PhD ceremony Mr. J.T. Mall: Individual differences in working memory capacity: storage and strategy

PhD ceremony: Mr. J.T. Mall, 12.45 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Individual differences in working memory capacity: storage and strategy

Promotor(s): prof. A. Johnson

Faculty: Behavioural and Social Sciences

Working memory capacity (WMC) is the workspace in which we process, retrieve and hold the most relevant information while ignoring distracting stimuli. In this thesis, it is argued that WMC reflects a mainly domain-general resource which represents memory capacity and some attentional control abilities.

To support these statements, three empirical chapters are presented. First, simultaneously maintaining stimuli from the verbal and spatial domain in working memory provoked substantial interference compared to maintaining stimuli from only a single domain. Therefore, working memory may be understood as a predominantly domain-general resource (Chapter 2).

Second, WMC appeared not to be synonymous with the ability to filter irrelevant information. While individuals with low and high-WMC were equally able to attend relevant information, high-WMC individuals seemed to utilize their bigger memory capacity to encode less relevant information when it could benefit performance (Chapter 3).

Third, individuals with high-WMC appeared capable of a more focused memory search. When competition between memory traces during retrieval from long-term memory was strong, low-WMC individuals exhibited patterns of forgetting which suggested that they were searching in a bigger search set (Chapter 4).

In conclusion, the studies presented in this thesis emphasize the importance of an individuals’ storage capacity and the strategy when trying to remember information.