5C: Synesthesia

Question 1

Cross-modal perception

Answer 1

occurs where perception involves interactions between two or more different sensory modalities.

Question 2

Synesthesia

Answer 2

A phenomenon where stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway; a type of cross-modal perception. May be associated with improved memory and faster reaction times on certain tasks (e.g., visual search task).

Question 3

Grapheme to color

Answer 3

[written letters/numbers evoke numbers]

Question 4

sound to color

Answer 4

sounds evoke colors; also called chromesthesia

Question 5

lexical to gustatory

Answer 5

spoken or written words evoke tastes (and often also temperature, textures or food)

Question 6

Number-form & spatial-sequence

Answer 6

[numbers and sequences evoke shapes
and forms]; these types may overlap significantly

Question 7

Ordinal-linguistic personification

Answer 7

[ordered sequences like numbers and
letters are associated with personalities and/or genders]

Question 8

Misophonia

Answer 8

[possible synesthesia vs. neurological disorder; sounds evoke strong negative emotions; also associated with anxiety, obsessive compulsive disorder, Tourrette’s syndrome, and maybe autism

Question 9

X -> Y notation

Answer 9

X is the “inducing stimulus”, is the “concurrent sensory experience”

Question 10

causes of X -> Y notation

Answer 10

developmental: from differences in white matter connections, such as a decrease in synaptic pruning
acquired: from sensory, drugs, or trauma

Question 11

Projector synesthetes

Answer 11

these people experience their synesthetic percepts as similar in quality to real-world perceptions. For example, synesthetic colors might appear as projected onto external objects and be difficult to dissociate from real-world colors. These synesthetes might not be able to tell whether letter are in black/white or color. This type likely arises from changes earlier in the sensory processing pathways (like
apperceptive agnosia) and is rarer.

Question 12

Associator synesthetes

Answer 12

these people experience their synesthetic sensations within their internal mental space. For example, they would see letters as appearing black/white, but would automatically associate the letters with colors in their mind/memory. This type is more common, and may arise from higher-order sensory regions (like associative agnosia), linking basic sensory perception with an associated memory, emotion, or sensory mental imagery.

Question 13

Visual search task

Answer 13

In the visual search task, it takes longer to find the number 2 hidden among 5’s when they are all the same color. Reaction time is much faster when there is a color difference. Grapheme-color synesthetes have a reaction time like there is a clear color difference when the numbers used match their synesthetic perceptions, even when the written text is all in black. This speeded-up response is driven by the pop-out effect of the colored number.