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Dr. Andrew and Alexander Fingelkurts
BM-Science
P.O. Box 77
FI-02601 ESPOO
FINLAND
Previous Research
1. Microstructural analysis of EEG/MEG signals under pharmacological influence.
EEG has been used to detect drug effects for decades but studies using MEG are scarce. Since psychotropic drugs are often used for clinical purposes, knowledge of the validated EEG/MEG effects of these drugs, and temporal characteristics of these effects are necessary for the interpretation of the results. Very often psychotropic drugs produce effects whose link to clinical efficacy or side effects are not well established. For example, interpretation of increased EEG beta activity under the benzodiazepines is often difficult from different studies, thus making it important a closer investigation of the cause of changes in the power estimates.
Some of these difficulties can be resolved through a more uniform application of the micro-structural signal analysis techniques (Fingelkurts et al., 2005b http://www.bm-science.com/team/art34.pdf). The selection of a set of sensitive EEG/MEG indices, which reflect the dynamic behavior of temporal EEG/MEG structure, may enable the prediction of the brain’s response to the drug and adds additional value to standard spectral analysis (Fingelkurts et al., 2004a http://www.bm-science.com/team/art27.pdf , 2004b http://www.bm-science.com/team/art28.pdf , 2004c http://www.bm-science.com/team/art29.pdf).
2. Dynamic processes in EEG/MEG during multisensory perception and cognition.
People usually perceive the external world as a seamless whole. Our perception of the external world depends on the integration of information from different senses. When and where in the human brain the integration of such multisensory information occurs is not yet known. Inputs from different sensory modalities are processed in different cortical regions, but our daily perception is based on the global multisensory percept resulting from the integration of information from various sensory modalities. Indeed, the integration of information from different sensory modalities is clearly beneficial: multimodal events are detected more accurately and faster than unimodal events. Human speech is a prime example of this.
Although audio-visual speech integration is well-established experimentally, the brain (neural) processes that subserve it remain to be assessed. Most research in humans only demonstrates the existence of the phenomenon rather than reveals the physiological processes underlying it. It is possible to plausibly argue that the crossmodal binding in the human brain may be achieved by the synchronized processing of sensory inputs between the unimodal cortical areas (see Fingelkurts et al., 2003 http://www.bm-science.com/team/art22.pdf), rather than in so-called convergence regions of the cortex.
3. Advanced EEG analysis on un-medicated naïve out-patients with major depressive disorder (MDD).
Convergent neurophysiological data indicate that depression can be understood as dysfunctions in specific neural circuits. However, traditional diagnostic categories are extremely heterogeneous and are not likely to map onto brain circuitry. At the same time, examination of the functioning of neurocircuits underlying the representation and regulation of emotion and mood would help researchers to understand better mood disorders and to subtype patients with the same disorder according to neurocircuit malfunctions. What can be the objective markers of such neurocircuits malfunctioning?
During the past two decades frontal asymmetry in alpha EEG band has been considered to be almost the only indicator of depression and emotional affect. However, it is important to examine actual brain oscillations carefully in a wide frequency range, as these may provide additional information not reflected in alpha band. The frontal cortex is clearly a significant component of the distributed system related to major depression, but one should not view it as the only “location” of the complex neuronal processes associated with depressive state. Rather, it appears that the affective brain systems are implemented in a particular net of functional relations, only part of which is frontal. Therefore we predict that depression might be related to altered or even impaired functional brain connectivity.
The aim of the present project was to explore and extend this hypothesis of functional connectivity reorganization during major depression, using EEG frequency domain analysis; to study the actual composition of brain oscillations in ongoing multichannel EEG during depression in a broad frequency range (0.5-30 Hz); and to examine interhemisphere asymmetry of the composition of brain oscillations.
It was found (Fingelkurts et al., 2007 http://www.bm-science.com/team/art43_in-press.pdf) that in depressive patients the number and strength of short cortex functional connections were significantly larger for the left than for the right hemisphere, while the number and strength of long functional connections were significantly larger for the right than for the left hemisphere. Some of the functional connections were positively correlated with the severity of depression, thus being predictive. These were short-range anterior, posterior, and left hemisphere functional connections for the alpha frequency band and short-range anterior functional connections for the theta frequency band. The topology of the most representative functional connections among all patients with major depression indicated that the right anterior and left posterior brain parts may discriminate depressive patients from healthy controls. The obtained data support our hypothesis that there is an increase in brain functional connectivity in major depression. This finding was interpreted within the semantic framework, where different specialization of left (monosemantic context) and right (polysemantic context) hemispheres is functionally insufficient in patients with depression.
