The contribution of the central executive to visuo-spatial bootstrapping in younger adults, older adults and patients with mild cognitive impairment.

摘要

Background. Recent studies on verbal immediate serial recall (Darling & Havelka, 2010; Darling et al., 2012, 2014; Allen et al., 2015) show evidence of the integration of information from verbal and visuo-spatial short term memory with long-term memory representations. This so-called ‗visuo-spatial bootstrapping‘ (VSB) pattern, in which verbal serial recall is improved when the information is arranged in a familiar spatially distributed pattern, such as a telephone keypad, is consistent with the existence within working memory of an episodic buffer.udObjective. The general purpose was to investigate the structure of working memory, and in particular the relationship between verbal and visuo-spatial working memory. Specifically, this thesis aimed to determine the contribution of the central executive and the implications of the VSB paradigm in younger and older adults and patients with Mild Cognitive Impairment (MCI).udMaterials and Methods. The first study explored the role of the central executive. The VSB task with digit sequences, visually presented both in single and in a typical keypad display, was administered under conditions of verbal and central executive load. In the second study VSB was investigated in older and younger adults using three conditions: single digit display, typical and random keypad. In the third study, examining performance in VSB in a typical elderly sample compared with people with MCI. Each participant was assessed with a neuropsychological battery of tests and the VSB task composed by single digit and typical keypad display.udResults and Conclusion.udCentral executive load demonstrated to have a negative effect on digit recall performance without affecting the bootstrapping effect. VSB does not need to recruit executive resources. No difference was observed in the bootstrapping pattern as a consequence of age and cognitive difficulties and the beneficial impact of additional visual information was comparable for MCI, older and younger participants.