Thalamocortical interactions underlying visual fear conditioning in humans.
Despite a strong focus on the role of the amygdala in fear conditioning, recent works point to a more distributed network supporting fear conditioning. We aimed to elucidate interactions between subcortical and cortical regions in fear conditioning in humans. To do this, we used two fearful faces as conditioned stimuli (CS) and an electrical stimulation at the left hand, paired with one of the CS, as unconditioned stimulus (US). The luminance of the CS was rhythmically modulated leading to "entrainment" of brain oscillations at a predefined modulation frequency. Steady-state responses (SSR) were recorded by MEG. In addition to occipital regions, spectral analysis of SSR revealed increased power during fear conditioning particularly for thalamus and cerebellum contralateral to the upcoming US. Using thalamus and amygdala as seed-regions, directed functional connectivity was calculated to capture the modulation of interactions that underlie fear conditioning. Importantly, this analysis showed that the thalamus drives the fusiform area during fear conditioning, while amygdala captures the more general effect of fearful faces perception. This study confirms ideas from the animal literature, and demonstrates for the first time the central role of the thalamus in fear conditioning in humans.
Center for Mind/Brain Sciences, CIMeC, University of Trento, Italy.
Chrysa
C
Lithari
Departamento De Psicología Básica I, Universidad Complutense De Madrid, Spain.|Center for Biomedical Technology, Laboratory for Cognitive and Computational Neuroscience, Universidad Politecnica De Madrid, Spain.
Stephan
S
Moratti
Center for Mind/Brain Sciences, CIMeC, University of Trento, Italy.
Nathan
N
Weisz
D000328:Adult; D000679:Amygdala / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D003213:Conditioning, Psychological / Q000502:physiology; D004558:Electric Stimulation; D005149:Facial Expression; D000066499:Facial Recognition / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D013788:Thalamus / Q000502:physiology*
fear conditioning; functional connectivity; magnetoencephalography; thalamus; visual steady state