Negative emotional stimulation decreases respiratory sensory gating in healthy humans

We tested the hypothesis that negative emotions decrease the respiratory-related evoked potentials (RREP) sensory gating (RSG). RREP were elicited by paired inspiratory occlusions. RSG was calculated as the difference in the averaged RREP peak N1 amplitude between the second (S2) and the first occlusion (S1). RSG was compared between unpleasant and neutral emotional conditions elicited by viewing affective pictures from the IAPS system in thirteen healthy adults. Results are expressed as median [min; max]. Compared to neutral pictures, viewing unpleasant pictures decreased the RREP N1(S1) amplitude (-3.37 μV [-4.62; -1.37] versus -4.59 μV [-6.08; -1.36]; p=0.017) but not the RREP N1(S2) amplitude (-0.26 [-3.24; 2.36] versus -0.7 [-1.54; 3.6]; p = 0.68), and reduced the difference score S2-S1 (3.73 μV [0; 5.82] versus 4.79 μV [3; 6.2]; p = 0.038). We concluded that a negative emotional stimulation could attract subject's attention to the detriment of the respiratory sensory inputs and produced an overall decrease in the RSG. This latter finding might participate in an over-perception of repeatedly presented respiratory stimuli.