Disinhibiting the Body: Toward an Ontology of Subtractive Ambidexterity [Disinibire il corpo. Per un'ontologia dell'ambidestria sottrattiva]

Summary

The human body can become ambidextrous through two distinct mechanisms. The additive path builds missing bilateral skill through repetition and Hebbian plasticity, adding a new ability. The subtractive path releases already latent bilateral symmetry by reducing chronic co-contraction and interhemispheric inhibition that kept the non-dominant side silent. Grounded in Yang-style Taiji practice and theorized through Merleau-Ponty's intentional arc and body schema, Varela's neurophenomenology, and Gallagher's body schema/body image distinction, the subtractive mechanism does not abolish lateralization but renders it elective: dominance becomes revocable rather than imposed. The work proposes a threefold taxonomy of ambidexterity (symptomatic, additive, subtractive) and formulates falsifiable predictions testable through electromyography, transcranial magnetic stimulation, and kinematic analysis.

Study at a glance

Abstract

[EN]This thesis distinguishes two distinct mechanisms by which the human body attains ambidexterity. The first, the ADDITIVE path, builds the missing bilateral competence through repetition and Hebbian plasticity: it adds a skill that was absent. The second, the SUBTRACTIVE path, adds nothing. It releases an already latent bilateral symmetry by reducing chronic co-contraction and interhemispheric inhibition — the constraints that kept the non-dominant side silent. This mechanism is grounded in the practice of Yang-style Taiji (Patrick Kelly lineage) and theorised through Merleau-Ponty's intentional arc and body schema, Varela's neurophenomenology, and Gallagher's distinction between body schema and body image. The central claim is that the subtractive mechanism does not abolish lateralization: it renders it ELECTIVE. Dominance is not erased — it becomes revocable. The practitioner retains the freedom to choose which side to engage, rather than suffering an imposed dominance. The work proposes a threefold taxonomy of ambidexterity (symptomatic / additive / subtractive) and formulates falsifiable predictions, testable through electromyography (reduction of co-contraction), transcranial magnetic stimulation (decreased interhemispheric inhibition) and kinematic analysis. Full text in Italian. --- [IT]La tesi distingue due meccanismi distinti attraverso cui il corpo umano raggiunge l'ambidestria. Il primo, la via ADDITIVA, costruisce la competenza bilaterale mancante tramite ripetizione e plasticità hebbiana: aggiunge un'abilità che era assente. Il secondo, la via SOTTRATTIVA, non aggiunge nulla. Libera una simmetria bilaterale già latente, riducendo la co-contrazione cronica e l'inibizione interemisferica — i vincoli che tenevano silenzioso il lato non dominante. Questo meccanismo è radicato nella pratica del Taiji stile Yang (lignéa Patrick Kelly) ed è teorizzato attraverso l'arco intenzionale e lo schema corporeo di Merleau-Ponty, la neurofenomenologia di Varela e la distinzione di Gallagher fra schema e immagine corporea. La tesi centrale è che il meccanismo sottrattivo non abolisce la lateralizzazione: la rende ELETTIVA. La dominanza non viene cancellata — diventa revocabile. Il praticante conserva la libertà di scegliere quale lato ingaggiare, invece di subire una dominanza imposta. Il lavoro propone una tassonomia tripartita dell'ambidestria (sintomatica / additiva / sottrattiva) e formula predizioni falsificabili, verificabili tramite elettromiografia (riduzione della co-contrazione), stimolazione magnetica transcranica (calo dell'inibizione interemisferica) e analisi cinematica. Testo integrale in italiano. --- Project website: https://www.bilateral.education