The serial position curve in a free recall test in subjects with probable dementia

Objectives: The main aim of this research is to draw the serial position curve of subjects with probable dementia through a free recall test, in order to find out possible variations in the Primacy effect and Recency effect in comparison with normal subjects. A further aim is to observe the learning process through a sequence of five recalls of the same list. Methods: The observed sample is composed by 187 subjects, 103 with a probable dementia (Experimental Group or EG) and 84 normal (Checking Group or CG). All the subjects were administered with the Rey's Auditory Verbal Learning Test. The first free recall was used to draw the serial curve, whereas the sequence of five recalls was used to observe how the list was learnt by the subjects. The statistical analysis was done with SPSS for Windows. Results: In the free recall the CG's performance is better than the EG's in 8 items among 15; in particular the gap is deeper in the first 2 items (p < 0.05) and in the last 3 (P < 0.05). The sequence of five recalls shows that the Primacy and Recency effects are much more pronounced in the CG (p < 0.05) than in the EG (p < 0.05), although the difference between the two groups is much more marked in the Primacy effect. Conclusions: For what concerns both the free recall and the learning process, the subjects with probable dementia show a substantial decrease in the Primacy effect and a reduction, though less remarkable, in the Recency effect.