Image:
-
The Wisdom of Psychopaths
In this engrossing journey into the lives of psychopaths and their infamously crafty behaviors, the renowned psychologist Kevin Dutton reveals that there is a...
Read More »
Eighteen years ago, in a laboratory at the University of Parma in Italy, a neuroscientist named Giacomo Rizzolatti and his graduate students were recording electrical activity from neurons in the brain of a macaque monkey. It was a typical study in neurophysiology: needle thin electrodes ran into the monkey’s head through a small window cut out of its skull; the tips of the electrodes were placed within individual neurons in a brain region called the premotor cortex. At the time, the premotor cortex was known to be involved in the planning and initiation of movements, and, just as Rizzolatti expected, when the monkey moved its arm to grab an object the electrodes signaled that premotor neurons were firing. And then, neglecting to turn off their equipment, Rizzolatti and his team got lunch.
What followed lunch that day was a serendipitous discovery. One of Rizzolatti’s graduate students decided to have an ice cream cone for dessert, which he ate in full view of the wired-up monkey. To his surprise, the electrodes suddenly began to signal a spike in cellular activity in the premotor cortex, even though the monkey was motionless.
After shoveling more food into their mouths, the scientists determined that some of the neurons they were recording from fired when the monkey made certain movements – like bringing a piece of food to its mouth – and when the monkey watched someone make similar movements. In other words, the neurons were mirroring observed actions: when the monkey watched someone perform an action its brain seemed to be simulating neural activity as if the monkey was performing the action itself. These “mirror neurons”, as Rizzolatti later dubbed them, were hypothesized to constitute a brain system responsible for our ability to understand the actions of others. We know about our world because we’ve interacted with it and only by simulating this interaction in our heads can we comprehend the behaviour of someone else.
In 1992, almost a year after the ice cream cone incident, Rizzolatti published a short report in a minor neuroscience journal describing his discovery of mirror neurons. The paper was largely ignored. Then, almost four years later, he published a more detailed account of the finding in the journal Brain that launched a torrent of research – more than 300 papers in the past ten years – into mirror neurons and their properties. As he explained to The New York Times in an interview, "It took us several years to believe what we were seeing.”
Since Rizzolatti’s 1996 paper, studies in primates and humans support the idea that mirror neurons help us understand observed behaviour. One primate study found that mirror neurons were activated simply by the sound of an action, like the ripping of paper, while another found that the mental representation of actions was enough to cause mirror neuron firing. These are important results because they demonstrate a mirror neuron response to the meaning of an action and not just the observation of one.
In humans, brain imaging studies of people with autism – a deficit characterized by an inability to comprehend observed behavior – have shown that autistics have less activity in premotor regions during the observation of actions than normal subjects. And more recently, in a dramatic example of the importance of mirror neurons in our understanding of others, apraxia patients with cortical damage in mirror neuron areas were shown to have difficulty recognizing whether hand gestures, like sticking out a thumb to hitch a ride, were performed correctly.
A new paper by Vittorio Caggiano and colleagues at the University of Tubingen in Germany – Rizzolatti is a co-author - suggests that mirror neurons might also play a role in helping us choose appropriate responses to behaviors we observe. Using similar methods to the original mirror neuron studies in macaques, the latest paper found that some mirror neurons fired when a monkey watched the experimenter grasp an object within its reach, while other mirror neurons fired when the monkey watched the experimenter grasp an object that was out of its reach. These mirror neurons, it seemed, responded differently to observed behavior depending on how far the behavior occurred from the monkey.
The authors of the paper then repeated the experiment but with an important twist: they placed a neck-high wall in front of the monkey, forcing the animal to make an intermediate movement – a reach over the wall in this case – to grasp any object. In this situation, the mirror neurons that responded before only to the observation of an action within the monkey’s reach completely stopped firing. And the mirror neurons that responded only to the observation of an action outside of the monkey’s reach now fired vigorously, no matter where the experimenter grasped the object. The mirror neurons were not simply encoding the distance of an observed act, they were encoding whether the monkey could perform the act without an intermediate behavior.
One can only speculate, of course, as to the behavioral consequences of mirror neurons that differentiate between actions that can be immediately performed and actions that require intermediate behaviors. But an intriguing idea proposed by the paper’s authors is that such a system might help us choose behaviors of our own. If mirror neurons help us understand the act of a basketball player making a jump shot by simulating neural activity as if we were making the jump shot, perhaps, if we don’t have a basketball within reach, they run simulations of behaviors that might allow us to get the ball – calling for a pass or grabbing a rebound. Such neural simulations might help us decide how best to quickly respond to changing events.
