Prader-Willi syndrome (PWS) is a neurological developmental disorder caused by a genetic variation on the paternal allele of chromosome 15 (q11-q13) associated with hypothalamic dysfunction and physical problems, intellectual disabilities, and behavioural disorders. Individuals with PWS also show reduced sensitivity to pain and thermal dysregulation, pointing to possible sensory information processing deficits. This study aims to describe comprehensive and in depth profiles of sensory information processing and intellectual functioning in patients with PWS, as well as to establish relationships between sensory information processing and intellectual functioning, in order to find treatment options that promote development and diminish behavioural problems.

Included were 43 Dutch patients with confirmed PWS aged 17 to 57 years (M = 28, SD = 9.6). Data were obtained using the Sensory Profile proxy version, Dutch translation (SP-NL) and the test Wechsler Adult Intelligence Scale, fourth edition, Dutch translation. To test statistical differences One-Way Repeated Analyses of Variance were carried out. To evaluate if intelligence was predicted by sensory information processing, Multiple Regression Analysis (MRA), using backward entry, was carried out. Different MRA’s were performed with SP-NL scores as  predictors (independent variables), and scores of the FSIQ and the four indices of the WAIS-IV-NL as dependent variables.

Individuals with PWS showed remarkably low sensory information registration (>2SD), and noticeably more difficulties with modulating endurance/tone, movement, and emotional responses (>2SD). The average full size intelligence quotient (FSIQ; M = 56.17), working memory index (WMI; M = 55.64), were both significantly lower than verbal comprehension (VCI; M = 63.22; p <. 001) and perceptual reasoning (PR; (M = 63.36; p < .001). Also processing speed (PS; M = 55.19) was significantly lower than VCI (p < .003) and PRI (p < .001). In addition, low registration of sensory information predicted lower FSIQ (16.0%) (p = .039) and lower VCI (34.8%) (p = .001). Also, the deviant modulation of endurance/tone predicted FSIQ (19.8%) (p = .012), and VCI (33.1%) (p < .001).

Sensory information processing in individuals with PWS appears to be deviant as compared to healthy norm group controls. Individuals with PWS particularly suffer from low registration of sensory information, modulation problems (lack of endurance, low muscle tone, weak body posture, lack of movement), and challenging behaviours. In PWS, specifically low working memory capacity and slow information processing speed explain low overall intelligence levels. Sensory information processing predicts intellectual functioning in adults with PWS.
This study identifies the importance of the influence of lower order sensory information processing (‘bottom up input’) on higher order cognitive functioning and behaviour (‘top down control’).