Neural Responses to Consciously and Unconsciously Perceived Emotional Faces: A Spinal fMRI Study

Abstract

Emotional stimuli modulate activity in brain areas related to attention, perception, and movement. Similar increases in neural activity have been detected in the spinal cord, suggesting that this understudied component of the central nervous system is an important part of our emotional responses. To date, previous studies of emotion-dependent spinal cord activity have utilized long presentations of complex emotional scenes. The current study differs from this research by (1) examining whether emotional faces will lead to enhanced spinal cord activity and (2) testing whether these stimuli require conscious perception to influence neural responses. Fifteen healthy undergraduate participants completed six spinal functional magnetic resonance imaging (fMRI) runs in which three one-minute blocks of fearful, angry, or neutral faces were interleaved with 40-s rest periods. In half of the runs, the faces were clearly visible while in the other half, the faces were displayed for only 17 ms. Spinal fMRI consisted of half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences targeting the cervical spinal cord. The results indicated that consciously perceived faces expressing anger elicited significantly more activity than fearful or neutral faces in ventral (motoric) regions of the cervical spinal cord. When stimuli were presented below the threshold of conscious awareness, neutral faces elicited significantly more activity than angry or fearful faces. Together, these data suggest that the emotional modulation of spinal cord activity is most impactful when the stimuli are consciously perceived and imply a potential threat toward the observer.

Lateralized Brainstem and Cervical Spinal Cord Responses to Aversive Sounds: A Spinal fMRI Study

“…The cervical spinal cord data are consistent with earlier studies reporting that negative images elicit greater activity than neutral images in both dorsal and ventral regions of the cervical spinal cord [ 2 , 3 , 44 ]. The fact that aversive auditory stimuli also led to increased spinal cord activity suggests that the emo-motoric responses found in earlier research are part of a general threat-response system rather than being modality-specific.…”

“…Spinal cord fMRI data were preprocessed with the custom-written Matlab scripts ‘spinalfMRI8’ (version 8, P.W. Stroman, Kingston, ON, Canada) [ 40 , 41 ] used in previous studies [ 2 , 3 , 42 , 43 , 44 ]. Slice timing correction and coalignment to correct for bulk motion using a non-linear 3D adjustment was applied.…”

Tingles down the spinal cord: A spinal functional magnetic resonance imaging investigation of the autonomous sensory meridian response

“…The last half of each video was analyzed to ensure the ASMR tingles were occurring. Spinal fMRI data were acquired using a HASTE scanning sequence identical to that used in our previous investigations of the emotional modulation of spinal cord activity (e.g., Wilson et al, 2018): 44 volumes, nine 2 mm slices; TR = 6750 ms; TE = 76 ms; resolution = 1.04 × 1.04 mm; FOV = 200 mm × 100 mm. Data were preprocessed with motion correction, coalignment, spatial normalization, and smoothing in the rostral-caudal direction.…”