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In 1909 Korbinian Brodmann (1868-1918) published his delineated sections of the primate cortex based on cell types and distributions. He divided the brain into 52 areas in each hemisphere for non-human primates (and 47 for humans) based on the technology of his day, the light microscope. Years earlier he published a morphological organization of the neocortex, but this was an exhaustive evaluation of cortical structure across the brain, with the possibility that certain functions might be associated with specific cellular organizations. In many instances there is a clear link between microscopic organization and function, such as the primary visual cortex (area 17). However, visual appearance does not necessarily reflect function and higher functions often involve multiple areas simultaneously or sequentially, such as reading aloud (e.g., area 17, 39, and Broca's area, minimally). An example of such microscopic changes can be seen at

http://webvision.med.utah.edu/imageswv/VisualCortex-Nissl.jpg

A significant issue with using stereotaxic coordinates for an ideal head (x,y,z-space e.g., Talairach or MNI) is that functional and structurally heterogeneity is the rule across humans and other higher species, not homogeneity, so akin to the Heisenberg principle, the tighter we localize activity of a single voxel in someone's head, the less certain can we be of its function and also that this voxel serves the same function in another head. With this in mind, I created the Brodmann montage in November 2006 while developing the new SKIL 3 analysis software, relying on Pascual-Marqui et al's 1988 Laplacian solution to pinpoint energy differences at the surface (which I corrected empirically with a tape measure and a dozen willing skulls) and functional and structural data from Van Essen & Drury (1997) and others. The LORETA solution solves the inverse solution (EEG tomography) using 2,000 or more voxels whereas I reduced this to essentially "mega-voxels", or center points of 55 Brodmann areas which had sufficient size to contribute to the scalp given their distances from the scalp. In other words the Brodmann montage approximates surface EEG from 55 sources placed in the center of structurally homogeneous areas whereas LORETA places thousands of equally spaced sources throughout the cortex. In the Brodmann montage all 55 sources are chattering away, with energy equal to their area, and the surface EEG informs me as to the amount of chatter per area.

Is LORETA with 2,000+ voxels more accurate than the Brodmann montage? Yes and no, may be the answer. In science we are always faced with how accurate to measure a phenomenon, given the nature of the phenomenon. We can answer this by considering the goal of our measurement. With the Brodmann montage I wanted to create ideal brain divisionsthat would map reasonably well to the functions of all or most of the people we would record EEG from. If humans exhibited no structural or functional variability across individuals, then we can cut up the brain into an infinite number of voxels and accurately resolve functional changes in all individuals; but this is not the case. We have an amazing diversity of structure and function below the skull across individuals, ranging from reverse dominance (speech motor centers in the right hemisphere), differences due to handedness, gender, age, maturation, injury, and other factors. So considering all this variability I cautioned on the side of fewer sources in order to increase the reliability for each source. For instance, the voxel 9, -53, 14 , which refers to x, y, z coordinates in millimeters in Talairach space, falls in the right posterior cingulate gyrus for most people, though not all, and it may serve emotional perception in one person and somato-emotional processes in another. By limiting activity to Brodmann areas only, instead of sub-area voxels, we also have reasonable mapping to neuropsychological test data. Further divisions of Brodmann areas may be reliable, but I resist the equally-spaced technique of LORETA for this more neuroanatomically-constrained solution. To further understand why I like to limit our measurement, consider the following:

In science we have to decide how best to measure a phenomenon. We can easily measure or sample a phenomenon too tightly or too loosely and we want a measure that best captures a phenomenon that suits our communication and various purposes. Let me explain what I mean by analogy. If I want to estimate the number of people who are baseball fans and I make my sample very tight chronologically or spatially; in so doing I may omit a vast number of people who consider themselves baseball fans. If my definition or measurement of what constitutes a baseball fan is whether they attended a baseball game yesterday or are currently sitting in the stands at a game, this is too tight a sample by most people standards. If my definition of a fan is anyone who has attended a major league game during their life, or everyone in the greater Boston metropolitan area a baseball fan, I include many people who do not consider themselves baseball fans. Too tight or too loose a definition or measurement will be unreliable, even nonsensical. So we want to measure the middle ground of a definition, and this is how I chose the reasonably large Brodmann area, smaller than a cortical lobe, over the cubic millimeter voxel used by fMRI and other technologies as it served communication and correspondence to other fields well (neuropsychology, neurotherapy).

