Learning functions for unilaterally brain damaged patients for serially and randomly ordered stimulus material: Analysis of retrieval strategies and their relationship to rehabilitation

Abstract

Unilaterally brain-damaged subjects were tested for their use of stimulus order information in performing verbal learning tasks. We evaluated the nature and extent to which these individuals used stimulus order in organizing and structuring their recall. Based on our findings, we hoped to evaluate the feasibility of a rehabilitation program to improve performance of patients with verbal learning deficits using stimulus order information as a cuing device. Information was presented either in a constant order from trial to trial (serial order condition), or in a varying order from trial to trial (random order condition). Presentation was either visual, in a memory drum, or auditory, spoken by the experimenter. There were four conditions: Visual Serial, Visual Random, Auditory Serial, and Auditory Random. Sixteen Right Brain-Damaged (RBD) and 16 Left Brain-Damaged (LBD) aphasic patients were included. Both LBD and RBD subjects showed significant improvement across trials for all four conditions. LBD subjects were significantly better in their performance in serial as opposed to random presentation order. RBD subjects showed no difference in their performance with serially ordered or randomly ordered information. For LBD subjects, order information was an important cue for improving recall. RBD subjects appeared to be more flexible in their recall strategies and were not overly dependent on this factor. We developed a training program for LBD individuals with verbal learning deficits, which was based on the use of serial order cues to structure recall.