Definitions

Click on the words to go to each definition.

Synesthesia (or Synaesthesia)

Inducer, Concurrent

Projective and associative / Projector and associator

Photism

Ideasthesia

Synesthesia (or synaesthesia)

Synesthesia is a neurological trait possessed by 4% of the general population (this is an approximate figure, and it could be more).

   For these people, perceiving a certain stimulus – which can be sensory or conceptual – involuntarily and consistently triggers a second perceptual experience, typically via a different sense.

   Synesthesia is the US/international spelling and Synaesthesia is the British and Australian spelling. A person who has synesthesia is called a synesthete (or a synaesthete).

   For a fuller description, go to the page All About Synesthesia.

Inducer, Concurrent

In synesthesia, the inducer is the stimulus that triggers the synesthetic experience, and the concurrent is the synesthetic experience itself.

    Examples of inducers and concurrents:

Inducer: the sound of a violin.

Concurrent: seeing a yellow line.

(In auditory-visual synesthesia.)

Inducer: reading the word “telephone”.

Concurrent: experiencing a taste of melon.

(In lexical-gustatory synesthesia.)

Projective and associative / Projector and associator

In visual types of synesthesia, the term “projective synesthesia” is used when the synesthetic concurrent is seen physically before the eyes as if it was on a screen in space, and “associative synesthesia” is when it is perceived only in the mind’s eye but not seen physically.

    Taking the example of someone with auditory-visual synesthesia who sees a yellow line when they hear the sound of a violin:

    If the person sees the yellow line physically in external space as if it was really there in front of them, they have projective synesthesia. This person is 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 can have occasional experiences with projection, although this is not very common and seems to only happen if their synesthesia is suddenly very much intensified for some reason.

Photism

A photism is the image (normally abstract and usually a colour or shape) seen or perceived by a synesthete in response to a specific stimulus.

    For example, someone with auditory-visual synesthesia might hear the sound of a violin and see or perceive a photism consisting of a yellow line.

    The word photism is used to describe visual synesthetic concurrents. If the concurrent is an auditory sensation, the word “phonism” is used.

Ideasthesia

 The term ideasthesia is an alternative name for synesthesia proposed by the neuroscientist Danko Nikolić in 2009. In accordance with this theory, rather than being an interaction between one sense and another, synesthesia actually always consists of an interaction between a concept or idea and a sense.

    You can read more about this subject on the page about ideasthesia.