The Role of Angular Gyrus in Prediction, Production and Comprehension

This Ph.D. project will lead to a novel, neurally-grounded theory of how we make sense of the world around us, by testing how we compare internal predictions about incoming information with sensory inputs, and why this is crucial for learning as well as for healthy language production.
Previous research suggests that the angular gyrus (AG), a part of the brain found only in apes and humans, may play a key role in this sense-making process, across different domains and tasks. Yet, its specific role in sense-making remains elusive. This is an issue both for developing accurate theories of prediction mechanisms as well as for identifying when sense-making difficulties are behind cognitive impairments.
A recent cross-domain synthesis has proposed that AG would reflect an online dynamic buffer of multi-sensory spatiotemporally extended representations. Whilst this hypothesis aligns with some evidence, the nature of this buffering mechanism is underspecified and its adaptive benefits (i.e., behavioural advantages brought by the development of an online dynamic buffer) are unknown. More problematic, strong evidence for the 'AG buffer' is lacking, likely because most studies did not employ high-temporal resolution techniques able to capture the building-up of neural activity associated with stimulus-buffering (millisecond time scale).
In this context, there are 4 aims of this project.
The first aim (A1) of this Ph.D. project is to examine the time course of AG's responses using electroencephalography (EEG) and test the hypothesis that, rather than a buffering function, AG reflects a domain-general 'sense-making hub', where external (sensory) and internal (predictions) inputs are compared, the prediction error calculated, and the ongoing representation updated accordingly.
The second aim (A2) is to establish if the adaptive benefit of the proposed 'AG sense-making hub' is related to learning.
The third aim (A3) is to establish whether the functioning of the 'AG sense-making hub' depends on the language production system.
The fourth aim (A4) is to establish whether stuttering might depend on inefficient AG's integration of internal (articulatory planning) and external (sensory feedback) inputs. Because adults who stutter (developmental stuttering) are less efficient in prediction-making during sentence comprehension. This might be because of impaired AG functioning and/or disconnection between the AG and the inferior frontal gyrus, a key region for predictions. Therefore, this project will acquire diffusion data of both healthy adults and adults who stutter using Diffusion Tensor Imaging (DTI) to explore whether developmental stuttering relates to impairment of the AG's prediction-related function.