Alterations in perception: when the senses are not reliable

Human beings need our five senses to relate to the world around us.. Thanks to them, we can know what is happening around us and act accordingly. However, the information that comes from the senses is not always reliable. There are various disorders that cause alterations in perception; and, in these cases, the person’s quality of life can be significantly reduced.

Sometimes, these anomalies in perception constitute important indications of the existence of a pathology, such as schizophrenia or psychotic depression. In other cases, these can be caused by the effect of certain substances on the body. Even There are perceptual alterations that can appear in isolation and are completely benign. (for example, hypnagogic or hypnopompic hallucinations or visual illusions). Let’s look at some of them in more depth.

Classification of perceptual alterations

The perceptual alterations are large and heterogeneous. Nevertheless, Two main categories can be distinguished, differentiated by the presence or absence of a real physical stimulus.. Thus, we speak of perceptual distortions when there truly is an external element that is received by the senses; However, this is perceived in an altered way.

On the contrary, Perceptual deceptions are characterized by the absence of an objective stimulus. In this case, what is perceived has no real entity and is a product of the individual’s mind.

Perceptual distortions

Perceptual distortions occur when The individual perceives a real element in a different way than expected. Thus, the following phenomena may occur (among others):

Macropsia or micropsia: the stimulus is perceived as larger or smaller (respectively) than it actually is. Furthermore, this size alteration can occur partially or affect the entire object. Thus, for example, when a person observes his or her hand, he or she may see it several times larger than it is. Hyperesthesia or hypoesthesia: it occurs an enhanced or attenuated perception of a real stimulus. For example, sounds, colors, or tastes are experienced much more (or much less) vividly than normal. Illusions: Perceiving an ambiguous element gives it (involuntarily) a structure that he doesn’t really have. This is the case of those situations in which we believe we see a face in a spot on the wall.

Perceptual deceptions

In this case images, sounds or any other type of sensory information that has no basis in the real world is perceived and that, furthermore, coexists with other stimuli that are real. Some of them are the following:

hallucinations: They can occur in any sensory modality (visual, auditory, olfactory, tactile…) and are characterized because the person has the total conviction that what they are perceiving is real. Furthermore, this perceptual alteration does not alter other perceptions, which are adequate.Hypnagogic and hypnopompic images: occur in the transition between sleep and wakefulness (falling asleep or waking up, respectively). People can see, hear or feel figures or presences around them without them actually being present.Autoscope: the person sees himself (sees his own body) from the outside; for example, as if she were suspended in the air, observing herself from above. When, when looking in a mirror, the individual is not detected, it is called negative autoscopy.Pseudohallucinations: As in the case of hallucinations, the individual sees, hears or perceives unreal stimuli in some way. However, in this case he is aware that they are not true and that they come from his own mind.

Are perceptual alterations worrying?

The above are just some of the many perceptual alterations that exist. However, as we mentioned before, not all of them have the same origin. Sometimes They may be due to organic causes (illnesses or substance use), in others to psychological causes and in others to transitory states. (such as sleep deprivation).

Some of these anomalies occur punctually or sporadically and are not related to any type of physical or mental pathology. However, Perceptual failures can often indicate serious conditions that require treatment. For this reason, it is best to always go to a professional and perform the appropriate tests to find the cause.

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