Dark condition normalization of smooth pursuit tracking: evidence of cerebellar dysfunction in psychosis

“Dark Nights of the Soul”: Phenomenology and Neurocognition of Spiritual Suffering in Mysticism and Psychosis

Phenomenological, clinical, and neurocognitive levels of analysis are combined to understand the cognitive bases of spirituality and spiritual suffering. In particular, the “dark night of the soul” in classical mysticism, with its painful “metapathological” loss of felt meaning is compared with the anhedonias central to the negative symptoms of schizophrenia and schizotypicality. Paul Schilder's early understanding of instabilities in the body image, as our core sense of self, offers a key to both the disorganized hallucinatory syndromes of psychosis and to the relative enhancements of body image/ecological self in spirituality. Expanded versus deleted felt presence/embodiment, as outwardly indexed in measures of physical balance and spatial abilities, becomes the general dimension underlying integrative versus disintegrative transformations of consciousness. “Dark night” suffering can be seen as a semantic satiation leading to a relative deletion of experienced presence in the context of its previous enhancement, a focalized version of the more general anhedonic despair shared by clinical schizotypy and aspects of a larger secularized culture.

Comparison of the smooth eye tracking disorder of schizophrenics with that of nonhuman primates with specific brain lesions

The smooth pursuit eye tracking deficit (ETD) often associated with schizophrenia has generated enormous interest over the last 20 years. The deficit is observed in about 80% of schizophrenics and in half of their first degree relatives. It is not affected by neuroleptic medication and is not due to inattention. A review of 52 studies (and actual records when available) on ETD in schizophrenia reveals that the deficit can consistently be described as low gain pursuit augmented with catch-up saccades and often peppered with intrusive saccades. A review of the brain areas that have been shown to be involved in pursuit provides the necessary background for the subsequent section which details the nature of the smooth tracking deficits following experimental lesions. This section reveals that the ETD following lesions of the frontal lobe is unique in that it closely resembles the ETD of schizophrenics. This finding lends further support for frontal lobe theories of schizophrenia.