Stimuli that resemble humans, but are not perfectly human-like, are disliked compared to distinctly human and nonhuman stimuli. Accounts of this “Uncanny Valley” effect often focus on how changes in human resemblance can evoke different emotional responses. We present an alternate account based on the novel hypothesis that the Uncanny Valley is not directly related to ‘human-likeness’ per se, but instead reflects a more general form of stimulus devaluation that occurs when inhibition is triggered to resolve conflict between competing (...) stimulus-related representations. We consider existing support for this inhibitory-devaluation hypothesis and further assess its feasibility through tests of two corresponding predictions that arise from the link between conflict-resolving inhibition and aversive response: 1) that the pronounced disliking of Uncanny-type stimuli will occur for any image that strongly activates multiple competing stimulus representations, even in the absence of any human-likeness, and 2) that the negative peak of an ‘Uncanny Valley’ should occur at the point of greatest stimulus-related conflict and not (in the presence of human-likeness) always closer to the ‘human’ end of a perceptual continuum. We measured affective responses to a set of line drawings representing nonhuman animal-animal morphs, in which each continuum midpoint was a bistable image (Exp. 1), as well as to sets of human-robot and human-animal computer-generated morphs (Exp. 2). Affective trends depicting classic Uncanny Valley functions occurred for all continua, including the nonhuman stimuli. Images at continua midpoints elicited significantly more negative affect than images at endpoints, even when the continua included a human endpoint. This illustrates the feasibility of the inhibitory-devaluation hypothesis and the need for further research into the possibility that the strong dislike of Uncanny-type stimuli reflects the negative affective consequences of cognitive inhibition. (shrink)

This commentary focuses on the stimulus-reinforcer hypothesis of resistance to change. The overall context of reinforcement can account for resistance to extinction. There are ways to systematically test the hypothesis that Pavlovian contingencies account for the behavioral “mass” of discriminated operant behavior.

The Component Process Model posits that attention is appraisal-driven rather than stimulus-driven and that the appraisal of relevance is of critical importance in such a mechanism. This means that any stimulus can attract attention or not depending on how relevant it is appraised. This hypothesis was tested in an implicit border similarity judgement task, in which thirsty participants were presented with bottles and vases that were respectively very relevant and weakly relevant to their goal to quench their thirst. (...) These stimuli were also presented to quenched participants for whom none of the stimuli was relevant. The findings support the idea that our attention is more likely to be appraisal-driven than stimulus-driven, since bottles produced an attentional interference in thirsty participants only. It was also observed that, even if vases were judged weakly relevant by thirsty participants, they produced an attentional interference compared to empty stimuli, which was not the case in the quenched participants group. The concept of goal relatedness was proposed as an explanation for this result, and methodological implications were also discussed. (shrink)