Emotions And Color: Synesthesia's Intriguing Link Explained

Synesthesia is a perceptual phenomenon where stimulation of one sensory or cognitive pathway leads to involuntary experiences in a second sensory or cognitive pathway. People with synesthesia may experience colours when listening to music, see shapes when smelling certain scents, or perceive tastes when looking at words. For example, in chromesthesia (sound to colour), a projector may hear a trumpet and see an orange triangle in space, while an associator might hear a trumpet and think very strongly that it sounds orange.

One type of synesthesia is emotion-colour synesthesia, where people experience visual perceptions of colour in response to different emotions. Some synesthetes actually see these colours physically in front of them (projector synesthetes), while others only see them in their mind's eye (associator synesthetes). The colours perceived for each emotion are consistent and idiosyncratic, varying greatly from person to person. They are not guided by conventional correspondences such as red = anger or passion, or grey = seriousness or boredom, although they may occasionally coincide.

Emotion-colour synesthesia is not very common. In Sean Day's study of 1,143 synesthetes, 3.24% reported having visual experiences in response to emotions. However, it is a type of synesthesia that has captured the public imagination, with numerous examples of novels and TV series featuring characters who see other people's emotions as colours.

Projector vs. associative synesthesia

Synesthesia is a perceptual phenomenon in which individuals experience unusual percepts triggered by the activation of an unrelated sensory modality or a cognitive process. For example, hearing the sound of a trumpet may elicit the vision of brightly coloured triangles dancing in front of one's eyes. The stimuli that generate these unusual experiences are called 'inducers', and the internally produced synesthetic percepts are called 'concurrents'.

Projective synesthesia is when the synesthetic concurrent is seen physically before the eyes, as if it was on a screen in space. On the other hand, associative synesthesia is when the concurrent is perceived only in the mind's eye but not seen physically.

For example, a person with auditory-visual synesthesia may see a yellow line when they hear the sound of a violin. If they see the yellow line physically in external space as if it was really there in front of them, they have projective synesthesia and are called a "projector synesthete". However, if they automatically perceive the visual sensation of the yellow line in their mind but not physically, they have associative synesthesia and are called an "associator synesthete".

Associative synesthesia is much more common than projective synesthesia. Associator synesthetes have been known to have occasional experiences with projection, although this is not typical and seems to only happen if their synesthesia is suddenly very much intensified for some reason.

The projector/associator distinction was first phrased in terms of grapheme-colour synesthesia, in which colours are triggered by letters and/or digits. Some grapheme-colour synesthetes report that their colours are experienced outside their own body space, projected into the world, and these are termed "projector" synesthetes. There are two types of projectors: surface-projectors experience colour projected onto the written type-face, and space-projectors project colour onto some other externalised near-space.

In contrast, "associators" can be thought of as "non-projectors" as their colours exist within their internal mental space. Those associators who claim to see colours in their mind's eye are called "see-associators", while those who simply claim to know the colours of graphemes without any associated impression of "seeing" are called "know-associators". In other words, there is a four-way divide between synesthetes experiencing colours in a way resembling real-world experiences (projected onto the stimulus or into near-space) and those experiencing them "internally" (in the mind's eye or as a type of propositional association).

It has been proposed that these differences might emerge from an otherwise unrelated individual difference in the ability to form a visual mental image. Visual imagery—the mental construction of a scene-like object—is known to vary across individuals. At the upper extreme end, there are individuals with "eidetic" imagery who report strongly evoked mental images with an almost veridical quality. At the opposite end of the healthy spectrum are those who report being unable to form mental images at all.

It has been suggested that individual and randomly dispersed variations in mental imagery within the synesthesia population would lead to some synesthetes having high imagery and therefore highly imaged synesthetic colours. This, in turn, could lead to enhanced conscious awareness and, consequently, a greater likelihood of self-referral for scientific studies.

Synesthesia as a perceptual phenomenon

Synesthesia is a perceptual phenomenon in which stimulation of one sensory or cognitive pathway leads to involuntary experiences in a second sensory or cognitive pathway. This phenomenon is commonly classified as developmental and acquired.

