How to measure working memory capacity in the change detection paradigm

Area of Science:

• Cognitive Psychology
• Neuroscience
• Psychophysics

Background:

• Accurate measurement of working memory capacity is vital for understanding cognition.
• Existing literature shows inconsistencies in how working memory capacity is measured.
• The change detection paradigm is a common method for assessing working memory capacity.

Purpose of the Study:

• To address inconsistencies in working memory capacity measurement within the change detection paradigm.
• To differentiate between two commonly used capacity measures (Pashler, 1988; Cowan, 2001).
• To investigate the interchangeability of these measures and their theoretical underpinnings.

Main Methods:

• Analysis of two distinct working memory capacity measures applied to the change detection task.
• Theoretical derivation and comparison of the Pashler (1988) and Cowan (2001) measures.
• Examination of the underlying discrete-slots working memory model.

Main Results:

• The two measures are not interchangeable and are task-specific.
• Each measure is applicable only under specific experimental conditions.
• The choice of measure can lead to qualitatively different conclusions about working memory capacity.

Conclusions:

• The selection between Pashler's and Cowan's measures is not arbitrary.
• Subtle flaws in the discrete-slots model necessitate revisions.
• The study motivates updates to the modal model of working memory and its capacity measures.