Inducing and Detecting Hallucination-like Auditory Experiences in Healthy Subjects via Conditioning and Electroencephalogram Analysis: A Proof of Concept

Background: Auditory hallucinations (AHs)—perceptions of sound without external stimuli—are common in clinical populations but rarely investigated in healthy individuals. This study aimed to employ Pavlovian conditioning to induce AH-like experiences in healthy subjects and to examine their neural correlations using electroencephalography (EEG). Methods: Seven healthy volunteers were exposed to auditory, non-auditory, and conditioned non-auditory stimuli while recording their EEG with a 32-channel system. Results: When comparing “sound” (auditory) and “conditioned no sound” (conditioned non-auditory) scenarios, the differences in average EEG power were much less pronounced compared to regular sound/no sound scenario. However, significant alterations (p = 0.05) in β and γ rhythms were observed in bilateral temporal regions when comparing the “no sound” and “conditioned no sound” scenario, resembling the spectral patterns observed during real sound perception. These EEG alterations indicate successful induction of hallucination-like auditory experiences through Pavlovian conditioning. A three-class k-nearest neighbor (kNN) classifier detected AH-like events with >80% accuracy in six out of seven participants. Conclusions: Pavlovian conditioning can induce AH-like perceptions in healthy individuals, accompanied by measurable EEG alterations. Therefore, EEG-based methods have the potential for objective detection and assessment of auditory hallucinations and offer a foundation for future research on their neural mechanisms.