The Binding Hypothesis
A unified account of cognitive individual differences?
Almost all cognitive processing requires the temporary storage of information. When solving (3 + 6) * 2, you have to hold the intermediate result in mind while completing the calculation. The system responsible for this is working memory (WM). Working memory capacity — how much information a person can hold active at once — predicts a surprisingly broad range of other abilities, including fluid intelligence, processing speed, and learning. What limits that capacity, though, is still not well understood.
The Binding Hypothesis
The binding hypothesis proposes that working memory capacity (WMC) is limited by the number and strength of bindings a person can form and maintain in WM.
Two types of binding matter here. Declarative bindings link pieces of information to each other — a digit to its position in a PIN, for example. Procedural bindings link information to actions — a letter to a specific key on a keyboard. In this project, I develop tasks and formal models that measure binding ability in both domains, then test whether individual differences in that ability can explain why working memory capacity is limited and why those limits track so closely with intelligence and other cognitive abilities.
Project goals
Two problems have blocked a clean test of the binding hypothesis so far. First, standard tests for procedural bindings — speeded choice tasks, mainly — do not adequately control for contributions from long-term memory, which contaminates the measure. Second, behavioral performance indicators alone cannot isolate binding ability; measurement models are needed to separate it from other sources of variance.
I address both problems directly, using newly developed tasks and measurement models to ask: does a general binding ability explain why WMC is limited, and does it account for why individual differences in WMC predict intelligence, processing speed, and learning?
That is the test the binding hypothesis has been waiting for.