What is neuroarchitecture?

What is NEUROARCHITECTURE?

Do the spaces we inhabit have an impact on our emotions? Is there a direct relationship between architecture and emotional well-being?

When we arrive at a restaurant to celebrate a romantic evening, we expect the light to be warm and dim, to be given a secluded and quiet table preferably next to a window, and for there to be a background murmur that allows us to engage in a quiet conversation. If, on the contrary, we find a place without windows, illuminated with white fluorescent lights, where we are placed in the center of the room at a metal table, our mood will change.

In just a few seconds, our brain will have gathered information about layout, temperature, lighting, table configuration, or exterior views, among many other aspects of which we will not even have been conscious, leading us to make the decision to stay or leave as soon as we walk through the door.

The layout of a space, its relationship with the exterior, the materials that compose it, the hygrothermal conditions of the environment, or the color and texture of surfaces affect our perception of it and shape the emotions and sensations we experience when occupying it.

These sensations and the stimuli that shape them are what neuroarchitecture studies, a discipline that analyzes the effects of the composition of an architectural space on living beings.

Origin of the concept of neuroarchitecture

Neuroarchitecture was born from the need to explain, from a scientific point of view, the sensations produced by the spaces we pass through.

The World Health Organization (WHO) has determined that human beings spend around 90% of our time in indoor spaces.

Thanks to our adaptive capacity, we have moved from living linked to nature in natural open spaces to closed indoor spaces in urban environments. This translates into a series of both physical and psychological effects that determine our behavior.

Through neuroscience—the study of the human brain and the reactions we experience to different stimuli from our environment—neuroarchitecture attempts to decipher the link between inhabited space and the central nervous system.

History of neuroarchitecture

The idea of understanding space as an influential factor in our physical and mental health dates back to the most primitive times. Since antiquity, buildings have served as a tool to express and provoke certain emotions in people.

While the scientific proof of brain neuroplasticity based on the inhabited environment was not demonstrated until the end of the 20th century, some contemporary architects had intuitively experimented with neuroarchitecture some years earlier.

In the 1950s, Jonas Salk, an American medical researcher and virologist, was looking for a vaccine against polio, a disease that had caused thousands of deaths in the United States.

After several years of research in his laboratory—a closed, dark room at the University of Pittsburgh—Salk realized he was blocked and decided to take a few days of retreat. To do so, he traveled to Italy and stayed at the Monastery of San Francisco in Assisi. There, he was able to deepen his reflection and finally find the solution to his research. Upon returning to the United States, Salk put his new ideas into practice and developed the first polio vaccine, which saved millions of people from contracting the disease.

“The spirituality of the architecture was so inspiring that I was able to think intuitively and go beyond.” – Jonas Salk

After this experience, Salk concluded that work environments play a decisive role in our creativity and decided he should find a way to turn his workplace into a place that fostered inspiration and the development of new ideas.

Together with architect Louis Kahn, they designed and built what is now known as the Salk Institute, located in San Diego, California. The center was conceived holistically, taking into account the functioning of our brain in order to promote the physical and mental well-being of researchers.

The result is a pink-toned pozzolanic concrete building, with open-plan interior spaces and high ceilings organized around a central plaza with sea views, free of obstacles, marking the symmetrical and harmonious character of the complex. [1]

Neuroplasticity of the brain according to the inhabited environment

Neural principles have been applied in architecture more or less intuitively for as long as memory exists. However, it was not until 1998 that the term neuroarchitecture was conceived.

Neuroscientists Fred H. Gage, a researcher at the genetics laboratory of the Salk Institute in California, and Peter Eriksson, from the University of Gothenburg in Sweden, demonstrated for the first time that our brain was capable of creating nerve cells in the hippocampus. This represented a paradigm shift: for the first time, it was concluded that our brain could vary its structure based on stimuli received from the outside.

“While the brain controls our behavior and genes direct the design and structure of the brain, the environment can modulate gene function and, ultimately, the structure of the brain, changing our behavior. By planning the environments in which we live, architectural design changes our brain and our conduct.” – Fred Gage

The first academy of Neuroarchitecture

In 2003, the ANFA (Academy of Neuroscience For Architecture) was formed, the first official academy specialized in researching and deepening the discipline of neuroarchitecture.

