How does the brain process information?

Many questions about the brain continue to intrigue neuroscientists today. How does this organ develop? Are there stages of brain development? Are there critical periods in which certain events must occur for the brain to develop normally? And, perhaps the most important: how does the brain process information?

Throughout this article we will try to understand the latter: how our brain processes the information it receives from outside, and how you store and retrieve such information; But first, we will address some basic concepts that will help us better understand the functioning of this wonderful and complex organ.

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Some basics

To understand how our brain is able to process the information it receives from the environment, we must first know how it works inside. Nerve cells or neurons are those that receive information from other nerve cells or sensory organs. These neurons are equipped with a cell body, a kind of metabolic heart, and a huge tree-like structure called the dendritic field, which is the input side of the neuron.

Information reaches the cell from projections called axons. Most of the excitatory information reaches the cell from the dendritic field, often through small dendritic projections called spines. The junctions through which information passes from one neuron to another are called synapses, which can be excitatory or inhibitory in nature.

Synaptic connections are added to the brain in various ways; one of them is through synapse overproduction and subsequent selective loss. The overproduction and loss of synapses is a fundamental mechanism that the brain uses to incorporate information from experience, and tends to occur during the first periods of growth.

For example, in the visual cortex, the area of ​​the brain's cerebral cortex that controls sight, a person has many more synapses at 6 months of age than in adulthood. This is because more and more synapses form in the first few months of life, and then disappear, sometimes in large numbers. The time required for this phenomenon to run its course varies in different parts of the brain, from 2 to 3 years in the human visual cortex to 8 to 10 years in some parts of the frontal cortex.

The nervous system makes a lot of connections; the experience is reproduced on this network, selecting the appropriate connections and removing the inappropriate ones. What remains is a refined final form that forms the sensory and perhaps cognitive foundations for later stages of development. The second method of synapse formation is by adding new synapses.

Unlike synapse overproduction and loss, this process of synapse addition operates throughout human life and is especially important in later life. Not only is this process sensitive to experience, it is actually driven by it. Synapse addition is likely at the base of some, or even most, forms of memory. But before storing and processing information, the brain needs to encode and filter it. Let's see how.

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How does the brain process information?

Information processing begins with the input of the sensory organs, which transform physical stimuli such as touch, heat, sound waves or photons of light into electrochemical signals. Sensory information is repeatedly transformed by the brain's algorithms in both top-down and bottom-up processing.

For example, when looking at an image of a black box on a white background, bottom-up processing gathers very simple information such as color, orientation and where the edges of the object are, where the color changes significantly in a short space (to decide that you are looking at a box). Top-down processing uses the decisions made in some steps of the bottom-up process to speed up recognition of the object.

Once the information is processed to a certain extent, an attention filter decides how important the signal is and what cognitive processes should be available. For example, although your brain processes every blade of grass when you look at your shoes, a specific attention filter prevents you from noticing them individually. On the contrary, your brain is able to perceive and hear your name, even when you are in a noisy room.

There are many stages of processing, and the results of processing are modulated by attention repeatedly. However, for the brain to process information, it must first be stored. Let's see how it does it.

Information storage

For the brain to process information, it must first be stored. There are multiple types of memory, including sensory and short-term memory, working memory, and long-term memory. First, the information must be encoded, and there are different types of specific encoding for different types of sensory input.

For example, verbal input can be structurally coded, referring to what the printed word looks like; phonologically, referring to how the word sounds; or semantically, referring to what the word means. Once information is stored, it must be maintained. Some animal studies suggest that working memory, which stores information for about 20 seconds, it is maintained by an electrical signal that travels through a particular series of neurons for a short period of time. weather.

With regard to long-term memory, it has been suggested that the information that manages to consolidate in this store is kept in the structure of certain types of proteins. With everything, there are numerous models of how knowledge is organized in the brain, some based on the way human subjects retrieve memories, others based on computing and computing, and others based on neurophysiology.

The semantic network model, for example, states that there are nodes that represent concepts and that these nodes are linked based on their relationship. For example, in a semantic network, the word "chair" could be linked to "table", which can be linked to "wood", and so on. Another model is the connectionist, which states that a piece of knowledge is represented simply by a pattern of neural activation rather than by meaning.

There is still no universally accepted knowledge organization model, because each one has their strengths and weaknesses, so in this sense more research is required in this regard.

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The recovery of information

Once stored, the memories must eventually be retrieved from the memory store. Remembering past events is not like watching a video recording. In fact, it has more to do with a process of reconstructing what may have happened based on the details that the brain chose to store and was able to remember.

Information retrieval is triggered by a signal, an environmental stimulus that prompts the brain to retrieve the memory in question. Evidence shows that the better the recovery signal, the better the chances of remembering something. It is important to note that the recovery signal can also cause a person to incorrectly reconstruct a memory.

Distortions in memories can occur in a number of ways, including varying the wording of a question. For example, simply asking someone if a black car had left the scene of a crime can cause the person to remember seeing a black car during an interrogation later. This has been consistently observed in witness studies of court cases, which have shown how easy it is to manipulate and implant false memories.

Studies in this field also indicate that the mind is not just a passive event recorderrather, it actively works to both store and retrieve information. Research shows that when a series of events occur in a random sequence, people rearrange them into sequences that make sense when trying to remember them.

Memory recall, therefore, requires revisiting the nerve pathways of the formed by encoding a memory, and the strength of those pathways determines how quickly can retrieve. Said recovery effectively returns a long-term stored memory to short-term or working memory, where it can be accessed again, in a kind of mirror image of the encoding process.

After all, the memory is stored back in long-term memory, consolidating and strengthening it again. Ultimately, our memory system is as complex as it is efficient, although there is still much to investigate.

Bibliographic references:

• Anderson, J. A., & Hinton, G. AND. (2014). Models of information processing in the brain. In Parallel models of associative memory (pp. 33-74). Psychology Press.
• Cabrera Cortés, I. TO. (2003). Human Information Processing: In Search of an Explanation. acimed, 11 (6).
• Insel, T. R., & Fernald, R. D. (2004). How the brain processes social information: searching for the social brain. Annu. Rev. Neurosci., 27, 697-722.
• Sakurai, Y. (1999). How do cell assemblies encode information in the brain?. Neuroscience & Biobehavioral Reviews, 23 (6), 785-796.