Imagining a Better Memory: Theoretical and Clinical Implications of the Self-Imagination Effect in Memory

Abstract

Prior research suggests that aspects of self-knowledge are relatively intact in many memory-impaired patients with acquired brain injury. Therefore, cognitive strategies that rely on preserved mechanisms of the self may be particularly effective in this population. The three studies presented in this dissertation investigated the practical utility and mnemonic mechanisms of a novel cognitive strategy designed to capitalize on self-referential processing: self-imagination. Study 1 investigated the effect of self-imagining on cued recall in memory-impaired patients with acquired brain injury and healthy controls. Sixteen patients and sixteen healthy controls intentionally encoded word pairs under four separate conditions: visual imagery, semantic elaboration, other person imagining, and self-imagining. The results revealed that self-imagining enhanced cued recall more than the other encoding conditions in patients and healthy controls. Study 2 was an initial investigation of the effect of self-imagining on free recall. Twenty healthy adults intentionally encoded word pairs under four conditions: self-imagining, a self-descriptiveness task thought to rely on access to semantic information in self-knowledge, an autobiographical memory task requiring retrieval of a self-relevant episodic memory, and a structural processing task. The results demonstrated that self-imagining improved free recall more than the other encoding conditions in healthy adults. Study 3 investigated the effect of self-imagining on free recall in memory-impaired patients with acquired brain injury and healthy controls. Fifteen patients and fifteen healthy controls intentionally encoded personality trait adjectives under five conditions: a self-imagining task, a self-descriptiveness task, an episodic autobiographical memory task, a semantic elaboration task, and a phonemic processing task. The results revealed that the advantage of self-imagining over the other cognitive strategies extended to free recall in patients. Furthermore, the results indicated that the mnemonic benefit of self-imagining was partly attributable to preserved mechanisms associated with the retrieval of semantic information in self-knowledge. The findings from this dissertation indicate that self-imagining is a self-referential cognitive strategy that generates robust and reliable mnemonic improvement in memory-impaired patients with acquired brain injury and healthy controls. Cognitive strategies that involve preserved mnemonic mechanisms of the self, such as self-imagination, may provide a new direction in cognitive rehabilitation.