The posterior parietal cortex (PPC) is involved in planning movements. To do this, it combines information from different sensory areas to get an idea of the position of the body relative to other objects in the environment.
This area plays an important role in planning movements. In order to properly execute a movement, the body must have knowledge of its own position, and of the objects in the space it is in. Without this knowledge, it is difficult to maintain balance, or to not run into any objects.
The PPC is divided into small areas, with each area specializing in a specific movement.
This area is part of Brodmann Area 7, and is located directly behind the primary somatosensory cortex.
This area receives input from three different sensory systems, the visual system, the auditory system, and the somatosensory system. These different systems are combined to get a good idea of how the body relates to the other objects in the room. Most of the output from the PPC goes to areas of the motor cortex. The motor cortex is responsible for carrying out planned movements.
Damage to this area can lead to many different problems, such as difficulty picking up objects or controlling eye movements. In very severe cases, damage to this brain area can cause apraxia or hemispheric neglect. Apraxia is a disorder in which it is difficult to perform planned movements. This can occur in different forms, with different types of movements. An example is ideational apraxia, in which the execution of various tasks in the correct order is difficult. For example, some patients would put on their pajamas before taking off their clothes. Hemispheric neglect is a disorder in which attention is paid only to one part of the visual field. These people can perceive all visual stimuli, but this is not further processed and remembered. Hemispheric neglect is manifested so that, for example, when drawing a house, people who suffer from this only draw one half of the house.
Author: Myrthe Princen (translated by Melanie Smekal)