Claire Petitmengin

Neuronal dynamics and conscious experience: an example of reciprocal causation before epileptic seizures.

Neurophenomenology (Varela 1996) is not only philosophical but also empirical and experimental. Our purpose in this article is to illustrate concretely the efficiency of this approach in the field of neuroscience and, more precisely here, in epileptology. A number of recent observations have indicated that epileptic seizures do not arise suddenly simply as the effect of random fluctuations of brain activity, but require a process of ‘pre-seizure’ changes that start long before. This has been reported at two different levels of description: on the one hand, the epileptic patient often experiences some warning symptoms that precede seizures from several minutes to hours in the form of very specific lived events. On the other hand, the analyses of brain electrical activities have provided strong evidence that it is possible to detect a pre-seizure state in the neuronal dynamics several minutes before the electro-clinical onset of a seizure. We review here some of the ongoing work of our research group concerning seizure anticipation. In particular, we discuss experimental evidence of ‘upward’ (local-to-global) formation of conscious experience and its neural substrate, but also of the “downward” (global-to-local) determination of local neuronal activity by situated conscious activity and its substrate large-scale neural assemblies. This causal role of conscious experience may lead to new kinds of therapy for epileptic patients.

Microcognitive science: bridging experiential and neuronal microdynamics

Neurophenomenology, as an attempt to combine and mutually enlighten neural and experiential descriptions of cognitive processes, has met practical difficulties which have limited its implementation into actual research projects. The main difficulty seems to be the disparity of the levels of description: while neurophenomenology strongly emphasizes the micro-dynamics of experience, at the level of brief mental events with very specific content, most neural measures have much coarser functional selectivity, because they mix functionally heterogeneous neural processes either in space or in time. We propose a new starting point for this neurophenomenology, based on (a) the recent development of human intra-cerebral EEG (iEEG) research to highlight the neural micro-dynamics of human cognition, with millimetric and millisecond precision and (b) a disciplined access to the experiential micro-dynamics, through specific elicitation techniques. This lays the foundation for a microcognitive science, the practical implementation of neurophenomenology to combine the neural and experiential investigations of human cognition at the subsecond level.

Toothbrush-thinking seizures.

Summary:  Seizures associated with toothbrushing have been reported in patients with precentral or postcentral partial epilepsy. Seizures precipitated by thinking have been described in patients with idiopathic generalized epilepsy. We report a patient with intractable partial epilepsy in which seizures were induced both by toothbrushing, and by seeing or thinking about toothbrush and toothpaste. Video‐EEG analysis revealed a left temporal lobe origin for these reflex seizures. We discuss how complex multimodal stimuli may trigger these reflex seizures.

A Neurophenomenological Study of Epileptic Seizure Anticipation

This article sets out to retrace the course of a neurophenomenological project initiated by Francisco Varela, the purpose of which is the anticipation of epileptic seizure, and to evaluate the relevance of the neurophenomenological approach from the methodological, therapeutic and epistemological viewpoints. New mathematical methods for analysing the neuro-electric activity of the brain have recently enabled researchers to detect subtle modifications of the cerebral activity a few minutes before the onset of an epileptic seizure. Do these neuro-electric changes correspond to modifications in the patients’ subjective experience, and if that is the case, what are they? In a first part, after having recalled the context of the project, I will describe the methods I used for trying to detect the dynamic micro-structure of preictal experience, the difficulties I met and the results I obtained. Then I will show how the “pheno-dynamic” and neuro-dynamic analyses have guided, determined and mutually enriched each other throughout this project. In a third part, I will show that this genetic approach to epileptic seizure opens a new line of research into a cognitive and non-pharmacological therapy for epilepsy. Finally, I will argue through this example that neurophenomenological co-determination could shed new light on the difficult problem of the “gap” which supposedly separates subjective experience from neurophysiological activity.