Mind, Brain & Consciousness

Insights with Professor Todd E. Feinberg


Published in The Neuropsychotherapist Issue #1

Todd E. Feinberg, MD, Professor of Clinical Psychiatry and Neurology at Albert Einstein College of Medicine and Chief of the Yarmon Neurobehavior and Alzheimer’s Disease Center at Beth Israel Medical Center in New York, is internationally recognized as a leading authority on how the neurobiology of the brain creates the individual’s sense of identity.

Dr Feinberg has been featured on Dateline NBC, The Leonard Lopate Show, Fresh Air with Terry Gross, The Learning Channel, and numerous appearances on local New York television. His work on disturbances of the brain was highlighted in the 2006 National Book Award winner, The Echo Maker by Richard Powers, a novel about a patient who develops Capgras syndrome, which Dr Feinberg has researched extensively.

Professor Feinberg is editor of this column on consciousness, and we thought it would be interesting for our premier issue to talk to him about his work and his passions.

Matthew Dahlitz: Hi Professor Feinberg and welcome to The Neuropsychotherapist! Tell us Why you chose to go into neuropsychiatry?

Todd Feinberg: I trained in both neurology and psychiatry for two reasons. First clinically, I find those conditions that reflect mind–brain interactions were the most fascinating. In medicine it’s important to be truly in love with and be fascinated by the area of your speciality; it drives devotion to the clinical craft.  Second, I chose neuropsychiatry as well to pursue my life’s ambition of finding out how the brain creates a self and consciousness. From a very early age – sometime in grade school – I became fascinated by the work of Sigmund Freud, but I eventually felt that I could take his work further by exploring to what extent psychoanalytic and dynamic theories could be applied to actual brain functioning and brain pathology. Observing and analyzing how the whole person reacts to selective brain damage provides a unique window into how ego functions, defense, and fantasy operate.

Neuropathologies of the self

Matthew Dahlitz: What are some the big questions what have interested you most , and what discoveries have you made along the way?

NPS idagram1Todd Feinberg: Clinically, one of the areas I have studied is what I refer to as neuropathologies of the self (NPS). These disorders create alterations in the individual’s view of their personal identity. It can affect how they feel about their relatedness to the body, to other persons, or to their personal histories or experiences.

The NPS I have focused on include anosognosia for hemiplegia, that is the unawareness of paralysis, somatoparaphrenia that are delusions and confabulations about the body, especially a paralyzed left arm; and the delusional misidentification syndromes such as Capgras Syndrome, or delusional personal under-relatedness to persons, places, or things;  and its opposite, Frégoli syndrome, in which the problem is over-personal relatedness.

Based upon the study of these disorders, one of my chief arguments has been that simple deficit or disconnectionistic accounts do not capture the richness and complexity of these conditions, and those theories provide only partial explanations of their mechanisms. Thus has led me to the view that one must analyze both the negative (deficit) and positive (adaptive) features of these conditions in order to explain them.

I have proposed that these disorders are best explained as the result of an interaction between the negative factors of neuropsychological impairment and disorders and ego boundary impairments and positive (productive; adaptive, defensive, and motivational) variables. This figure to the left shows a four-tiered model of the NPS that I developed to emphasize a multi-factorial, hierarchical approach and includes both negative and positive, bottom up and top down, and neuropsychological and psychological factors.

One fairly consistent and interesting feature of these conditions is that we find lesions of the right hemisphere, especially right medial-frontal and orbitofrontal lesions, are the most frequent focal cause of the NPS. It’s really a very robust finding. In fact, in one study we found 28/29 cases had right frontal damage. So I wondered why is this the case?

Firstly I tried to figure out what really is the psychological disturbance. I found that one way to view these conditions is that most of the thought processes that we see in these patients represent a return or a Freudian regression to more immature ego functions, patterns of defense, and fantasy that are characteristic of the child between ages 3-8. This led me to propose that in normal development there must be a gradual a shift from immature defensive functions and fantasies to mature defenses and fantasy, and that this shift critically depends upon maturational processes within the right hemisphere. Thus, in the adult cases of NPS, the right frontal damage creates a return to developmentally immature styles of thought and ego functioning and the preservation and activation of the verbal defenses that are under the control of the remaining and relatively intact left verbal hemisphere. It is even possible that the left hemisphere is “dominant” for these immature defenses and patterns of thought.