ANFA was founded by Fred H. Gage and aims to define the most essential aspects of architectural space design taking into account neural principles, in order to improve our well-being and quality of life. [2]

Neuroscience and architecture

Neuroarchitecture defines the relationship established between our mind and the physical environment that surrounds us. The fusion between these two disciplines stems from the need to find an explanation for the link between spaces and neural connections.

“Bottom-up” and “top-down” effects

Neuroarchitecture is largely based on the study of the central nervous system, a system that activates different mechanisms depending on the type of stimuli we receive from the space in which we find ourselves. These mechanisms generate “bottom-up” and “top-down” effects.

The way of processing information according to the “bottom-up” mechanism starts from the limbic system, a brain structure that includes the thalamus, hypothalamus, and amygdala. The limbic system regulates the functioning of the sympathetic nervous systems—that is, the most primitive and emotional part of our brain, typically known for provoking the strongest and most instinctive reactions that go beyond our reasoning.

For its part, the “top-down” effect is the opposite mechanism to the one mentioned above. It refers to reactions that originate from the most evolved areas of the cerebral cortex, called the neocortex, developed during adolescence. The cortex represents the part of the nervous system where rationality prevails, characteristic of adult life, which allows us to reach conclusions and carry out projects.

Faced with a stimulus, the brain sequence moves from the activation of the first-impact “bottom-up” mechanism (the most essential emotionality) to a subsequent return to calm thanks to the “top-down” effect (information processing). [3]

The senses in architecture

The challenge of neuroarchitecture is to understand how different environments can influence states such as stress, emotions, memory, or even learning.

Interacting with living ecosystems, walking through a natural environment, listening to the sound of water, and breathing fresh air allows us to understand the cognitive perception of the senses and re-evaluate the way we conceive spaces for design, taking into account the non-tangible benefits of architectural space. [4]

Sight

The first sensation we receive from a space is through sight.

Sight allows us to distinguish the conditions of the environment in which we find ourselves—the eye therefore behaves as an open communication channel between what is visually perceptible and the brain.

The information collected by the retina travels through the optic nerve to the neural system. Each area of the cerebral cortex extracts different types of information: spatial perception, orientation, contrast, movement, shape, luminosity, or color.

Hearing

Hearing becomes a supplementary tool to the eyes. When we cannot navigate our environment visually—due to a lack of lighting, for example—our auditory system tells us how to react.

The cochlea of our inner ear is the organ responsible for transforming the vibrations perceived by the auditory system into interpretable and understandable information. Through our memory and our most primary instinct, humans are able to differentiate when a sound produces a state of alarm and danger, or, on the contrary, relaxation and a sense of security.

Smell

Smell has the ability to activate memory-based bodily reactions; that is, a smell is associated with a past memory, a place, or a person and, consequently, an emotion. Olfactory stimuli, unlike other sensory stimuli, do not pass through the thalamus but go directly to the amygdala, which is responsible for our emotional reactions.

It is estimated that the plasticity of the olfactory bulb in mammals could be linked to neurogenesis, the process by which the brain continues to produce neurons throughout its life, especially during childhood. The olfactory system, however, is one of the few regions of the brain where neurogenesis occurs in more adult ages. This is because olfactory neurons develop from local stem cells in the olfactory bulb.

The production of these neurons decreases as age advances, which is why memory capacity tends to be affected. [5]

Touch

The skin is the organ that occupies the most surface area of our body; it is the sensory interface most in contact with space. Tactile perception allows us, along with sight, to evaluate material elements and perceive a medium. Touch contributes to understanding factors such as temperature, texture, hardness, weight, etc.

The somatosensory cortex is an area of the brain that processes sensory information from the skin. Each area of the somatosensory cortex is connected to its corresponding body part through neural pathways, which maintain the topographical relationship of each point of the skin throughout the nervous system.

The 10 fundamentals of neuroarchitecture

Thanks to the growing research in the discipline, and the most essential and logical human experience, it is possible to compile the principles that underpin neuroarchitectural design.

1. Lighting

Light is the main environmental stimulus involved in the regulation of the circadian rhythm, the so-called biological clock.

The cycles of light and darkness captured by the retina influence the suprachiasmatic nuclei of the brain, responsible for the biological clock, and the body’s natural hormonal secretion, especially the production of melatonin and cortisol.

Our brain functions under a 24-hour environmental light pattern. Cortisol, the hormone of activity and stress that keeps us awake, reaches its peak in the morning after being secreted during the night. Melatonin, known as the sleep hormone, responsible for preparing the body for rest, comes into play in the middle of the afternoon as cortisol levels drop. Cortisol activates the sympathetic nervous system, which promotes activation and alertness, while melatonin activates the parasympathetic nervous system, responsible for the feeling of relaxation.

