Hamm, JPHa, HyunYoung2018-07-022017https://hdl.handle.net/2292/37371Full text is available to authenticated members of The University of Auckland only.The famous experiment by Benjamin Libet and his colleagues showed that the neural activity called the BereitschaftsPotential (BP), previously described to be movement related, anteceded conscious awareness of intention to move (Libet, Gleason, Wright, & Pearl, 1983). However, it was suggested that conscious veto regulated unconsciously initiated movements. To investigate the presence of the veto, the current study used template matching analysis using cross-correlation to search for manifestations of the veto in the movement-free portions of the electroencephalogram (EEG) data. Simultaneously, to establish whether the BP only occurred with movements, the same technique was used to search for movement-independent occurrences of the BP. A total of 7 participants were recruited for a replication of the Libet’s experiment, where they had to make a keypress whenever they felt like and later report when they felt the urge to do make that movement. The experiment was successfully replicated with participants experiencing conscious intention around -150ms and the BP beginning around -1700ms relative to movement onset. However, there were notable differences in the individual BP waveform, latencies and presence of the early BP. To establish a general idea of the strength of the correlation, the BP and its single-trial event related potentials (ERP)s were correlated. Interestingly, the BP negatively correlated with some ERPs and the correlation values varied substantially. The main template matching analysis showed no significant occurrences of strongly correlating activity. Despite the lack of any significant results from the correlational analysis, overall the results of the current study bring into question the validity of the timing of conscious intent and the early BP as a neural signature of movement preparation. The main analysis was highly dependent on the preliminary analysis. In turn, the results from the preliminary analysis are thought to be heavily influenced by the single-trial variability of the early BP component. It is critical, before we make draw any conclusions about how humans initiates movements, that we clearly establish the validity of the measures that are used in Libet-type studies.Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher.Restricted Item. Available to authenticated members of The University of Auckland.https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htmhttps://creativecommons.org/licenses/by-nc-sa/3.0/nz/ThesisCopyright: The authorQ112933861