A Brodmann area trainer that uses multiple electrodes to triangulate activity from each Brodmann area is under development (part of the SKIL EEG Operant trainer), but until that is complete, we can use a "poor-man's version" of Brodmann area training by training the electrode nearest each Brodmann area. Below is the 10-10 electrode position closest to each area in the Brodmann montage, and distance in millimeters from each cortical projection of an electrode.

Closest 10-10 Electrode position to each Brodmann area*

Area LEFT RIGHT ba01 C3 C4 ba02 C3 C4 ba03 C3 C4 ba04 C3 C4 ba05 C1 CP2 ba06 FC3 FC4 ba07 P1 P2 ba08 F1 F2 ba09 AF3 AF4 ba10 FP1 FP2 ba11 AF7 FPz ba17 O1 O2 ba18 O1 O2 ba19 PO7 PO4 ba20 FT9 FT10

Area LEFT RIGHT ba21 T7 T8 ba22 T7 T8 ba23 Pz Pz ba24 F1 F2 ba31 Pz Pz ba32 F1 AFz ba37 P7 P8 ba38 FT9 FT10 ba39 P5 P6 ba40 CP3 CP4 ba41 C5 T8 ba42 T7 C6 BROCA/44R F5 FC6 ba45 F8 ba46 AF7 F6 ba47 F7 F8

* limited to SKIL Brodmann montage areas

Closest Brodmann area to each 10-10 electrode

ELECTRODE SITE FP1 ba10L FPz ba10L FP2 ba10R AF7 ba46L AF3 ba09L AFz ba09L AF4 ba09R AF8 ba46R F7 ba47L F5 ba46L F3 ba08L F1 ba08L Fz ba08L F2 ba08R F4 ba08R F6 ba46R F8 ba45R FT9 ba20L FT7 ba47L FC5 BROCLA FC3 ba06L FC1 ba06L

ELECTRODE SITE FCz ba06R FC2 ba06R FC4 ba06R FC6 ba44R FT8 ba47R FT10 ba20R T7 ba42L C5 ba42L C3 ba02L C1 ba05L Cz ba05L C2 ba05R C4 ba01R C6 ba41R T8 ba21R TP7 ba21L CP5 ba40L CP3 ba02L CP1 ba05L CPz ba05R CP2 ba05R

ELECTRODE SITE CP4 ba40R CP6 ba40R TP8 ba21R P9 ba20L P7 ba37L P5 ba39L P3 ba39L P1 ba07L Pz ba07R P2 ba07R P4 ba39R P6 ba39R P8 ba37R P10 ba37R PO7 ba19L PO3 ba19L POz ba17L PO4 ba19R PO8 ba19R O1 ba18L Oz ba17R O2 ba18R

* limited to SKIL Brodmann montage areas

Here is the anatomical gyral names of the various Brodmann areas. Recall that there is a Brodmann area in both left and right hemisphere, the homologues.

Gyrus (Functional name)

EXCLUDED FROM SKIL BRODMANN MONTAGE due to small size and distance from scalp
25 - subgenual*
26 - ectosplenial*
28 - entorhinal*
29 - granular retrolimbic *
30 - agranular retrolimbic *
33 - pregenual *
34 - dorsal entorhinal *
35 - perirhinal *
36 - ectorhinal *
43 - subcentral *
52 - parainsular *

13, 14, 15, 16, 27, 49, 50, 51 - monkey only

Ironically, we name our cytoarchitechtonic scheme after Brodmann but early researchers relied on von Economo and Koskinas (1925) for a cytoarchitechtonic description of the human cortex.

-DK

References:

Brodmann K (1909). "Comparative Localization Studies in the Brain Cortex, its Fundamentals Represented on the Basis of its Cellular Architecture" (Vergleichende Lokalisationslehre der Grosshirnrinde in ihren Prinzipien dargestellt auf Grund des Zellenbaues), Johann Ambrosius Barth Verlag, Leipzig.

Brodmann K (1905). Beiträge zur histologischen Lokalisation der Grosshirnrinde: dritte Mitteilung: Die Rindenfelder der niederen Affen, Journal für Psychologie und Neurologie, 4, 177–226.

Pascual-Marqui RD, Gonzalez-Andino SL, Valdes-Sosa PA, Biscay-Lirio R. (1998). Current source density estimation and interpolation based on the spherical harmonic Fourier expansion. Int J Neuroscience, 43, 237-49.

