How does emotional arousal modulate population spatial frequency tuning?

Emotional arousal guides cognition and visual perception to improve the detection of threats and opportunities, which can be critical in poor visual conditions. One way emotional arousal can influence vision is by altering spatial frequency (SF) processing, altering the scale of visual detail encoded by the visual system. Previous studies investigating the interaction between emotion and SF processing report an impairment in the processing of higher spatial frequencies (HSFs), while prioritizing lower spatial frequencies (LSFs) under fearful conditions (relative to a baseline or neutral condition). However, there is scant neural evidence supporting these changes in SF perception with emotion. To address this, we leveraged a population spatial frequency tuning mapping (pSFT) approach with fMRI to test how emotionally arousing auditory stimuli (Neutral vs. Negative) modulate SF processing in early visual cortex (V1–V3). If emotional arousal modulates SF processing, we expect negative/fearful stimuli to trigger the prioritization of LSFs at the cost of HSFs, which would be reflected in SF preference-specific changes in pSFT. Indeed, we found that emotional auditory stimuli profoundly altered SF processing: HSF-preferring populations experienced a decrease in preferred SF and increased tuning bandwidth, while LSF-preferring populations experienced an increase in preferred SF and decreased bandwidth. While our physiological markers of arousal reveal greater pupil diameter and skin conductance with Negative sounds vs. Neutral sounds, the observed changes in pSFT were found in both the Neutral and Negative conditions, suggesting that the processing of emotional auditory stimuli differentially impacts SF processing in early visual cortex.