There are many ways to learn, and many are well known to everyone. But there are others less popular, as is the case with perceptual learning, which constantly occurs in us.
The mechanism underlying this particular way of acquiring knowledge is fascinating. We invite you to discover it through the following paragraphs.
What is perceptual learning?
Perceptual or perceptual learning is a mechanism by which, through our senses (especially sight, as this is what provides the vast majority of information about our environment), we perceive stimuli in a certain way and not on the other, in a stable manner which, however, can be changed by certain procedures.
A classic definition is that made by Gibson in 1963, referring to perceptual learning as any change occurring within the framework of the perceptual system, as long as it presents a certain stability, and comes from the subject’s experience with respect to a certain stimulus. (the stimuli).
Because of this phenomenon, if we show the same photograph to a varied sample of the population and ask them to know what they see and what particularly catches their attention, we will get very varied responses, as some will focus on the ’emotional expression of the people depicted, others in clothes, others in the landscape and climate, others in their location, etc.
The funny thing is that even the same person’s response may change over time, based on their own learning, Their experience with similar stimuli, their own thoughts and concerns at the time of the study, and many other factors. We would therefore verify that the response given depends on the receptor and the internal processing it performs, 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 offered an exercise in which they had to visually find certain elements in an image that included both that pattern and different elements that acted as distractors.
After several days of repeating this task, it was found that there was an obvious improvement, and therefore learning in their way of perceiving through sight (they became more and more skilled and needed less time to find the desired goal), at least for these specific stimuli and under these conditions.
In this study, the EEG was measured during the repetition of the task, and it was concluded that there was, not one, but three neurological changes that would explain the improvement in perceptual learning. These changes have been observed in the frontal lobe, which cognitively regulates visual sensory information processed by the occipital lobe..
Now let’s take a closer look at each of these three changes.
1. Then N2PC
On the one hand, it was found that the N2PC wave grew larger as the subject repeated the activity (And therefore, the more I learned). And it is that this wave has a direct relation with the level of attention in the treatment.
2. Then P3
On the other hand, it was also determined that a second wave, in this case P3, was present to the same degree throughout the duration of the task, regardless of which stimulus they were to seek at that time.
The P3 wave signals the search for significant changes in the environment, And if it was kept with the same intensity all the time, that means it was associated with the search task in general, and not with the specific pattern that they had to find each time.
3. Brain oscillation
The third characteristic regarding perceptual learning that was verified in the EEG measurement was that throughout the process a cerebral oscillation could be observed, a neurological mechanism that occurs when the action potentials reorganize to prepare for creation. neural networks, and therefore to forge learning in our brain.
In fact, cerebral oscillations have been observed at two levels: In high frequency (> 40Hz), or gamma, and in low frequency (from 8 to 10 Hz), or alpha. The important thing here is to know that alpha occurs during the asynchrony of neurons and therefore the destruction of neural networks, while gamma is observed during the reverse process: when new networks are established and therefore neurons they synchronize.
The funny thing about the experiment is that in the early stages an increasing gamma frequency was observed, whereas it decreased as the trials progressed. On the other hand, the alpha frequency did the exact opposite: it started weak and intensified the more the exercises were practiced, which made the authors think that the perceptual learning process took place at two different times.
First the brain facilitates the search for the desired visual pattern by creating neural assemblies for this purpose. But as the subject trains and acquires skills in this task, these neural networks disintegrate, leaving only certain brain cells (the most efficient for this exercise) in charge of this process. It is a way of optimizing the procedure, allocating the minimum of resources but obtaining the best result.
What is concluded in this study is that the whole perceptual process in the subject is active and occurs through the exposed mechanisms and phases.
Brain areas involved
We have already seen the neurological procedure of perceptual learning and the changes at the neural level that occur during this process, but now let’s see which regions of the brain are somehow involved in this whole mechanism.
The first place where changes at the synaptic level can be found is the sensory association cortex. Thanks to the technique of functional neuroimaging, it has been verified that when a person evokes elements stored in his memory, whether of visual, auditory or other type, significant activity occurs in this area of the cortex.
This region is also activated when we use short term memory during the process of perception. In fact, it is proven that the use of the technique of transnscranial magnetic stimulation in the sensory association cortex has as a side effect a disturbance in the process of memorizing perceived stimuli with active or primary memory.
Another area of the brain involved in perceptual learning is the prefrontal cortex, as it is also responsible for the tasks involved in the functioning of short-term memory. It would be in that part of the brain where the data on the things we need to remember would be integrated.
When the perceptual processes occur through the ocular (that is, in most cases), the primary visual cortex would be activated. This collects data from the lateral geniculate nucleus, another brain structure, in this case located in the thalamus., And responsible for the first processing of the data obtained, before sending them to the extruded crust.
In addition, the primary visual cortex can use two different pathways, depending on the task it is performing. When it comes to recognizing a particular element, the ventral path is taken, which passes through the cortex of the lower temporal lobe. Therefore, if this area has been affected by some type of injury or illness, it is possible that the subject has lost the ability to recognize certain objects.
On the other hand, there would be the dorsal pathway, a pathway that crosses the cortex of the posterior parietal lobe, and the function would be related to the location of a particular element in space.
The visual association cortex is a key area when learning perceptiveSince it is here and through the establishment of successive neuronal connections or synapses that the process of visual recognition of a given stimulus occurs.
Finally, it should be noted that such a daily and standardized procedure, but in reality extremely complex, such as the recognition of a face, is possible thanks to the synapses which are generated within the aforementioned visual cortex. associative, but in a very specific area known as the spindle-shaped area of the faces, so it would be another part of the brain active during some of the perceptual learning procedures.
- Gibson, EJ (1963). Perceptual learning. Annual review of psychology.
- Price, MSM Hainaut, J. (2011). Influence of visual perception on learning. Science and technology for vision and eye health. Dialnet.
- Hamamé, CM (2011). Active vision and perceptual learning: how experience changes our visual world. Lyon Neuroscience Research Center, Brain Dynamics and Cognition.
- Hamamé, CM, Cosmelli, D., Henriquez, R., Aboitiz, F. (2011). Neural mechanisms of human perceptual learning: electrophysiological evidence of a two-step process. PLoS One.