Controlling environmental lighting conditions is fundamental to avoid negatively altering the circadian cycle. A space that takes the biological clock into account must be exposed to sunlight—unaltered natural light will always be preferable to artificial light. During the central hours of the day, the space is fully illuminated naturally, and as evening arrives, the light intensity progressively decreases. [6]

Light temperature

The tone of light has a direct relationship with bodily reactions. Therefore, it is necessary for artificial light, taking natural light behavior as a reference, to adapt to the needs of each space’s use. Warm tones, with a color temperature around 3000K, promote a sense of relaxation, peace, and seclusion, while white tones, known as blue light, around 4000K, contribute to body activation, attention, and sensory stimulation. [7]

2. Colors

Color psychology studies the psychological impact of colors on people. Beyond aesthetic value, colors are capable of influencing mood and the way a space is experienced. Despite subjective cultural, social, and personal taste aspects coming into play, colors—separately or combined—stimulate the construction of emotions.

Good color control can visually modify the geometry of an architectural space, interfering with the relationship between its components and affecting our perception of the elements that shape the space: dimensions, depth, materiality, or texture.

Effects of color choice

In the home environment, it is preferable for color to exert a calming, restorative effect. To achieve this, it is advisable to use strong colors on walls or in rooms where the user stays for a short time, or on very focused elements. Avoiding the mixing of different color varieties with strong contrasts will help create a peaceful atmosphere and reduce nervousness. The goal is to combine colors harmoniously with similar tones and soft contrasts.

On the other hand, the choice of a color has a direct relationship with the degree of absorption/reflection of light radiation.

White reflects approximately 80% of solar radiation, while black reflects around 10%, being the most absorbent color. These values influence not only the clarity of spaces but also thermal radiation for the purpose of utilizing solar energy. [8]

3. Natural spaces

The historical link between human beings and their environment explains, from a biological point of view, the innate need we have to be in contact with nature.

Interacting with other living beings provides us with instinctive well-being—just as we seek to relate to other human beings, living with more life forms such as animals or, in this case, plants, improves our mood.

The adaptation of human beings to the urban environment has resulted in a radical disconnection from the natural environment. This nature deficit translates into an increase in both physical and psychological pathologies.

Effects of natural environments

Environmental psychology ensures that contemplating and moving through a natural space creates positive emotions that activate the parasympathetic system, the part of the nervous system responsible for restoring bodily and mental calm after experiencing an episode of stress.

Natural spaces also have restorative effects on attention—by directing attention involuntarily, they provide a positive distraction, contributing to the rest and restoration of cognitive mechanisms.

On the other hand, the presence of vegetation contributes to the creation of healthier environments, helping to regulate humidity, absorbing toxic particles from the air, or reducing direct solar radiation in the case of green pergolas.

In short, the integration of vegetation into our inhabited environments is one of the irreplaceable foundations upon which our physical-mental comfort rests. Understanding the spaces we inhabit from a biophilic perspective helps to increase people’s quality of life, resulting in a positive impact on our health. [10]

4. Morphology of space

The forms with which the environment is materialized generate sensory stimuli. The morphology of the elements that make up the space affects the amygdala, which is the part of the limbic system linked to fear and stress.

Organic shapes, curves, and soft contours tend to produce a sense of well-being and relaxation, while very sharp angles, by reminding us of sharp objects, activate an instinctive danger alert, generating a greater sense of stress. [11]

Paths

Avoiding overly marked paths and rigid space distribution encourages free exploration by users. The permeability of spaces allows them to be traversed freely, favoring decision-making—a more permeable and open space allows for choosing different paths adapted to each action.

It is preferable to plan paths with gentle changes in direction, widening the dimensions of passage spaces and avoiding narrow right angles that require abrupt movements.

Proportion

A space with high ceilings and open areas favors abstract and collective thinking, while a more secluded space with lower ceilings favors concrete and individual thinking. Ultimately, playing with human scale directly affects the sensation a space produces.

Maintaining strict proportions in accordance with the scale of people provides a sense of control, both spatial and mental, which sometimes evokes security and seclusion, and at other times oppression or monotony.

Spaces with disproportionate dimensions that break with the human scale—such as high ceilings, double or triple heights, and oversized vertical elements—favor the idea of freedom thanks to spatial amplitude and decongestion, while also producing a sense of lack of control and emptiness.