Van Essen DC, Drury HA. (1997).Structural and functional analyses of human cerebral cortex using a surface-based atlas. J Neuroscience, 17, 7079-7102.

von Economo C & Koskinas GN (1925). Die Cytoarchitektonik der Hirnrinde des erwachsenen Menschen. Berlin: Julius Springer.

Reviews NEW &/OR USEFUL BOOKS

Fundamental Neuroscience, Third Edition by Larry R. Squire

Cellular and Molecular Neurophysiology, Third Edition by Constance Hammond

Development of the Nervous System, Second Edition by Dan H. Sanes

Handbook of the Neuroscience of Language by Brigitte Stemmer

Neurobiology of Learning and Memory, Second Edition by Raymond P. Kesner

Neurobiology of Attention by Laurent Itti

Theoretical Neuroscience: Computational and Mathematical Modeling of Neural Systems by Peter Dayan

Barry RJ, Clarke AR, Johnstone SJ, McCarthy R, Selikowitz M. (2009). Electroencephalogram theta/beta Ratio and Arousal in Attention-Deficit/Hyperactivity Disorder: Evidence of Independent processes. Biologiical Psychiatry. Jun 3.
Theta/beta ratio did not correlate with a skin conductance index of arousal in ADHD

Cohen MX, Axmacher N, Lenartz D, Elger CE, Sturm V, Schlaepfer TE.(2009). Nuclei accumbens phase synchrony predicts decision-making reversals following negative feedback. Journal of Neuroscience, 29, 7591-8.
Strategy switches following losses were preceded by enhanced theta (4-8 Hz) phase synchrony between the nuclei accumbens, and a break-down of gamma (20-80 Hz)-alpha (8-12 Hz) coupling.

Cvetkovic D, Cosic I.(2009). EEG inter/intra-hemispheric coherence and asymmetric responses to visual stimulations. Medical & Biological Engineering & Computing Jun 17.
High coherence in the EEG beta band was found during visual processing.

de Fockert JW, Ramchurn A, van Velzen J, Bergström Z, Bunce D.(2009). Behavioral and ERP evidence of greater distractor processing in old age. Brain Research, Jun 2.
The N170 component (ERP) had greater amplitude in older adults during unattended stimuli, suggesting an electrophysiological correlate of a reduced ability to prevent distraction.

De Smedt B, Grabner RH, Studer B.(2009). Oscillatory EEG correlates of arithmetic strategy use in addition and subtraction. Experimental Brain Research, 195,635-42.
Arithmetic fact retrieval produces left-hemispheric event-related synchronisation of theta activity whereas application of procedural strategies is accompanied by bilateral parietooccipital alpha desynchronization.

Flores AB, Digiacomo MR, Meneres S, Trigo E, Gómez CM.(2009). Development of preparatory activity indexed by the contingent negative variation in children. Brain & Cognition. Jun 3.
Young adults show a contingent negative variation in contralateral cortical activation related to motor preparation whereas children do not.

Friedman DE, Gilliam FG.(2009). Seizure-related injuries are underreported in pharmacoresistant localization-related epilepsy. Epilepsia. Jun 10.
A survey revealed that many serious injuries are not documented as seizure related.

Hale TS, Smalley SL, Hanada G, Macion J, McCracken JT, McGough JJ, Loo SK.(2009). Atypical alpha asymmetry in adults with ADHD. Neuropsychologia, 47,2082-8.
Increased rightward alpha asymmetry is adevelopmentally persistent feature of ADHD.

Herrmann MJ, Mader K, Schreppel T, Jacob C, Heine M, Boreatti-Hummer A, Ehlis AC, Scheuerpflug P, Pauli P, Fallgatter AJ.(2009). Neural correlates of performance monitoring in adult patients with attention deficit hyperactivity disorder (ADHD). World Journal of Biologiical Psychiatry, 19, 1-8.
Adults with ADHD are characterized by deficits in error processing, which diminish significantly with age.

Irimia A, Swinney KR, Wikswo JP.(2009). Partial independence of bioelectric and biomagnetic fields and its implications for encephalography and cardiography. Physics Review E: Stat Nonlinear Soft Matter Physics, 79(5 Pt 1), 051908.
This research group argues that electric potential and the magnetic field find different sources in the brain.

