Perceptual learning: characteristics and brain areas involved.

Summary of the characteristics of this basic type of learning, which takes place constantly.

There are many ways of learning, and many are well known to everyone. But But there are others that are not so popular, as is the case of perceptual learning, which occurs in us all the time..

The mechanism underlying this peculiar way of acquiring knowledge is fascinating. We invite you to discover it through the following paragraphs.

What does perceptual learning consist of?

Perceptual or perceptual learning is a mechanism by which, through our senses (especially sight, since it is the one that provides the vast majority of information about our environment), we perceive stimuli in a certain way and not in another, in a stable way that, nevertheless, can be modified through certain procedures.

A classic definition is Gibson's 1963 definition, referring to perceptual learning as any change that occurs within the framework of the perceptual system, provided that it presents a certain stability, and comes from the subject's experience in relation to a certain stimulus (or stimuli). (or stimuli).

Due to this phenomenon, if we show the same photograph to a varied sample of the population and ask them to tell us what they see and what particularly attracts their attention, we will obtain a wide variety of responses, since some will focus on the emotional expression of the people represented, others on the clothing, others on the landscape and the weather, others on the location in which they are found, etc.

The most curious thing is that even the response of the same person can change over time, depending on his or her own learning, experience with similar stimuli, and so on.The most curious thing is that even the response of the same person can change over time, depending on their own learning, their experience with similar stimuli, their own thoughts and concerns at the time of the study, and many other factors. Therefore, we would be proving that the response given depends on the receptor and the internal processing performed, and not on the stimulus itself.

Neurophysiology of perceptual learning

But what are the psychophysiological bases that explain perceptual learning? In one of the experiments carried out to find out (Hamamé, 2011), volunteers were given an exercise in which they had to visually find certain elements within an image that included both that pattern and different ones that acted as distractors. visually find certain elements within an image that included both that pattern and other different patterns that acted as distractors..

After several days repeating this task, it was found that there was a clear improvement, and therefore a learning process in their way of perceiving through sight (they became more and more skilled and needed less time to find the target they were looking for), at least for those specific stimuli and under those conditions.

In this study, the electroencephalogram was measured during the repetition of the task, and it was concluded that there were not one, but three changes at the neurological level that would explain the improvement in perceptual learning. These changes were observed in the frontal lobe, which cognitively regulates the visual sensory information processed by the occipital lobe..

Let us now look at each of these three changes in detail.

1. N2PC wave

On the one hand, it was found that the N2PC wave became larger and larger the more the subject repeated the activity (and thus the more the (and therefore, the more the subject learned). And this wave has a direct relationship with the level of attention in processing.

2. P3 wave

On the other hand, it was also determined that a second wave, in this case the P3, was present to the same degree throughout the duration of the task, regardless of the stimulus they had to search for at that moment.

The P3 wave signals the search for significant changes in the environment.If it remained with the same intensity all the time, it means that it was associated with the search task in general, and not with the specific pattern they had to find each time.

3. Brain oscillation

The third characteristic regarding perceptual learning that was verified in the EEG measurement was that during the whole process a brain oscillation could be observed, a neurological mechanism that occurs when action potentials are reorganized to prepare the creation of neural networks, and therefore to forge learning in our brain.

In fact, brain oscillations were brain oscillations were observed at two levelsat high frequency (>40Hz), or gamma, and at low frequency (8 to 10 Hz), or alpha. The important thing to know here is that alpha frequencies occur during the desynchrony of neurons and therefore in the destruction of neuronal networks, while gamma frequencies are observed during the opposite process: when new networks are established and therefore neurons are synchronizing.

The curious thing about the experiment is that, in the early phases, an increasing gamma frequency was observed, while it declined as the trials progressed. In contrast, the alpha frequency did exactly the opposite, the alpha frequency did exactly the opposite: it started weakly and intensified the more the exercises were the more the exercises were practiced, which led the authors to believe that the perceptual learning process was occurring at two distinct times.

First, the brain would the brain would facilitate the search for the desired visual pattern by creating neural assemblies for this purpose.. But as the subject trains and acquires skill in this task, these neural networks are disintegrated, leaving only certain brain cells (the most efficient for this exercise) in charge of this process. This is a way of optimizing the procedure, using the minimum resources but obtaining the best results.

The conclusion of this study is that the entire perceptual process in the subject is active, and occurs through the mechanisms and phases described above.

Brain areas involved

We have already seen the neurological procedure of perceptual learning and the changes at the neuronal level that occur during this process, but now let's see which brain regions are involved in one way or another in this whole mechanism.

The first place where changes can be found at the synaptic level is the sensory association cortex.. Functional neuroimaging techniques have shown that when a person evokes elements stored in his or her memory, whether visual, auditory or of other types, there is significant activity in this area of the cortex.

This region is also activated when we make use of short-term memory, during the perception process. In fact, it has been shown that the use of the technique of transcranial magnetic stimulation in the sensory association cortex has as a secondary effect a disturbance in the recall process of perceived stimuli with the active or primary memory.

Another brain area involved in perceptual learning is the prefrontal cortex, since it is also responsible for tasks involving short-term memory functioning. It would be in this part of the brain where the data about the elements we have to remember would be integrated.

When the perception processes occur through the ocular pathway (i.e., in most cases), the primary visual cortex is activated. This picks up the data from the lateral geniculate nucleus, another brain structure, in this case located in the thalamus, and responsible for a first processing of the visual information.It is responsible for a first processing of the data obtained, before sending it to the extrastriate cortex.

In addition, the primary visual cortex can use two different pathways, depending on the task it is performing. When it comes to recognizing a certain element, it takes the ventral pathway, which goes through the inferior temporal lobe cortex. Therefore, if this area were affected by some kind of lesion or disease, it is possible that the subject would lose the ability to recognize certain objects.

On the other hand, there would be the dorsal pathway, a pathway that passes through the posterior parietal lobe cortex, and whose function would be related to the location of a specific element in space.

The visual association cortex is a key area during perceptual learning.It is in this place and through the establishment of successive neuronal connections or synapses that the process of visual recognition of a given stimulus is generated.

Finally, it should be noted that such an everyday and standardized, but in reality enormously complex procedure, such as recognizing a face, is possible thanks to the synapses that are generated within the aforementioned associative visual cortex, but in a very specific area known as the fusiform area of faces, so this would be another of the parts of the brain active during some of the perceptual learning procedures.

Bibliographical references:

• Gibson, E.J. (1963). Perceptual learning. Annual review of psychology.
• Price, M.S.M. Henao, J. (2011). Influence of visual perception on learning. Science and technology for visual and eye health. Dialnet.
• Hamamé, C.M. (2011). Active vision and perceptual learning: How experience changes our visual world. Lyon Neuroscience Research Center, Brain Dynamics and Cognition.
• Hamamé, C.M., Cosmelli, D., Henriquez, R., Aboitiz, F. (2011). Neural mechanisms of human perceptual learning: electrophysiological evidence for a two-stage process. PLoS One.