Abstract
The present study sought to extend past research on frontal brain asymmetry and individual differences by examining relationships of individual differences in behavioral inhibition/approach system (BIS/BAS) sensitivity with asymmetrical frontal event-related brain responses to startle probes presented during viewing of affective pictures. One hundred and ten participants were shown unpleasant, neutral, and pleasant affective pictures, and presented startle probes during picture presentations. Individual differences in BIS sensitivity related to relatively greater right frontal N100 amplitude to startle probes presented during pleasant and unpleasant pictures, whereas individual differences in BAS sensitivity related to reduced left frontal P300 amplitude to startle probes presented during pleasant pictures. The results of this study suggest that BIS sensitivity is related to greater relative right frontal cortical activity during affective states, while BAS sensitivity is related to greater relative left frontal cortical activity during appetitive states.
Acknowledgements
This research was supported by a grant from the National Science Foundation (BCS 0350435).
We gratefully acknowledge the technical support provided by Ziggy Bialzik. We also thank Meghan Fearn and Lacey Lueck for their help with this research, and Cindy Harmon-Jones and Brandon Schmeichel for their helpful suggestions during the preparation of this manuscript. The experiment was run using DmDX software developed at Monash University and at the University of Arizona by Kenneth J. Forster and Jonathan C. Forster.
Notes
1An additional 28 participants were run but their data were not analyzed, because of equipment problems: 16 were due to failed startle eyeblink collection, 9 were due to failed EEG collection, and 3 were due to no self-report measures.
2IAPS picture numbers: 1050, 1090, 1200, 1300, 2190, 2200, 2240, 2440, 2480, 2500, 2620, 2850, 2880, 3060, 3150, 3400, 3550, 4672, 4608, 4611, 4641, 4653, 4658, 4659, 4670, 5470, 5500, 5621, 5626, 5731, 6230, 7000, 7004, 7006, 7010, 7020, 7031, 7080, 7175, 7270, 7380, 8080, 8170, 8190, 8370, 9250, 9300, 9405, 9500, 9620, and 9630.
3To assess whether gender affected the ERP responses, we conducted regression analyses in which centered BIS/BAS scores, gender, their interaction, and the response to startle probes during neutral pictures were entered as predictors of a given ERP response. The interaction of gender and BIS sensitivity did not predict any ERP responses when controlling for ERP responses to startle probes during neutral pictures.