The observation that the lesions in the NPS tend to be medial further suggested a general model of how the brain creates neural hierarchy of self-related functions. I felt that we could discern three great developmental trends in the neurohierarchical growth of the self. There is a medial-lateral trend in which the nervous system expands from its center outward, like the growth rings of a tree. Georg Northoff and his co-workers have provided an excellent meta-analysis of functional image studies that supports the view the medial structures are indeed selectively activated by self-related tasks. The second pattern is the classical caudal-rostral trend that results in the hierarchical growth of later developing and more complex neurological sructures upon those with more simple and basic organization and function. Progressive growth under the influence of the medial-lateral trend in both evolution and in the course of development of the individual gives rise to an interoself system that is primarily involved with the internal milieu and homeostatic needs of the organism, and an exterosensorimotor system that is primarily concerned with organism’s interactions with the environment. A third system – the integrative self system – serves to assimilate the interoself systems with the extero systems, and integrate the organism’s internal needs with the external environment. It is within the integrative self systems that the most advanced aspects of the self and those we consider the most characteristic of the human individual take center stage.

NPS idagram2The neural self is constructed from three interlocking system(s): The interoself system, the integrative self system, and the exterosensorimotor system. Lower levels of each system are nested within higher (more abstract) levels. These levels can be visualized as anatomically concentric rings with the interoself system representing the anatomically innermost (core) ring that is synaptically closest to the internal milieu and serves the requirements of homeostasis, the exterosensorimotor system is anatomically peripheral, synaptically closet to the external environment and serves the needs of the organism’s interaction with the external environment, and the integrative self system is anatomically interposed between the other two (From Feinberg, 2011).

Consciousness studies: Split brains, mental unity, and the nested neural hierarchy of consciousness

Matthew Dahlitz: Tell us a bit about your studies into consciousness and neural processes.

Todd Feinberg:  I have been especially interested in the problem of the relationship between consciousness and brain processes, and especially understanding why consciousness cannot be simply reduced to brain processes, the way that, for example, digestion is reduced to the structure and physiology of the organs of digestion  – such as the stomach, bowel, gall bladder – that comprise the digestive system, and the various digestive processes such as enzymatic secretion and peristalsis involved in breaking down food into energy.

In neurology, we typically begin with a macroscopic scientific observation or a definable property such as how nerves innervate muscles or how an epileptic seizure occurs, and then attempt to explain their mechanism based upon more fundamental or known functional or anatomical properties. Now, in most areas of neurology, we have achieved many such reductions. There currently is no “mystery of epilepsy” because we understand how a seizure can be reduced to abnormal electrical discharges of cortical neurons. And even if we do not currently have a complete understanding of all neurological processes, we do not foresee any insurmountable obstacles to future complete reductions. However, with consciousness, as many have pointed out, it seems that even if we could understand all there is to know about the brain and the underlying neural basis of consciousness, there always seems to be something that is “left out”.

In fact, I have argued that  there are several subjective characteristics of consciousness that are “left out” from a purely objective reduction of consciousness to the brain; I call theses features neuroontologically subjective or neuroontologically irreducible  features of consciousness. I identified at least four of these neuroontologically subjective features of consciousness (NOSFC) in which the subject has an experience that defies objective reduction. These are: The referral of neural states  – the fact that any neural process that results in a conscious experience does not refer to the material brain itself but instead refers to something other than the neurons that create it, either in the world or to someplace upon or within the body;  Mental unity – while the nervous system as objectively analyzed is comprised of many billions of individual neurons with no central location, consciousness as subjectively experienced appears as a unified field; Qualia – neurons as objectively observed are not “red” “painful” “hot” or “sweet”, but certain neural states possess these subjective properties; Mental causation – how can we  explain how consciousness-  an apparently intangible, objectively unobservable, and wholly subjective entity – can have causal properties upon objectively observable neurons.

