Loading wiki pages...

Wiki Version:
<h3><b>Manuscript</b></h3> <p>This project is associated with the following manuscript:</p> <p>Ngiam WXQ, Adam KCS, Quirk C, Vogel EK, Awh E. (submitted). Estimating the statistical power to detect set size effects in contralateral delay activity.</p> <p>A preprint can be downloaded from <a href="https://psyarxiv.com/nbvkc" rel="nofollow">here</a>.</p> <h3><b>Open Data</b></h3> <p>The data used in this project can be accessed at the following repositories:</p> <p>Unsworth et al. (2015): <a href="https://osf.io/qeaet/" rel="nofollow">https://osf.io/qeaet/</a><br> Hakim et al. (2019): <a href="https://osf.io/ws3j9/" rel="nofollow">https://osf.io/ws3j9/</a></p> <h3><b>Abstract</b></h3> <p>The contralateral delay activity (CDA) is an event-related potential component commonly used to examine the online processes of visual working memory. Here, we provide a robust analysis of the statistical power that is needed to achieve reliable and reproducible results with the CDA. Using two very large EEG datasets that examined the contrast between CDA amplitude with set sizes 2 and 6 items (Unsworth et al., 2015) and set sizes 2 and 4 items (Hakim et al., 2019), we present a subsampling analysis that estimates the statistical power achieved with varying numbers of subjects and trials based on the proportion of significant tests in 10,000 iterations. We also generated simulated data using Bayesian multilevel modelling to estimate power beyond the bounds of the original datasets. The number of trials and subjects required depends critically on the effect size. Detecting the presence of the CDA – a reliable difference between contralateral and ipsilateral electrodes during the memory period – required only 30-50 clean trials with a sample of 25 subjects to achieve approximately 80% statistical power. However, for detecting a difference in CDA amplitude between two set sizes, a substantially larger number of trials and subjects was required; approximately 400 clean trials with 25 subjects to achieve 80% power. Thus, to achieve robust tests of how CDA activity differs across conditions, it is essential to be mindful of the estimated effect size. We recommend researchers designing experiments to detect set size differences in the CDA collect substantially more trials per subject.</p>
OSF does not support the use of Internet Explorer. For optimal performance, please switch to another browser.
This website relies on cookies to help provide a better user experience. By clicking Accept or continuing to use the site, you agree. For more information, see our Privacy Policy and information on cookie use.

Start managing your projects on the OSF today.

Free and easy to use, the Open Science Framework supports the entire research lifecycle: planning, execution, reporting, archiving, and discovery.