Eliciting false auditory perceptions using speech frequencies and semantic priming: a signal detection approach

Area of Science:

• Cognitive Neuroscience
• Psychology

Background:

• Auditory hallucinations (AH) are often experienced by individuals perceiving voices in random noise.
• The underlying mechanisms, particularly the interplay of internal expectations and external sensory input, remain incompletely understood.

Purpose of the Study:

• To investigate the interaction between top-down (expectations) and bottom-up (noise type) processes in auditory hallucination proneness.
• To elucidate the mechanisms contributing to the tendency to experience auditory hallucinations.

Main Methods:

• A signal detection task was administered to 52 healthy participants with varying proneness to AH.
• Participants listened to sentences with the final word masked by either speech-related or unrelated noise, under high or low semantic expectation conditions.

Main Results:

• Individuals with high AH proneness exhibited a more liberal decision bias and reduced discrimination ability.
• This effect was specifically observed when words were masked by speech-related noise and semantic expectation was high.
• A more liberal decision bias was negatively correlated with the tendency to experience AH.

Conclusions:

• The study successfully demonstrated an interaction between top-down expectations and bottom-up noise processing in the context of AH proneness.
• Findings support current theoretical models of auditory hallucinations and provide a novel paradigm for their investigation.