Developmental Synesthesia

Developmental synesthesia is the most frequent type of this condition, with a 4.4% estimated prevalence rate. It can run in families and demonstrate Mendelian transmission. Different forms of synesthesia can be observed in the same person or in the same family. The condition is occasionally associated with autism spectrum disorders, like Asperger syndrome.

The following criteria have been proposed to help establish a diagnosis of developmental synesthesia: induced percepts should be elicited by a specific stimulus, they should be automatically generated, and typically have percept-like qualities. Usually, pairings of inducers and concurrents are specific (i.e., a particular stimulus consistently triggers the same synesthetic percept). They tend to be stable over time in a given individual, although this has recently been challenged by the finding that synesthetic ability can disappear over time.

Acquired Synesthesia

Acquired forms of synesthesia have also been reported, essentially associated with neurological disorders or following psychotropic drug ingestion. In contrast to its developmental counterpart, acquired synesthesia does not demonstrate either idiosyncrasy or automaticity or stability.

Emotional Reactions in Synesthesia

Emotional reactions play a prominent role in synesthetic processes. They are commonly experienced in such conditions, acting as either inducer, concurrent, or modulator. A conflict between the actual color of a stimulus and synesthetically induced percepts can generate discomfort, whereas ‘pleasantness’ is experienced when synesthetic and actual stimulus features match. Some synesthetes indicate that all disagreeable events generate the same color, specific for the given individual. Saturation of evoked colors is susceptible to be altered by mood. In some personality–color type of synesthesia, viewing known faces elicits emotionally mediated color percepts, presenting either as colored faces or colored auras around heads.

Synesthesia as a neurological trait

Synesthesia is a neurological condition where stimulation in one sensory or cognitive pathway leads to involuntary experiences in a second sensory or cognitive pathway. In other words, it is a phenomenon where the stimulation of one sense leads to involuntary experiences in another. For example, someone with synesthesia might see colours when they hear music, or taste flavours when they see specific shapes. These connections are consistent for the individual and are a natural part of their experiences.

The condition is not considered a disorder, and many people consider synesthesia to be a fascinating and positive trait. People who report a lifelong history of such experiences are known as synesthetes. Awareness of synesthetic perceptions varies from person to person, with the perception of synesthesia differing based on an individual's unique life experiences and the specific type of synesthesia that they have.

There are two overall forms of synesthesia:

• Projective synesthesia: seeing colours, forms, or shapes when stimulated (the widely understood version of synesthesia)
• Associative synesthesia: feeling a very strong and involuntary connection between the stimulus and the sense that it triggers

For example, in chromesthesia (sound to colour), a projector may hear a trumpet and see an orange triangle in space, while an associator might hear a trumpet and think very strongly that it sounds "orange".

There are at least 80 types of synesthesia, and it can occur between nearly any two senses or perceptual modes. While nearly every logically possible combination of experiences can occur, several types are more common than others. One of the most common forms is grapheme-colour synesthesia, where individual letters of the alphabet and numbers are "shaded" or "tinged" with a colour. Another common form is the association of sounds with colours.

Synesthesia usually develops during childhood and has a genetic component, meaning it can run in families. It is associated with unique structural and functional differences in the brain, and people with synesthesia often show differences in memory and mental imagery compared to others.

While synesthesia is not considered a disorder, it can sometimes be distracting or even make it harder to function due to a person being overwhelmed by so much sensory information. For example, if a person experiences overwhelming colours when listening to a song, then they may avoid concerts or even listening to the radio. If this occurs, a mental health expert can provide therapeutic strategies to help regulate the sensory information and interrupt any related cycles of distress.

Synesthesia as a neurological condition

Synesthesia is a neurological condition in which the stimulation of one sense or cognitive pathway triggers an involuntary experience in a second sense or cognitive pathway. For example, people with synesthesia may experience colours when listening to music, see shapes when smelling certain scents, or perceive tastes when looking at words. People who experience synesthesia are known as synesthetes.