5. Materials

Each material influences the interior and exterior perception of a space. The choice of a material encompasses a broad sensory spectrum: texture, color, temperature to the touch, aging, and even the scent of the elements shape the perceptible surface layer of the space.

Opting for the integration of natural materials brings warmth to the interior environment. Synthetic or industrialized materials such as concrete or plastic elements produce cold sensations, while natural, minimally processed materials like wood, ceramics, or earth, with warm tones, produce a sense of warmth and well-being.

Beyond the aesthetic value associated with each materiality, the non-tangible aspects of building materials are fundamental to ensuring healthy indoor environmental conditions.

Thermal Mass

A key point to evaluate when choosing a material is its thermal mass—the property by which certain construction elements are able to store temperature (coolness or heat), retain it, and release it progressively.

Materials with higher thermal mass, meaning a greater capacity for temperature accumulation, include rammed earth, stone, or ceramic materials. Topsoil, due to its high water content—the natural element with the highest heat capacity—acts as an alternative that ensures high thermal mass.

We can use thermal mass to our advantage in the design of so-called passive architecture, a way of constructing buildings that reduces energy demand through bioclimatic design.

In winter, we capture heat through south-facing openings, which is stored in thermal mass walls and is not lost thanks to high exterior insulation and airtightness.

In summer, we protect ourselves from the sun using plant-covered pergolas, porches, or slats, and we maintain the coolness stored overnight in the thermal mass elements, which is preserved again thanks to proper exterior insulation.

Hygroscopicity

Hygroscopicity is understood as the moisture-buffering capacity of certain building materials—they absorb or release moisture into the air, balancing imbalances and regulating indoor air quality.

Materials with the best performance regarding breathability and regulation of atmospheric humidity in the interior environment are earth, clay, or wood-based materials. The use of ecological paints or natural clay coatings also promotes this effect due to their moisture-regulating properties.

Thermal and acoustic buffering

The quality of an interior space is also measured by its degree of protection against external noise and temperatures that are unsuitable for health.

It is essential to ensure that building materials meet thermal-acoustic buffering levels capable of maintaining interior conditions adapted to these requirements.

Cork is one of the natural materials that best responds to these thermal-acoustic insulation needs. Other natural alternatives include wood fiber, cellulose, or hemp panels.

Protection against toxic compounds

Building materials can emit toxic chemical compounds that have a direct impact on the health of occupants.

It is fundamental that materials do not emit toxic substances into the air, whether in the materials used for construction systems, furniture, coatings, or appliances linked to installations.

6. Hygrothermal comfort

The human body is an organism very sensitive to temperature changes; it is advisable to keep it at a constant temperature—an average of 37°C—to avoid overheating or sudden cooling that alters our well-being.

While the definition of comfort is complex due to the many aspects involved, hygrothermal comfort plays a crucial role in how an architectural space affects a person’s physical well-being.

Hygrothermal comfort is understood as the set of conditions regarding temperature, relative humidity, and ventilation capable of generating a healthy and, therefore, comfortable environment.

Unfavorable thermal conditions with inadequate humidity levels or a lack of ventilation and air renewal are triggers for pathologies and health disorders. [12]

Thermal comfort

The temperature range in which the human body experiences a sense of comfort is between 17°C and 27°C.

Feeling excessive heat—above 27°C—reduces concentration and performance. To carry out activities that demand attention, it is advisable that study or work spaces do not exceed this maximum temperature.

Furthermore, heat increases the pulse and generates drowsiness and discomfort, so it is important to ensure an adequate temperature in rest areas during the night—with a temperature around 18°C.

Conversely, the sensation of cold—below 17°C—activates the body and puts it on alert, producing nervousness and a need to move. In rooms linked to rest and seclusion—such as the bedroom or living room—being below the recommended temperature has negative effects on our regeneration process.

However, a lower thermal sensation in rooms that require more movement—such as the kitchen, bathrooms, or hallways—will not have the same impact on our sense of comfort.

Humidity

Optimal relative humidity values to ensure healthy spaces are between 40% and 60%.

An environment that is too dry—below 30% relative humidity—contributes to drying out the body’s mucous membranes, weakening our defenses and exposing our organism to external agents harmful to health, such as viruses and bacteria.

Dry environments favor the appearance of volatile dust particles in the air, causing allergic reactions in those inhabiting the space.

