BRAIN NOTES 8

10-13-6

“The orbitofrontal cortex – the part of the brain just behind the eyes and located at a strategic spot at the top of the emotional limbic system, next to the “higher” associational cortex responsible for various forms of thought and consciousness – plays an important role in affect regulation.  (siegel/tdm/280)”

“This area of the brain is especially sensitive to face-to-face communication and eye contact.  Because it serves as an important center for appraisal, it has a direct influence on the elaboration of states of arousal into various types of emotional experience.  (siegel/tdm/280)” copied from prenotes ch44 child brain

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also see parasympathetic and sympathetic from above pages, written into prenotes ch 44 along with info on the above

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INTEGRATION PROCESSES IN BRAIN

“Within the brain itself, complex functions emerge from the coordination of neural activity in a range of circuits.  (siegel/tdm/301)”

++  limbic regions and associational circuits, especially the prefrontal areas such as the orbitofrontal cortex – serve coordinating function – play important role in neural integration – receive input and send output to widely distributed areas of the brain

++  “…neural integration is fundamental to self-organization, and indeed to the capacity of the brain to create a sense of self.  (siegel/tdm/302)”

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++  at least three forms of integration within the brain

++  they focus on particular aspects of anatomic circuits

++  each involves aspects of the primitive paralimbic cortex [region]

++  may actually be interdependent

++  “At a minimum, then, the orbitofrontal cortex coordinates vertical and lateral integration.  (siegel/tdm/303)”

++  vertical –

++  integration of the “lower” functions of brainstem and limbic regions with the “higher” operations of the frontal neocortex such as cognitive an motor planning

++  somewhat isolated processes at various layers of complexity or “order are coordinated into a function system

++  vertical process is common throughout the brain

“For example, vertical integration is revealed in the capacity of the right hemisphere (especially the paralimbic orbitofrontal cortex) to have predominant control over certain “lower” functions, such as the regulation and representation of bodily function as mediated via the autonomic nervous system.  (siegel/tdm/303)”

++ dorsal-ventral:

++  focuses on dual origins of frontal cortex from the archicortical and paleocortical regions of the paralimbic cortex

++  these differences begin in the embryo “and may stem from the asymmetry     …   [of] “intrinsic motive formation.”

++  each hemisphere with dominant pathway

++  DORSAL FOR RIGHT

++  VENTRAL FOR LEFT

++  each circuit or stream mediates differential forms of motivational processes and motor control

++ creates different representational processes on either side of the brain

++  less hemispheric specialization in women may be partly due to participation of both dorsal and ventral circuits in each hemisphere  —  “Dorsal-ventral integration would allow for less lateralization of the more complex representational processes originating from each side of the brain.  (siegel/tdm/302)”

++  lateral:

++  “coordination of functions of the circuits at a smilar level of complexity or order”  (siegel/tdm/302)

++  this integration may be mediated by associational neurons which link distinct systems

++  “When lateral integration connects the complex representational processes of one hemisphere to another, the term “bilateral” or “interhemispheric” integration can be used.  (siegel/tdm/302)” copied to endnotes brain laterality 7

++  “The associational neurons that link various anatomically and functionally distinct (siegle.tdm.302) regions on either side of the brain may be the means by which the coordination of interhemispheric information processing occurs.  (siegel/tdm/303)”  copied to endnotes brain laterality 7

++   the cerebral commissures (the corpus callosum and the anterior commissures) are only pathway thru which higher functions of perception and cognition, learning and voluntary motor coordination can be unified —  achieved through a sorting process which creates complementary sets of associative links between the cortical maps of various sensory and motor functions (he quotes somebody else for this stuff)

++  “In this form of lateral integration, the isolated functions of each hemisphere can be coordinated into a functionally linked system.  (siegel/tdm/303)” copied to endnotes brain laterality 7

“Lateral integration is revealed within REM sleep and encoding-retrieval processes, in which left and right orbitofrontal cortices are involved in representational integration in dreams and the consolidation of memory.  (siegel/tdm/303)” copied to end notes later 8

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all one paragraph

“Another illustration of how distinct regions of the brain may be coordinated into integrated circuits is the connections of frontal cortex to the basal ganglia….this integrated system functions to guide behavior by assessing a variety of inputs…

“.the basal ganglia mediate rule-guided behavior, whereas the frontal cortex provides alternatives that incorporate context-dependent processing.

