Brain Response of Sensitive People to Emotional Pictures

Study aim

This study examined the relationship between brain activity and responses to emotional pictures in adults high in Sensory Processing Sensitivity (SPS) and how this relationship was affected by how these adults were parented.

How the study was conducted

Fourteen women (ages 18-25) looked at positive, negative and neutral pictures while in an brain scanner (fMRI). They also completed the Highly Sensitive Person (HSP) scale, a measure of SPS; a neuroticism (low-grade anxiety and depression) scale; and various scales measuring the type of parenting they remembered receiving in childhood.

Key findings

Reward/Motivation

When they viewed positive pictures, sensitive people, compared to less sensitive ones, had more activation in brain areas responsible for reward and motivation (ventral tegmental area, substantia nigra) among other areas, and this relationship was even stronger for sensitive people with supportive parenting during childhood.

Both the ventral tegmental area and the substantia nigra are major sites of dopamine, the neurochemical associated with motivation and survival drives such as feeding and sex.

This association of SPS with dopamine-rich areas supports the premise that SPS is one of several diverse strategies that may help to promote survival of the species by deeper processing of environmental stimuli and better learning and memorization of associations between stimuli and emotions, so that once a situation has been encountered, the decisions and behaviours made in that moment can be retrieved and repeated in a similar future situation.

Fear and Vigilance

When sensitive people viewed negative images, they had more activation in a brain area responsible for fear and vigilance (amygdala). However, if the sensitive people had a supportive childhood, an emotional regulation area of the brain (dorsolateral prefrontal cortex) was also active along with the amygdala.

Emotional Memory

Whether viewing positive or negative images, the brains of sensitive people were also more active in areas associated with storing emotional memories (entorhinal area/ hippocampus), as well as maintaining a stable internal environment and energy balance in the body (hypothalamus).

The hypothalamus plays an essential role in controlling stress, metabolism, growth, sexual behaviors, immune response, gastrointestinal functioning, breathing, and sleep, among other behaviours.

As part of its stress-control function, it releases cortisol to enhance emotional memory consolidation. The hypothalamus also shows increased connectivity with emotional areas (the amygdala) and memory areas (the hippocampus), in response to emotional stimuli.

These results support behavioural evidence that emotional arousal, in conjunction with memory, may facilitate deep processing of relevant incoming information, one of the main characteristics of sensitivity.

Deeper Processing of Information

Our results also reported that a brain circuit called “the default mode network” was more active in sensitive people when they viewed both positive and negative pictures.

The default mode network of brain areas includes the precuneus, the parietal and temporal regions, and the temporo‒parietal junction (the area where the temporal and parietal lobes meet).

These areas are involved in deep, detailed thinking, language, and using multisensory input to make sense of the present moment and relevant stimuli.

Researchers believe that the default mode network is associated with a basal level of brain activity when the brain is at rest, i.e. not concentrating on a specific task.

Thus, our research suggests that sensitive people process brain input more thoroughly, even when their brains are at rest. No wonder they become more easily overwhelmed than less-sensitive individuals when they need to process more information!

Implications for the public

These results provide support for theories which propose that some individuals are highly sensitive to the effects of their environment.

For example, supportively-parented sensitive people activated emotional regulation areas of the brain, as well as the vigilance/fear area (amygdala) while viewing negative pictures. Such results suggest that supportively-parented sensitive people may have been taught by their parents to regulate the fear and vigilance of the amygdala by using an area of the brain responsible for reflective thinking and self-regulation.

These findings also describe the brain mechanisms by which SPS and environmental conditions (such as the quality of childhood parenting) affect long-term outcomes ‒ namely via circuits that mediate mood (reward), deeper thinking, self-regulation, reflective- thinking, thinking about the self and others, and awareness.

Promisingly, these circuits are the main targets for mindfulness, yoga and meditative practices, thus providing at least one approach that may over-ride the effects of negative experiences and stress. Other techniques include behavioural interventions as shown by at least one study with pre-adolescent females [2], in which, unlike less sensitive girls, highly sensitive girls still benefited one year later from the procedures designed to reduce adolescent depression.