4. The influence of chronic opioid addiction on the spatio-temporal structure of the EEG signal (longitudinal study).
Substantial progress has been made in understanding the molecular and cellular mechanisms of drug addiction. However, there is still little understanding of the systemic neural substrates of compulsive drug use and its strong persistence.
Drug addictive behavior may emerge from the dynamic activity of entire neural networks rather than from any single brain structure. Indeed, recently brain is seen as a massively interactive, dynamic system, without centralized control which displays a characteristic metastability around certain homeostatic levels (for the review, see Fingelkurts and Fingelkurts, 2004 http://www.bm-science.com/team/art30.pdf). In this context drug addiction may be conceptualized as an adapted state - a new metastable regimen of brain functioning around altered homeostatic levels. Here, the electroencephalogram (EEG) provides a satisfactory measure for accessing integrative brain functions and large-scale dynamic of the brain activity (with a temporal resolution in the order of milliseconds) associated with health and pathology.
The aim of the present study was (a) to investigate the actual composition of brain oscillations and their temporal behavior in EEG of chronic heroin-abuse patients during resting conditions, and (b) to study the cumulative heroin exposure in chronic heroin-abuse patients on the local and remote functional connectivity in their neocortex. Considering that repeated exposure to opiates induces a widespread remodeling of cortical regions and might result (according to our hypothesis) in a metastable state around new homeostatic levels of the brain, we predict that EEG of heroin-abusers would have a considerable reorganization of the composition of brain oscillations and their functional connectivity.
The present study was designed as a longitudinal research program aiming to explore actual composition of brain oscillations and their temporal behavior (1) in current heroin addicts (see Fingelkurts et al., 2006a http://www.bm-science.com/team/art43_in-press.pdf and Fingelkurts et al., 2006b http://www.bm-science.com/team/art42.pdf), (2) during abstinent period of 10-14 days in the same subjects (Fingelkurts et al., 2007 http://www.bm-science.com/team/art46_in-press.pdf), and (3) after one year of methadone maintenance (Fingelkurts et al., 2007 http://www.bm-science.com/team/art45_in-press.pdf) in the same chronic heroine-abuse patients.
5. Characterization of hypnotic state with and without hallucination, as altered states of consciousness using advanced EEG analysis.
For more than 200 years the phenomena that comprise the domain of ‘hypnosis’ have attracted the curiosity of researchers, clinicians, and everyone, who have witnessed the seemingly magical changes in hypnotized persons’ behavior and experience (Kallio and Revonsuo, 2003).
At present, there are many different theories about hypnosis in the literature, overlapping in many respects yet also having major differences. Some researchers state that hypnotic phenomena cannot be explained without positing a special psychological state (e.g. altered state of consciousness, trance, dissociation), while others regard all phenomena seen in association with hypnosis as being explainable by using ordinary psychological concepts (e.g. role-playing or expectations). Indeed, is there a special psychological state, an altered state of consciousness (ASC), involved in the generation of hypnotic phenomena?
This project starts as an attempt to test the hypothesis that hypnosis may lead to an ASC (in the sense in which Kallio and Revonsuo (2003) define ASC). According to this conception, hypnotic behavior is thought to consist of two distinct elements: a special state of hypnosis and a degree of suggestibility that is not dependent on the presence of the state but is affected by it. ASC theory postulates that hypnosis proper is a rare phenomenon and its occurrence is for the most part confined only to very highly hypnotizable individuals (referred to as hypnotic “virtuosos”). If a special hypnotic state (ASC) exists at all, it should be most prominent in these individuals. In the present project a small group of carefully selected virtuosos will be used as subjects.
Current Research
1. Development of Operational Architectonics framework of brain and mind functioning.
It is assumed that the level of brain organization at which mental states and cognition (in particular consciousness) reside might be the highly organized macro-level electrophysiological phenomena (metastable operational modules) in the brain, realized by the coordinated electrical activity (operational synchrony) of many neuronal populations dispersed throughout the brain (Fingelkurts & Fingelkurts, 2004 http://www.bm-science.com/team/art30.pdf). This framework plausibly unifies the major influential concepts of modern cognitive neuroscience (symbolicism, representationalism, dynamicism and connectionism) and describes one and the same principle for perception, recognition, acting, memory, planning, anticipation, and thinking.