Jones NA, Field T, Almeida A.(2009). Right frontal EEG asymmetry and behavioral inhibition in infants of depressed mothers. Infant Behavioral Development, 32,298-304.
Behavioral inhibition for infants exposed to early maternal psychopathology were explored with EEG.

Kislova OO, Rusalova MN.(2009). EEG coherence in humans: relationship with success in recognizing emotions in the voice. Neuroscience & Behavioral Physiology, 39,545-52.
EEG coherence correlated with recognition of emotions from voices.

Leung H, Schindler K, Chan AY, Lau AY, Leung KL, Ng EH, Wong KS. (2009). Wavelet-denoising of electroencephalogram and the absolute slope method: A new tool to improve electroencephalographic localization and lateralization. Clinical Neurophysiology, Jun 8.
Use of quantitative methods proved superior to conventional classification of seizure EEG in localizing and lateralizing.

Consider the 1988 Best Picture film "Rainman." It opens on conflict and it takes more than an hour into the film before we learn of the original stable state: an autistic brother (Raymond), age 9, lives with and tries to care for his baby brother (Charlie). We imagine the conflict scene retrospectively, what separated Charlie from Raymond, the start of the story we see. Charlier was accidentally burned by hot water during a bath given by his older disabled brother. Order is restored when Raymond and Charlie reconnect and restore a brothership, which also requires Raymond's return to his institutional home and Charlie's promise to visit him.

Narrative (or story) is an informational format by which the two cerebral hemispheres communicate well with each other. And given that all narratives center on deception -- be it deception between people, a suppression of information from the audience, or self-deception in which a character deceives him or herself as to the state of the world -- one goes to wonder whether self-consciousness is a response of the right hemisphere's detecting deception in the information sent by the left hemisphere (LH).

As a narrative unfolds, this deception is manifested and eventually removed. Deception in self-narrative may involve interhemispheric monitoring. One must monitor a representation of an event in order to misrepresent that event to another. This seems best handled in the brain by one hemisphere monitoring the modelling that goes on in the other hemisphere. If deception may occur when one hemisphere has decided (forgive the anthropomorphism) to monitor the processing of the other. Communication between the two hemispheres is interrupted. What could cause this interruption? In my opinion the left hemisphere (in normal right- handers) has developed with the strategy that all stimuli it encounters are interior to it, in essence, its own self- creation, and the right hemisphere processing the contents of its perception as if they are exterior to it, the integrity of the stimuli's existence is maintained, as is. Also, each side of the brain is likely modelling the system which sends it information. Deception may come about from the left hemisphere believing that the right hemisphere's processing is also interior to it, its own self-creation.

Consequently, cooperation between the two hemispheres are lost and the left hemisphere begins to dominate the behavior and processing of the organism. Given that the LH strategy is that all information it receives is interior to it, the results of any action are in a sense prespecified: the end of any act or thought will result in what is already interior to the mind creating the action or thought. Schizophrenia, particularly paranoid schizophrenia, may be an extreme example of this form of deception: the LH of a paranoid schizophrenic dominates the processing of the individual to such restrictive points such that a RH contribution to processing is viewed as coming from a source exterior to the person -- which may explain many of the thought disorders experienced by such patients. In this fashion psychopathology can be viewed as self-deception, which is in turn a narrative infliction.

Repair of a narrative infliction may occur with a return to hemispheric cooperation, a return to a progressing self-narrative. In the case of paranoid schizophrenics, for example, the autonomy of the right hemisphere must be reinstated. Most likely, both hemispheres have a model of the individual's self, created from the experiences of the individual with the world. To repair the self-narrative, these selves need to be reinstated equally, cooperatively. The past should serve the integration of a self-narrative. The optimal situation would be a complete reintegration of both hemispheres, which would, I suggest, result in what Jaynes and others have called the contentless "I". In this case, the self would be both formulated and contentless (or unformulated) at each point in time. In such a situation, I would argue that the two hemispheres have essentially returned to a cooperative effort, a self-narrative. An individual's self returns to the subjective universe of individual experience, one directed towards a constant reinstituting of order. This enables the individual to achieve an understanding of the initial stability of the past, even if the future is unclear. Such knowledge provides the individual with labels, formulas, and information about the past self which can be used to direct the individual to the next experience. In other words, having the past in order helps us understand the future.