); and
finally, the cup was picked up shown by itself, with not other objects
around, again with the two different kinds of grip. The 22 subjects
were divided into two groups, one which was given no instruction
except to watch the clips (called the Implicit group), and the other
which was told to pay attention to the objects in the clips and to the
kinds of grips being used (the Explicit group).

The basic idea of the experiment was to investigate whether the brain
responds only to different actions, or it also responded to
"intentions." The core of the experiment was to compare brain
activity in the three "contexts" the cup was picked up in - a) when
the objects were ready to eat, b) when they were a mess and ready to
be cleaned up, and c) when the cup was by itself with no other
objects. The design of the experiment allowed the researchers to also
compare brain activity of the subjects when they were just looking at
the two versions of the tea setting with nothing happening, and at the
cup being picked up with no surrounding context. The use of the two
grips was also used to tease out differences in brain response between
action and intention.

All subjects were able to appropriately answer questions about what
they thought the intentions of the actions in the clips were. When
the tea setting was ready to consume, they thought the cup was being
picked up to drink from, and when the setting was a mess and mostly
consumed, they thought the cup was being picked up to be cleaned.
When there was no context, they were unsure why the cup was being
picked up.

By comparing quantities and locations of brain activity during these
clips, the researchers were able to make a number of inferences about
the role of a) context, b) type of action, and c) sequence of
logically related actions - in automatically grasping the *intentions*
of actions.

Very strongly implicated in their reasoning were mirror neurons, and
the possibility that there are at least two different kinds of mirror
neurons. The first kind they call classical mirror neurons, which
fire under two different situations: when a monkey (and theoretically,
a person) is performing a particular action, AND when a person
observes another performing that same action. Only monkeys have been
physically detected as having mirror neurons, by hooking up electrodes
to individual neurons and watching them fire while actions are
performed or observed.

The discovery of mirror neurons has been a startling advance in
neurology, challenging traditional concepts of nature and nurture,
biology and culture. Apparently, according to this theory, cultural
experiences, such as grasping and drinking, can be hardwired such that
certain neurons will fire when a particular action is performed, or
observed being performed. To my knowledge, little or nothing is yet
known about under what conditions and what ages mirror neurons develop
or atrophy. That will be a very interesting area of research, if the
existence of mirror neurons in humans indeed becomes fully
established, as many now think it will.

The researchers in this paper felt that the "classical" mirror neuron
was not adequate for explaining all the results in this study. They
discussed a second kind of mirror neuron that has not been empirically
demonstrated before. According to their theory, these kinds of mirror
neurons, which they call "logically related" mirror neurons, fire
after not just one, but *two* related actions are performed or
observed, such as picking up an apple and then moving it toward the
mouth (as opposed to handing it to another person, which would cause a
different set of "logically related" mirror neurons to fire).

The researchers propose that this second kind of mirror neuron
explains a number of things they saw in this study, such as the
difference in neuronal firing between the "drinking" and "cleaning"
action. First of all, the existence of a recognizable context, either
ready to consume or ready to clean, made a significant difference,
compared to brain activity measured when the subjects were just
watching the cup being picked up without a context. That alone is a
significant finding - the brain not only responds to actions, it
responds to cultural contexts. Second, the brain activity during the
drinking action was different from that for the cleaning action,
indicating a different neuronal firing pattern was "dedicated" for
each situation. Third, since the same action was combined with two
different contexts, and therefore associated with two different
intentions, there is a strong implication that the perception of
action-in-context (a culturally understood action and context, of
course) creates unique brain responses.
According to their thinking, while the first kind of mirror neuron
offers a strong explanation for the capacity, as a hard wired ability,
for the imitation and recognition of the actions of others by monkeys
and humans, the second kind offers an explanation not just for
recognizing actions, but recognizing the *intentions* of actions,
automatically, also as a hard wired ability. Monkeys and humans,
according to these researchers, not only can automatically recognize
actions in others, but can also *automatically* detect their

Just to have a little fun and speculate a little, this approach could
open up a whole new set of explanations for how humans learn to engage
in learned cultural activities (like speaking and emotionally relating
to others) at speeds much faster than deliberate cognition allows, a
phenomena that has hitherto been something of a mystery. It might
also help explain certain "subjective" reactions people can have to
one another. Everyone seems so unique in how they react and respond
to specific things and people in their everyday lives - perhaps our
brains act at different speeds and resolutions for thousands upon
thousands of different actions and intentions, each in our own unique
way. That is, our individual "collections" of "classical" and
"logically related" mirror neurons, dedicated to millions of things,
might be quite different from one person to the next. Perhaps persons
we feel special subject affinities for are "on our wavelength" in this
or that common activity because we share similar (or perhaps
contrasting but complementary) patterns of mirror neurons - we can
"sense" things at similar and/or complementary speeds and intensities,
or at some other compatible level. Hence, we can sense certain things
in ways very alike with one person, but very unalike with another.
Hence, "rapport," and so forth. Mirror neurons might be an essential
neurological component of what Vygotsky-oriented thinkers refer to
when they speak of "internalization". And think about the implication
that we might be able to find ways to "train" ourselves to "grow" or
"sharpen" our mirror neurons, perhaps learning how to directly "hard
wire" our minds.

- Steve

On Jan 31, 2008, at 12:45 PM, Michael A. Evans wrote:

> Thought this article might be of interest to the list:
> Excerpt:
> “The findings ‘fairly clearly show that monkey tool use involves the
> incorporation of tools into the body schema, literally as extensions
> of the
> body,’ says Dietrich Stout, an archaeologist specializing in tool
> use at
> University College London. Scott Frey, a neuroscientist at the
> University of
> Oregon, Eugene, says that in humans, this ability to represent tools
> in the
> brain, combined with a capacity for innovation, ‘was no doubt a
> fundamental
> step in the development of technology.’”
> Full article is available at bottom of linked page...
> Cheers,
> Michael~
> --
> ____________________________________
> michael a. evans
> assistant professor
> 306 war memorial hall (0313)
> department of learning sciences & technologies
> school of education
> virginia tech
> email:
> phone: +1 540.231.3743
> fax: +1 540.231.9075
> _______________________________________________
> xmca mailing list

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