Attention to Affective Pictures in Closed Head Injury: Event-Related Brain Potentials and Cardiac Responses

Abstract

We examined whether closed head injury patients show altered patterns of selective attention to stimulus categories that naturally evoke differential responses in healthy people. Self-reported rating and electrophysiological (event-related potentials [ERPs], heart rate [HR]) responses to affective pictures were studied in patients with mild head injury (n = 20; CT/MRI negative), in patients with predominantly frontal brain lesions (n = 12; CT/MRI confirmed), and in healthy controls (n = 20). Affective valence similarly modulated HR and ERP responses in all groups, but group differences occurred that were independent of picture valence. The attenuation of P3-slow wave amplitudes in the mild head injury group indicates a reduction in the engagement of attentional resources to the task. In contrast, the general enhancement of ERP amplitudes at occipital sites in the group with primarily frontal brain injury may reflect disinhibition of input at sensory receptive areas, possibly due to a deficit in top-down modulation performed by anterior control systems.

Support for this research was provided to A.-K. Solbakk by the Research Council of Norway, grant no. 109500/320. The authors are grateful to Søren Jakob Bakke for evaluating the CT and MRI scans of the brain injured participants. We thank Magnus Lindgren for valuable help and advice in the preparation of this article. We also thank Kaisa Hartikainen, Robert T. Knight, and Semir Zeki for helpful comments on this manuscript. We thank two anonymous reviewers for their helpful suggestion on a previous draft of this article.

Notes

Support for this research was provided to A.-K. Solbakk by the Research Council of Norway, grant no. 109500/320. The authors are grateful to Søren Jakob Bakke for evaluating the CT and MRI scans of the brain injured participants. We thank Magnus Lindgren for valuable help and advice in the preparation of this article. We also thank Kaisa Hartikainen, Robert T. Knight, and Semir Zeki for helpful comments on this manuscript. We thank two anonymous reviewers for their helpful suggestion on a previous draft of this article.

Patient no. 4 died before the MRI scans were taken, and the existing CT scans were not available for a detailed specification of lesion location.

Skin conductance responses were also recorded, but the data was excluded due to artifact-contamination of many of the individual recordings.

The numbers of the IAPS pictures used in this study were as follows: Pleasant: 1440, 1460, 1710, 1750, 2070, 2080, 2340, 2530, 2550, 4220, 4250, 4520, 4640, 4650, 4660, 5830, 8030, 8080, 8190, and 8490; Unpleasant: 1040, 1050, 1200, 1220, 1300, 1930, 2800, 3150, 3170, 3230, 6230, 6350, 6550, 6560, 8230, 9000, 9040, 9259, 9330, and 9910; Neutral: 2200, 2210, 5500, 5720, 5800, 6150, 7000, 7010, 7030, 7040, 7050, 7080, 7090, 7100, 7130, 7150, 7170, 7190, 7500, and 7830.

Center for the Study of Emotion and Attention [CSEA-NIMH] (1995). The international affective picture system: [IAPS; photographic slides]. Gainesville, FL: The Center for Research in Psychophysiology, University of Florida