Brain mechanisms that allow learning by subconscious stimuli have been identified for the first time. The finding could lead to new therapeutic strategies for mental disorders.

A new international study has identified for the first time the processes that take place in the brains of animals when they learn from subconscious visual stimuli. New data on how exactly this unconscious perceptual learning occurs could lead to more efficient treatments for different mental conditions.

Psychology, psychoanalysis, and other branches of the behavioral sciences basically define the subconscious as anything that is “below the threshold of consciousness.” Consequently, there would be the information in principle inaccessible during daily, automatic or conscious life: it would manifest itself through dreams, lapses, metaphors and all expressions that evade conscious logic and, in a certain way, common sense. .

However, access to this level of brain activity can also be used to achieve meaningful learning, the impact of which can be even more lasting and efficient than those achieved through conscious tasks. For example, so-called implicit learning occurs unconsciously and effortlessly: we learn without thinking about that particular action, for example through simple repetitions.

Subconscious visual stimuli

Now, a new investigation conducted by specialists from the KU Leuven University of Belgium and in which researchers from the Massachusetts General Hospital and Harvard University also participated, has managed to begin to unravel the inherent mysteries of subconscious learning, determining the processes they have. place in the same by means of a study carried out in Rhesus monkeys. According to a statement, they worked on visual stimuli that are not consciously perceptible, and that nevertheless can later be remembered.

In the research, published in the journal Neuron, the experts activated part of the reward system at the base of the brain stem of monkeys, specifically in the ventral tegmental area, releasing dopamine. This hormone is not only crucial for pleasure and happiness: it also plays a vital role in cognitive and learning processes.

While carrying out this action, the researchers showed the monkeys practically invisible images of human faces and bodies, among other visual stimuli that were difficult to perceive consciously, at the same time that they required other highly complex tasks.

Everything indicated that in normal situations the animals would not be able to remember the stimuli presented: what would happen, instead, when the base of the brainstem is activated?

Important results

The experiment showed that by activating the indicated area of ​​the brain stem, the monkeys were able to recognize and remember the subconscious visual stimuli, while they were unable to do so when the mentioned stimulation was interrupted. According to scientists, this shows that there is a direct relationship between this region of the brain and subconscious stimuli.

In addition, they remarked that it was found that dopamine stimulates subconscious learning. They also stated that during the experiment, areas of the brain’s visual cortex and other areas important for memory were activated.

In this sense, and taking into account the similarities between monkeys and humans, the researchers believe that by deepening this knowledge in future studies it will be possible to develop new treatments for diseases related to the production of dopamine, such as depression, addictions or Parkinson’s. .

According to professor Wim Vanduffel, one of those responsible for the study, “by checking the results in humans and stimulating areas of the brain that produce dopamine, we could, for example, allow people to regain speech more quickly or improve their motor skills after an accident or disease, “he concluded.


Electrical stimulation of the macaque ventral tegmental area drives category-selective learning without attention. Sjoerd R. Murris et al. Neuron (2021) .DOI: https: //

Photo: Gerd Altmann on Pixabay.