In contrast, environments with too much relative humidity—above 60%—tend to cause a feeling of heaviness and fatigue. Humidity acts as a barrier to our body’s natural evaporation, even resulting in respiratory problems. Furthermore, humidity favors bacteria associated with multiple respiratory diseases such as asthma and allergies.

Ventilation

Ventilation is directly related to hygrothermal comfort. Especially in summer, our sense of comfort improves in the presence of an air current. Implementing design strategies that favor proper ventilation improves well-being inside a space.

It is advisable to generate natural cross-ventilation currents by opening windows on opposite facades.

7. Acoustic comfort

Current urban lifestyles maintain a relationship with noise that, despite its normalization as a result of human evolutionary adaptation, carries negative consequences for health.

The effect of noise pollution on the body goes beyond simple acoustic perception. Noise waves propagate toward the nervous system, especially through the hypothalamus, deteriorating the quality of sleep and rest. [13]

Excessive noise affects speech comprehension, especially at early ages – up to 14 years. Children experience greater sensitivity to noise than adults. When childhood development occurs in noisy environments, communicative interactions are hindered, resulting in altered language development, learning, and memory.

Attention capacity is notably affected in noisy situations. The distraction effect caused by noise pollution results in attention deficit disorders – ADD or ADHD – that prevent carrying out daily tasks requiring specific mental effort. [14]

Acoustic insulation

It is essential to design a good acoustic insulation system that takes into account airborne and impact noise in order to silence or at least attenuate them.

When we talk about airborne noise, we refer to noise transmitted through the air due to insufficient acoustic insulation. It is caused by air disturbance from sound sources whose sound level is higher than that of the dwelling. An example of airborne noise can be hearing traffic, neighbors, television, household appliances, etc.

To protect ourselves from airborne noise, we use materials that absorb and reduce it, such as dense insulation or double-glazed glass.

Impact noise, on the other hand, refers to noise caused by a blow to a solid medium that propagates through the structure, usually the floor slab. The most common impact noises are footsteps from the floor above. These noises are dampened with structural joints or flexible materials.

8. Olfactory comfort

Human beings perceive air as the sum of two sensations that are difficult to differentiate: one olfactory and one chemical.

The olfactory sensation is directly linked to our tastes and memory. It is perceived in a small area of the nasal cavity, which sends a message to the brain indicating whether an aroma is pleasant or, conversely, unpleasant.

However, detecting the impact that certain aromas have on our health is not related to the nervous system; instead, it affects the mucous membranes, generating, in some cases, instantaneous reactions of itching, irritation, burning, coolness, discomfort, etc.

It is important to distinguish between odors coming from the outside, which enter the building through openings or mechanical ventilation systems. However, indoor air quality, from an olfactory point of view, depends largely on the building itself—it has to do, on the one hand, with construction materials and finishes and, on the other, with cleaning, hygiene, and home care products. [15]

Toxic-free indoor environment

It is essential to find a balance between a pleasant and a healthy aroma, integrating the idea that something that apparently smells “bad” is not necessarily harmful to health.

For example, we associate the feeling of cleanliness with certain aromas from household chemical products which, despite generating positive emotional responses, negatively affect our health due to their synthetic composition.

The same occurs with the paints that cover the surfaces of our rooms. The “freshly painted” smell is associated with a feeling of renewal and linked to the start of new projects; however, in most cases, these aromas correspond to synthetic products with high levels of VOCs—Volatile Organic Compounds—harmful to our health in the long term.

9. Surroundings and views

The sense of well-being produced by views of the sea, at the top of a mountain, in a green grass meadow, a straw field, is directly related to our brain’s tendency to seek varied and natural spaces with distant perspectives that provide us with security.

In urbanized environments, our views are reduced to planes close to us: tall buildings that prevent seeing behind them, little distance between elements that configure free public space, remaining in enclosed interiors, etc. In short, human beings have become disconnected from the horizon line, have lost the ability to look into the distance.

Despite this urban reality, a pleasurable instinctive sensation continues to occur in situations where the foreground is freed. In public space, this happens with large avenues and squares, and in private space, with the enhancement of the surroundings by providing the dwelling with exterior space. [16]

Exterior space in the dwelling

It is necessary for a dwelling to be connected to exterior space through terraces and windows that allow looking toward distant points, free of obstacles, promoting visual rest. This interaction between interior and exterior space contributes to creating healthier routines while avoiding the sensation of claustrophobia. [17]