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1. 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.

1. 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.

1. Glossary

Posterior parietal cortex

The posterior parietal lobe receives inputs from numerous visual, auditory, somatosensory, and proprioceptive cortical areas. It integrates this information into an overall spatial picture that enables orientation, spatial attention, and the planning and execution of goal-directed movements.

1. Glossary

Postcentral gyrus

The postcentral gyrus is the fold on the surface of the cerebrum located immediately behind the central sulcus. It contains the primary somatosensory cortex, where touch, pressure, temperature, and proprioceptive stimuli are processed.

1. Glossary

Pre-dementia

Alzheimer's disease typically progresses through several clinical stages, preceded by an early phase with initial cognitive impairments. This phase, formerly known as pre-dementia, is now usually referred to as mild cognitive impairment (MCI) due to Alzheimer's disease. It can manifest itself through symptoms such as declining short-term memory. With modern imaging techniques, especially amyloid PET, characteristic amyloid deposits in the brain can already be detected in this early phase. Laboratory chemical analyses of blood or cerebrospinal fluid can also provide indications of changes in protein concentrations typical of Alzheimer's disease. Although the clinical diagnosis of dementia is only made in later stages, the underlying Alzheimer's pathology can often be detected in advance today.

1. Glossary

Prefrontal cortex

The prefrontal cortex (PFC) forms the front part of the frontal lobe and is one of the brain's most important integration and control centers. It receives highly processed information from many other areas of the cortex and is responsible for planning, controlling, and flexibly adapting one's own behavior. Its central tasks include executive functions, working memory, emotion regulation, and decision-making. In addition, the PFC plays an important role in the cognitive evaluation and modulation of pain.

1. Glossary

Premotor cortex

Part of the motor cortex in the frontal lobe. It is connected to the primary motor cortex and numerous other brain regions and is involved in the planning, preparation, and coordination of complex, voluntary movements. Examples of its functions include reaching for an object or the sequence of movements involved in targeted actions.

1. Glossary

Primary auditory cortex

The first processing station in the cerebral cortex for auditory information. The primary auditory cortex is located in the Heschl's gyrus and receives inputs from the medial geniculate nucleus of the thalamus. It is organized tonotopically – its neurons are arranged continuously according to frequency.

1. Glossary

Primary gustatory cortex

Term for the areas of the insular cortex where information from the taste receptors is processed. Further processing takes place in the secondary gustatory cortex in the orbitofrontal cortex.

1. Glossary

Primary motor cortex

An area of the frontal lobe in the anterior wall of the central sulcus. It is considered to be the higher-level control unit responsible for voluntary and fine motor skills. This is where the cell bodies of the central motor neurons are located, whose axons primarily extend to the spinal cord (via the corticospinal tract). Only in the primary motor cortex do Betz giant cells occur, which are particularly large motor neurons whose axons extend directly to the motor neurons in the anterior horn of the spinal cord without prior synaptic switching.