A Cognitive Exploration of the Development and Control of Attentional Bias

Abstract

Human behaviour is shaped by what we attend to in the visual world. This visual attention can be internally guided by behavioural goals, which forms the basis of attentional bias. Attentional bias is a phenomenon where certain items capture and hold visual attention over others, and is a driving force of many behaviours (e.g. seeking food when hungry). However despite the obvious links between visual cognition and attentional bias, much of the research relating to attentional bias is actually based in psychopathology, examining drivers for addictive substances. Consequently, little is known of the shared, cognitive aspects of attentional bias. This thesis addresses this by firstly examining the cognitive mechanisms that underlie attentional biases in a normative sample. It was found to be possible to induce an attentional bias towards an arbitrary stimulus. This induced bias is both highly persistent and robust. The cognitive basis of this induced bias is believed to be altered attentional control settings, which can form in the absence of emotion or motivation. Since attentional bias most often manifests in abnormal populations, the effects of these altered attentional control settings was then examined in a controlled, sub-clinical population of heavy social drinkers. This offered a means to examine the role of existing attentional biases yet free from confounds of using a clinical sample. No difference in the establishment of an attentional bias between light and heavy drinkers was found, however heavy social drinkers were less distracted by irrelevant, bias-related information suggesting previous experience controlling for attentional biases aids the cognitive control of bias-related distractions albeit with limited capacity. Finally, a neural substrate of attentional bias was probed via neurostimulation, finding a causal role of the left dorsolateral prefrontal cortex in the establishment of attentional control settings, and the control we have over distractions resulting from these settings.