Neurobiological data & Husserlian constitution - IV
A neural correlate of the noema of the other
At the level of the individual neuron, biological support has been uncovered
for the understanding of the intentional signification of the actions of an other
agent (di Pellegrino et al. 1992; Gallese et al. 1996; Rizzolatti and Gallese
1997). To the extent that an organism is capable of understanding the intentional
signification of its own actions, it acquires the possibility of immediately
understanding the signification of the actions of others, that is, without
the mediation of any perception of an initially non-interpreted bodily movement
followed by a judgement which attributes meaning on the basis of a
special interpretation. In the pre-motor cortex of the macaque monkey (frontal
area 5) a class of “mirror neurons” was found, the characteristic of which
is that they are activated both when the animal accomplishes certain goaldirected
hand movements and when he observes the experimenter in the process
of accomplishing what one is obliged to call the same action. Where the
latter is defined as a series of articulated movements aimed at one and the same
goal no matter what the limb, or muscles of the movements brought into play.
These neurons make up a vocabulary of all the actions necessary for the animal
to bring its food to its mouth: “grasp with the hand,” “grasp with the hand
and the mouth,” “reach,” “catch with precision,” or “with the full hand,” etc.
When another monkey was placed in the presence of the recorded one, a
synchronised firing of the neurons of area 5 was noted each time this other
monkey grasped some food. Trying to establish the existence of mirror-neurons
in humans, it has been discovered that observing the experimenter grasping
an object induced in the human subject an increase in the motor potential
evoked by magnetic stimulation of the cortex in the muscles which bring into
play the execution of the same movement (Fadiga et al. 1995). In both cases,
positron emission tomography shows an activation in Broca’s area, the analog
of monkey’s frontal area 5 known for associating a somatotopic representation
of the hand (predominant with the monkey) and a somatotopic
representation of the mouth (predominant with the human).
What could be the functional role of these mirror-neurons in humans, neurons
whose schema of activation seems capable of representing the identity
between the meaning of one’s own actions and those of the other, but not the
emotional state nor the predisposition of the subject to action? The scientists
speculate that this comprehension of the actions of others lies at the root of
speech (Rizzolatti et al., 1996). We understand each other through language
because, in advance, we have already understood each other’s actions by visual
observation, which is the most basic intersubjective precondition. Without
pressing too far the question of an empirical confirmation of phenomenology,
it must be admitted that these findings justify Husserl’s upholding of the idea
that our empathic experience of the other is an internal imitation of the movement
accomplished by the other. This implies an actualisation of the kinesthetic
sensations corresponding to the movement in question, and not its effective
execution nor even (against Max Scheler) an affective fusion with the other. In
addition, Husserl was also amply justified in holding that the constitution of the
world is intersubjective and practical and not solipsistic and representational.
Notes
1. This paper was presented at The Naturalistic Tension: An International Symposium on
Phenomenology and Cognitive Science, University of Tampere, May 16–17, 2002. I
would like to express my appreciation to Dr. Christopher Macann for the English translation,
and to Professor Leila Haaparanta, and the participants at this colloquium for their
friendly reception and interesting comments.
2. Concerning the role of kinesthesia in (late) Husserlian constitution theory, we rely on
Husserl’s manuscripts of the thirties, series B and D, at Archives Husserl de Paris, ENS,
45, rue d’Ulm.
3. Husserl himself expresses his theory of constitution in terms of System (ms D13, 1921).
To the system of appearances of spatial things in perspective whose sense of being we
constitute by moving our eyes, our neck and our whole body there corresponds the system
of postures and movements of our body parts, such as sense organs. This correspondence
is no mere mapping, but a motivating running through of our motor and sensory
organs by our kinesthetic sensations as we orient ourselves in relation to objects. An analogy
in scientific physiology might be the motor or sensory systems, as the physiologist
understand them. With the following reservation: that most neuroscientists, when they
are not uniquely interested in the anatomical structures (receptors, effectors, conduction
paths, cortical maps, etc.), have a piecemeal (“modular”) approach to the functions sustained
by these structures, one that is wholly opposed to the holistic and highly differentiated
approach of Husserl.
4. On experience as a factor of cerebral plasticity cf. Elbert et al. (1995); Mogilner et al.
(1993); Pascual-Leone and Torres (1993); Pascual-Leone, Grafman, and Hallett (1994);
Sterr et al. (1998); Wall, Felleman, and Kaas (1983), and the papers by Merzenich and
collaborators in the references.