Parametric Working Memory of Abstract Quantities on Multiple Modalities and Formats : from Frequency to Numerosity

Abstract

Working memory is central to the complex cognitive functions that are involved in goal-directed behavior. At the core of working memory research, the question remains how and in what format information is retained in the brain. Immense progress has been made using neuroimaging to determine the location of information maintenance using experiments with sensory features, however, it remains unclear how more abstract stimuli are stored.

The aim of this dissertation is to uncover the neural underpinnings of working memory during abstract quantity processing. Specifically, I conducted three functional magnetic resonance imaging (fMRI) studies to address the question of which brain regions represent the abstract quantity content. We found parametric working memory representation of auditory, visual and vibrotactile frequencies distributed across sensory, posterior parietal, and prefrontal cortices. Additionally, the numerosity-specific information is represented in the prefrontal cortex.

These results provide novel insights into how the brain maintains information in working memory and give support to the view that mental representations are distributed across the cortex depending on whether they are maintained as sensory-specific or abstract features.