Summary: Skin conductance offers a promising new way to measure emotional states, bypassing the limitations of facial recognition. In an experiment, volunteers watched videos evoking fear, humor, and family bonding while their skin’s electrical properties were recorded.
The analysis revealed unique patterns in the speed and duration of conductance changes linked to different emotions, like fear lasting the longest. These findings suggest that combining such signals with other measures could enable emotionally aware technologies, enhancing how devices understand and respond to human feelings.
Key Facts:
- Skin conductance changes within 1-3 seconds of an emotional stimulus.
- Fear responses lasted longer, potentially due to evolutionary advantages.
- Conductance dynamics can statistically predict emotions like fear or bonding.
Source: Tokyo Metropolitan University
Researchers from Tokyo Metropolitan University have used measurements of skin conductance over time to tell emotions apart. Volunteers were shown videos depicting fearful scenes, family bonding, and humor, while their skin conductance trace was recorded.
The team’s analysis showed that traces could be used to make good guesses of which emotions were being felt. Advances like this help break down an over-reliance on facial data, bringing emotionally aware technologies closer to home.
A new frontier is being pioneered in consumer electronics: one day, digital devices might be able to offer services depending on your emotional state. While this sounds amazing, this depends on whether devices can correctly tell what people are feeling.
The most common methods depend on facial expressions: while these have had some success, such data may not always be available. This has led to researchers looking for different biological signals which could be interpreted to access emotional states, like brain wave measurements or cardiograms.
A team of scientists led by Professor Shogo Okamoto from Tokyo Metropolitan University have been using skin conductance as a doorway to human emotions.
When people feel different things, the electrical properties of their skin change drastically due to perspiration, with signals showing up within one to three seconds of the original stimulus.
Previous research has already shown that measurements of peak conductance, for example, can be correlated with certain emotions. In their most recent work, the team focused on the dynamics of the response i.e. how quickly the conductance trace following some stimulus reaches a peak, and how it decays back to normal.
In their experiment, volunteers were asked to wear probes on the skin and watch videos which were either scary scenes from horror movies, emotional scenes of family bonding, or funny acts performed by comedians. Importantly, each of the scenes had well-defined points at which a certain emotional stimulus was sought.
Analyzing the traces, the team found many interesting and significant trends. For example, they found that the response to fear lasted the longest. This may be a biologically evolved trait, since there are benefits to perceptions of danger lasting longer.
Comparing responses to humor and emotional scenes of family bonding, they found responses to family bonding seemed to increase more slowly. The emotions that were evoked were most likely a mixture of sadness and happiness, so it may be that they interfere with each other, leading to a slower change.
Importantly, the team’s statistical analysis revealed that the different numbers extracted from the dynamics of the trace could be used to discriminate the emotional state of an individual.
Though they can’t yet tell the emotions apart perfectly, the data could, for example, be used to make statistically significant predictions of whether a subject was experiencing fear or feeling the warmth of a family bond.
Combined with other signals, the team believe we are one step closer to devices knowing how we are feeling, with scope for a better understanding of human emotions.
Funding: This work was supported in part by an Institutional Research Grant from Tokyo Metropolitan University.
About this neurotech and emotion research news
Author: GO TOTSUKAWA
Source: Tokyo Metropolitan University
Contact: GO TOTSUKAWA – Tokyo Metropolitan University
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Differences in Dynamics of Skin Conductance Responses Caused by Videos Evoking Fear, Family Bonding, and Funniness” by Shogo Okamoto et al. IEEE Access
Abstract
Differences in Dynamics of Skin Conductance Responses Caused by Videos Evoking Fear, Family Bonding, and Funniness
There is a growing demand for techniques to estimate individuals’ subjective experiences based on their physiological signals to provide them with emotionally evocative services.
We investigated differences in the dynamics of the skin conductance response among three types of emotions and whether they are emotion-dependent.
Through a user study involving 33 participants, we analyzed the skin conductance responses that are observed when fear, family bond emotions, and funniness were aroused in video scenes.
The skin conductance response was approximated by using an exponential function model. Subsequently, the parameters that are used to determine the waveform of the skin conductance response were compared for the three types of emotions.
The results showed that the dynamics of the skin conductance response depended on emotions. The response caused by fear decreased more slowly than that caused by family bonding. Those associated with the family bond emotion rise more slowly than those associated with funniness.
These findings can be useful for a more accurate emotion estimation when combined with other physiological signals.
