Theory of sensory recall: causes and ramifications

published on: October 30, 2024

A simple exercise – can you imagine a vase in front of you? Try? What color is it?

Turns out that most people can visualize objects – either somewhere in front of them, like augmented reality, or when their eyes are closed. Commonly known as “mind’s eye”, but everyone does it with a different intensity of details – some people can only “see” the outlines of the objects, some “see” it very faded, some – pretty good, others – in incredibly realistic details and some can even animate those visualizations. Furthermore some people not only visualize an object, but a whole scene alongside it.

Let’s continue with another practical example – how would you go about providing a description of a giraffe? Do you know the answer already or the question is a bit unclear? And no – I’m not asking for the description of the animal, but rather how you would obtain that information. Try? For most people the process is the following – first they visualize the object and then start visually searching it to pick which information to present as an answer. So they approach the problem as if they’re “seeing” the animal for the very first time now and know nothing about it and will just start to “look” at it in the search for the information they need. Here are some shortcomings of this approach:

  • initial points may not prioritize the most crucial aspects.
  • there is a risk of overlooking key information
  • descriptions may inadvertently focus on details unrelated to the specified animal, but be based on the visualized scene surrounding it.
  • additionally, it’s essential to acknowledge that the process of visualization requires a substantial volume of information. Given that our memories are prone to change, fade or be lost over time, there is a significant risk that the object or scene being visualized may deviate from the real one.

Communication

What’s the first thing that comes to mind, when asked to point to something similar to a vase? Try? For most people the process follows this path – they use the skill they’re most used to – either visual clues, sound or texture and link the objects based on such similarities instead of basing it on the actual meaning of the word – a vase serves the purpose of preserving the vitality of flowers by holding their stems in water. Typically of a tall design, it accommodates the height of the stems, minimizing the risk of tipping over. It must possess water resistance and a secure, well-fitted opening, preventing any imbalance or potential overturning caused by a disproportionate opening compared to the base. So usually people’s answers vary from some useful objects like bottles to some things that are totally different – for instance “a woman’s body” – with the similarity lying in the vases’ curved lines, which echo the aesthetics of the woman’s body.

Currently, interpersonal communication often breaks down when individuals interpret words and concepts differently, based on factors outside their intended meaning. We see this in our daily interactions: some people seem to understand each other effortlessly (“clicking” with someone instantly), likely because they share a similar way of assigning meaning. This shared approach could stem from a mutual preference for visual, auditory, or other sensory cues when interpreting words. The issue is that language, whether spoken, written, or gestural, is meant to convey specific information. When these meanings are shaped by individual biases, communication does falter. Increasingly, we misunderstand one another without realizing it. For example – imagine we’re communicating through a chat app that changes words based on each user’s interpretation – for instance, it changes “sheep” to “goat” for me and “goat” to “sheep” for the other person. Although we can see each other’s messages, respond, repeat them, and even ask for clarifications, there’s no indication that we may be describing completely different things. This undermines the fundamental purpose of communication which is to transfer information and received the same information on the other end.

Sleeping, memories and remembering

Do you remember what you did on January 3rd last year? Try? Most people use both approaches here: they logically reconstruct past events based on major markers, like New Year, and then work from that point, recalling events and using sensory cues (like sights, sounds, and smells) to mentally piece together a “memory movie” that leads them to the desired moment.

How are memories formed and stored – information is being stored in our body from all kinds of inputs – sight, sound, touch, smell, taste and vibrations – that information is processed by different cells and cell parts throughout the body, but we’ll focus on the brain at the moment. In the brain the information is stored in multiple ways: through synaptic connections, distinct molecules and proteins, etc. We’ll again only focus on one of these methods of storing/processing information – the synaptic connections. They work by generating an electrical and/or chemical charge in the neuron (and glia cells), which is then transmitted through its axon to dendrites. For a neuron to “activate” it requires a minimum amount of charge from signals sent via its dendrites. Thus, the more active synapses are sending impulses, the more readily a neuron/glia cell can activate. That leads to the following conclusion (and observation) – the more (or the right/specific) active neurons/glia you have, the easier it is to reach another piece of information stored by the other cells. In other words, if you can recall visual, auditory, and olfactory details, this abundance of active cells acts as a stimuli and makes it easier to reach more information that you’re seeking.

Memory and remembering are distinct processes. “Memory” is the actual storing of information somewhere. “Remembering” is our ability to retrieve that information, and it’s accessed by the necessity of a large volume of stimuli (active neurons and glia cells). In theory, the more stimuli associated with a piece of information, the easier it is to recall. However, more stimuli can also trigger unrelated information, so while representing memories visually or through other senses can often improve recall, it doesn’t necessarily ensure accuracy.

What does that actually mean – if you try to remember a piece of information – “what happened on a particular date” – the initial information that is provided to the brain is negligible – a date as a visual text/number or sound. The neuronal activation it would cause will be low (as the volume of stimuli information is low) and thus it may fail to excite enough other brain cells to retrieve a “memory”, but if you work by using, for instance, visualizations and can cause one that is somewhat related – a nearby date/event/person – that visualization is actually a cue with a huge number of activation patterns in the brain all acting as a stimuli to retrieve the next piece of information, and as the neurons require a threshold to activate – the more stimuli you have, the easier to activate the connected cells – it becomes increasingly easier to work your way from visual cue to visual cue to the information you were searching for.