In the framework of this methodological approach (Fingelkurts and Fingelurts, 2005 http://www.bm-science.com/team/chapt3.pdf):
• The single neurons (highly distributed along the cortex) can quickly become associated (or dis-associated) by synchronization of their activity and giving rise to transient assembles. Each of these functional assembles represent discrete elemental brain operations some of which process different attributes of object or environmental scene. These brain operations are revealed in the form of quasi-stationary segments in the EEG/MEG.
• The temporal synchronization of such brain operations together (Operational Synchrony (OS) of EEG/MEG segments) gives rise to a new level of brain abstractness – metastable brain states. These metastable brain states or functional Operational Modules (OM), as we name them, may underlie the cognitive percepts and mental states which have representational nature. The sequence of these metastable OMs thus represents the stream of thoughts. Each step of cognition/behavior follows a dynamic state transition, in which an OM rapidly breaks functional couplings within one set of brain areas and establishes new couplings within another set, as the cognition/behavior evolves. These distinctive and rapid jumps between OMs have the appearance of a spatio-temporal discontinuity revealed in the EEG/MEG global field.
• OMs may be further operationally synchronized (on other temporal scale) to form new OMs of even larger abstractness from the initial brain state. In the limit, such process may lead to the generation of the most complex mental state, which corresponds to the personal self.
• Also the reverse process is possible – when complex mental state guided by attention is decomposed to several simpler mental states which in their turn may be further decomposed.
2. Isomorphism between EEG/MEG microstructure and a structure of phenomenal experience (consciousness).
Human brain is the junction point of the body and the mind, the objective and subjective. Somewhere here consciousness is emerged. Consciousness is the most crucial ingredient of the mind; no system totally lacking subjective phenomenal consciousness can be regarded as a truly mental system possessing a mind. However, the global principles of coding and representing in human brain the environmental scenes and objects, in particular the relations of these representations to mental states and thoughts are still an enigma for modern science. Most likely the reason for that is a lack of adequate methodology, consistent theory and understanding of the mechanisms through which the brain orchestrate the symphony of perceptions, thoughts and actions.
It is tempting to believe that electromagnetic brain field complexity is mirrored in phenomenological (functional) complexity and vice versa. Assuming this and as a step further in development of our Operational Architectonics Concept, we suggested the functional isomorphism between STRUCTURE (not just features) of phenomenal consciousness and STRUCTURE of operational architectonics of brain electromagnetic field (Fingelkurts & Fingelkurts, 2001 http://www.bm-science.com/team/art18.pdf ; 2003 http://www.bm-science.com/team/art24.pdf ; 2006 http://www.bm-science.com/team/art39.pdf).
One can see that the structure of electrical brain field, the structure of cognition and the phenomenal structure of consciousness have the same organization: the succession of discrete and relatively stable periods (metastable operational modules – OMs, cognitive acts or thoughts correspondently) separated by rapid transitive processes (abrupt changes between OMs, cognitive acts or thoughts correspondently).
Indeed, experimental evidence suggests that the behavioral or cognitive continuum is a succession of discrete behavioral/cognitive acts performed by an individual. Each separate act is the integration of a certain number of operations, which are important and appropriate for the realization of this act. The change from one behavioral/cognitive act to another is embedded in a rapid “transitional process”. The same is true for the phenomenological structure of human consciousness which consists of stable nuclei (or thoughts) and transitive fringes (or periods) – as it is described by James’ metaphor of “Stream of Thoughts.” It seems that metastability provides a mechanism of the functional isomorphism realization. This understanding is directly connected to the Kelso’ coordination dynamics phenomena in informationally coupled dynamical systems (Fingelkurts & Fingelkurts, 2004 http://www.bm-science.com/team/art30.pdf).
Although this framework is plausible, and it captures a strong intuition about the brain mechanisms that constitute perception, cognition and consciousness, its tenets require further systematic experimental investigations and mathematical modeling.
Research Objectives
To understand how information about the "objective" physical entities of the external world can be integrated, and how unified and coherent mental states (or Gestalts) can be established in the internal entities of distributed neuronal systems. We are developing a unified methodological and conceptual basis (Operational Architectonics of brain and mind functioning) for a possible mechanism of how the transient synchronization of brain operations may construct the unified and relatively stable neural states, which underlie mental states
Research Keywords
EEG, MEG, functional synchrony, synchronization, connectivity, neuronal assemblies, brain operations, mind, temporal structure, binding, perception, cognition, consciousness, dynamical, symbolic, neurocomputational, isomorphism, metastability, large-scale, self-organization
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