Both negatively valenced and positively valenced stimuli can increase disinhibition. For example, increased disinhibition is seen in response to stimuli depicting painful situations (71), fear and biological threats (72). Positively valenced stimuli have similar disinhibiting effects (73, 74), that may be stronger than those produced by negative stimuli (75). In an interesting parallel to the literature on stress and disinhibition, it seems that the emotional intensity of the stimuli may be an important factor, because both positive facial expressions and (low intensity) threat images can reduce disinhibition, whilst high intensity threat increase it (76). Given that highly valenced images (both positive and negative) are also highly arousing (77), we can speculate that the relationship between arousal and disinhibition may also be U-shaped, much like the relationship between stress and disinhibition. High and low levels of arousal may interfere with the allocation of attention, creating conflict, and competition between inhibitory and attentional processes (74, 78). However, this is speculative and we highlight the need for further research to clarify the relationships between stress, arousal, and disinhibition.
