The nature of consciousness is considered one of science’s most perplexing and persistent mysteries. We all know the subjective experience of consciousness, but where does it arise? What is its purpose? What are its full capacities? The assumption within today’s neuroscience is that all aspects of consciousness arise solely from interactions among neurons in the brain. However, the origin and mechanisms of qualia are not understood. David Chalmers coined the term “the hard problem” to describe the difficulties in elucidating the (...) origins of subjectivity from the point of view of reductive materialism. We propose that the hard problem arises because one or more assumptions within a materialistic worldview are either wrong or incomplete. If consciousness entails more than the activity of neurons, then we can contemplate new ways of thinking about the hard problem. This review examines phenomena that apparently contradict the notion that consciousness is exclusively dependent on brain activity, including phenomena where consciousness appears to extend beyond the physical brain and body in both space and time. The mechanisms underlying these “non-local” properties are vaguely suggestive of quantum entanglement in physics, but how such effects might manifest remains highly speculative. The existence of these non-local effects appears to support the proposal that post-materialistic models of consciousness may be required to break the conceptual impasse presented by the hard problem of consciousness. (shrink)

A broad range of evidence regarding the functional organization of the vertebrate brain – spanning from comparative neurology to experimental psychology and neurophysiology to clinical data – is reviewed for its bearing on conceptions of the neural organization of consciousness. A novel principle relating target selection, action selection, and motivation to one another, as a means to optimize integration for action in real time, is introduced. With its help, the principal macrosystems of the vertebrate brain can be seen to form (...) a centralized functional design in which an upper brain stem system organized for conscious function performs a penultimate step in action control. This upper brain stem system retained a key role throughout the evolutionary process by which an expanding forebrain – culminating in the cerebral cortex of mammals – came to serve as a medium for the elaboration of conscious contents. This highly conserved upper brainstem system, which extends from the roof of the midbrain to the basal diencephalon, integrates the massively parallel and distributed information capacity of the cerebral hemispheres into the limited-capacity, sequential mode of operation required for coherent behavior. It maintains special connective relations with cortical territories implicated in attentional and conscious functions, but is not rendered nonfunctional in the absence of cortical input. This helps explain the purposive, goal-directed behavior exhibited by mammals after experimental decortication, as well as the evidence that children born without a cortex are conscious. Taken together these circumstances suggest that brainstem mechanisms are integral to the constitution of the conscious state, and that an adequate account of neural mechanisms of conscious function cannot be confined to the thalamocortical complex alone. (Published Online May 1 2007) Key Words: action selection; anencephaly; central decision making; consciousness; control architectures; hydranencephaly; macrosystems; motivation; target selection; zona incerta. (shrink)

According to many first-person accounts, consciousness comprises a subject-object structure involving a mental action or attitude starting from the “subjective pole” upon an object of experience. In recent years, many paradigms have been developed to manipulate and empirically investigate the object of consciousness. However, well-controlled investigation of subjective aspects of consciousness has been more challenging. One way, subjective aspects of consciousness are proposed to be studied is using meditation states that alter its subject-object structure. Most work to study consciousness in (...) this way has been done using Buddhist meditation traditions and techniques. There is another meditation tradition that has been around for at least as long as early Buddhist traditions with the central goal of developing a fine-grained first-person understanding of consciousness and its constituents by its manipulation through meditation, namely the Tantric tradition of Yoga. However, due to the heavy reliance of Yogic traditions on the ancient Indian Samkhya philosophical system, their insights about consciousness have been more challenging to translate into contemporary research. Where such translation has been attempted, they have lacked accompanying phenomenological description of the procedures undertaken for making the precise subject-object manipulations as postulated. In this paper, I address these issues by first detailing how Tantric Yoga philosophy can be effectively translated as a systematic phenomenological account of consciousness spanning the entirety of the subject-object space divided into four “structures of consciousness” from subject to object. This follows from the work of the 20th century polymath and founder of the Tantric Yoga school of Ananda Marga, Prabhat Ranjan Sarkar, who expounded on the “cognitivization” of Samkhya philosophy. I then detail stepwise meditation procedures that make theoretical knowledge of these structures of consciousness a practical reality to a Tantric Yoga meditator in the first-person. This is achieved by entering meditative states through stepwise experiential reduction of the structures of consciousness from object to subject, as part of their meditative goal of “self-realization.” I end by briefly discussing the overlap of these putative meditation states with proposed states from other meditation traditions, and how these states could help advance an empirical study of consciousness. (shrink)

