Locked-in Syndrome, BCI, and a Confusion about Embodied, Embedded, Extended, and Enacted Cognition

Abstract

In a recent contribution to this journal, Andrew Fenton and Sheri Alpert have argued that the so-called ``extended mind hypothesis'' allows us to understand why Brain Computer Interfaces (BCIs) have the potential to change the self of patients suffering from Locked-in syndrome (LIS) by extending their minds beyond their bodies. I deny that this can shed any light on the theoretical, or philosophical, underpinnings of BCIs as a tool for enabling communication with, or bodily action by, patients with LIS: BCIs are not a case of cognitive extension. I argue that Fenton and Alpert's claim to the contrary is the result of a widespread confusion about some related, but significantly different, approaches to cognition that all fall under the heading of ``situated cognition.'' I first provide a short taxonomy of various situated approaches to cognition, highlighting (some of) their important commonalities and differences, which should dissolve some of the confusions surrounding them. Then I show why the extended mind hypothesis is unsuitable as a model of BCI enhancements of LIS patients' capacity to interact with their surroundings, and I argue that the situated approach with obvious bearings on the sort of questions that were driving Fenton and Alpert is not the idea that cognition is extended, but the idea that cognition is enacted.