Mind your left: spatial bias in subcortical fear processing.
Hemispheric lateralization of emotional processing has long been suggested, but its underlying neural mechanisms have not yet been defined. In this functional magnetic resonance imaging study, facial expressions were presented to 10 right-handed healthy adult females in an event-related visual half-field presentation paradigm. Differential activations to fearful versus neutral faces were observed in the amygdala, pulvinar, and superior colliculus only for faces presented in the left hemifield. Interestingly, the left hemifield advantage for fear processing was observed in both hemispheres. These results suggest a leftward bias in subcortical fear processing, consistent with the well-documented leftward bias of danger-associated behaviors in animals. The current finding highlights the importance of hemifield advantage in emotional lateralization, which might reflect the combination of hemispheric dominance and asymmetric interhemispheric information transfer.
Siman-Tov
Tali
T
Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
Papo
David
D
Gadoth
Natan
N
Schonberg
Tom
T
Mendelsohn
Avi
A
Perry
Daniella
D
Hendler
Talma
T
D000328:Adult; D000704:Analysis of Variance; D015982:Bias; D001921:Brain / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D005133:Eye Movements / Q000502:physiology; D005149:Facial Expression; D005239:Fear; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult
D010100:Oxygen