ColourBlind: Machine Imagination, Closed Eye Hallucination and the Ganzfeld Effect (original) (raw)

Flickering light induces visual hallucinations in human observers. Despite a long history of the phenomenon, little is known about the dependence of flicker-induced subjective impressions on the flicker frequency. We investigate this question using Ganzfeld stimulation and an experimental paradigm combining a continuous frequency scan (1–50 Hz) with a focus on re-occurring, whole percepts. On the single-subject level, we find a high degree of frequency stability of percepts. To generalize across subjects, we apply two rating systems, (1) a set of complex percept classes derived from subjects’ reports and (2) an enumeration of elementary percept features, and determine distributions of occurrences over flicker frequency. We observe a stronger frequency specificity for complex percept classes than elementary percept features. Comparing the similarity relations among percept categories to those among frequency profiles, we observe that though percepts are preferentially induced by particular frequencies, the frequency does not unambiguously determine the experienced percept.

A natural starting point for theories of perceptual states is ordinary perception, in which a subject is successfully related to her mind-independent surroundings. Correspondingly, the simplest theory of perceptual states models all such states on perception. Typically, this simple, common-factor relational view of perceptual states has received a perfunctory dismissal on the grounds that hallucinations are nonperceptual. But I argue that the nonperceptual view of hallucinations has been accepted too quickly. I consider three observations thought to support the view, and argue that all three are dealt with equally well by an alternative view, illusionism, on which hallucinations do involve perception. Since this is so, adopting a common-factor relational view of all perceptual states remains a tenable option.

Spectral Catalysis Investigates infrasound (frequencies below the audible range) and other sound-like modulations that have increasingly blanketed the earth since industrialization. I cast this field as a man-made unknown in which human technologies begin to exceed our knowledge of them and enter into unforeseen, sometimes uncanny, material relations. Broadly defined hauntings - "ghosts" attributed to infrasound, and a global mystery called The Hum - are the focus, while an extensive scientific literature on low-frequency noise and vibration is treated as a catalogue of anomalies, tales, and working concepts. A constant theme is the confounding perception of presence- absence, or activity by an unseen agent, that can arise from inadvertent or unconscious encounters with low vibrations that escape the ear while impinging unevenly on other perceptual registers. Here, sound works to unsettle the sonic body's sense of self and surroundings. It unhomes, forcing fleshborne thought to ask difficult questions: "Am I haunted or hallucinating?" Building on Brian Massumi, combined with research on paranormal experience and the startle reflex, I theorize this as the catalytic moment when a new operative reality (a collectively livable “haunting”) begins to take hold. Drawing on Gilles Deleuze/Francis Bacon's concepts of "the figural" and "the logic of sensation" I develop several aspects of the spectral to account for weird minglings of frequency, flesh, and imagination.

Research on computational painters usually focuses on simulating rational parts of the generative process. From an art-historic perspective it is plausible to assume that also an arational process, namely visual hallucination , played an important role in modern fine art movements like Surrealism. The present work investigates this connection between creativity and hallucination. Using psychological findings, a three-step process of perception-based creativity is derived to connect the two phenomena. Insights on the neurological correlates of hallucination are used to define properties necessary for modelling them. Based on these properties a recent technique for feature visualisation in Convolutional Neural Networks is identified as a computational model of hallucination. Contrasting the thus enabled perception-based approach with the Painting Fool allows to introduce a distinction between two distinct creative acts, sketch composition and rendering. The contribution of this work is threefold: First, a computational model of hallucination is presented and discussed in the context of a computational painter. Second , a theoretic distinction is introduced that aligns research on different strands of computational creativity and captures the differences to current computational painters. Third, the case is made that computational methods can be used to simulate abnormal mental patterns , thus investigating the role that "madness" might play in creativity – instead of simply renouncing the myth of the mad artist.