Recognizing and reacting to emotionally-charged situations are crucial for the evolutionary success of a species. A recent study sheds light on how the brain responds to emotionally charged objects and scenes.
A research team led by Prof. Sonia Bishop from Trinity College Dublin and Samy Abdel-Ghaffar, formerly a Ph.D. student in Prof. Bishop’s lab at UC Berkeley and now a Google researcher, has delved into how the brain processes various categories of emotional stimuli, moving beyond a simple ‘approach avoid’ response when guiding behavioral reactions. The study was funded by the National Institutes of Health in the USA.
Sonia Bishop, now Chair of Psychology at Trinity’s School of Psychology, explains the significance of the study in understanding how the brain manages nuanced responses to emotionally-charged stimuli in various scenarios.
The study examined the brain activity of a small group of volunteers as they viewed over 1,500 images depicting emotional scenes, such as a couple hugging, an injured person in a hospital bed, a luxurious home, and an aggressive dog. Participants categorized the images as positive, negative, or neutral and rated their emotional intensity. Another group of participants selected the behavioral responses that best matched each scene.
The team used advanced modeling techniques on brain activity to reveal that the occipital temporal cortex (OTC) in the back of the brain is finely tuned to represent both the type of stimulus and its emotional characteristics, such as whether it is negative, positive, neutral, high, or low in emotional intensity.
Utilizing machine learning methods, the study found that the OTC efficiently extracts and represents the information needed to guide behavior based on the emotional and categorical features of the stimuli. This approach provided a more detailed understanding of how the brain processes and predicts responses to emotional stimuli.
By analyzing a large dataset of emotional images and conducting functional magnetic resonance imaging with adult human volunteers, the study uncovered how the brain regions specialize in representing semantic categories of stimuli and their affective values, contributing to the selection of suitable behavioral responses to different emotional stimuli.
The findings not only expand our understanding of how the human brain processes emotional information but also offer insights into potential applications in studying neurological and psychiatric conditions related to emotional processing.
More about the study method:
The research team utilized a large dataset of emotional natural images and conducted functional magnetic resonance imaging with adult volunteers to capture brain activity during image viewing. Participants assessed the images based on their emotional valence (positive, negative, neutral) and arousal levels. By modeling this data at a small voxel level, the researchers revealed differential representations in the occipital temporal cortex based on stimulus categories and affective values, highlighting how the brain organizes and processes emotional stimuli to guide behavioral responses.
