The neural correlates of joint action

Primates constantly observe each other*s actions. The movements of other
conspecifics provide critical information for them. Humans in particular *read*
the actions of others and act together with other humans (Puce & Perrett,
2003). Talking, dancing, playing football and many other collective actions are
examples of what are called joint actions: actions where two or more people
coordinate their actions in space and time to produce a change in the
environment (Sebanz, N. et al., 2006). Astonishingly we can engage in many
joint actions effortlessly although each of these activities requires
coordination of two separate bodies and minds. The neural basis of this
capacity remains unknown.

Puce, A. and Perrett, D. (2003). Electrophysiology and brain imaging of
biological motion. Phil. Trans. R. Soc. Lond. B, 358: 434-445.
Sebanz, N., Bekkering, H., Knoblich, G. (2006). Joint actions: Bodies and minds
moving together. Trends in Cognitive Sciences (10), 2, 70-76.

for further information please see:
protocol page 6&7

This study aims to investigate the relevance of mirror neurons for our capacity
to engage in joint actions and cooperation by using functional magnetic
resonance imaging (fMRI). We suggest that the mirror neuron system might
provide a basis for joint actions as it does in many aspects of social
interactions suggested by recent studies (action understanding (i.e. Gazzola et
al., 2006), imitation (i.e. Iacoboni et al., 1999) and empathy (i.e. Gazzola et
al., 2006).


for further information please see:
protocol page 6&7

In this study right-handed subjects will play a cooperation game together with
the experimenter (right-handed) in the scanner room. The aim of the players
will be to win the game which is achievable only when 2 players perform joint
actions and cooperate.
For this game we will use a custom made MRI-compatible device (game box) which
will be placed on the lower abdomen of the subject who is lying on the scanner
table. The subject can touch the game box with his right hand and, through a
mirror, see the game box, his own fingers and that of the experimenter who will
stand next to the subject.
The task of each player is to take his stick with his index finger from the
initial position and to drag it to a side to press a destination button.
However, two players have to perform complementary actions in pressing the
destination buttons because the sticks have to create a final shape at the end
of the trial. Moreover, although each player has to move his stick singly and
as quickly as possible, players have to act together and press the buttons
simultaneously in order to win the game.

for further information please see:
Study Design part in the protocol page 9-11.

Subjects will be exposed to a magnetic field of 3 Tesla and rapidly alternating
magnet gradients and radio frequency fields. This field strength is used on a
routinely basis in fMRI and MRI research. So far, no side effects have been
described. On rare occasions, a peripheral nerve (abdomen) is stimulated by the
changing magnet gradients. This will cause an itching feeling, but it is not
harmful.


for further information please see:
2.5 Ethical and Safety Aspects part of the protocol page 12&13