Program

Abstract: Predictive coding is a fundamental function of the cortex. The predictive routing model proposes a neurophysiological implementation for predictive coding. Predictions are fed back from the deep-layer cortex via alpha/beta (8 to 30 Hz) oscillations. They inhibit the gamma (40 to 100 Hz) and spiking that feed sensory inputs forward. Unpredicted inputs arrive in circuits unprepared by alpha/beta, resulting in enhanced gamma and spiking. To test the predictive routing model and its role in consciousness, we collected data from intracranial recordings of macaque monkeys during passive presentation of auditory oddballs before and after propofol-mediated loss of consciousness (LOC). In line with the predictive routing model, alpha/beta oscillations in the awake state served to inhibit the processing of predictable stimuli. Propofol-mediated LOC eliminated alpha/beta modulation by a predictable stimulus in the sensory cortex and alpha/beta coherence between sensory and frontal areas. As a result, oddball stimuli evoked enhanced gamma power, late period (>200 ms from stimulus onset) spiking, and superficial layer sinks in the sensory cortex. LOC also resulted in diminished decodability of pattern-level prediction error signals in the higher-order cortex. Therefore, the auditory cortex was in a disinhibited state during propofol-mediated LOC. However, despite these enhanced feedforward responses in the auditory cortex, there was a loss of differential spiking to oddballs in the higher-order cortex. This may be a consequence of a loss of within-area and interareal spike-field coupling in the alpha/beta and gamma frequency bands. These results provide strong constraints for current theories of consciousness.

In this talk, I will discuss how mindfulness of the body alters how the brain processes both pain and fear of pain. I will also discuss the impact of mindfulness training on hippocampal structure and function and how these changes can lead to long-lasting changes in emotion regulation. Finally, I will discuss the role of mindfulness training in the context of healthy brain aging and enhanced cognition.

Abstract: Predictive coding is a fundamental function of the cortex. The predictive routing model proposes a neurophysiological implementation for predictive coding. Predictions are fed back from the deep-layer cortex via alpha/beta (8 to 30 Hz) oscillations. They inhibit the gamma (40 to 100 Hz) and spiking that feed sensory inputs forward. Unpredicted inputs arrive in circuits unprepared by alpha/beta, resulting in enhanced gamma and spiking. To test the predictive routing model and its role in consciousness, we collected data from intracranial recordings of macaque monkeys during passive presentation of auditory oddballs before and after propofol-mediated loss of consciousness (LOC). In line with the predictive routing model, alpha/beta oscillations in the awake state served to inhibit the processing of predictable stimuli. Propofol-mediated LOC eliminated alpha/beta modulation by a predictable stimulus in the sensory cortex and alpha/beta coherence between sensory and frontal areas. As a result, oddball stimuli evoked enhanced gamma power, late period (>200 ms from stimulus onset) spiking, and superficial layer sinks in the sensory cortex. LOC also resulted in diminished decodability of pattern-level prediction error signals in the higher-order cortex. Therefore, the auditory cortex was in a disinhibited state during propofol-mediated LOC. However, despite these enhanced feedforward responses in the auditory cortex, there was a loss of differential spiking to oddballs in the higher-order cortex. This may be a consequence of a loss of within-area and interareal spike-field coupling in the alpha/beta and gamma frequency bands. These results provide strong constraints for current theories of consciousness.

Humans have long thought of their bodies and minds as separate spheres of existence. The body is physical—the source of aches and pains. But the mind is mental; it perceives, remembers, believes, feels, and imagines. Although modern science has largely eliminated this mind–body dualism, people still tend to imagine their minds as separate from their physical being. Even in research, the notion of a “self” that is somehow distinct from the rest of the organism persists. But such ideas are increasingly barriers to discovery and understanding, and a new framework is needed. I propose that a human being can be characterized as a composite or ensemble of four fundamental, parallel, entwined realms of existence that reflect our evolutionary past and account for our present ways of being—biological, neurobiological, cognitive, and conscious. All four are, deep down, biological. But the neurobiological realm transcends the mere biological, the cognitive transcends the mere neurobiological, and the conscious transcends the mere cognitive. We each exist uniquely within our own realms every moment of adult life, and together our realms account for all of what and who we are. 

