Disgust, an emotion related to avoiding harmful substances, has been linked to moral judgments in many behavioral studies. However, the fact that participants report feelings of disgust when thinking about feces and a heinous crime does not necessarily indicate that the same mechanisms mediate these reactions. Humans might instead have separate neural and physiological systems guiding aversive behaviors and judgments across different domains. The present interdisciplinary study used functional magnetic resonance imaging (n = 50) and behavioral assessment to investigate the biological homology of pathogen-related and moral disgust. We provide evidence that pathogen-related and sociomoral acts entrain many common as well as unique brain networks. We also investigated whether morality itself is composed of distinct neural and behavioral subdomains. We provide evidence that, despite their tendency to elicit similar ratings of moral wrongness, incestuous and nonsexual immoral acts entrain dramatically separate, while still overlapping, brain networks. These results (i) provide support for the view that the biological response of disgust is intimately tied to immorality, (ii) demonstrate that there are at least three separate domains of disgust, and (iii) suggest strongly that morality, like disgust, is not a unified psychological or neurological phenomenon.

The traditional philosophical doctrines of Consequentialism, Doing and Allowing, and Double Effect prescribe that moral judgments and decisions should be based on consequences, action (as opposed to inaction), and intention. This study uses functional magnetic resonance imaging to investigate how these three factors affect brain processes associated with moral judgments. We find the following: (1) Moral scenarios involving only a choice between consequences with different amounts of harm elicit activity in similar areas of the brain as analogous non-moral scenarios; (2) Compared to analogous non-moral scenarios, moral scenarios in which action and inaction result in the same amount of harm elicit more activity in areas associated with cognition (such as the dorsolateral prefrontal cortex) and less activity in areas associated with emotion (such as the orbitofrontal cortex and temporal pole); (3) Compared to analogous non-moral scenarios, conflicts between goals of minimizing harm and of refraining from harmful action elicit more activity in areas associated with emotion (orbitofrontal cortex and temporal pole) and less activity in areas associated with cognition (including the angular gyrus and superior frontal gyrus); (4) Compared to moral scenarios involving only unintentional harm, moral scenarios involving intentional harm elicit more activity in areas associated with emotion (orbitofrontal cortex and temporal pole) and less activity in areas associated with cognition (including the angular gyrus and superior frontal gyrus). These findings suggest that different kinds of moral judgment are preferentially supported by distinguishable brain systems.

To demonstrate the capability of computer vision analysis to detect atypical orienting and attention behaviors in toddlers with autism spectrum disorder. One hundered and four toddlers of 16-31 months old (mean = 22) participated in this study. Twenty-two of the toddlers had autism spectrum disorder and 82 had typical development or developmental delay. Toddlers watched video stimuli on a tablet while the built-in camera recorded their head movement. Computer vision analysis measured participants' attention and orienting in response to name calls. Reliability of the computer vision analysis algorithm was tested against a human rater. Differences in behavior were analyzed between the autism spectrum disorder group and the comparison group. Reliability between computer vision analysis and human coding for orienting to name was excellent (intra-class coefficient 0.84, 95% confidence interval 0.67-0.91). Only 8% of toddlers with autism spectrum disorder oriented to name calling on >1 trial, compared to 63% of toddlers in the comparison group (p = 0.002). Mean latency to orient was significantly longer for toddlers with autism spectrum disorder (2.02 vs 1.06 s, p = 0.04). Sensitivity for autism spectrum disorder of atypical orienting was 96% and specificity was 38%. Older toddlers with autism spectrum disorder showed less attention to the videos overall (p = 0.03). Automated coding offers a reliable, quantitative method for detecting atypical social orienting and reduced sustained attention in toddlers with autism spectrum disorder.

The hypocretins (abbreviated “Hcrts”—also called “orexins”) are two neuropeptides secreted exclusively by a small population of neurons in the lateral hypothalamus. These peptides bind to two receptors located throughout the brain in nuclei associated with diverse cognitive and physiological functions. Initially, the brain Hcrt system was found to have a major role in the regulation of sleep/wake transitions. More recent studies indicate Hcrts may play a role in other physiological functions, including food intake, addiction, and stress. Taken together, these studies suggest a general role for Hcrts in mediating arousal, especially when an organism must respond to unexpected stressors and challenges in the environment.