Live Lecture week 4

Live Lecture: Part 1 - Olfactory Social Neuroscience

Smell loss is inversely associated with color vision emergence, suggesting a trade-off between these sensory abilities. Humans, however, can outperform some animals in olfaction, but a certain level of olfactory strength is needed to be detected by humans.

The olfactory processing pathway involves the olfactory bulb, piriform cortex, and orbitofrontal cortex. The piriform cortex exhibits ensemble coding for odor identification, creating different maps of activity for various smells.

Smell serves functions such as judging edibility, avoiding environmental hazards, and social communication. Olfactory cues can convey identity, sickness, or diseases. Sickness affects attractiveness and liking, as observed in studies injecting individuals with saline or lipopolysaccharide (LPS).

The smell of fear is examined through individuals with a genetic variance related to body odor. The ABCC11 gene mutation results in almost odorless individuals. Fear-induced experiments show increased signs of fear and higher skin conductance responses.

Emotional contagion in receivers indicates the ability to detect fear odor. Chemical analysis reveals consistent molecules in the smell of fear, with hexadecanoic acid identified as a potential biomarker.

Possible neural mechanisms in the smell of fear involve connections between the olfactory bulb, piriform cortex, and amygdala, suggesting learned connections between odors.

Urbach-Wiethe disease (UWD) and smell research explore reactions to innate and learned fear, providing insights into the neural mechanisms of smell.

Part 2: Social Preferences or Emotion - Irrational Rejection of Unfair Offers

Homo economicus, from an economic perspective, focuses on personal gain. However, humans exhibit sensitivity to equity and inequity, willing to punish unfairness at a cost to themselves.

The ultimatum game (UG) and impunity game (IG) are explored, with the latter indicating rejection of unfairness even without punishment. The study aims to test whether emotion predicts rejection in IG and UG, focusing on real proposer/responder behavior.

Hypotheses from social preferences and emotional commitment accounts are tested, analyzing rejection rates, social value orientation, anger, subjective emotion measures, facial EMG, EEG, and frontal negativity ERP.

Results indicate that rejection rates are lower in IG than UG, supporting social preferences. Prosocialness and anger influence rejection more in UG than IG. Facial EMG and ERP data suggest that MFN (medial frontal negativity) predicts rejection in UG, particularly for prosocial individuals.

Conclusion: The data supports the social preferences account, highlighting the role of social value orientation and expectancy in rejection behavior. The study has limitations, including low data for IG analysis and missing SCR data.