Microbiota-gut-brain research is a fast-growing field of inquiry with important implications for how human brain function and behaviour are understood. Researchers manipulate gut microbes to reveal connections between intestinal microbiota and normal brain functions or pathological states. Many claims are made about causal relationships between gut microbiota and human behaviour. By uncovering these relationships, MGB research aims to offer new explanations of mental health and potential avenues of treatment. So far, limited evaluation has been made of MGB's methods and its (...) core experimental findings, many of which are extensively reiterated in copious reviews of the field. These factors, plus the self-help potential of MGB, have combined to encourage uncritical public uptake of MGB discoveries. Both social and professional media focus on the potential for dietary intervention in mental health, and causal relationships are assumed to be established. Our target article has two main aims. One is to examine critically the core practices and findings of experimental MGB research and to raise questions about them for brain and behavioural scientists who may not be familiar with the field. The other is to challenge the way in which MGB findings are presented. Our positive goal is to suggest how current problems and weaknesses may be addressed, in order for both scientific and public audiences to gain a clearer picture of MGB research and its strengths and limitations. (shrink)

The philosopher Ludwig Wittgenstein chose as his prime exemplar of certainty the fact that the skulls of normal people are filled with neural tissue, not sawdust. In 1980 the British pediatrician John Lorber reported that some normal adults, apparently cured of childhood hydrocephaly, had no more than 5 % of the volume of normal brain tissue. While initially disbelieved, Lorber’s observations have since been independently confirmed by clinicians in France and Brazil. Thus Wittgenstein’s certainty has become uncertain. Furthermore, the paradox (...) that the human brain’s information content appears to exceed the storage capacity of even normal-sized brains, requires resolution. This article is one of a series on disparities between brain size and its assumed information content, as seen in cases of savant syndrome, microcephaly, and hydrocephaly, and with special reference to the Victorian era views of Conan Doyle, Samuel Butler, and Darwin’s research associate, George Romanes. The articles argue that, albeit unlikely, the scope of explanations must not exclude extracorporeal information storage. (shrink)

We call affective brainocentrism the tendency to privilege the brain over other parts of the organism when defining or explaining emotions. We distinguish two versions of this tendency. According to brain-sufficient, emotional states are entirely realized by brain processes. According to brain-master, emotional states are realized by both brain and bodily processes, but the latter are entirely driven by the brain: the brain is the master regulator of bodily processes. We argue that both these claims are problematic, and we draw (...) on physiological accounts of stress to make our main case. These accounts illustrate the existence of complex interactions between the brain and endocrine systems, the immune system, the enteric nervous system, and even gut microbiota. We argue that, because of these complex brain–body interactions, the brain cannot be isolated and identified as the basis of stress. We also mention recent evidence suggesting that complex brain–body interactions characterize the physiology of depression and anxiety. Finally, we call for an alternative dynamical, systemic, and embodied approach to the study of the physiology of emotions that does not privilege the brain, but rather aims at understanding how mutually regulating brain and bodily processes jointly realize a variety of emotional states. (shrink)

A monumental work by an important modern philosopher, Matter and Memory (1896) represents one of the great inquiries into perception and memory, movement and time, matter and mind. Nobel Prize-winner Henri Bergson surveys these independent but related spheres, exploring the connection of mind and body to individual freedom of choice. Bergson’s efforts to reconcile the facts of biology to a theory of consciousness offered a challenge to the mechanistic view of nature, and his original and innovative views exercised a profound (...) influence on other philosophers--including James, Whitehead, and Santayana--as well as novelists such as Dos Passos and Proust. Matter and Memory is essential to an understanding of Bergson’s philosophy and its legacy. (shrink)

The Life Divine explores for the Modern mind the great streams of Indian metaphysical thought, reconciling the truths behind each and from this synthesis ...

To make progress on the problem of consciousness, we have to confront it directly. In this paper, I first isolate the truly hard part of the problem, separating it from more tractable parts and giving an account of why it is so difficult to explain. I critique some recent work that uses reductive methods to address consciousness, and argue that such methods inevitably fail to come to grips with the hardest part of the problem. Once this failure is recognized, the (...) door to further progress is opened. In the second half of the paper, I argue that if we move to a new kind of nonreductive explanation, a naturalistic account of consciousness can be given. I put forward my own candidate for such an account: a nonreductive theory based on principles of structural coherence and organizational invariance, and a double-aspect theory of information. (shrink)

A broad pattern of correlations between mechanisms of brain function impairment and self-transcendence is shown. The pattern includes such mechanisms as cerebral hypoxia, physiological stress, transcranial magnetic stimulation, trance-induced physiological effects, the action of psychoactive substances and even physical trauma to the brain. In all these cases, subjects report self-transcending experiences o en described as ‘mystical’ and ‘awareness-expanding,’ as well as self-transcending skills o en described as ‘savant.’ The idea that these correlations could be rather trivially accounted for on the (...) basis of disruptions to inhibitory neural processes is reviewed and shown to be implausible. Instead, this paper suggests that an as-of-yet unrecognized causal principle underlying the entire pattern might be at work, whose further elucidation through systematic research could hold great promise. (shrink)