Perceptual excision: definition, causes and possible treatments.

A rare perceptual disturbance. We explain exactly what it consists of.

Human beings constantly perceive the reality that surrounds them, obtaining information from the environment through the different senses and then integrating the various data and processing them in different brain nuclei.

However, sometimes alterations occur that cause objects and stimuli to be perceived incorrectly. This is the case of perceptual splitting.

Perceptual splitting as a perceptual alteration

Perceptual splitting is understood as that type of perceptual disturbance in which the information concerning the stimuli is not perceived in an integrated manner. This can occur with information coming from different sensory modalities, but in general the concept of perceptual splitting tends to refer to the separation of perceptual elements captured by the same sense, the most common case being the disintegration of visual information.

It is important to bear in mind that the problem does not occur at the visual level or in the sensory organs, which are fully functional.these being fully functional. And although it is an alteration of perception, it is not a hallucination either: the perceived stimuli are always real. The problem in question is that although we capture the information correctly, we are not able to integrate it, which generates two competing perceptions.

In this way, before the perceptual splitting, we see the stimulus disintegrated, appreciating separately aspects that we should see as a whole, such as the shape of the objects and their content, or separating color and shape. We would not see a red apple, but on the one hand the color red and on the other hand an apple.

Types of perceptual splitting

There is no single type of perceptual splitting.. Generally speaking, we can consider that, as regards the type of excision occurring in the same sensory modality and specifically in that of sight, there are two main types of perceptual excision: morpholysis and metachromia. In addition, it is also possible to have perceptual excision between different senses.

Morpholysis

Morpholysis is the perceptual cleavage that occurs only at the level of form and shape.. We are unable to join the information of the form of objects from their content. It is possible, for example, to see someone's face separated from his or her body.

2. Metachromia

Metachromias refer to those perceptual splits in which we perceive color and shape separately. those perceptual splits in which we perceive color and form separately.. For example, we see them separately or the color exceeds the form (as if we go out of the line when painting an object), or colors that do not correspond to the real ones.

3. Disintegration of information coming from different sensory modalities.

Generally, this is the dissociation between sight and hearing, although other senses could also fall into this category. Thus, what we hear and what we see are perceived separately, as if coming from two different stimuli. For example, we are unable to relate the voice to the movement of the lips of the person in front of us. It could also happen with sight and touch, for example.

Causes

Morpholysis and metachromia often appear in the context of a psychotic break.. Likewise, the hyperstimulation characteristic of epilepsy can also generate phenomena of perceptual excision. It is not rare to appear in the context of intoxication or consumption of substances such as psychodysleptics. Another context in which perceptual excision may appear is in the presence of brain lesions caused by cranioencephalic trauma and cerebrovascular accidents, or by the compression of some nerve pathways in cases, for example, of brain tumor.

The most probable cause of this type of phenomena is found in the malfunctioning of some of the relay nuclei or nerve pathways where processing is carried out. or nerve pathways where the information from the different perceptual pathways is processed and integrated, both from the same sense and from the external information as a whole. This causes different elements of the same perception to be perceived separately.

Treatment

Perceptual splitting is not a disorder per se, but a symptom. As such, its treatment will depend to a great extent on the type of alteration that generates it. For example, drugs can be prescribed that annul the effect of the substances taken that generate the alteration, or neuroleptics that can diminish and stop the psychotic outbreak and reduce the possibility of new ones. In some cases, occupational therapy and rehabilitation may be recommended to help restore the normal functioning of the nerve connections.

However, what will always be advisable is to provide the patient with information about what is happening, given that this type of alteration can be very serious.This is because this type of alteration can involve a great deal of distress and worry.