Although I had hoped to find a single factor or unknown principle that would explain all these NOSFC, in turns out that there is no single explanation. Indeed, I think one of the biggest problem in consciousness research is there are too many claims for the “single explanation”. In fact, I found that each of the NOSFC has its own constellation of neurobiologically unique features that help explain subjectivity, or I express it where S (subject) ≠ O (object). For instance, mental unity is made possible by brain operations that allow it to function as both a non-nested or convergent neural system but also as a nested neural hierarchy that is based upon hierarchical principles of functional constraint that allows elements to be expressed as a unity in consciousness without there being any physically centralized convergence. This is accomplished by a number of physiological processes including synchronized oscillations that bridge higher order neurons across and within hierarchical levels. What is fascinating is that far as I have been able to determine, only the nervous system simultaneously operates in this particular nested and non-nested fashion and in this regard is unique among biological and non-biological systems. Thus, consciousness results from neurobiologically unique, hierarchically arranged neural-neural interactions that not surprisingly result in experientially unique features.

Matthew Dahlitz: What are you currently working on?

Todd Feinberg:  Most recently I have been studying the simplest organisms that I believe can be reasonably inferred to be conscious in order to better guess when or how consciousness arose in the development of the vertebrate brain that led to our own consciousness. While we know that the vertebrate nervous system evolved during the Early Cambrian period approximately 520 million years ago, opinions vary regarding when consciousness first appeared and what are simplest species that are conscious? To help answer this question, I am using the presence of isomorphic neural maps as a marker for sensory consciousness. Isomorphic maps in the brain are spatially organized maps such as somatotopic maps of the body or retinotopic maps of the visual fields as well as non-spatially organized maps such as the chomtopic map of olfaction. On this basis the evidence suggests to me that primary consciousness extends at a minimum to the origins of the phylum Craniata during the early Cambrian period as much as 520 million years old. Furthermore, it seems almost certain sensory consciousness was a primary driver – perhaps the primary driver –  of vertebrate evolution. As far as the simplest living vertebrates with consciousness, excluding the possibility of consciousness (that some claim) in non-vertebrates like cephalopods (octopi) or insects, I think that it is most likely that vertebrates as simple as the lamprey eel possess all these neural requisites and sensory experiences to have a primary or basic form of consciousness.

Matthew Dahlitz: Thank you so much for sharing with us today Professor Feinberg. We look forward to your oversight of this column Brain, Mind & Consciousness here at the Neuropsycotherapist, as you keep us up-to-date with the latest research and findings in the world of consciousness.


Feinberg, T. E. (2001). Altered egos: How the brain creates the self. New York: Oxford University Press.

Feinberg, T. E. (2001). Why the mind is not a radically emergent feature of the brain. Journal of Consciousness Studies, 8, 123–145.

Feinberg, T.E. (2008). The nested hierarchy theory of consciousness (NHTC).Toward a Science of Consciousness, April 8-12, 2008. Consciousness Research Abstracts, 158.

Feinberg, T. E. (2009). From axons to identity: Neurological explorations of the nature of the self. New York: W.W. Norton.

Feinberg, T. E. (2010). Neuropathologies of the self: A general theory. Neuropsychoanalysis, 12, 133–158.

Feinberg, T.E. (2011. ) The nested neural hierarchy and the self. Consciousness and Cognition, 20(1):4-15

Feinberg, T.E. (2011) Neuropathologies of the self: Clinical and anatomical features. Consciousness and Cognition, 20(1):75-81.

Feinberg, T. E., DeLuca, J., Giacino, J. T., Roane, D. M., & Solms, M. (2005). Right hemisphere pathology and the self: Delusional misidentification and reduplication. In T. E. Feinberg & J. P. Keenan (Eds.), The lost self: Pathologies of the brain and identity (pp. 100–130). New York: Oxford.

Feinberg, T. E., Venneri, A., Simone, A. M., Fan, Y., & Northoff, G. (2010). The neuroanatomy of asomatognosia and somatoparaphrenia. Journal of Neurology, Neurosurgery and Psychiatry, 81, 276–2781.

Dr Feinberg is the author of Altered Egos: How the Brain Creates the Self (Oxford, 2001), and co-editor of the textbook Behavioral Neurology and Neuropsychology (McGraw-Hill) now in its second edition and The Lost Self: Pathologies of the Brain and Identity (Oxford, 2005), and has written nearly 100 articles, abstracts, or books. His most recent book is From Axons to Identity: Neurological Explorations of the Nature of the Self (W.W.Norton)

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