“This can also be seen as an example of the integration of implicit encoding in the basal ganglia and explicit processing in the fontal cortex.

“This frontal cortex-basal ganglia system serves to allow the individual to reject maladaptive rules that are no longer useful in the currently assessed situation.

“The integrated functioning of such a system has powerful implications for the acquisition and application of new behavioral responses.

“This integration of “motor” areas (basal ganglia) with (siegel.tdm.303) those thought of as responsible for more abstract “planning” (frontal lobes) may be an adaptive way through evolution that our brains have come to integrate a wide array of systems

“…orbitofrontal cortex’s role in mediating response flexibility, the altering of responses based on unexpected or changing conditions. (siegel/tdm/304)”

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++  more basic level of neurobiology, neurons integrate their functioning within neural networks to produce neural net activation profiles [he has called states of mind]

++  brain learns from experience through the shaping of patterns of neuronal firing that create these networks

++  “…basic neuronal connectivity creates representational abilities and also directly influences the nature of the network activity itself.  (siegel/tdm/304)”

++  “…a process that links distinct circuits not only creates a new form of information processing, but also establishes a more complex, integrated network that influences its own capacities.  (siegel/tdm/304)”

++  “Integrated systems, by virtue of their coordinated activities, establish their own characteristic features; the whole is greater than merely the sum of the individual parts.  (siegel/tdm/304)”

++  “…such neural integration becomes a central process that is directly related to self-regulation.  (siegel/tdm/304)”

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“The fundamental role of complexity has helped to clarify the development and functioning of neural networks and has pointed to the central role of “spatiotemporal integration.”  Various levels of hierarchical systems – from sets of neurons to the interaction of complex circuits – involve space-time patterns of neuronal activity.  What this suggests is that the brain is capable of representing, in the moment, patterns of activity in which direct influences from the past (siegel/tdm/304) are encoded…the organization of memory and the brain’s function as an anticipation machine enable it to “represent the future.”  Such anticipatory mechanisms directly shape the ways in which linkages may be made across various processes and across time.  (siegel/tdm/305)” copied to pre notes time 8

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all one paragraph – copied to pre notes time 8

“For example, the ways in which neural circuits anticipate experience may help us understand how the mind develops through a recursive set of interactions.  As representational processes anticipate experience, they also seek particular forms of interactions to match their expectations.  In this way, the “bias” of a system leads it to perceive, process, and act in a particular manner.  The outcome of this bias is to reinforce the very features creating the system’s bias.  As development evolves, the circuits involved become more differentiated and more elaborately engrained in an integrated system that continues to support its own characteristics.  These recursive and anticipatory features of development may be at the core of how the dorsal and ventral circuits influence the unfolding of the lateralization in hemispheric functioning.  (siegel/tdm/305)”

“…a clearer understanding of the developmental origins of these different systems [hemispheric lateralization and brain asymmetry] may be achieved by examining how the anticipation of encounters with the world influences each hemisphere in quite distinct ways…..This anticipation can be seen as emanating from a form of spatiotemporal integration:  The mind creates complex representations as a process between perception (input) and action (output) in an effort to interact with an environment that changes across time and space.  The value of such a representational process is that it allows the individual to anticipate the next moment in time and in this way to act in a more adaptive manner, enhancing the chance for survival.  Spatiotemporal integration may therefore be a fundamental feature of how the human mind has evolved.  (siegel/tdm/305)”

