Philosophical (p-) zombies are constructs that possess all of the behavioral features and responses of a sentient human being, yet are not conscious. P-zombies are intimately linked to the hard problem of consciousness and have been invoked as arguments against physicalist approaches. But what if we were to invert the characteristics of p-zombies? Such an inverse (i-) zombie would possess all of the behavioral features and responses of an insensate being yet would nonetheless be conscious. While p-zombies are logically possible (...) but naturally improbable, an approximation of i-zombies actually exists: individuals experiencing what is referred to as “anesthesia awareness.” Patients under general anesthesia may be intubated (preventing speech), paralyzed (preventing movement), and narcotized (minimizing response to nociceptive stimuli). Thus, they appear—and typically are—unconscious. In 1-2 cases/1000, however, patients may be aware of intraoperative events, sometimes without any objective indices. Furthermore, a much higher percentage of patients (22% in a recent study) may have the subjective experience of dreaming during general anesthesia. P-zombies confront us with the hard problem of consciousness—how do we explain the presence of qualia? I-zombies present a more practical problem—how do we detect the presence of qualia? The current investigation compares p-zombies to i-zombies and explores the “hard problem” of unconsciousness with a focus on anesthesia awareness. (shrink)

In this commentary we discuss the possibility of subcortical consciousness and its implications for fetal anesthesia and analgesia. We review the neural development of structural and functional elements that may participate in conscious representation, with a particular focus on the experience of pain. (Published Online May 1 2007).

Current thinking suggests that dissociation could be a significant comorbid diagnosis in a proportion of schizophrenic patients with a history of trauma. This potentially may explain the term “schizophrenia” in its original definition by Bleuler, as influenced by his clinical experience and personal view. Additionally, recent findings suggest a partial overlap between dissociative symptoms and the positive symptoms of schizophrenia, which could be explained by inhibitory deficits. In this context, the process of dissociation could serve as an important conceptual framework (...) for understanding schizophrenia, which is supported by current neuroimaging studies and research of corollary discharges. These data indicate that the original conception of “split mind” may be relevant in an updated context. Finally, recent data suggest that the phenomenal aspects of dissociation and conscious disintegration could be related to underlying disruptions of connectivity patterns and neural integration. (shrink)

The cognitive unbinding paradigm suggests that the synthesis of neural information is attenuated by general anesthesia. Here, we analyzed the functional organization of brain activities in the conscious and anesthetized states, based on functional segregation and integration. Electroencephalography recordings were obtained from 14 subjects undergoing induction of general anesthesia with propofol. We quantified changes in mean information integration capacity in each band of the EEG. After induction with propofol, mean information integration capacity was reduced most prominently in the γ band (...) of the EEG . Furthermore, we demonstrate that loss of consciousness is reflected by the breakdown of the spatiotemporal organization of γ waves. We conclude that induction of general anesthesia with propofol reduces the capacity for information integration in the brain. These data directly support the information integration theory of consciousness and the cognitive unbinding paradigm of general anesthesia. (shrink)

Psychedelics have been recognized as model interventions for studying altered states of consciousness. However, few empirical studies of the shamanic state of consciousness, which is anecdotally similar to the psychedelic state, exist. We investigated the neural correlates of shamanic trance using high-density electroencephalography (EEG) in 24 shamanic practitioners and 24 healthy controls during 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, 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 psychedelics. Shamanic practitioners were significantly different from controls in several domains of altered states of consciousness, with scores comparable to or exceeding that of healthy volunteers under the influence of psychedelics. Practitioners also displayed increased gamma power during drumming that positively correlated with elementary visual alterations. Furthermore, shamanic practitioners had decreased low alpha and increased low beta connectivity during drumming and classical music and decreased neural signal diversity in the gamma band during drumming that inversely correlated with insightfulness. Finally, criticality in practitioners was increased during drumming in the low and high beta and gamma bands, with increases in the low beta band correlating with complex imagery and elementary visual alterations. 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 shamanic trance compared to previous literature investigating the psychedelic state. (shrink)

Frontoparietal connectivity has been suggested to be important in conscious processing and its interruption is thought to be one mechanism of general anesthesia. Data in animals demonstrate that feedforward processing of information may persist during the anesthetized state, while feedback processing is inhibited. We investigated the directionality and functional organization of frontoparietal connectivity in 10 human subjects anesthetized with propofol on two separate occasions. Multichannel electroencephalography and a computational method of assessing directed functional connectivity were employed. We demonstrate that directed (...) feedback connectivity is diminished with loss of consciousness and returns with responsiveness to verbal command. We also applied the Dendrogram classification method to assess the global organization of directed functional connectivity during consciousness and anesthesia. We demonstrate a state-specific hierarchy and subject-specific subhierarchy in functional organization. These data support the hypothesis that specific states of human consciousness are defined by specific states of frontoparietal connectivity. (shrink)

