This thesis reports experiments conducted with human adults and infants, to investigate the neural effects of observing actions towards food. The rationale behind studying neural responses to these actions in particular was to gain a better understanding of one possible mechanism behind social influences on food intake: the putative mirror neuron response. The first chapter (Chapter 1) presents a thorough review of the literature on the human mirror neuron system, with a focus on studies using transcranial magnetic stimulation (TMS). Based on this review, I designed my experiments to address some fundamental aspects of the mirror response that are as yet unclear, namely, the timing, specificity, and direction of the mirror response. My first experiments investigated the muscle activity and kinematics associated with grasp-to-eat and grasp-to-place actions (Chapter 2), and then whether it is possible for an observer to distinguish these actions based on seeing only part of the movement (Chapter 3). The main outcome of these studies was that there are early differences in the execution of these two movements; however, observers are not able to recognise a movement as grasp-to-eat or grasp-to-place based on viewing these differences alone. In the subsequent chapters, I report work using TMS (Chapter 4) and electroencephalography (EEG) in adults (Chapter 5) and infants (Chapter 6), which examined changes in corticospinal excitability and cortical activity during the observation of eating and placing actions. The data arising from my TMS experiment indicated that corticospinal excitability is suppressed in some muscles during action observation, while the EEG experiments indicated that the effects of action observation might be more widespread than the sensorimotor regions classically considered to be 'mirror'. In Chapter 7, I discuss my findings in the context of the wider literature, and consider how the methods, analyses, and practices commonly used to study the human mirror neuron system are perhaps not optimal for addressing the important questions that remain unanswered in the field.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:627641 |
| Date | January 2013 |
| Creators | Naish, Katherine R. |
| Publisher | University of Reading |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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