Project Description

Disturbances of attentional control are considered a key symptom of schizophrenia (SZ). Evidence for attentional deficits is usually inferred using tasks that compare the ability to select or inhibit stimuli in the visual field. Contrasts between individuals with and without SZ on these tasks, are typically based on summary statistics that aggregate responses across multiple trials. Whilst informative, these analyses are insensitive to fluctuations in attentional control that occur at smaller time intervals, for example on a trial-by-trial basis. Recent evidence suggests attentional control is mediated by interactions between neural networks that prioritise external or internal stimuli over time. Connectivity between these networks fluctuates, with lapses of attention during task performance reflecting competitive interactions between the internally directed default mode and externally directed dorsal and ventral attentional systems. Resting state fMRI data indicate SZ is associated with changes in the connectivity between these networks, which is thought to underlie symptomatic dissociations between self-representation, salience, and task-oriented endogenous attention to external stimuli. SZ related fluctuations in connectivity between networks should elicit measurable interference on tasks that require the ongoing evaluation of external visual input. The objective of this studentship is to evaluate the sensitivity and reliability of time-locked changes in sustained attention as a measure of network connectivity in SZ and controls. To do this, the project will investigate the relationship between clinical symptoms of SZ and trial-by-trial variability in behavioural, pupillometric and electrophysiological measures of performance on tasks that measure the consistency of visual selective attention over short-periods of time.