ERPs to transitions in facial expression: experiment 1
Datasets usually provide raw data for analysis. This raw data often comes in spreadsheet form, but can be any collection of data, on which analysis can be performed.
These are 32 channel EEG raw data files (with blinks removed) recorded from 19 (anonymous) young adult participants. Full details of methods are given in a paper currently accepted for publication in PLoS One, which compares ERPs and recognition scores to dynamic changes in face images of 10 individuals (JAFFE dataset, link below). In Expt. 1, changes in emotional facial expression (angry/neutral or neutral/angry) are compared with changes in magnification (larger/smaller or smaller/larger).
The .cnt files are in Neuroscan Scan 3.3 format. Electrode locations are standard 10/20 locations for the 32 channel quik-cap. Stimulus events coincide with the instantaneous transition between two 500ms duration face images.The event codes are as follows: 46 = neutral-angry; 47 = neutral-magnified; 55 = angry-neutral, 56 = magnified-neutral. Response events are button presses indicating perceived change type: 33 = emotional expression change, 34 = magnification change.
Neuroscan files can be read by open access software such as EEGlab, SPM or Brainstorm (links below) as well as Neuroscan proprietary software.
Rejected data for 1 participant is included in a separate zip file: it was rejected due to an erroneous 1Hz high pass filter setting during data acquisition.
The excel file revised_angryzoom_xls contains paired t-values (group level t-map) for comparison of experimental conditions. Columns represent electrodes and rows time samples (downsampled to 15 ms/sample by spline interpolation). The data corresponds to Fig 3.
The corresponding excel file for experiment 2 contains the formulae to convert t-values into uncorrected p-values and format the data for FDR correction using a spreadsheet available from:
Pike N. Using false discovery rates for multiple comparisons in ecology and evolution. Method Ecol Evol 2010; 2: 278-282.