The limbic system was first considered as the anatomical basis of emotional reactions. Comparative neuro-anatomical, physiological and clinical studies have then shown that the limbic system is involved in addition to the control of affective behavior in learning processes and plays an important role in storing memories. Thus, the limbic system, now regarded as an association system that processes the meaning and impetus to the individual physical needs can take place. (See Dictionary of Biology 2000 Vol 2 p. 309)
Development Historically older limbic regions add information about taste, smell and pain. The anterior cingulate cortex is an important link between the neocortex and the centers, which are indeed involved in the development of consciousness, work itself, however unconsciously. These centers are called "subcortical" because they are outside or below the cortex. There are also those brain centers with messengers (so-called "neurotransmitters") such as adrenaline for "excitement" care in our brain when we fall in threatening or stressful situations. The limbic system has very different functions, but they are all involved in the creation and unconscious in the regulation of physical needs, emotions and feelings.
An important part of the limbic system is the hypothalamus. It is located in the lower part of the forebrain. He is the main control center for basic biological functions such as food and fluid intake, sleep and wakefulness, temperature and cardiovascular regulation, offensive and defensive behavior as well as sexual behavior. Therefore, it is also the origin the associated drive and affect states. The hypothalamus is connected with almost all behavioral parts of the rest of the brain. (Cf. Roth 2007, p. 43-48)
The emergence of unconscious emotions in the strict sense is primarily the responsibility of the amygdala and the mesolimbic system . The amygdala is at the lower edge of the temporal lobe. It occupies a central role in the emergence of predominantly negative emotions or strong and moving in emotional learning. It is considered as a center of fear and anxiety behavior led assessment. An opponent of the amygdala, at least as fear, anxiety and stress affects the mesolimbic system. (Cf. ibid) has
The mesolimbic system has three functions: First, it is the reward system is the brain because the brain's own opiates are here particularly effective, which can lead to positive feelings to the euphoria. Second, it is the system, the positive consequences of events or actions recorded and this makes the basis for the third function, namely to motivate the people so that he repeated the done, which has
previously brought to a satisfactory condition. ( ibid.)
The hippocampus is an important institution of the preconscious and takes an intermediate position between the corresponding neocortex and the limbic system. He is the organizer of consciousness capable and declarative memory linguistically formulated. He determines which consciously experienced events such as in which of the many "drawers" of this memory system are stored. The hippocampus is indeed the organizer, but not the place of declarative memory, which is located in the cerebral cortex. In this case, is that each memory is localized at the site of the cerebral cortex, in which also the related sensory information is processed. So the place is for the visual memory there, where visual information is processed. The hippocampus cooperates fully
unconsciously. (Vgl.ebd.)
Closely associated with the hippocampus, the amygdala, the mesolimbic system and the entire cortex, the septal region, which together with adjacent structures of the basal forebrain. The basal forebrain has also affective - vegetative functions, eg in the field of reproduction and feeding, but in cooperation with the hippocampus and cerebral cortex is exercising cognitive and motivational functions associated with learning, attention control and memory. (Ibid.)
diencephalon and brain stem
The diencephalon consists of the top to the bottom of Epithalamus, dasalen thalamus, ventral thalamus and hypothalamus. (Ibid. p. 48-52)
dasale The thalamus is a complex of functionally very different areas of closely packed nerve cells and is associated with the cerebral cortex on ascending and descending fibers, the thalamus - are cortical system. ends in the nuclei of the thalamus dasalen from the eye, the ear, the organ of balance in the skin and muscles and sensory pathways come to be redirected to other paths to the cerebral cortex. Similarly, motor Paths of the cerebral cortex, which take their way to the medulla and spinal cord diverted. Nuclei of the thalamus have accordingly dasalen partly sensory and partly motor functions, but are also involved in cognitive and limbic functions and play in the regulation of Truth, awareness and attention states an important
role. Located at the intermediate and subsequent brain in humans is relatively small midbrain (mesencephalon) is divided into an upper part, the so-called Mittehlhirndach (tectum), and a lower part, known as the tegmentum .