Previous work employing graph theory and nonlinear analysis has found increased spatial and temporal disorder, respectively, of functional brain connectivity in schizophrenia. We present a new method combining graph theory and nonlinear techniques that measures the temporal disorder of functional brain connections. Multichannel electroencephalographic data were windowed and functional networks were reconstructed using the minimum spanning trees of correlation matrices. Using a method based on Shannon entropy, we found elevated connection entropy in gamma activity of patients with schizophrenia; however, gamma (...) connection entropy remained elevated in patients with schizophrenia even after a reduction in symptoms due to treatment with antipsychotics. Our results are consistent with several possibilities: aberrant functional connectivity is epiphenomenal to schizophrenia, aberrant functional connectivity is a central feature but antipsychotics reduce symptoms by an independent mechanism, or connection entropy is not an appropriately sensitive measure of brain abnormalities in schizophrenia. (shrink)

"This book is a sorely needed corrective. Animal Spirits is an important--maybe even a decisive--contribution at a difficult juncture in macroeconomic theory.

A revision of George Kennedy's translation of, introdution to, and commentary on Aristotle's On Rhetoric. His translation is most accurate, his general introduction is the most thorough and insightful, and his brief introductions to sections of the work, along with his explanatory footnotes, are the most useful available.

This intriguing and ground-breaking book is the first in-depth study of the development of philosophy of science in the United States during the Cold War. It documents the political vitality of logical empiricism and Otto Neurath's Unity of Science Movement when these projects emigrated to the US in the 1930s and follows their de-politicization by a convergence of intellectual, cultural and political forces in the 1950s. Students of logical empiricism and the Vienna Circle treat these as strictly intellectual non-political projects. (...) In fact, the refugee philosophers of science were highly active politically and debated questions about values inside and outside science, as a result of which their philosophy of science was scrutinized politically both from within and without the profession, by such institutions as J. Edgar Hoover's FBI. It will prove absorbing reading to philosophers and historians of science, intellectual historians, and scholars of Cold War studies. (shrink)

Identity Economics provides an important and compelling new way to understand human behavior, revealing how our identities--and not just economic incentives--influence our decisions. In 1995, economist Rachel Kranton wrote future Nobel Prize-winner George Akerlof a letter insisting that his most recent paper was wrong. Identity, she argued, was the missing element that would help to explain why people--facing the same economic circumstances--would make different choices. This was the beginning of a fourteen-year collaboration--and of Identity Economics. The authors explain how (...) our conception of who we are and who we want to be may shape our economic lives more than any other factor, affecting how hard we work, and how we learn, spend, and save. Identity economics is a new way to understand people's decisions--at work, at school, and at home. With it, we can better appreciate why incentives like stock options work or don't; why some schools succeed and others don't; why some cities and towns don't invest in their futures--and much, much more. Identity Economics bridges a critical gap in the social sciences. It brings identity and norms to economics. People's notions of what is proper, and what is forbidden, and for whom, are fundamental to how hard they work, and how they learn, spend, and save. Thus people's identity--their conception of who they are, and of who they choose to be--may be the most important factor affecting their economic lives. And the limits placed by society on people's identity can also be crucial determinants of their economic well-being. (shrink)

Identity Economics provides an important and compelling new way to understand human behavior, revealing how our identities--and not just economic incentives--influence our decisions. In 1995, economist Rachel Kranton wrote future Nobel Prize-winner George Akerlof a letter insisting that his most recent paper was wrong. Identity, she argued, was the missing element that would help to explain why people--facing the same economic circumstances--would make different choices. This was the beginning of a fourteen-year collaboration--and of Identity Economics. The authors explain how (...) our conception of who we are and who we want to be may shape our economic lives more than any other factor, affecting how hard we work, and how we learn, spend, and save. Identity economics is a new way to understand people's decisions--at work, at school, and at home. With it, we can better appreciate why incentives like stock options work or don't; why some schools succeed and others don't; why some cities and towns don't invest in their futures--and much, much more. Identity Economics bridges a critical gap in the social sciences. It brings identity and norms to economics. People's notions of what is proper, and what is forbidden, and for whom, are fundamental to how hard they work, and how they learn, spend, and save. Thus people's identity--their conception of who they are, and of who they choose to be--may be the most important factor affecting their economic lives. And the limits placed by society on people's identity can also be crucial determinants of their economic well-being. (shrink)

Akerlof's substantial introduction to this volume tells the story of these papers, connecting them and showing how his later work has built upon his early contributions, in many cases improving their arguments, their subtlety, and their usefulness today.

In the light of two unpublished letters from Carnap to Kuhn, this essay examines the relationship between Kuhn's The Structure of Scientific Revolutions and Carnap's philosophical views. Contrary to the common wisdom that Kuhn's book refuted logical empiricism, it argues that Carnap's views of revolutionary scientific change are rather similar to those detailed by Kuhn. This serves both to explain Carnap's appreciation of The Structure of Scientific Revolutions and to suggest that logical empiricism, insofar as that program rested on Carnap's (...) shoulders, was not substantially upstaged by Kuhn's book. (shrink)