Electrocortical and electrodermal responses covary as a function of emotional arousal: a single-trial analysis.
Electrophysiological studies of human visual perception typically involve averaging across trials distributed over time during an experimental session. Using an oscillatory presentation, in which affective or neutral pictures were presented for 6 s, flickering on and off at a rate of 10 Hz, the present study examined single trials of steady-state visual evoked potentials. Moving window averaging and subsequent Fourier analysis at the stimulation frequency yielded spectral amplitude measures of electrocortical activity. Cronbach's alpha reached values >.79, across electrodes. Single-trial electrocortical activation was significantly related to the size of the skin conductance response recorded during affective picture viewing. These results suggest that individual trials of steady-state potentials may yield reliable indices of electrocortical activity in visual cortex and that amplitude modulation of these indices varies with emotional engagement.
Keil
Andreas
A
NIMH Center for the Study of Emotion & Attention, University of Florida, PO Box 112766, Gainesville, FL 32611, USA. akeil@ufl.edu
Smith
J Carson
JC
Wangelin
Bethany C
BC
Sabatinelli
Dean
D
Bradley
Margaret M
MM
Lang
Peter J
PJ
D000293:Adolescent; D000328:Adult; D001143:Arousal / Q000502:physiology*; D003627:Data Interpretation, Statistical; D004569:Electroencephalography; D004644:Emotions / Q000502:physiology*; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology*; D006801:Humans; D008297:Male; D012044:Regression Analysis