Year: 2016
Type: dissertation
Abstract: This thesis set out to investigate whether individual differences in concentrations of the \nneurotransmitter γ-aminobutyric acid (GABA) could predict the extent of alcohol induced \nimpairment to measures of behavioural inhibition. However, investigations in to the reliability \nof magnetic resonance spectroscopy (MRS) methods to measure GABA, and of the stop signal \nreaction time (SSRT) demonstrated that neither measure was sufficiently reliable to be used in \ncorrelational research. Instead, this thesis first investigated the effects of alcohol on neuronal \noscillations measured by magnetoencephalography (MEG) in the gamma frequency band that \nare associated with GABA. In response to a visual stimulus alcohol was found to increase \ngamma power and decrease gamma frequency in the visual cortex. In response to a motor \nstimulus increases in gamma power were also observed over the motor cortex whilst \nintoxicated. During resting state recordings alcohol was found to increase power in central, \nparietal and occipital areas across a number of frequency bands and also to alter activity across \nfunctional resting state networks including the fronto-parietal, visual and motor networks. \nSecondly, alcohol was found to impair behavioural inhibition in line with previous literature. \nHowever, this effect was smaller than expected and did not extend from the manual response \ndomain to saccadic responses. It was also found that the stop signal task was not exclusively \nmeasuring behavioural inhibition where alcohol also affected action-updating abilities. In the \nsaccadic version of the stop signal task it was found that a saccadic inhibition effect was also \npresent indicating top-down behavioural inhibition is aided by bottom-up automatic inhibition. \nAltogether this body of work provides a basis for future research wishing to investigate the \nrelationship between acute effects of alcohol on GABAergic functioning and impulsivity in \norder to better inform intervention and prevention treatments.
Author: Anne Campbell
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2509496583