mirror neurons and autism Flashcards
How could early imitation be important for the development of ToM?
Both involve translating the perspective of another to oneself.2. The link becomes especially clear in Simulation Theory.3. Imitation could be precursor to ToM.
Is there behavioural evidence for an imitation deficit in autism ?
Some difficulties in copying others’ actions (especially meaningless actions: echopraxia).2. Problems in inhibiting stereotyped mimicking of words or phrases (echolalia), or actions (e.g. a peculiar way of walking).Thus there are issues with imitation in ASD, but not necessarily a reduction of imitation!
The imitation deficit may in itself be small, but may give rise to a cascade of cognitive impairments, up to and including ToM. ~ Maybe caused by a malfunctioning of mirror-neuron system (Williams et al., 2001).
If mirror neurones indeed form the basis of Imitation, and possibly also for empathy and ToM, then why do monkeys have mirror neurones as they don’t imitate (that much) and probably don’t have ToM and empathy?
They use their mirror mechanism for basic forms of action understanding (in terms of goals).
In humans, other cortical systems are build on top of this. Dysfunction of mirror neurones causes a cascade of developmental/cognitive problems (ASD symptoms).
studies relating to MNs and asd
Dapretto et al. (2006). Understanding emotions in others: mirror neuron dysfunction in children with autism spectrum disorders. Nature Neuroscience, 9, 28-30.
Williams et al. (2001). Imitation, mirror neurons and autism. Neuroscience and Biobehavioral Reviews, 25, 287-295.
L. M. Oberman & V. S. Ramachandran (2007). The simulating social mind: The role of the mirror neuron system and simulation in the social and communicative deficits of autism spectrum disorders. Psychological Bulletin, 133, 310-327
But see also: Fan et al. (2010). Unbroken mirror neurons in autism spectrum disorders. Journal of Child Psychology and Psychiatry, 51, 981-988.
ramachandran on MNs
Ghandi neurons
‘Horizontal’ spread of culture thanks to mirror mechanisms
Role of peripheral feedback in deciding whether I or the other
is touched.
Phantom limb: no feedback possible > miss-interpretation >
you believe you are being touched
Eastern philosophy vs. western philosophy
Consciousness
MNs in F5
Command motor neurons: code for the goal of an action
allow execution of a coordinated action involving several muscles (antagonists), e.g. when grasping, holding, or manipulating objects.
However, an object can be grasped in various ways:
left arm, right arm, mouth etc. (Rizzolatti, Fogassi, & Gallese, 2000).
Hierarchy:
mirror neuron 1: coding for grasping with hand
mirror neuron 2: coding for grasping with mouth
Etc…..
Their outputs project onto another mirror neuron, which then codes
for grasping in all possible ways:
> Abstract representation of grasping in motor cortex
attempts at understanding underlying mechanisms of autism
- Deficit in Theory of Mind, or in its precursors.2. Deficit in executive functions (planning, inhibition, working-memory, attention switching).3. Deficit in global processing: Central-coherence (or preference for local processing).4. Deficit in imitation (malfunctioning mirror-neuron system).
Arguments against ToM explanation of autism
- Normal children acquire ToM at age of 4 years, but autism starts earlier. (Baron-Cohen: precursors such as Shared attention Mechanism)2. Real problem is socio-affective (lack of empathy). Hobson (psychoanalyst).3. The non-social symptoms can’t be explained by ToM.
rizzolatti motor system explanation of autism
Even tough motor deficits in autism are prominent, they have never the less been neglected.
> Focus on deficiencies in the motor system. It prevents you from understanding other people “from inside”, i.e. through simulation within your own motor system.
> ToM and ‘Broken Mirror System’ theory are wrong (modules). The real problem is in an ‘experiential’ understanding of one self and therefore of the other (action chain model).
> Wii (home video game) to help people with autism to take account of the other’s actions and to learn coordinate their own actions with those of others.
Oberman, Winkielman & Ramachandran (2007)
mimicry
People spontaneously mimic a variety of behaviours, including emotional facial expressions. - Embodied cognition theory suggests mimicry reflects internal simulation of perceived emotion to facilitate its understanding. - If so, blocking facial mimicry should impair recognition of expressions.- Mimicry-interfering manipulations (1) biting on a pen and (2) chewing gum.- Bite manipulation interfered with recognition of happiness
`Avanzini, Fabbri-Destro, Dalla Volta, Daprati, Rizzolatti, Cantalupo. (2012).
Typical brain:
passive mu rhythm from motor cortex
perform an action disruption of murhythm
observe an action disruption of mu rhythm ASD:
passive mu rhythm from motor cortex
perform an action disruption of mu rhythm
observe an action less disruption of mu rhythm
McIntosh, Reichmann-Decker, Winkielman & Wilbarger (2006
When the social mirror breaks: deficits in automatic, but notvoluntary, mimicry of emotional facial expressions in autism.
mimicry in ASD
Dapretto, Davies, Pfeifer, Scott, Sigman, Bookheimer & Iacoboni (2006
Children with autism: less activity in the frontal part of the mirror-neuron system (inferior frontal gyrus ~ F5 ~ pars opercularis, Brodman area 44) when imitating or observing facial expressions. Especially in the right hemisphere.
2. Activity in this area was inversely related to severity of social symptoms as measured with ADOS and ADI (very strong on ADI).
