So you’ve recorded and cleaned (processed) some ERP data... Now what? If you’re not a programmer, or are new to ERPs, the next step may be a bit daunting, or at the very least, time consuming if done by hand. The erp.easy package provides an intuitive approach to exploring your processed data, without requiring a background in computer programming. The erp.easy package provides three categories of functions, optimized to be easy to use: loading ERP files, plotting ERP data, and analyzing ERP data.
Loading Functions
The function load.data exists to save you the hassle of opening each individual ERP file and adding a header or other identifying information to the files. This function expects data formatted with electrodes across the columns and time points as rows. Additional columns (i.e., "Subject", "Stimulus", and "Time") will be added upon import to help organize your data. The erp.easy package will use existing headers provided in raw data files to refer to electrodes for use in functions, or will assign headers if none are present (see load.data.) Single electrodes can be passed to the package functions, or several electrodes can be provided (i.e., when using dense arrays) and those electrodes will be averaged together as a single electrode. Also see the function easy.load for a user-friendly way to import your data using the erp.easy data import wizard.
See help files/pdf manual for examples
The plotting functions grandaverage, individual, and mosaic provide several ways to visualize both grand average and individual data. Color-coding and labeling happens automatically for ease of use.
Example: grandaverage(ERPdata, electrodes = "V78")
The analysis functions m.measures and p.measures calculate standard ERP measures such as mean amplitude, standard deviation, peak amplitude and peak latency for both grand average and individual waveforms.
Example: m.measures(ERPdata, electrodes = "V78", window = c(1000, 1500))