Age-related difficulties in recognizing faces and emotions are linked to cognitive decline in Parkinson's disease with dementia.
In a recent study, researchers investigated the relationship between age, cognition, and face processing deficits in Parkinson's Disease Dementia (PD-D). The findings suggest that cognitive decline associated with aging and PD-D contributes to impairments in social cognition, including facial emotion recognition and face processing.
The study involved 24 patients with PD-D, with a mean age of 74.0 ± 5.55, and 18 age-matched healthy controls (HC) with a mean age of 71.0 ± 6.20.
The results showed that PD-D patients had lower sensitivity (d') and greater neural internal noises in discriminating faces compared to healthy controls. They also responded slower and had difficulties with negative emotions during dynamic facial emotion recognition. Moreover, PD-D patients imitated expressions but with lower strength compared to healthy controls during expression imitation.
The study found consistent deficits in face processing correlated with slow mentation, advancing age, and poor cognition in PD-D patients. These correlations were absent in the age-matched healthy controls.
The relationship between age, cognition, and face processing deficits in PD-D can be explained by several key points. PD-D often follows a period of mild cognitive impairment (MCI) and manifests with heterogeneous cognitive deficits, especially in executive function, visuospatial skills, and attention, which are crucial for face processing. Older age is a major risk factor for conversion from MCI to PD dementia.
Social cognition deficits in PD and related dementias include impaired facial emotion recognition, which has been correlated with dopaminergic dysfunction in the striatum (putamen and caudate). Dopamine transporter levels relate both to motor symptoms and cognitive/social cognition functions in Parkinsonian syndromes, suggesting dopaminergic degeneration contributes to facial processing deficits.
Aging itself leads to changes in emotion recognition; older adults may show a positivity bias, mislabeling negative or neutral emotions as positive. This bias has been linked to poorer cognitive performance and brain structure changes in emotional processing regions, which may signal early cognitive decline. Such age-related emotional processing changes could exacerbate facial recognition deficits in PD-D.
Dementia with Lewy bodies (which has overlapping features with PD-D) also shows impaired facial recognition, supporting that dementia progression impacts the ability to process and recognize faces.
The study suggests that the face discrimination task could be a potential test for the early detection of dementia in PD, particularly in older patients and those with slow mentation. The consistent deficits in face processing correlated with advancing age and slow mentation in PD-D patients further support this potential.
References:
- Cognitive and social cognition deficits, including facial emotion recognition, associate with dopamine transporter levels in PD-spectrum dementias.
- Older age predicts higher risk of cognitive impairment and dementia in PD, with cognitive heterogeneity affecting face processing.
- Age-related positive emotion recognition bias correlates with cognitive decline and functional brain changes linked to emotional processing.
- Dementia with Lewy bodies also shows impaired facial recognition, supporting overlap in PD-D.
- The study investigated three aspects of face processing capacity in PD-D: morphing-face discrimination, dynamic facial emotion recognition, and expression imitation.
- The study reveals that chronic diseases like Parkinson's Disease Dementia (PD-D) have detrimental effects on health-and-wellness aspects, particularly in the realm of neurological-disorders, such as the processing and recognition of faces.
- The research findings suggest that aging, medical-conditions like PD-D, and the associated cognitive decline contribute significantly to impairments in social cognition, including facial emotion recognition and face processing, potentially making them crucial indicators for the early detection of neurological disorders.
