Limiting the recruitment of degrees of freedom reduces the stability of perception-action patterns

The goal of the present study was to examine how recruiting/suppressing degrees of freedom affects the (differential) stability of two rhythmic perception-action patterns. In particular, participants synchronized either adduction-on-the-beat or abduction-on-the-beat movements of the right index finger with an auditory metronome. The stability of both patterns as performed in the horizontal plane was predicted to depend on the utilization, or recruitment, of the vertical plane of motion. Movements of the index finger were either free or physically restricted to the horizontal plane. The results showed that in the free condition, the vertical plane was recruited more in the more stable pattern (abduction-on-the-beat) than in the less stable pattern (adduction-on-the-beat). In the constrained condition, abduction-on-the-beat pattern was destabilized, whereas the stability of the adduction-on-the-beat pattern was preserved. These results suggest that the recruitment of the vertical plane of motion in the abduction-on-the-beat movements brought about an increase in the stability of this pattern. More generally, the trade-off between the stability of coordination patterns in the horizontal plane is based on a self-organizing process of recruitment in which neuromuscular factors are an intrinsic aspect.     

Freudian modalities of disbelief

This article can be characterized as a ‘rediscovery’ of a notion of psychoanalysis that had disappeared or had been confused by later operations. The authors explore a Freudian notion that has been unjustly misunderstood, especially because of the multiple ways in which ‘Unglaube’ – disbelief – has been translated. We shall establish the archaeology of this term in Freud by extracting its three significant modes. Firstly, paranoiac disbelief designates an unconscious process of the rejection of belief in the subject's first encounter with a sexual reality that is always traumatic. Secondly, the obsessional neurotic's disbelief, which we shall call ‘incredulity’, is a secondary, less radical refusal of belief, one that is different from its paranoiac counterpart. Finally, we shall envision a third – dialectical – type of disbelief, which Freud called ‘act of disbelief’ and which will enable us to approach the fundamental epistemic and ethical stakes for psychoanalysis.     

Questions épistémologiques et méthodologiques sur la validation en psychanalyse

The question of the psychoanalysis as science is recurring. We can consider, at the very least, that it is a practice based on a rational and formal theory. But, according to the project of Freud to give it statute of an empirical science, remains to find the method which would allow, in a field which lends itself badly to the traditional experimentation or even “with single case”, to validate its proposals empirically. Here the difficulties and condition of such a validation are examined, which would allow, moreover, of advancing on the question of the evaluation of its therapeutic effects.