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LINKAGES

Important parts of this are in dissociation notes 6

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see brain plasticity put into chp 51 reg con’t

which includes this:

“For example, in studying the progressively increasing myelination across the lifespan in the hippocampal pathways that interconnect widely distributed regions….[quote he puts here from Francine Benes) (siegel/tdm/307)  …In this manner, experiences and innate developmental processes may allow our neural capacity to integrate an array of processes to continue to develop throughout our lives. The mechanism of this differentiation of circuits…may involve a range of processes from the growth of axons into widely distributed regions of the brain, the establishment of new synaptic connections, and the increased conductance of nerve fibers via their increased myelination.  These mechanisms may be at work in the dramatic maturation of the corpus callosum during the first decade of life, and perhaps, we can propose, in its possible ongoing development throughout life.  (siegel/tdm/308)”  copied from chp 51 reg con’t on plasticity

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“Clinical dissociation can be viewed as a dis-association in the usually integrative functioning of the mind.  How does this happen?  Mental functioning emanates from anatomically distinct and fairly autonomous circuits, each of which can be dis-associated from the function of the others.  Studies of a drug called ketamine demonstrate (siegel/tdm/319) that administering it to normal subjects leads to dissociative symptoms, such as depersonalization and derealization.  Subjects with prior histories of trauma experience the additional symptoms of terror and panic.  Ketamine blocks the transmission of signals across the synapses of large neurons, which are especially plentiful in the associational regions of the cortex.  This finding suggests that the disassociation of functions in dissociation may be mediated by a blockage in the integrative capacity of associational regions, which coordinate an array of neural pathways.  (siegel/tdm/320)”  coped from dissociation notes 6

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“As an information-processing system, the mind has layers of representational processes that are created by various inputs from more and more complex representational levels.  Studies of brain function reveal that neural pathways have such layers of input, in which secondary and tertiary association areas link streams of neural activity into more and more complex networks of activation.  These processes in turn influence a widely distributed set of neural processes responsible for our emotional states, bodily response, reasoning, memory retrieval, and perceptual biases.  Regions of the brain such as the orbitofrontal cortex, which function to coordinate these disparate functions across time, may be proposed to play a crucial role in the integrative process.  Various mental processes may thus be functionally isolated from one another with the blockage of integrative circuits…these associational functions include social cognition, autonoetic consciousness, response flexibility, stimulus appraisal, and affect regulation.  Isolation of these functions may be at the core of incoherence during dissociative experiences.  (siegel.tdm.320)”

coped from dissociation notes 6

++++ AN INTERPERSONAL NEUROBIOLOGY OF STORIES

NARRATIVE AND NEURAL INTEGRATION

“The hippocampus is considered a “cognitive mapper”:  It gives the brain a sense of the self in space and in time, regulates the order of perceptual categorizations, and links mental representations to emotional appraisal centers.  These are multiple layers of integration.  (siegel/tdm/330)”

“A number of authors propose that the associational areas of the neocortex, such as the prefrontal regions (including the orbitofrontal cortex) that link various widely distributed representational processes together, form dynamic global maps or complex representations from the input of widely distributed regions in order to establish a sensori-motor integration of the self across space and time.  This capacity allows for the anticipation of and planning for future events as they are created from the integrated  representation of the experiences of the self.  [I couldn’t do this as a child and not sure I can do it now] This is autonoetic consciousness.  Such a spatiotemporal integrating process can be proposed to be fundamental to the narrative mode of cognition.  This mapping process may be at the heart of autobiographical narrative and the way the mind attempts to achieve a sense of coherence among its various states; trying to make sense of the self in the past, the present and the anticipated future.  We can propose that the capacity of the mind to create such a global map of the self across time and various contexts – to have autonoetic consciousness – is an essential feature of integration that may continue to develop throughout life.  (siegel/tdm/330)”  copied to prenotes time 8

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