Abstract: In the last 15 years, there has been a dramatic increase in empirical research in boredom, interoception, mindfulness, and mind wandering. In this talk, I will propose a novel theory to connect these popular research topics, by means of the concept of mental pain and its possible physiological origins. Most of the recent research on mental pain is concerned with mental pain so severe that it is associated with intractable depression and suicidal ideation. My interest is in the relatively mild mental pain that is often labeled as boredom, loneliness, or perhaps a vague malaise or negative mood. My speculative hypothesis is that much mild mental pain is of a bodily origin in the form of diffuse nociception (DN); that is, widely distributed stimuli from the body that are capable of producing a feeling of discomfort, unless they can be pushed out of conscious awareness and into the preconscious by various distractions. This principle can explain feelings of boredom when distractions fail or are unavailable, and, consequently, our addiction to various forms of distraction, including mind wandering. In support of my theory, I will describe how past stress reactions can create chronic DN, beginning as early as infancy or even fetal development. In my optimistic conclusion, I will explain how mindfulness and improved interoception can mitigate mental pain better than mere distractions. 

Abstract: In the Western tradition, the term meditation originally meant thinking deeply about a particular topic or perhaps allowing thoughts to arise somewhat spontaneously while keeping one's attention on the topic in question (or Descartes' approach, which attempts to avoid preconceptions while thinking about the topic).  The Eastern approach is very different in that the meaning of one's thoughts is not the focus; instead the emphasis is on the mechanisms of thinking and of sustained attention. However, there are many distinct methods that are referred to as meditation, and it follows that the experience of meditation can differ, accordingly. The meditative experience can also be expected to change with increasing practice and the experiences produced by different methods may converge over time. We will discuss the experiences of Eastern meditation as a function of broad categories, such as focused attention and open monitoring.

Abstract: The neuroscience of religion and the scientific study of meditation stand to greatly benefit from one another by sharing insights into how distinct brain networks are activated through different spiritual practices. Meditation research can inform the neuroscience of religion by highlighting how contemplative states shape cognitive and emotional responses, providing a framework for understanding spiritual experiences. Conversely, the neuroscience of religion offers models of brain network dominance across various subcategories of spirituality, as evidenced by Dr. Michael Ferguson’s pioneering research, which has functionally mapped a subset of these networks. Dr. Ferguson's talk will detail how integrating findings from both fields could advance a more complete understanding of how spiritual and meditative practices engage the brain in ways that support resilience and well-being.

Abstract: In this talk, Dr. Julio Rodriguez-Larios will present his research on the brain correlates of mindfulness meditation practice. Specifically, he will present the results of several studies in which he showed that meditation training impacts ‘brain waves’ during meditation. Before that, he will give a short introduction to mindfulness, Electroencephalography (EEG) and the role of human ‘brain waves’ in cognition. 

Abstract: The shamanic state of consciousness is a non-pharmacologically induced altered state of consciousness anecdotally similar to the psychedelic state. However, despite a resurgence of psychedelic research, few empirical studies of the shamanic state of consciousness exist. We investigated the neural correlates of the shamanic state of consciousness using high-density electroencephalogram (EEG) recordings in 24 shamanic practitioners and 24 healthy controls during periods of rest, shamanic drumming, and classical music listening, followed by an assessment of altered states of consciousness. EEG data were used to assess changes in absolute power, functional connectivity, signal diversity, and criticality, which were correlated with assessment measures. We also compared assessment scores to those of individuals in a previous study under the influence of ketamine, LSD, or psilocybin. Shamanic practitioners were significantly different from controls in several altered states of consciousness domains, with scores comparable to or exceeding that of healthy volunteers under the influence of all three psychedelics. Shamanic practitioners, but not control participants, also endured various changes in EEG measures that correlated with altered states of consciousness domain scores. These findings suggest that psychedelic drug-induced and non-pharmacologic alterations in consciousness have overlapping phenomenal traits but are distinct states of consciousness, as reflected by the unique brain-related changes during the shamanic state of consciousness compared to previous studies investigating the psychedelic state.

