title: Apathy and Attentional Biases in Alzheimer's Disease.
abstract: BACKGROUND
  Apathy, one of the most prevalent neuropsychiatric symptoms in Alzheimer's disease (AD), can be difficult to assess as cognition deteriorates. There is a need for more objective assessments that do not rely on patient insight, communicative capacities, or caregiver observation.
  
  
  OBJECTIVE
  We measured visual scanning behavior, using an eye-tracker, to explore attentional bias in the presence of competing stimuli to assess apathy in AD patients.
  
  
  METHODS
  Mild-to-moderate AD patients (Standardized Mini-Mental Status Examination, sMMSE >10) were assessed for apathy (Neuropsychiatric Inventory [NPI] apathy, Apathy Evaluation Scale [AES]). Participants were presented with 16 slides, each containing 4 images of different emotional themes (2 neutral, 1 social, 1 dysphoric). The duration of time spent, and fixation frequency on images were measured.
  
  
  RESULTS
  Of the 36 AD patients (14 females, age = 78.2±7.8, sMMSE = 22.4±3.5) included, 17 had significant apathy (based on NPI apathy ≥4) and 19 did not. These groups had comparable age and sMMSE. Repeated-measures analysis of covariance models, controlling for total NPI, showed group (apathetic versus non-apathetic) by image (social versus dysphoric) interactions for duration (F(1,32) = 4.31, p = 0.046) and fixation frequency (F(1,32) = 11.34, p = 0.002). Apathetic patients demonstrated reduced duration and fixation frequency on social images compared with non-apathetic patients. Additionally, linear regression models suggest that more severe apathy predicted decreasing fixation frequency on social images (R2 = 0.26, Adjusted R2 = 0.19, F(3,32) = 3.65, p = 0.023).
  
  
  CONCLUSIONS
  These results suggest that diminished attentional bias toward social-themed stimuli is a marker of apathy in AD. Measurements of visual scanning behavior may have the potential to predict and monitor treatment response in apathy.
authors.affiliation: Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada.|Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Chau
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, ON, Canada.|Department of Electrical and Computer Engineering, University of Toronto, ON, Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Chung
authors.affiliation: Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada.|Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
authors.forename: Nathan
authors.initials: N
authors.lastname: Herrmann
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, ON, Canada.|Department of Electrical and Computer Engineering, University of Toronto, ON, Canada.|Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada.
authors.forename: Moshe
authors.initials: M
authors.lastname: Eizenman
authors.affiliation: Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada.|Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada.|Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
authors.forename: Krista L
authors.initials: KL
authors.lastname: Lanctôt
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology / Q000523:psychology*; D057565:Apathy; D000070379:Attentional Bias; D003071:Cognition; D003430:Cross-Sectional Studies; D004644:Emotions; D053483:Eye Movement Measurements; D005133:Eye Movements; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D012720:Severity of Illness Index; D012938:Social Perception
keywords: Alzheimer’s disease; apathy; attention; cognition; eye movements