Synesthesia

Question 1

Synesthesia

Answer 1

A condition in which stimulation on one sensory dimension also gives rise to an experience in a different dimension (called a photism when a visual experience) *literally, synesthesia means “together sensation”

• Consistent: associations are stable over time
• Automatic: associations are involuntary
• Elicited: association requires presence of eliciting stimulus, in contrast to hallucinations, dreams

Question 2

Intramodal synesthesia

Answer 2

interaction within one sensory modality

* e.g., color-grapheme (letter/number) synesthesia

Question 3

Intermodal synesthesia

Answer 3

interaction across sensory modalities
* e.g., color-tone synesthesia
(crossing vision and audition)

Question 4

Associators

Answer 4

Synesthesia is experienced as mental associations, in the “mind’s eye”.
*Most synesthetes are associators

Question 5

Projectors

Answer 5

Synesthesia is experienced as percepts in outside world

Question 6

Sound-color synesthesia (chromesthesia)

Answer 6

individuals experience colors in response to tones or other aspects of musical stimuli (e.g., timbre, key, or volume) or other sounds.

Question 7

Grapheme-color synesthesia

Answer 7

Letters or numbers are perceived as inherently colored (the most common synesthesia)
*V4

Question 8

Number-form synesthesia

Answer 8

numbers, months of the year, and/or days of the week elicit precise locations in space (for example, 1980 may be “farther away” than 1990), or may have colors, or have a three-dimensional view of a year as a map (clockwise or counterclockwise).

Question 9

Lexical-gustatory

Answer 9

is a rare form in which words and phonemes of spoken language evoke the sensations of taste in the mouth.

Question 10

Taste- shape synethesia

Answer 10

flavors invoke the perception of 3-dimensional shapes.

Question 11

Face-color synethesia

Answer 11

Colors associated with individual faces. Could this be the basis of why some people perceive ‘auras’?

Question 12

Cross-activation model

Answer 12

• Grapheme-color synesthesia
• Sensory cross-activation hypothesis: The visual grapheme area is located in the fusiform gyrus which represents visual appearance and is adjacent to color area V4 in the same gyrus; accidental cross- activation between these areas caused by a gene mutation that causes either defective pruning of axons
• “higher synesthetes” perceive color associated with more abstract numerical concepts

Question 13

Two ideas of synesthesia

Answer 13

• Failure to “prune” congenital cross-modal synaptic connections.
• Reduction of inhibition of normal cross-modal feedback from higher brain centers

Question 14

The Stroop effect

Answer 14

it is difficult to override the written meaning of the word when naming the color of the text.

Question 15

Stroop-like speed tests

Answer 15

Reaction times for answers that are congruent with a synesthete’s automatic colors are faster than those whose answers are incongruent.

Question 16

Crowding task

Answer 16

when placed in the periphery, it is difficult to identify the center number when surrounded by other numbers.
But if the center number is a different color, it is easier to identify.