Declarative and procedural learning in children and adolescents with posterior fossa tumours

Abstract

Background: This quasi-experimental study was designed to assess two important learning types - procedural and declarative--in children and adolescents affected by posterior fossa tumours (astrocytoma vs. medulloblastoma), given that memory has an important impact on the child's academic achievement and personal development.

Methods: We had three groups: two clinical (eighteen subjects) and one control (twelve subjects). The learning types in these groups were assessed by two experimental tasks evaluating procedural-implicit and declarative memory. A Serial Reaction-Time Task was used to measure procedural sequence learning, and the Spanish version 1 of the California Verbal Learning Test-Children's Version- CVLT- 2 to measure declarative-explicit learning. The learning capacity was assessed considering only the blocks that represent learning, and were compared with MANOVA in clinical and normal subjects. The Raven, simple reaction-time, finger-tapping test, and grooved pegboard tests were used to assess the overall functioning of subjects. The results were compared with those from a control group of the same age, and with Spanish norm-referenced tools where available.

Results: The results indicate the absence of procedural-implicit learning in both clinical groups, whereas declarative-explicit learning is maintained in both groups.

Conclusion: The clinical groups showed a conservation of declarative learning and a clear impairment of procedural learning. The results support the role of the cerebellum in the early phase of procedural learning.

Figure 1

Results of groups C, CE, and CE+ during the five blocks of the sequential experiments for mean reaction times. The Standard Error of Measurement is also represented.

Figure 2

Results of groups C, CE, and CE+ during the five blocks of the sequential experiments for mean response accuracy. The Standard Error of Measurement is also represented.

Figure 3

Results of groups C, CE, and CE+ during five blocks for the frequency of words remembered. The Standard Error of Measurement is also represented.

Figure 4

Z-values for groups C, CE, and CE+ in the first and fifth blocks of the declarative learning test. The displayed Z-values are compared to a Spanish "norm"