This center plays in humans an important role in visually triggered unconsciously view and head movement and the orientation services. The tegmental area also contains centers for movement, action control and assessment are important. Inside the midbrain is the central gray matter, which is the seat of switching elements of affective responses and instinctive behaviors. The bridge contains, such as the midbrain tegmentum, a number of important motor and limbic nuclei and is the connection between cerebral cortex
and cerebellum ago. The cerebellum is attached to the bridge and is divided anatomically and functionally into three parts: The first one has the control of balance and to do the eye movements and is Vertibulo - called Verebellum. The second part is Spino - called the cerebellum . It receives inputs from the spinal cord of the muscles and the coordination of the musculoskeletal system to do. The third part, called cerebro cerebellum,
is closely associated with the cerebral cortex and to the controller which deals with the control of fine motor skills.
The cerebellum is an important site, according to Roth motor learning, but is also involved in many cognitive functions such as language and thought. The medulla is the direct continuation of the spinal cord and connects
det the brain with the largest part of the body. The medulla contains the so-called reticular formation, extending from the medulla over the bridge to the anterior midbrain and a crucial role in vital bodily functions such as sleep and wakefulness, blood circulation and respiration, as well as arousal, attention, and consciousness plays. (Ibid.)
The nerve cells
nerve cells (neurons) are the "building blocks" of the brain. The entire brain consists of neurons which are interlinked and intertwined in ways hardly countable. According to Wolf Singer, resulting phenomena such as loading
consciousness, feelings, but also the ability to learn only through the complex network of neurons. (See Singer 2000)
The human brain consists of about 50-100 billion neurons, and according to Gerhard Roth, at least twice the number of support, supplies and food cells, the so-called glial cells. After Roth neurons a kind
are "mini battery" and the network a kind of "electrical circuit". Neurons take up to an electric signal to change them and give them back further, but also chemical communication signals called neurotransmitters
add, change and release. (Cf. Roth 2007, p. 54)
their particular neurons excitability and conductivity obtained here by electrically charged atoms (ions), especially by sodium and potassium ions. All neurons contact at least a third of them are available coast-
outgoing energy for sodium from the cell and pumping potassium into the cell. This occurs at the cell membrane, a charge difference of about 70 millivolts (inside negative), referred to as resting potential
is. (see Spitzer 2000 p.20)
neurons input structures have so-called dendrites through which it excitations record in the form of electrical or chemical signals, and output structures, called axons, which have long and thin fibers are neurons.
At the end of the axons there is a small bump, the synapse, which is responsible for the transmission of signals from one cell to another. Synaptic contact in the dendrites and cell bodies of other neurons. They are not bound to the cell body, but neuron and synapse are by the so-called synaptic cleft from each other separated. Signals from them both electronically than be transferred in a combination of electrical and chemical signals. Each neuron of this type of connection with up to 20,000 (in the cerebral cortex) other
connected neurons. The process of information processing or further task is carried out largely via chemical synapses. (Cf. Roth 2007, p. 54ff)
provides in detail the process of information transmission as follows: At the chemical synapse is an incoming electrical signal is converted so-called action potential , into a chemical signal that then of neurotransmitters , across the synaptic gap to the downstream neuron migrates. It so excited to chemical way that neuron, and there is finally a chemical signal to the cell body of the neuron and its axon migrates back to the next neuron. (Ibid. P. 56)
An action potential occurs when the resting potential is attenuated by 20 millivolts, this quickly leads to changes in the overall short-lasting weakening or reversal of the resting potential to
episode have. This process is called depolarization. The resting potential was raised by this "disturbing" but very quickly, within one - to restore tens of milliseconds. This recovery process, call the
neuroscientists repolarization. The value of the voltage, the resting potential must cross so that it becomes an action potential, called the neuroscientists "threshold". If a neuron excited, then his resting potential shifts more and more of the threshold below which the neuron produces an action potential itself . This process is called also "fire". It should be noted here that cause usually several cells, or whole groups of cells that are involved in synaptic transmission and action potentials . (See Spitzer 2000 p. 20f)
The signal transmission from neuron to neuron is done quickly, in a period of less than one millisecond. (Roth 2007 p.56)
Wow! Done! The structure of the brain in two, admittedly rather dry and complicated, blog articles is verfasst.Im next part of this series will get down to it, namely the question of how humans learn and what the brain research about it knows (or believes to know).
As always with friendly Regards ...
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