Pleasant Emotional Feelings Follow One of the Most Basic Psychophysical Laws (Weber's Law) as Most Sensations Do

Emotion episodes may include a conscious aspect of the emotion, namely being aware of our own emotional experience. Despite explosion in research over previous years, it remains unclear how emotions reach awareness and become feelings. Already in 1884, William James argued that emotional feelings resemble ordinary sensations in this respect. Here, using a novel model-based ratio scale of emotion intensity, we provide one of the strongest pieces of evidence supporting James' perceptual theory by showing that emotion awareness obeys one of the most fundamental laws of perception, Weber's law. According to this law, stimulus encoding accuracy decreases with intensity. In this work, we asked participants to provide binary pleasant-versus-unpleasant reports of their experience when watching normed emotion-eliciting pictures (NAPS; Marchewka et al., 2014). The results validate our model's measure of emotion intensity by showing its monotonous relation to picture norms. Most importantly, they show, for the first time, that in humans, pleasant emotion experiences follow Weber's classical psychophysical law-indicating decreased encoding precision with increasing pleasantness. This result supports James' theory, suggesting that (pleasant) emotions reach awareness just as ordinary sensations do.