Psychogenic depersonalization is an altered mental state consisting of an unusual discontinuity in the phenomenological perception of personal being; the individual is engulfed by feelings of unreality, self-detachment and unfamiliarity in which the self is felt to lack subjective perspective and the intuitive feeling of personal embodiment. A new sub-feature of depersonalization is delineated. 'Prosthesis' consists in the thought that the thinker is a 'mere thing'. It is a subjectively realized sense of the specific and objective 'thingness' of the particular (...) object thought about. I show that prosthesis is an important cognitive feature of depersonalization, and may be psychologically connected with the tendency of depersonalized individuals to report 'philosophical' types of thinking. Indeed, several philosophical issues concerning the identity of the self appear to have been enhanced by prosthesis experiences. Thus, far more efficient than William James's experimental attempts to uncover philosophical truths under the influence of nitrous oxide intoxication, prosthesis may be a safe and recommended experience for philosophers. The history of depersonalization theories is presented from Krishaber to Freud, and the main approaches to prosthesis criticized. Finally, a fresh approach to psychogenic depersonalization is outlined on the basis of certain cognitive similarities with visual agnosia. This paper may be understood as continuing the Jamesian tradition 'experimental abnormal psychology', that is, of examining extraordinary mental states with an eye to their philosophical implications. (shrink)

What we perceive is the product of an intrinsic process and not part of external physical reality. This notion is consistent with the philosophical position of transcendental idealism but also agrees with physiological findings on the thalamocortical system. -Frequency rhythms of discharge activity from thalamic and cortical neurons are facilitated by cholinergic arousal and resonate in thalamocortical networks, thereby transiently forming assemblies of coherent oscillations under constraints of sensory input and prefrontal attentional mechanisms. Perception and conscious experience may be based (...) on such assemblies and sensory input to thalamic nuclei plays merely a constraining role in their formation. In schizophrenia, the ability of sensory input to modulate self-organisation of thalamocortical activity may be generally reduced. If during arousal thalamocortical self-organisation is underconstrained by sensory input, then attentional mechanisms alone may determine the content of perception and hallucinations may arise. (shrink)

Cognitive functions associated with the frontal lobes of the brain may be specifi cally involved in hypnosis. Thus, the frontal area of the brain has recently been of great interest when searching for neural changes associated with hypnosis. We tested the hypothesis that EEG during pure hypnosis would differ from the normal non-hypnotic EEG especially above the frontal area of the brain. The composition of brain oscillations was examined in a broad frequency band (130 Hz) in the electroencephalogram (EEG) of (...) a single virtuoso subject. Data was collected in two independent data collection periods separated by one year. The hypnotic and non-hypnotic conditions were repeated multiple times during each data acquisition session. We found that pure hypnosis induced reorganization in the composition of brain oscillations especially in prefrontal and right occipital EEG channels. Additionally, hypnosis was characterized by consistent rightside-dominance asymmetry. In the prefrontal EEG channels the composition of brain oscillations included spectral patterns during hypnosis that were completely different from those observed during non-hypnosis. Furthermore, the EEG spectral patterns observed overall during the hypnotic condition did not return to the pre-hypnotic baseline EEG immediately when hypnosis was terminated. This suggests that for the brain, the return to a normal neurophysiological baseline condition after hypnosis is a time-consuming process. The present results suggest that pure hypnosis is characterized by an increase in alertness and heightened attention, refl ected as cognitive and neuronal activation. Taken together, the present data provide support for the hypothesis that in a very highly hypnotizable person (a hypnotic virtuoso) hypnosis as such may be accompanied by a changed pattern of neural activity in the brain. (shrink)

Cortex functional connectivity associated with hypnosis was investigated in a single highly hypnotizable subject in a normal baseline condition and under neutral hypnosis during two sessions separated by a year. After the hypnotic induction, but without further suggestions as compared to the baseline condition, all studied parameters of local and remote functional connectivity were significantly changed. The significant differences between hypnosis and the baseline condition were observable (to different extent) in five studied independent frequency bands (delta, theta, alpha, beta, and (...) gamma). The results were consistent and stable after 1 year. Based on these findings we conclude that alteration in functional connectivity of the brain may be regarded as a neuronal correlate of hypnosis (at least in very highly hypnotizable subjects) in which separate cognitive modules and subsystems may be temporarily incapable of communicating with each other normally. (shrink)

Are mystical experiences primarily formed by the mystic's cultural background and concepts, as modern day "constructivists" maintain, or do mystics in some way transcend language, belief, and culturally conditioned expectations? Do mystical experiences differ in the different religious traditions, as "pluralists" contend, or are they identical across cultures? Twelve contributors here attempt to answer these questions through close examination of a particular form of mystical experience, "Pure Consciousness"--the experience of being awake but devoid of intentional content for consciousness. The contributors (...) analyze pure consciousness and other mystical experiences from historical Hindu, Buddhist, Christian, and Jewish sources, as well as from modern mystics. They demonstrate that pure consciousness poses serious conceptual problems for a contructivist understanding of mysticism. Revealing the inconsistencies and inadequacies of current models, they make significant strides towards developing new models for the phenomenon of mysticism, breaking new ground for our understanding of mysticism and of human experience in general. (shrink)

What happens when a worldly Israeli cognitive psychologist goes to the Amazon Basin where he ingests the famed psychotropic concoction Ayahuasca (the ‘vine of the dead’) again and again and again? Our intrepid philosophical psychologist is no longer a sprightly youth, maddened for adventure. He is instead an accomplished theoretician with widely published articles (several in this journal) and a noted book (Shanon, 1993) that speak the from the perspective of cognitive (or phenomenological, for Shanon) psychology against the reductive tendency (...) to view the mind’s activities as created by the the brain’s activities. Even before his Amazonian quest, he placed himself in the Gibsonian camp seeing the mind as dynamic intermediary between organism and environment and active participant in both. What did happen is this extraordinary book, a scientific analysis of his own visions and the education of both Shanon’s views and, perhaps, his soul. (shrink)

CHAPTER 1 Neurotransmitter networks Elaine Perry and Allan Young i. Introduction This first chapter sets the scene for subsequent exploration of potential ...