What does that actually mean?

If you try to remember a piece of information – such as “what happened on a particular date” – the initial input provided to the brain is negligible: just a date represented as text, a number, or a sound. This kind of input produces minimal neuronal activation because the volume of sensory information is low. As a result, it may fail to excite enough brain cells to retrieve an associated memory. However, if you instead use visualization – by recalling something related, like a nearby date, event, or person – that mental image acts as a cue with a large number of activation patterns in the brain. These patterns serve as stimuli that help trigger the retrieval of a another related piece of information. Since neurons require a certain threshold of activation to fire, the more stimuli you provide, the easier it becomes to activate the connected cells. This makes it progressively easier to move from one visual or other sensory cue to another until you reach the information you were searching for. This is a form of direct memory recall as you retrieve information that is directly linked to each other based on a sensory cue. The original approach of the brain to retrieve a piece of information would be to use logical/associatively related information – meaning not linked to a sensory input, but associated with an object/event/information. (For example, when you see something in the sky, it’s logical to assume it’s some type of aircraft. This assumption isn’t based solely on the object’s appearance, but on the context of the entire event. Given gravity and the atmosphere, only a limited number of things can plausibly be airborne – so even without clear visual details, you can logically narrow down the possibilities to just a few)

A major consequence

Recalling sensory information enables more direct access to related memories. For instance, if you’ve repeatedly seen certain information presented on TV, with only a few instances showing different details/conclusions on the same topic, you’re more likely to recall the frequently repeated information. Each repetition is used as an enormous amount of stimuli to the memory through sensory cues, making it easier to retrieve that specific information. Sensory recall allows abuses – frequent presentation of a particular information makes it easier to recall and thus more “valid”, as all other alternatives are harder to recall and the more used a person is to using visual (or other sensory) cues, the easier to circumvent the logical conclusions. Even more so, recalling via sensory cues has become a habit (most likely inherited at this point) for the majority of the population and thus reducing the logical associations and validation of the information.

How it relates to sleeping

Almost all living organism sleep (even those without brain cells, and according to some studies, even single-celled organisms), indicating that sleep serves multiple purposes. Here, we’ll focus specifically on some of its effects in the brain. Sensory information received by an organism is primarily processed through the formation of synaptic connections. In order for a connection to be established the dendritic extension of the neuron has to have a prepared dendritic spine – the actual “thing” that forms a synapse. Once a signal is sent to initiate synapse formation, the conversion process is relatively fast. The time needed to form the actual synaptic connection after that is of no particular importance in this case as once the trigger is received the spine can be counted as converted, however, the formation of a new dendritic spine takes anywhere from several minutes to a few hours (dendritic spine plasticity research paper). This means that using up available dendritic spines occurs rapidly in response to stimuli, while their replenishment is a much slower process.

During sleep, our eyes are closed, limiting visual stimuli, in a dark, quiet environment, with almost no movements and limited other new sensory information like smells, touch and taste. This means that the organism has a lot less information to process and is able to create an extra amount of spines that can be used later. However, when we dream during sleep, visual, auditory, and olfactory information is internally generated by activation of the neurons – and a huge amount of them – thus processing that information requires again expending those dendritic spines. As a result, the more vivid and diverse the sensory content of your dreams, the more dendritic spines are consumed, less and less spines are left to allow the organism to process the incoming information when being awake. For example, many people have experienced waking up tired after 10–12+ hours of sleep. One possible reason is that vivid dreaming has depleted more dendritic spines than were created, which leads to impaired cognitive functionality.

Several factors may trigger dreaming, with one likely cause being excessive neural connectivity due to frequent recall of sensory experiences as well as external factors – such as light, smell, sound, or even vibrations (e.g., from crystals).

A typical sleep duration for an adult under normal daily conditions may range from 2 to 4 hours. However, this estimate is based on observations from a very limited number of individuals, so more comprehensive data is needed. For example, in my own experience, having a crystal nearby – whether in the form of natural mineral rock like amethyst or embedded in devices like LCD TV screens (tested with several LG TVs) will trigger vivid dreaming and prevents full rest, even when my sleep time is more than doubled.

Some frustrating parts

For several years, I have engaged in discussions about the significant disparity between feeling fully rested after just three hours of sleep and requiring seven or more hours yet still feeling groggy upon waking, tired by the afternoon, and exhausted by night. Most people struggle to comprehend the concept of being fully rested (there isn’t even a word for this in the English language). The additional six hours of alert and energetic living each day equates to an extra 30 years of productive life over an 80-year lifespan, free from fatigue or drowsiness.

However, a frustrating observation is that some individuals are reluctant to forgo dreaming, as they use it as an escape or a means to counteract negativity in their real lives. Moreover, some people begin to perceive not only their dreams but any visualization as an equal reality, viewing it to be as real as their actual surroundings. This delusional behavior is prevalent among almost everyone, with the distinction between clinically diagnosed individuals being the severity of their condition and the perception of the others, who are the ones enforcing the diagnose. Therefore, even mild delusions can be perceived as severe depending on its nature.

