Transcript presentation5

Action Observation and Acquired Motor Skills:
An fMRI with Expert Dancers
Article by Calvo-Merine, Glaser,
Grezes, Passingham, Haggard,
2005.
Presented by
Stephanie Parent
Introduction: key terms

Action observation
Observing someone performing
an action
•Acquired motor skills
Actions that one has learned to do and
mastered. The actions are integrated in
the individual’s motor repertoire.
•Mirror mechanism
During action observation, the brain
stimulate making that action by activating
certain motor areas necessary to perform
that action
Background:
Discovery of the mirror mechanism

Monkey mirror mechanism (di Pelligrino, Fadiga,
Fogassi, Gallese, Rizzolatti 1992)
 Neurons in the macaque monkey’s premotor and
parietal cortices discharge



Human mirror mechanism (Decety and Greze, 2001)


when the monkey performs an action OR
When the monkey observe an action.
Premotor cortex, parietal areas and the superior
temporal sulcus (STS) neurons are activated during
action observation
Is the mirror mechanism tuned to the individual
motor repertoire?
Action Observation and Acquired skills: an
fMRI on expert dancers (Calvino et al., 2005)

Hypothesis


During action observation, the mirror system activity
(pre-motor & parietal cortices and STS) will be
stronger in individuals who have learned to perform
that action than those who have not.
Experimental task


10 professional ballet dancers, 10 Capoeira dancers
and 10 non-dancers (control group) watched videos
of ballet and capoeira while their brain activity was
recorded in an fMRI.
The difference in brain activation between expert
dancers and non-expert was the point of interest
Watch
Results

In line with hypothesis:
When expert dancers watched their own type of dance,
stronger activation (BOLD action) was found in the premotor cortex, the parietal area and the STS
Expertise effect
Discussion

Implications

Mirror system codes complete action patterns,
not just individual movement

Mirror system is sensitive to much more
abstract levels of action organisation
 Skilled
movements, meaningful movements
Strengths of the article

Experimental design eliminates counfounds
 Ballet and capoeira movements are
kinetically comparable
 Brain activation differences are not due
to differences in kinetic

Dancers on video were matched in body
shape and clothing and their faces were
blurred
 Subject can’t process facial/emotional
features

All subjects were right-handed males aged
18-28 with normal vision and no mental
illness history
 Diminishes individual differences
Limitations


Article focused on predicted area
(motor), but the expertise effect
activated other areas, some
related to emotional experience
 Ventromedial frontal lobe
 Responds to
pleasurable/rewarding
stimuli & social judgement
 Parahippocampal gyrus
 Responds to meaningful
rather than meaningless
actions
Next Step: Analyzing how the
expertise effect is associated
with emotional experience.