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Specific attentional impairments and complex visual hallucinations in eye disease
G Graham1, J Dean, U P Mosimann
1Clinical Psychology Programme, University of Teesside, Middlesbrough, UK.
International Journal of Geriatric Psychiatry
|August 5, 2010
Summary
Complex visual hallucinations in individuals with eye disease are linked to impaired visual attention, supporting the Perception and Attention Deficit (PAD) model. This cognitive deficit is a significant risk factor for experiencing these hallucinations.
Area of Science:
- Neuroscience
- Ophthalmology
- Cognitive Psychology
Background:
- Complex visual hallucinations (CVH) are a known phenomenon in individuals with acquired eye disease.
- The Perception and Attention Deficit (PAD) model proposes that cognitive impairments, particularly in visual attention, are risk factors for CVH.
Purpose of the Study:
- To investigate the association between cognitive impairment, specifically visual attention deficits, and the occurrence of complex visual hallucinations in elderly patients with acquired eye disease.
- To test the predictive validity of the PAD model in this patient population.
Main Methods:
- Two studies were conducted on elderly patients with acquired eye disease.
- Study 1 examined the relationship between CVH and general cognition/verbal attention.
- Study 2 focused on CVH, selective visual attention, and visual object perception, utilizing tasks like the modified Stroop and an imagery-based attentional task. The North East Visual Hallucinations Inventory classified CVH.
Main Results:
- Study 1 found no significant relationship between CVH and general cognitive screening or verbal attention tasks.
- Study 2 revealed that participants with CVH performed significantly worse on a modified Stroop task and an imagery-based attentional task.
- Performance on these attention-based tasks accurately classified 83% of participants as either hallucinators or non-hallucinators.
Conclusions:
- The findings support the PAD model's prediction that visual attention impairment is associated with complex visual hallucinations in individuals with acquired eye disease.
- These results highlight the role of specific cognitive deficits in the pathophysiology of visual hallucinations in ophthalmological conditions.
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