Stimulus-dichotomy synesthesia, dichotomy synesthesia or duality synesthesia

Some synesthetes involuntarily classify a wide range of concepts and objects as either odd or even. This is called stimulus-parity synesthesia. However, there are other variants of this phenomenon, where the two opposing categories are not odd and even but other concepts. The inducers that trigger this involuntary classification are words, letters, numbers, objects, colours, sounds or types of music, people, animals and even all concepts in general.

Some of the opposing categories that have been observed are:

Masculine or feminine

Positive or negative

Left or right

Up or down

Warm or cold

Light or dark

Wet or dry

Closed space or open space

Round or sharp

Good or bad

Pretty or ugly

Thin or thick

One pallet of colours or another (warm colours or cool colours, for example)

In 2015, the name "stimulus-dichotomy synesthesia" was used to refer to this phenomenon in this study by Rebekah C. White and Anna Plassart, the researchers who first reported on stimulus-parity synesthesia and coined the term for it. In this paper, entitled "Stimulus-parity synaesthesia versus stimulus-dichotomy synaesthesia: Odd, even or something else?", they also studied a case of a synesthete who labelled concepts as being either negative or positive.

Here are some descriptions written by people with this type of synesthesia:

Warm or cold

“I group words into two categories: warm and cold depending on the feeling I get from them. It's extremely difficult to explain. Like the word "vanilla" is warm, and "chocolate" is cold. Even common words apply. For example: "the", "and", "on", "these" are all warm. "There", "or", "over", "those" are all cold. My sister thinks this way too, but she calls it left and right.”

(Source: This post on Reddit/Synesthesia. 2020.)

Two opposing colour palettes

“I see numerous dichotomous concepts as having either one color palette (red, yellow, pink) or the other (dark blue, green, black).”

(Source: this contribution to the Facebook group Synesthesia World. 2020. The author of the image, Aurore Zelazny, writes an interesting blog called Synesthesia Research.)

Go to the page on stimulus-parity synesthesia

Go to the page on gender as a synesthetic concurrent

This page last updated: 31 August 2024