Robot-induced hallucinations in Parkinson’s disease depend on altered sensorimotor processing in fronto-temporal network

Bernasconi F, Blondiaux E, Potheegadoo J, Stripeikyte G, Pagonabarraga J, Bejr-Kasem H, Bassolino M, Akselrod M, Martinez-Horta S, Sampedro F, Hara M, Horvath J, Franza M, Konik S, Bereau M, Ghika JA, Burkhard PR,  VanDeVille D, Faivre N, Rognini G, Krack P, Kulisevsky J, Blanke O.

Science Translational Medicine  28 Apr 2021: Vol. 13, Issue 591, eabc8362

DOI: 10.1126/scitranslmed.abc8362 


Grasping hallucinations in PD

Nearly half of the patients with Parkinson’s disease (PD) experience hallucinations, and recent studies have shown that hallucinations are associated with negative cognitive outcome and higher mortality. Now, Bernasconi et al. used a robotic method to induce hallucinations in patients with PD to study the mechanisms behind this symptom. The authors identified a subgroup of patients with increased sensitivity to hallucinations and used magnetic resonance to show that frontotemporal connectivity, associated with hallucinations in healthy participants, was disrupted in patients with PD suffering from hallucinations. The results might improve diagnosis of hallucinations in patients with PD and facilitate the development of targeted therapies.


Hallucinations in Parkinson’s disease (PD) are disturbing and frequent non-motor symptoms and constitute a major risk factor for psychosis and dementia. We report a robotics-based approach applying conflicting sensorimotor stimulation, enabling the induction of presence hallucinations (PHs) and the characterization of a subgroup of patients with PD with enhanced sensitivity for conflicting sensorimotor stimulation and robot-induced PH. We next identify the fronto-temporal network of PH by combining MR-compatible robotics (and sensorimotor stimulation in healthy participants) and lesion network mapping (neurological patients without PD). This PH-network was selectively disrupted in an additional and independent cohort of patients with PD, predicted the presence of symptomatic PH, and associated with cognitive decline. These robotics-neuroimaging findings extend existing sensorimotor hallucination models to PD and reveal the pathological cortical sensorimotor processes of PH in PD, potentially indicating a more severe form of PD that has been associated with psychosis and cognitive decline.