Same 'depressed' body movements, opposite brain responses: KAIST study reveals differences by depressive symptom level

Can changing your posture change your mood?

Previous studies have suggested that body posture and movement can influence emotions. KAIST researchers have extended this line of research by showing that, when people perform the same “depressed” body movements, their brain responses differ depending on the level of their depressive symptoms. The findings are expected to provide a basis for research on which movements or exercises help which people, and on mental health care methods suited to each individual’s condition.

KAIST (President Choongsik Bae) announced on October 19 that a research team led by Professor Young-Gyun Park from the Department of Bio and Brain Engineering used a wireless brain imaging device to measure brain activity while people moved their bodies and identified differences in brain responses according to the level of depressive symptoms.

When people feel sad or exhausted, they may hug their knees, sigh deeply, or let their shoulders droop. These movements express emotions. However, body posture can also influence emotions. One study has reported that people with depressive symptoms may experience more positive emotions and less fatigue when they adopt an upright posture.

Building on previous studies of the relationship between posture and emotion, this study asked whether the brain responds differently to the same movements depending on the level of depressive symptoms. The researchers started from the question of whether brain responses can differ even when outward behavior is the same.

Answering this question requires measuring brain activity while the body is moving. However, functional magnetic resonance imaging (fMRI), a widely used brain imaging method, requires participants to lie still inside a narrow scanner. This makes it difficult to examine brain responses during movements such as hugging the knees or skipping.

The team instead used a wireless functional near-infrared spectroscopy (fNIRS) device worn on the forehead. The device uses light to measure changes in the oxygenation of blood in the brain. Because blood flow and oxygenation change when the brain is active, these measurements provide an indirect indicator of brain activity. Participants can move while wearing the sensor, which allows brain responses to be measured during actual movements.

Fifty-two adults aged 20 to 35 took part in the experiment. Using a depressive symptom questionnaire (PHQ-9) and a mental health screening interview, the researchers divided the participants into a group of 27 with minimal depressive symptoms and a group of 25 with elevated depressive symptoms. The questionnaire asks how often a person has experienced nine symptoms, such as loss of interest and sleep problems, over the past two weeks. The groups were defined by questionnaire-measured symptom levels rather than by a clinical diagnosis of depression.

Participants in each group were randomly assigned to either a negative or a positive emotional movement task. The negative emotional movements were hugging the knees, sighing loudly, and drooping the shoulders. The positive emotional movements were a victory pose, skipping, and laughing while clapping. Participants performed each movement for 30 seconds followed by 60 seconds of rest, and repeated this four times.

The researchers also took into account that, during movement, the sensor might shift and changes in scalp blood flow might mix into the measured signal. For example, a change caused by sensor movement could appear to be a change in brain activity. To address this, the team applied correction procedures that reduce these effects before analyzing brain responses.

The results showed that the two groups had opposite brain responses when they hugged their knees, sighed, or drooped their shoulders. The difference appeared in the left anterior prefrontal cortex, the front part of the brain region located just behind the forehead. Activity in this region increased in the group with minimal depressive symptoms but decreased in the group with elevated depressive symptoms.

This difference in the same region appeared repeatedly across all three distinct movements: hugging the knees, sighing, and drooping the shoulders. In contrast, no common brain activation pattern was observed across the three positive emotional movements.

These results show that the brain may process the same movements differently depending on the level of depressive symptoms. The researchers proposed the left anterior prefrontal cortex, where the difference appeared repeatedly, as an important candidate region for understanding the relationship between body movement and emotion.

The findings suggest that future research on movement- or exercise-based mental health care should take each individual’s condition into account. For example, examining both brain responses and actual mood changes after the same movement could lead to studies that test which movements help people at different levels of depressive symptoms.

The approach can also be used in studies that repeatedly measure responses to specific movements with portable brain imaging devices. It may further be extended to neurofeedback research, in which people practice movements while viewing their own brain responses on a screen.

However, this study did not confirm that any specific movement has a therapeutic effect on depression. An increase in brain activity does not mean that a person’s mood improved, and a decrease does not mean that the person became more depressed. Further research is needed to determine why the two groups responded differently and how these differences relate to actual changes in emotion.

“This study is significant in that it confirmed, through measurements taken during actual movements, that the brain responds differently to the same movements depending on the level of depressive symptoms,” said Professor Park. Professor Park added that the findings could provide a basis for understanding the relationship between body movement and emotion, and for future research on movement-based mental health care tailored to each individual’s condition.

Ratna Aditya Apsari, who earned a master’s degree in the KAIST Program of Brain and Cognitive Engineering, and Somi Lee, who earned a master’s degree in the Department of Bio and Brain Engineering, served as co-first authors, with Professor Park as the corresponding author. The findings were published online on July 31 in Brain Research Bulletin, an international journal in the field of neuroscience.

※ Paper title: Prefrontal responses to negative emotional movements in healthy and symptomatic individuals, DOI: 10.1016/j.brainresbull.2026.112064

This research was supported by National Research Foundation of Korea (NRF) grants funded by the Korean government (MSIT) (Grant Nos. RS-2021-NR061634 and RS-2024-00439379).