Determining whether such mirror neurons exist in humans will require more research, using indirect methods such as functional brain imaging. Even so, this finding suggests how mirror neurons might link the understanding of the behavior of other people with the production of our own behavior, which is a crucial step towards determining the neural processes that caused Rizzolatti’s graduate student to eat an ice cream cone on that fateful day in Italy, eighteen years ago.
See what we're tweeting about
20 Comments
Add CommentAbsolutely facinating!
Reply | Report Abuse | Link to thisI had read of the original findings but not the latter. One has to wonder if the ears and eyes are the only receptor. They are certainly the obvious but a blind study, merely to dismiss the thought would be interesting.
The concept of "Mirror neurons" might better explain classical and operant conditioning.
Reply | Report Abuse | Link to thisI think you've got it backwards, Roy. Most effects that have been attributed to mirror neurons can be better-explained through simple associative learning mechanisms.
Reply | Report Abuse | Link to thisYes, Magic, brain may well follow behavior, not (as the person-in-street idea would have it) behavior is a result of brain. That is, by performing behavior we modify the brain. Hence, the research on how some forms of remedial reading cause neural activity in "the dyslexic brain" to more closely approximate neural activity in "normal" brains.
Reply | Report Abuse | Link to thisYou make a good point. Mirror neurons may develop as a response to behavior and its consequences (reinforcement). Is there any evidence that mirror neurons are present at birth, or only appear sometime later?
Reply | Report Abuse | Link to thisIt seems to me that an important point is missed in this interesting article. Simulating an action anticipates a future act. This is fundamentally different to a direct automatic or conditioned response to sensory input which is driven causally from the past. We simulate actions all the time before we act them out in response to direct sensory input. This is what gives us the capacity to span space and time, past and future, and thus historically integrate phenomenal experience. We could not learn otherwise.
Reply | Report Abuse | Link to thisMuscle spindles of the proprioceptive nervous system are important in this regard. These tiny spindles that are distributed throughout the muscles of the body monitor the bodys spatial orientation with respect to itself and the environment. They also have an independent gamma motor supply that can activate them independently of the parent muscles. This allows for the simulation of anticipated patterns of action that generates rapid proprioceptive sensory feedback to motor areas of the spinal cord with parallel projections to the cerebellum as well as to areas of the cerebral cortex including the premotor cortex. This allows us to sense the feel of an action in space and time an instant before acting. We do this in dancing or playing a sport. We can also feel the urge and pattern of a dance without moving a muscle. We can observe this in our personal experience.
For more on this see the website articles on the Human Nervous System at www.cosmic-mindreach.com.
I'm wondering whether mirror neurons may provide an explanation for the phenomenon of projective identification; i.e., an analyst's mirror neurons fire in the presence of a patient who may be feeling unconscious anger, such that it's not the patient "projecting" the anger into the analyst, but an effect of the firing of mirror neurons. Opinions?
Reply | Report Abuse | Link to thisBut Weir's description of the muscle spindles of the proprioceptive nervous and what they are connected to and what feedback networks there are can make no predictions of when a person will dance, play a sport, speak, or perform any other type of behavior. Nor does it provide us with any guidelines for controlling unsuitable behavior or refining the behavior in some way.
Reply | Report Abuse | Link to thisThis ties in well with the work Susan Greenfield did measuring how the brain creates new networks, where she compared the brain growth in three groups (http://www.abc.net.au/rn/deakin/stories/s296994.htm) : "Perhaps the most awesome response was from the third group, who did not physically play the piano, but merely imagined they were doing so, and still created a thick knot of entirely new links and neurons created over that period, to wire them for piano playing."
Reply | Report Abuse | Link to thisThe picture (or our understanding of it) is slowly emerging!
We begin to find now the neurological basis for many consciousness-related phenomena in these studies of brain activity that in a way mirrors that activity, i.e. that our motor centers are activated as if we were doing the action: the observer's brain activity does not produce actual action, though there is the effect of almost taking action.... It's fascinating, I insist, and yet, all of this sounds to me as the experimental confirmation of what I. A. Richards called "attitudes", as a cornerstone of his materialist psychology in /Principles of Literary Criticism/ (1924)---"imaginal and incipient activities and tendencies to action"; "imaginal action and incipient action which does not go so far as actual muscular movement are more important than overt action in the well-developed human being".
