Visual and emotional processing in early Parkinson's disease
Parkinson's disease (PD) is a chronic degenerative neurological disorder that mainly affects the motor system via a process of irreversible cell death. Currently, treatment is aimed at improving symptoms as no cure exists. Diagnosis and hence treatment unfortunately often occurs once an advanced stage has been reached, i.e., a point at which motor symptoms are obvious and irreversible brain damage has occurred.
The current study is concerned with investigating two non-motor deficits other present in patients with Parkinson's disease.
This project is broadly split into the following two sub-sections:
(i) Visual Processing
Some deficits in the visual system have been shown to be present during the early stages of PD and hence may be suitable candidates for early detection markers. They include deficits in colour vision, spatial vision and additionally a variety of other vision related functions, for example, the involuntary reflex of the pupil to a luminance signal.
The current study will quantify some of the high- and low-level visual deficits associated with the early stages of PD, i.e., the relationship between low-level “texture” perception through to higher-level natural vision, e.g., the perception of complex natural scenes.
(ii) Emotional Processing
A number of emotional deficits have been identified in PD populations, for example, the socially important ability to perceive the expressed emotion conveyed by someone else’s face. It is however unclear as to whether this deterioration is actually due to a deficit in the processes controlling emotional cognition, the currently accepted view, or an alternative proposal that they are actually due to problems occurring earlier in the visual system that in turn input into emotion recognition.
The current study will determine the extent to which the deficit in facial emotion cognition (classification) can be explained as a function of basic visual dysfunction.
This work has the potential to provide new high-level cognitive indicators of Parkinson's disease. We additionally intend the acquired data to compose part of a longer term study that aims to predict the development of dementia.