Abstract
The serial position effect occurs when individuals are asked to recall a list of information that exceeds normal attention span. Alzheimer's disease (AD) patients show lower scores on word span recall tests when compared to healthy aging subjects, younger individuals or depressed patients.
Objective:
To evaluate the immediate free recall and the serial position effect of a 10-word list, emotionally neutral in tone, in Alzheimer's disease (AD) patients and two age-groups of healthy controls.
Methods:
The free word recall test was applied in a sample of 44 mild AD outpatients and 168 >50 year and 173 ≤50 year-old healthy controls. The span of recalled words and order of recollection of each item was recorded. Scores for serial position effect were analyzed. MMSE scores were recorded for all participants. Descriptive statistics and the ANOVA with Tukey test were performed.
Results:
The controls scored significantly better than AD patients on the MMSE and word span (p=0.0001). Older controls word span mean ±SD was 5.65±1.75, younger controls was 5.99±1.27, and AD patients was 2.86±1.42. The best recalled item in all groups was the first item of the list. Primacy was observed across the three groups, although AD patients presented lower scores. Recency was diminished among AD patients compared to control groups.
Conclusions:
Primacy effect was observed in AD patients as well as in both normal control groups. Recency effect was presented by the normal control groups but was extremely poor among AD patients. The first item was universally best retrieved.
Key words:
immediate recall; neuropsychological tests; memory; Alzheimer's disease; elderly; aging.