The condition is commonly classified as developmental and acquired. Developmental synesthesia is the most frequent type, with a 4.4% estimated prevalence rate. It can be inherited genetically and is often present in people with autism spectrum disorders. Acquired synesthesia, on the other hand, is less consistent and is usually associated with neurological disorders or drug ingestion.

There are two main forms of synesthesia: projective synesthesia and associative synesthesia. Projective synesthesia involves seeing colours, forms, or shapes when stimulated, which is the widely understood version of the condition. Associative synesthesia, on the other hand, involves feeling a strong and involuntary connection between the stimulus and the sense it triggers. For instance, in chromesthesia (sound-to-colour synesthesia), a projector may see an orange triangle in space when hearing a trumpet, while an associator might think very strongly that the trumpet sounds "orange".

While synesthesia can occur between almost any two senses or cognitive pathways, it is most commonly associated with colours. In one common form of synesthesia, known as grapheme-colour synesthesia, letters or numbers are perceived as inherently coloured. In spatial-sequence or number-form synesthesia, numbers, months of the year, or days of the week elicit precise locations in space or may appear as a three-dimensional map.

Synesthesia has been linked to increased creativity and higher intelligence. Many synesthetes pursue creative or art-based careers and tend to have better memory abilities. Some notable synesthetes include Vladimir Nabokov, Vincent van Gogh, Wassily Kandinsky, Billy Joel, and Kanye West.

Synesthesia as a semantic phenomenon

Synesthesia is a perceptual phenomenon in which individuals experience unusual percepts elicited by the activation of an unrelated sensory modality or by a cognitive process. Emotional reactions are commonly associated with this phenomenon. The most common form of synesthesia is color synesthesia, in which achromatic letters or digits automatically trigger an idiosyncratic color perceptual experience.

Synesthesia can be classified as developmental or acquired. Developmental synesthesia is the most frequent type and is characterized by changes in primary sensory processing and cognitive functions, with better performances in certain aspects and worse in others. It can also lead to heightened creativity. Acquired forms of synesthesia, on the other hand, often arise from drug ingestion or neurological disorders.

The development of synesthesia is linked to semantic mechanisms, with some forms of synesthesia driven by semantic representations and concepts rather than sensory inputs. For example, time-unit synesthesia, where weekdays or months are associated with colors, spatial positions, and other concurrents, does not involve direct sensory inputs as time units are purely conceptual.

Some researchers propose that synesthesia can be classified as "higher" or "lower," depending on whether it is triggered by conceptual or sensory properties of a stimulus, respectively. Higher synesthesia is further divided into "associators" and "projectors." Associators experience synesthetic colors internally in their "mind's eye", while projectors actually see the colors physically.

Recent studies on synesthesia have provided valuable insights into the mechanisms of perception, emotion, and consciousness. They have also shed light on the role of semantic representations in the development of synesthesia and challenged traditional views by demonstrating the involvement of semantic and cognitive processes.

Synesthesia and Emotional Reactions

Emotional reactions play a significant role in synesthetic processes and can act as inducers, concurrents, or modulators. The congruence or incongruence between the actual color of a stimulus and the synesthetically induced colors can evoke emotional reactions such as discomfort or pleasantness. The saturation of evoked colors can also be influenced by the individual's mood.

Some forms of synesthesia, such as personality-color synesthesia, involve viewing known faces and eliciting emotionally mediated color percepts, which can manifest as colored faces or auras around the head. This type of synesthesia is believed to result from cross-activation between the right face recognition area and the neighboring color cortex.

Synesthesia is a complex perceptual phenomenon that involves the integration of multiple sensory modalities and cognitive processes. Recent studies have highlighted the role of semantic mechanisms and concepts in the development of synesthesia, challenging traditional views that solely attributed it to sensory inputs and cross-activation between brain regions. Emotional reactions are also commonly associated with synesthesia and can act as inducers, concurrents, or modulators, further enriching our understanding of this fascinating phenomenon.

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