Learning Ability as a Function of Practice: Does It Apply to Farmworkers?
OBJECTIVE
Farmworkers experience significant work-related health risks including pesticide-associated cognitive impairment. Practice effect is a surrogate for learning ability. This study examined differences in cognitive function and learning capacity in Latino farmworkers and nonfarmworkers.


METHODS
Tasks of learning and short-term memory, executive function and working memory, perceptual coding, and psychomotor function were assessed at baseline and 3-month follow-up in 136 farmworkers and 116 nonfarmworkers.


RESULTS
Farmworkers had better performance on visuospatial learning and short-term memory at baseline (P < 0.05). Nevertheless, nonfarmworkers showed more practice effects, or improvement on cognitive performance, at 3-month follow-up relative to farmworkers. Furthermore, the amount of improvement on visuospatial learning ability, short-term visuospatial memory, and perceptual coding ability was significantly higher in nonfarmworkers than in farmworkers.


CONCLUSIONS
Practice effects may serve as an additional cognitive readout to differentiate healthy individuals from those with cognitive impairment.
From the Department of Family and Community Medicine (Dr Nguyen, Mr Summers, and Dr Arcury) and Department of Neurology (Dr Walker); Department of Epidemiology and Prevention (Dr Quandt) and Department of Biostatistical Sciences (Drs Morgan and Chen), Division of Public Health Sciences; Department of Pediatrics (Dr Howard), Center for Genomics and Personalized Medicine Research, Center for Worker Health, Wake Forest School of Medicine, Winston-Salem; and North Carolina Farmworkers Project (Mr Galván), Benson.
Ha T
HT
Nguyen
Sara A
SA
Quandt
Phillip
P
Summers
Timothy M
TM
Morgan
Haiying
H
Chen
Francis O
FO
Walker
Timothy D
TD
Howard
Leonardo
L
Galván
Thomas A
TA
Arcury
D000328:Adult; D003072:Cognition Disorders / Q000175:diagnosis; D000067565:Farmers; D006801:Humans; D007858:Learning; D016273:Occupational Exposure; D010575:Pesticides; D011214:Practice, Psychological
D010575:Pesticides