Functional MRI and the Study of Human Consciousness

Abstract

Functional brain imaging offers new opportunities for the study of that most pervasive of cognitive conditions, human consciousness. Since consciousness is attendant to so much of human cognitive life, its study requires secondary analysis of multiple experimental datasets. Here, four preprocessed datasets from the National fMRI Data Center are considered: Hazeltine et al., Neural activation during response competition; Ishai et al., The representation of objects in the human occipital and temporal cortex; Mechelli et al., The effects of presentation rate during word and pseudoword reading; and Postle et al., Activity in human frontal cortex associated with spatial working memory and saccadic behavior. The study of consciousness also draws from multiple disciplines. In this article, the philosophical subdiscipline of phenomenology provides initial characterization of phenomenal structures conceptually necessary for an analysis of consciousness. These structures include phenomenal intentionality, phenomenal superposition, and experienced temporality. The empirical predictions arising from these structures require new interpretive methods for their confirmation. These methods begin with single-subject (preprocessed) scan series, and consider the patterns of all voxels as potential multivariate encodings of phenomenal information. Twenty-seven subjects from the four studies were analyzed with multivariate methods, revealing analogues of phenomenal structures, particularly the structures of temporality. In a second interpretive approach, artificial neural networks were used to detect a more explicit prediction from phenomenology, namely, that present experience contains and is inflected by past states of awareness and anticipated events. In all of 21 subjects in this analysis, nets were successfully trained to extract aspects of relative past and future brain states, in comparison with statistically similar controls. This exploratory study thus concludes that the proposed methods for "neurophenomenology" warrant further application, including the exploration of individual differences, multivariate differences between cognitive task conditions, and exploration of specific brain regions possibly contributing to the observations. All of these attractive questions, however, must be reserved for future research.

Functional MRI of the kidney: tools for translational studies of pathophysiology of renal disease

“…Over the last decade, the field of fMRI has grown explosively and is fast becoming a regular feature in the news media. fMRI has diverse applications, such as probing human cognition (80,139), understanding how acupuncture may be beneficial (19,20), and serving as an expensive "lie" detector (53,64,81). Other organs and tissues within the body are also associated with specific functions and, while their evaluation may not be of interest to the lay audience, they may have significant implications in terms of understanding the physiology and pathophysiology of human disease.…”

Mountains and valleys: Binocular rivalry and the flow of experience

“…We propose that this analysis can have significant implications for the neuroscience of consciousness (see also Lloyd, 2002;Thompson, 2007;Varela, 1999;Vogeley & Kupke, 2007). In particular, it suggests that we might try to approach the experimental study of consciousness by taking the unique phenomenal temporality of conscious experience as our reference point.…”

“…A growing number of neuroscientists have argued for the need for single-trial approaches that take into account not only the invariant aspects of each individual event, but also their ineliminable variability. Single-trial analyses have been developed in several domains of cognitive neuroscience, such as the study of phase-relations between brain signals (Hurtado, Rubchinsky, & Sigvardt, 2004;Lachaux et al, 2000Lachaux et al, , 2002, the estimation of underlying brain sources from scalp EEG/MEG recordings David et al, , 2003Ioannides, 2001;Ioannides et al, 1995;Jensen & Vanni, 2002), evoked potential analysis and classification (Jung et al, 2001;Laskaris & Ioannides, 2001;Makeig et al, 2002) and the analysis of event-related BOLD responses (Bingel et al, 2004;Burke, Murphy, Garavan, & Reilly, 2004;Duann et al, 2002;Lloyd, 2002). In the case of complex dynamical systems-of which the nervous system is probably the most paradigmatic example (Friston, 2000)-this methodological constraint seems a basic requirement.…”

The Naturalization of Phenomenology

“…Cal fer-ne, això no obstant, una matisació: no es tracta del mer ús de la introspecció per donar descripcions en primera persona de dades de l'experiència. La mínima descripció d'allò que intenta fer la Fenomenologia és, utilitzant la terminologia de Lloyd (2002), «Fenomenologia analítica». En aquest sentit, la Fenomenologia es preguntaria com ha de ser la consciència o la ment per tal que sigui possible una experiència conscient o tractaria de fer una descripció completa i acurada «del món tal com apareix», un món del qual l'observador n'és una part 4 .…”