Abstract: We will describe the development of robust wearable sensors that have enabled the gathering of copious amounts of ambulatory data about the state of the human autonomic nervous system. Advanced methods for data cleaning and data analysis now make it possible to obtain insights that can enable near real time interventions to restore a healthy state in individuals that carry the burden of the body's inflammatory response to external stimuli. We will present promising results on ways to modulate the inflammatory response by externally applying focused ultrasound to specific organs, such as the spleen. We will also share some early findings that document the role of somatic practices, such as meditative breathing, that induce similar measurable effects on the human autonomic nervous system.

Abstract: Predictive coding is a fundamental function of the cortex. The predictive routing model proposes a neurophysiological implementation for predictive coding. Predictions are fed back from the deep-layer cortex via alpha/beta (8 to 30 Hz) oscillations. They inhibit the gamma (40 to 100 Hz) and spiking that feed sensory inputs forward. Unpredicted inputs arrive in circuits unprepared by alpha/beta, resulting in enhanced gamma and spiking. To test the predictive routing model and its role in consciousness, we collected data from intracranial recordings of macaque monkeys during passive presentation of auditory oddballs before and after propofol-mediated loss of consciousness (LOC). In line with the predictive routing model, alpha/beta oscillations in the awake state served to inhibit the processing of predictable stimuli. Propofol-mediated LOC eliminated alpha/beta modulation by a predictable stimulus in the sensory cortex and alpha/beta coherence between sensory and frontal areas. As a result, oddball stimuli evoked enhanced gamma power, late period (>200 ms from stimulus onset) spiking, and superficial layer sinks in the sensory cortex. LOC also resulted in diminished decodability of pattern-level prediction error signals in the higher-order cortex. Therefore, the auditory cortex was in a disinhibited state during propofol-mediated LOC. However, despite these enhanced feedforward responses in the auditory cortex, there was a loss of differential spiking to oddballs in the higher-order cortex. This may be a consequence of a loss of within-area and interareal spike-field coupling in the alpha/beta and gamma frequency bands. These results provide strong constraints for current theories of consciousness.

Abstract: Over the past 10 years, integrated information theory (IIT), while abstract, has become the most prominent theory of consciousness promoted to the lay public, even prompting some to embrace panpsychism. Nevertheless, the status of IIT remains quite controversial among neuroscientists.  A group of scientists opposed to IIT has recently denounced IIT as pseudoscience in a public letter to Nature Neuroscience. We will consider their arguments and also the reply by IIT's advocates, and an evaluation by two prominent scientists, who are skeptical but sympathetic. This controversy reflects the broader uncertainty about what a scientific theory of consciousness should look like. 

Abstract: I will begin by briefly reviewing the quantitative measurements that gave rise to the two leading theories of consciousness: global workspace theory (GWT) and integrated information theory. Both theories emphasize communication among brain regions, but don't spell out specific details about brain dynamics, and so it is unclear how to test their predictions in detail against data. I will propose a perspective that integrates key ideas from GWT & IIT, and that makes more specific predictions about dynamic communication among brain regions; these predictions can be tested by comprehensive high-resolution measurements of brain activity; such measures are difficult now, but will soon be feasible in small animals with new technology.

I argue that the central issue for quantitative analysis for theories of consciousness will be how to characterize the many-to-many interactions among sub-populations of neurons across several brain regions. I will briefly describe current analytic approaches for characterizing dynamic network interactions among brain regions using fMRI, EEG, LFP, and wide-field calcium imaging data. Then I will discuss methods for trying to understand coordination between high-dimensional neuronal population activity in two or more connected regions of the brain. A recurrent issue with all these methods is how to distinguish correlated activity, derived from common inputs, from direct interaction. Many scientists believe that anatomy can guide us toward causal relations. Therefore, I will describe methods that integrate fine-scale neuroanatomy with activity recordings. Finally, I will sketch some directions for the future of quantitative studies of consciousness.

Abstract: I will briefly review the methods discussed in Part 1. Through modern recording technologies, some researchers have recently obtained some data directly bearing on communication. I will show some examples of population coordinations in several dimensions between different brain regions in fish and also in rodents, with some applications of methods discussed in part 1. Many scientists believe that anatomy can guide us toward causal relations. I will describe a first approach to integrate anatomy and activity data using regularized regression, drawing on the fine-scale statistics of connectivity to construct the penalty. Finally, I will sketch some directions for the future of quantitative studies of consciousness, and I will discuss how ideas discussed here may shed light on qualia, which has been a problem for materialist theories of consciousness.