ERPs

1. Introduction to ERP research.

  • Presentation with content and images from different sources.

2. Design

  • Number of trials: Several factors influence the decision about how many trials are needed, the ERP component to be studied, the number of participants, the length of your session, the expected noise in the signal (due to fatigue, environment etc.), the experimental design (intra-participants, between groups etc).

Some useful articles on the topic:

Boudewyn, M.A., Luck, S. J., Farrens, J. L., and Kappenman, E. S. (2018). How many trials does it take to get a significant ERP effect? It depends. Psychophysiology, 55, e13049. doi:10.1111/psyp.13049.

  • Events: The type of events of interest in psychology are varied and the modality of the event to time-lock our epoch is important in the decision (i.d. a verbal, manual response, cognitive processing of auditory, visual stimuli etc). Also minimizing perceptual differences between events across conditions is important.



3. The lab and data acquisition

  • Protocol using ActiChamp in the lab

EEG_CAPPING_instructions.pdf

  • Cleaning the cap: It is important to carefully clean the cap. The procedure depends on the equipment.

4. Data preprocessing

  • Quantifiying data quality: Once researchers have controlled the conditions to acquired good-quality data (preparing a good design, consider duration to avoid fatigue, light, minimizing electrical noise by using a faraday cage, low impedances etc.) there are many variables that affect the data collected. Which participants should be rejected? Which is a good trial?

Useful article on the topic and materials

Luck, S. J., Stewart, A. X., Simmons, A. M., & Rhemtulla, M. (2020). Standardized Measurement Error: A Universal Measure of Data Quality for Averaged Event-Related Potentials. PsyArXiv. https://doi.org/10.31234/osf.io/dwm64

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