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- Glossary
Parietal lobe
The parietal lobe is one of the four large lobes of the cerebral cortex. It is located behind the frontal lobe and above the occipital lobe. Somatosensory processes take place in its anterior region, while sensory information is integrated in its posterior region, enabling the handling of objects and spatial orientation. In addition, the parietal lobe is involved in attention, the recognition of body parts and objects, as well as linguistic and mathematical abilities.
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- Glossary
Parvocellular
"Parvus" means "small." In the lateral geniculate nucleus, the switching station for visual stimuli in the thalamus, the outer four layers are called parvocellular because, unlike the magnocellular cell layers, they have small cell bodies. The parvocellular system transmits information for the perception of color and fine details.
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Perceptual field
The totality of all impressions that reach an individual at a given moment. This includes both stimuli from the environment and internal states that a living being perceives either consciously or unconsciously and combines into an overall picture.
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Phantom limb
A phantom limb is still felt by the patient even though it has been amputated. The sensations are usually tingling or negative in nature, often in the form of pain.
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- Glossary
Phantom limb pain
Phantom pains are called phantom pains because they occur in phantom limbs – limbs that have been amputated.
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Plaques
Senile plaques accumulate in the gray matter of the brain when a protein – known as amyloid precursor protein – is not broken down correctly. Inflammation and disorders of fat or sugar metabolism can promote plaque formation. On average, the deposits reach a diameter of 50 micrometers. The appearance of plaques is one of several anatomical changes in the brain that pathologists can use to diagnose Alzheimer's disease after death.
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- Glossary
Plasticity
The term neuroplasticity describes the ability of synapses, nerve cells, and entire areas of the brain to change structurally and functionally depending on the degree to which they are used. Synaptic plasticity refers to the adaptation of the signal transmission strength of synapses to the frequency and intensity of incoming stimuli, for example in the form of long-term potentiation or depression. In addition, the size, interconnection, and activity patterns of different areas of the brain also change depending on their use. This phenomenon is referred to as cortical plasticity when it specifically affects the cortex.
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- Glossary
Pons
Area in the brain stem between the medulla oblongata and the mesencephalon. It acts as a switching station for many nerve pathways between the brain and spinal cord and contains numerous nuclei, including cranial nerves and those involved in controlling motor function in cooperation with the cerebellum.
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- Glossary
Positron emission tomography
An imaging technique that helps doctors visualize metabolic processes in the body. The patient is injected with a weakly radioactive substance that emits positrons, i.e., beta radiation. When the positrons encounter electrons in the body, energy is released in the form of two photons. These photons travel in opposite directions. Detectors are arranged around the patient in the PET scanner to register the photons that strike them. This makes it possible to track whether the radioactive substance accumulates in certain areas of the body, which can indicate the presence of a tumor, for example. Positron emission tomography is also used in the early diagnosis of dementia. The radiation exposure is low and acceptable in a medical context.
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- Glossary
posterior
A positional term – posterior means "towards the back, located at the rear." In relation to the nervous system, it refers to a direction towards the tail.
