Oops. Once again not following Dale Carnegie; 'How to Win Friends and Influence People'.
http://journal.frontiersin.org/article/10.3389/fpsyg.2016.01129/full?
- 1Social and Cognitive Neuroscience Laboratory, Department of Psychology, Sapienza University of Rome, Rome, Italy
- 2Istituto di Ricovero e Cura a Carattere Scientifico, Fondazione Santa Lucia, Rome, Italy
A commentary on
Hand and Grasp Selection in a Preferential Reaching Task: The Effects of Object Location, Orientation, and Task Intention
Hand and Grasp Selection in a Preferential Reaching Task: The Effects of Object Location, Orientation, and Task Intention
by Scharoun, S. M., Scanlan, K. A., and Bryden, P. J. (2016). Front. Psychol. 7:360. doi: 10.3389/fpsyg.2016.00360
Reach-to-grasp actions are the outcomes of several voluntary sub-movements (Jeannerod, 1981, 1984; Paulignan et al., 1997) dependent on the object intrinsic position and shape characteristics (Fattori et al., 2009).
The behaviors implemented in order to achieve the proximal goal (i.e.,
grasping) are further modulated by the action one wants to perform once
the object has been grasped (distal goal; Cohen and Rosenbaum, 2004; Cattaneo et al., 2007).
These findings suggest that the reason why an object is grasped has an
effect on initial prehension kinematics (i.e., “end-goal effect”).
Grasping an object often serve the purpose of
interpersonal interactions, which are defined by matching behavioral
adaptation between subjects (Baldwin, 1992) and, more importantly, joint actions, where the presence of a common goal bounds individuals' behaviors (Sebanz et al., 2006).
In these interactive scenarios, the intentions one attributes to his
partner are crucial in shaping his own hand-preference for grasping
objects as well as the kinematics of his movements. For these different
features to be integrated in one movement, reach-to-grasp has been used
as a paradigmatic example of the interface between motor behavior and
cognition.
Recently, Scharoun et al. (2016)
aimed at studying hand-preference in an ecological set-up including
individual and so-called “joint actions” conditions. Here, we argue that
adding a social aspect to an individual condition does not capture the
essence of joint actions. The authors asked subjects to reach-and-grasp a
mug in order to perform four different actions without giving them any
instructions on how to perform their grasping. Such paradigms contribute
to the field of motor control by clarifying grasping hand-preference
embedded in the strategy of grasping. Furthermore, Scharoun and her
colleagues proposed four different experimental conditions to test the
role of the distal goal on hand-preferences: (1) pick-up (unimanual,
independent); (2) pick-up and pour (bimanual, independent); (3) pick-up
and pass (unimanual, joint action); and (4) pick-up, pour, and pass
(bimanual, joint action). The behavioral results of the study show that
the first two conditions offer clear support for the dominant hand
preference hypothesis during unimanual actions. The study needs to be
praised for showing all the aforementioned effects in a realistic
paradigm.
However, we think that calling “joint actions” their
third and fourth conditions is misleading and represent a misuse of the
“joint action” terminology and its actual conceptualization. Indeed, to
their “independent” condition, Scharoun and colleagues chose to oppose
the term “joint action” when participants had to pass the mug to a
confederate who was simply sitting in front of them.
We contend that joint actions are characterized by
specific features and need to be called into play with caution. One
crucial feature of joint actions is that they are activities involving
two or more individuals who need to voluntarily coordinate their actions
in time and space in order to achieve a desired change in the
environment (Sebanz et al., 2006).
In Scharoun's study, we argue that their set-up is not in phase with
this definition, making their “joint action” condition contestable and
more similar to a “social condition.” We do not deny the interest of
studying the way in which objects are grasped before passing them to another person (Becchio et al., 2008b) which is clearly inherent to social collaboration.
By choosing a passive experimenter as a confederate,
Scharoun and colleagues' set-up fails to measure the dynamic encounters
that adjust behavioral and cognitive processes of agents involved in
joint actions (Knoblich and Sebanz, 2006; Sebanz et al., 2006; Vesper et al., 2010; Di Paolo and De Jaegher, 2012; Dolk et al., 2014; Sacheli et al., 2015b).
Even though the “pick up and pass” and the “pick-up, pour and pass”
conditions show a different hand-preference pattern compared to the
individual ones, these modulations may be a consequence of the
confederate mere presence (i.e., social affordance; Becchio et al., 2008b; Ferri et al., 2011). Therefore, by lacking a condition directly testing the role of a social request (Ferri et al., 2011) to identify the direct influence of the possible interaction with a confederate, these modulations should not be interpreted as a result of a joint action.
Since humans and primates share grasping behaviors, a
great number of monkeys and humans studies have been using
reach-to-grasp actions which gained us a good understanding of grasping
physiology (Castiello, 2005). For these reasons, grasping has also been used in “social contexts” (Becchio et al., 2008a, 2012; Rozzi and Coudé, 2015)
during interpersonal interactions or, crucially, adopting joint actions
paradigms. Recording kinematics and/or brain dynamics during these
interactions improved the knowledge of social neurosciences in
non-verbal communication, coordination, competition, and leader–follower
situations (Rizzolatti and Fadiga, 1998; Ménoret et al., 2014; Candidi et al., 2015a; Sacheli et al., 2015a,b).
After years of philosophical and scientific debates,
social neurosciences need to now focus on “online,” dynamically mutual,
motor interactions (Schilbach et al., 2013), where “individualism” steps aside for “interactionism” to rise (Gallotti and Frith, 2013).
This suggests creating experimental paradigms that allow partners'
reciprocal and bidirectional adjustments during the interaction (Sacheli et al., 2015a). Such online paradigms allow closed-loop processes (Hari and Kujala, 2009; Tognoli and Kelso, 2015) that bound together individuals and constrain their individual behavior (Candidi et al., 2015b).
Experimentally speaking, this requires bidirectional set-ups, where
contributors' motor action and perception allow a shared representation
of the action between all participants (Sebanz et al., 2003, 2005, 2007).
In conclusion, we agree with Scharoun and her
colleagues' claims on the importance of creating ecological set-ups. But
in the field of joint actions these should be developed with the
constant constraint of involving reciprocal and bidirectional adaptation
between two agents. Thus, we argue that Scharoun and colleagues'
“non”-independent condition was not a joint action per se.
In order to bring the field of joint action to the
forefront of social neurosciences and build credibility concerning the
related literature, one should beware of their essential features and
use the joint action terminology prudently and parsimoniously. This is a
fundamental condition to attain greater continuity and coherence in our
field.
References available at the link.
References available at the link.
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