Examining
the hypothesized role of the human mirror neuron
system in contagious yawning: EEG
investigations.
Nicholas
Cooper
Department
of Psychology, University of Essex, Colchester,
UK
There is debate within the field of social
neuroscience as to whether there is a link
between contagious yawning and the human mirror
neuron system (hMNS). Several studies have
observed a relationship between the propensity
to yawn in a social situation and empathy but
until recently had failed to find brain
activation in areas thought to encompass the
hMNS. A recent neuroimaging paper however has
found evidence of hMNS involvement in contagious
yawning.
One potentially useful way of examining this
issue is with the use of EEG to measure changes
in mu activation during the observation of
yawns. Mu oscillations are typically seen in
the alpha and low beta bandwidths of the EEG
(8-12Hz & 13-20Hz) over sensorimotor areas.
Previous work has shown that mu-suppression is a
useful index of mirror neuron activation and is
sensitive for example, to individual differences
in empathy.
In 2 experiments, we presented participants
with videos of people either yawning or gaping
(opening and shutting their mouths). We found
greater mu-suppression for yawns compared to
gapes at various scalp sites over right motor
and pre-motor areas particularly for those
scoring higher for traits of empathy. In a 3rd
experiment, auditory recordings of yawns were
presented and compared against electronically
scrambled versions of the same yawns (control
stimuli). We observed greater mu-suppression
for yawns compared to control stimuli over right
lateral pre-motor areas. Again these findings
were driven by those scoring highly for empathy.
The results from these three experiments
support the notion of the involvement of the
human mirror neuron system in contagious yawning
and emphasise the link between contagious
yawning and empathy.
There is debate within
the field of social neuroscience as to whether
there is a link between contagious yawning and
the human mirror neuron system (hMNS). Several
studies have observed a relationship between the
propensity to yawn in a social situation and
empathy but until recently had failed to find
brain activation in areas thought to encompass
the hMNS.
A recent neuroimaging
paper however has found evidence of hMNS
involvement in contagious yawning. One
potentially useful way of examining this issue
is with the use of EEG to measure changes in mu
activation during the observation of yawns. Mu
oscillations are typically seen in the alpha and
low beta bandwidths of the EEG (8-12Hz &
13-20Hz) over sensorimotor areas. Previous work
has shown that mu-suppression is a useful index
of mirror neuron activation and is sensitive for
example, to individual differences in empathy.
We will be presenting a
series of EEG experiments examining mu
activation to yawns and control stimuli and
showing how this activation varies according to
empathy levels.
