studies and reviews Flashcards
dapretto et al 2006
fMRI where children observed and imitated facial expressions
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.
avanzini et al 2012
Mu rhythym reductions in EEG when observing others actions – ev becauses TT would not predict this as it claims the others mental states are represented theoretically, not embodied. Also shows differences between asd v nt
children with autism had less mu rhythym disruption in action observation condition
umilta et al 2001
found subset of MNs are active during action presentation, even when final part of movement is hidden, implies motor representaion of action can be internally generated even without full visual info, supporting hypothesis MN activation could be at the basis of action recognition
umilta et al 2008
Premotor neurons code for the goal of an action, rather than for the action per se.
reverse pliers
The capacity to use tools is based on an inherently
goal-centered functional organization of primate cortical motor areas.
kohler et al 2002
About 15% of mirror neurons responsive to the sight of an action also responded to the characteristic sound of that action
supports hypothesis of action meaning - If mirror neurons mediate action understanding,
then their activity should reflect the meaning of the
observed action, not merely its visual features.
iacaboni et al 2005
found actions embedded in contexts yielded a significant signal increase in the posterior IFG and adjancent ventral premotor cortex where hand actions are represented. This indicates the premotor areas thought to be responsible for action recognition are also involved in understanidng others’ intentions (inferring a new forthcoming goal - an operation the motor system does automatically)
gallesse and goldman 1998
link mirror neurons and simulation theory
rizzolatti et al 2004, 2010
MNS in monkeys and humans:
In monkeys only for action understanding.
Monkeys do not imitate a lot! (A popular misunderstanding)
In humans for action understanding and imitation.
The MNS transforms visual information into knowledge by using one’s own motor repertoire and experience.
The motor theory of speech perception:
brain areas involved in producing speech also participate
when hearing spoken language.
hamilton 2013
review showing current studies are very mixed and studies using weakly localised measures are hard to interpret. the better (fmri) atudies show group differences only when using emotional stimuli. overall, little evidence for global MNS dysfunction in autism. Suggests alternative STORM model where social top-down response modulation is abnormal in autism.
williams et al 2001
argue the MN autism hypothesis
argue in order for MN to become utilised for performing social cog functions inc imitation and ToM abilities, sophisticated cortical neuronal systems have evolved in which MNs are a key elelemnt. argue early dev failures of MN systems are likely to result in a consequent cascade of dev impairments characterised by the clinical syndrome of autism
fan et al 2010
EEG study against BMT. observed and executed hand actions. asd participatns failed to imitate but all MN activity appeared to be intact. Results were affect by experimental conmdition not goup membership and there was no interaction.
oberman and ramachandran 2007
aregue internal simulation mechanisms such as MNS are essential for normal development of recog, imitation, ToM, language, and empathy. argue dysfunctional simulation mechanisms may underlie scial and communication deficits in autosm
faDIGA et al 1995
using TMS
Motor Evoked Potentials (MEPs) recorded from the hand are enhanced during observation of hand actions.
~ MEPs are selectively enhanced in those muscles used to produce the action observed.
~ Listening to words enhances MEPs in the receiver’s tongue
cattaneo et al 2007
even with same goal different types of grasping activate different MNs. so propose a hierarchy action chain model. msny of these action constrained neurons have mirror neuron properties which fire selectively to the observation of the initial motor act. by activatiing a specific action chain from its very outset this mechanism allows the observer to have an internal copy of the whole action before its execution, enabling them to directly understand the targets intention. using electromyographic recordings they showed a similar chained organisation exists in NT children but it was impaired in children with aitism. they proposed that as a conseqwunce of this functional impairment, hfa children may understand others intentions cognitively but lack the mechanism for understanding them experientially
oberman, winkielman and ramachandran 2007
blocked mimicry, found biting pen impaired recognition of happy from neutral faces, supporting theory of internal embodied simulation for recognising emotional expressions