Synaesthesia-type associations and perceptual changes induced by hypnotic suggestion

Area of Science:

• Cognitive Neuroscience
• Psychology

Background:

• Synaesthesia, a condition where sensory pathways are cross-wired, is often considered congenital.
• The possibility of inducing functional analogues of synaesthesia remains an area of interest.

Purpose of the Study:

• To investigate whether a functional analogue of form-colour synaesthesia can be induced using hypnotic suggestion.
• To compare hypnotic induction with cognitive strategies in mimicking synaesthetic experiences.

Main Methods:

• Hypnotic suggestions were used to associate specific shapes (circles, crosses, squares) with particular colors.
• A Stroop-like task was administered to assess symbol-color associations.
• Participant subjective reports and objective eye-movement data were collected.
• Control groups used cognitive strategies to mimic the task.

Main Results:

• Three out of four highly hypnotizable participants demonstrated strong synaesthesia-type symbol-color associations after hypnosis.
• Objective and subjective measures confirmed the induced associations.
• Induced experiences differed from typical congenital synaesthesia in subjective reports.
• Cognitive strategies yielded different response patterns compared to hypnosis.

Conclusions:

• Hypnosis can rapidly induce targeted, preconscious associations and perceptual changes similar to congenital synaesthesia.
• Subjective experiences in induced synaesthesia warrant careful evaluation, particularly in studies of hypnotic hallucinations.
• This research offers insights into perception, automaticity, awareness, and consciousness, with potential applications in cognitive neuroscience.