Neuropsychological spectrum in early PD: Insights from controlled and automatic behavioural regulation

•Early stages of PD alter most domains (executive, attention, memory and visuo-spatial) except for language.•Severe effects were found in set-shifting in early PD, therefore extending to more than just executive dysfunction.•Automatic and controlled components do not differentiate the types of cognitive impairments in early PD.•Controlled tests are more impaired than automatic ones in early PD.•Methodological improvements are needed to cover both automatic and controlled tests to better characterise early cognitive signs in PD. Initial changes in Parkinson’s disease (PD) are marked by loss of automatic movements and decline of some cognitive functions. Yet, the exact profile and extent of cognitive impairments in early stages of PD as well as their mechanisms related to automatic motor dysfunction remain unclear. Our objective was to examine the neuropsychological changes in early PD and their association to automatic and controlled modes of behavioural control. Significant relationships between early PD and cognitive dysfunction in set-shifting, abstraction ability/concept formation, processing speed, visuospatial/constructional abilities and verbal-visual memory was found. We also noted that tests with a strong effortful and controlled component were similarly affected as automatic tests by early PD, particularly those testing verbal memory, processing speed and visuospatial/constructional functions. Our findings indicate that initial stages of PD sets constraints over most of the cognitive domains normally assessed and are not easily explained in terms of either automatic or controlled mechanisms, as both appear similarly altered in early PD.