Reply | Report Abuse | Link to thisIt's great to know about the experimental confirmation, but for some of the aesthetic consequences waiting to be drawn out, perhaps Richards and others "been there, done that"!
Thanks for this fascinating article. Being involved in the domain of autism, the subject of mirror neurons has been of the greatest interest to me since the very early publications by Rizzolatti et al.
Reply | Report Abuse | Link to thisI have a question about the developmental aspect of mirror neurons activation. It seems that early on, infants tend to simply imitate gestures and only later on do they internalise the imitation. Is this a domain that has been analysed?
Could the activation of the GABAergic system in the child development have something to do with the internalisation of imitation?
Thanks
Paul
Well we have all wanted to pee when one person proclaimed loudly he wanted to pee. We all gag when we see a person vomit...
Reply | Report Abuse | Link to thisThese are the more physical representations of the mirror neurons. Part of the learning from others system that gets encoded into the epigenome becomes personality etc etc .....
Very interesting. Questions it raises for me: Is the firing of mirror neurons part of an interpretive process or a learning process? I.e., when we see an action, do we simulate the motor actions that we would have to undertake to duplicate the perceived action as part of the activation of the whole nexus of neural connections that may be relevant to interpreting and responding to that action (and if so, is the simulation of the motor actions we would undertake the hub or starting place for the activation of other neural connections relevant to interpreting the perceived action, or is it just a sort of epiphenomenon). Or do we simulate the motor actions as a way of preparing ourselves to imitate the perceived action (behavior) as part of the learning through imitation process? Is there anything in these studies that indicates a difference in the firing of mirror neurons depending on whether the perceived action/behavior is a behavior the subject has already learned as opposed to a behavior that is new to the subject?
Reply | Report Abuse | Link to thisI think the monkey just wanted some ice-cream!
Reply | Report Abuse | Link to thisThis whole subject probably explains why spectator sports are such a huge attraction, they get the sensations of actually doing what they're seeing on TV or from the stands. That's an obvious statement but at least now we know why people are willing to fork over big money to see someone else playing a game.
Reply | Report Abuse | Link to thisThe bigger question impacted by Rizzolatti's research and subsequent work is not what the mechanism of mirror neurons do independent of the nervous system - but rather how they operate in relationship with all aspects of the human intelligence system. They are likely important to many aspects of socialization - but in the end they will be found to be one part of a remarkably complex interdependent suite of mechanisms. I don't say that to diminish the discovery. I agree with Ramachandran it is historic - merely to point out that even the invention of the wheel led to an axel.
Reply | Report Abuse | Link to thisI have recently thought that mirror neurons may provide the substrate for the notion of "what goes around, comes around", otherwise cultural encoded as the Golden Rule. If , as kwneverblinks suggests, the phenomenon of "projection" involves mirror neurons to "transmit" the emotion of anger between patient and therapist, might this help explain why it's hard not to smile when you see a bright sunny smiling person, and easy to frown when someone scowls? Do mirror neurons help us to influence our environment simply by modeling the behavior we wish to see in others?
Reply | Report Abuse | Link to thisI was thinking along this line as well. Could mirror neurons play a role in transference and countertransfernce?
Reply | Report Abuse | Link to thisIf you have a look at the website article Inside our Three Brains at www.cosmic-mindreach.com you should be able to see that there is a bi-polar moral dilemma at the roots of perception. The Limbic system serves to reflect emotional experience in neocortical conscious awareness in such a way that right brain intuition works in accord with the parasympathetic system while left brain language bound techniques of behavioural response work in accord with the sympathetic system. The former is concerned with long term archetypal interests of the individual and the species. The latter tends to be reactionary to immediate sensory input. We seek a satisfactory balance between these three focal points as reflected across the Limbic brain. I can not see how it can be possible to manipulate the behavioural control of others to one's liking. The point is that behavioural tailoring to circumstance is very much under personal control, albeit in a social context subject to social pressures and inclinations. We do have a good degree of free will. I think the main problem is that the integrating frameworks of understanding that we intuitively entertain are generally shallow and short sighted. Just seeing how the nervous system works to integrate experience can help to correct this.
Reply | Report Abuse | Link to thisI should have mentioned that my latest post was in response to RayWei's comment on 6/10/09 about my prior post on 6/09/09. I think if he has a look at my website he may see that ways are implictly available to tailor one's own behavior and learn from experience.
Reply | Report Abuse | Link to this