Where and when meaning occurs in the brain: Evidence for a neurobiological model of reading comprehension ability
Aboud, Katherine Swett
Reading comprehension (RC) is a complex neural task that requires coordination across multiple brain systems. The majority of neurobiological research to date has focused on how “sounding out” words (i.e. decoding ability) influences RC outcomes. However, RC ability is also determined by a diverse array of cognitive abilities beyond the influence of decoding, including meaning processes and executive functions, among others. Neurobiological studies have identified a wide range of areas in the brain that support RC ability that are independent from decoding regions. However, low spatiotemporal imaging resolution as well as an absence of neurobiologically-centered hypotheses have prevented a granular view of where and when RC ability interfaces with neural processes supportive of reading. The current dissertation examines the neurobiology of RC ability (independent of decoding) from word to text using both magnetic resonance imaging (MRI) and electroencephalography (EEG). We found that lower RC ability traces to decreased activation of semantic retrieval areas centered in the temporal poles which causes a cascade of inefficient neural processes in text comprehension. We describe this cascade and provide a preliminary neurobiological model for RC ability. Larger implications for brain network properties in RC ability are also discussed.