Even more concerning, people are effectively replacing nearly 30% of their lives with sleep and dreams instead of pursuing real goals. This creates a doom loop: the more they sleep and visualize, the more mentally and physically drained they become and the less time they have each day, reducing their ability to think clearly or take action. As exhaustion grows, they seek more sleep (or escape from reality), which leads to more dreaming – and the cycle continues.

Imagination

Let’s try another exercise: can you imagine an apple? Now, make it more realistic – add tiny dots in various colors and light reflecting off its surface. If you can, you may notice that it requires more focus and becomes somewhat “energy-intensive.” Now, picture a cup. Can you see it? Can you visualize ten variations of that cup? And then ten more for each of those? And ten more for each of those? And again, ten more for each of those? Most people would likely stop after the first round, as the task quickly becomes exhausting – especially if they’re actually visualizing each variation. On the other hand, if you’re not visualizing but merely selecting ten categories and defining how they differ, the process goes much more smoothly, with the only real challenge being the question of why you’d ever need to imagine 10,000 different cups.

What does this tell us? People’s imagination often relies on visualizing objects, which restricts it to familiar, viewable forms like 2D or 3D structures. Most people use known structural elements, such as colors, shapes, and materials, and the process can be limiting, as it quickly becomes energy-taxing with complexity and duration as well as favors linking objects not by logic, but external features like color, texture and such.

Imagination is the ability to come up with a different scenario than the current information justifies. It does not rely on visualizing it, but that it’s different from the logical conclusions in the particular aspect.

Thinking is the process of reaching connected data from the initial cues you had. Visualizing that data is an extra step that frequently limits our ability to reach the most logical conclusions – like when asked about the giraffe – the visualizing of some of the information causes it to act as a much stronger stimuli than the logical information you may reach and thus ignore/suppress it.

Another example I can give is this: when you speak very quickly, do you hear or see what you’re about to say beforehand? Probably not, right? This is what it’s like to skip the step of sensory recall. The “thinking” is the process before the visualization, and not the actual processing of the sensory information you created yourself.

Origin and mass adoption

Firstly, the ability to recall sensory information is a skill – anyone with a working complex nervous system can do it as it’s just replicating the response to a sensory input, but it’s not the default state of the brain – if you start visualizing and create other sensory information instead of noticing your environment, evolutionary, you will be in a less-ready state to react to a danger. Thus, it’s logical to assume that the recall of sensory information was not a prevailing skill.

Assuming the evolutionary origin of life, early human ancestors likely lived in small, hierarchical groups. Adults provided food and protection, while children, elders, and the sick depended on them, with their needs often taking lower priority. For dependent individuals, reliance on others for survival – food, safety, and avoiding danger – would logically heighten levels of fear and anxiety. If such a person envisioned a threat, whether in a dream, through psychoactive substances, or by vivid imagination (such as an animal attack, flood, or earthquake) and shared it with the group, their warnings might not be taken seriously, especially if such visions were frequent for that particular individual. If one of these predicted disasters came true, however, future warnings would likely be taken more seriously, elevating the individual’s status within the group. This newfound authority could lead to better satisfaction of their own needs and desires by others. Some individuals may notice the influence gained from such predictions and begin to exploit it. Since they can’t control whether a disaster occurs, they might need to shift blame elsewhere when one happens. The source of blame couldn’t be a fellow group member, as no one controls the forces of nature. It also can’t be an animal or object, as these could be captured, killed or destroyed. Instead, the blame should fall on an unseen, powerful entity that can’t be confronted – a force beyond human reach, able to control animals and natural events. Sound familiar? This is the concept of a “god” – a powerful, untouchable being beyond human control, accessible only through the shaman’s unique communication abilities. But how readily would others accept the existence of such a being- one they cannot see, touch, or hear or witness any proof of it? But what if one could visualize something in the sky or hear a mysterious voice in their mind, or see visions of it in their dreams? Such experiences would make belief much easier, providing a tangible sense of proof to this unseen entity.

Throughout our history, for the past few thousand years at least, the church has often persecuted, punished, or most often executed individuals for actions or beliefs that conflicted with its doctrines. People were targeted for various reasons: practicing so-called “witchcraft”, challenging theological teachings (like Galileo’s support of heliocentrism), promoting scientific discoveries that contradicted scripture, or adopting religious practices deemed heretical. Anyone seen as a threat to the church’s authority or teachings risked severe consequences, including imprisonment, torture, and death. The people most likely to question such beliefs would be those most likely to logically evaluate the provided information. Over thousands of years, this created a form of forced natural selection where individuals with these visualization skills (where direct information retrieval and not logical evaluation is used) were more likely to survive and pass on their traits.

Today, other factors contribute to the prevalence of these abilities, such as our stimulus-rich environment, which activates neural pathways and triggers sensory recall more easily. Additionally, societal demands for memorization, starting with early education, further reinforce these skills as the recall of the information is much easier using visualization.