It can be hard to fully convey emotion through mere text. Interoffice chats, long-distance texts, and emails occasionally go awry because of misunderstandings about the emotional intent behind a statement. Is that request passive aggressive, or just succinct?

Soon, you might be able to understand how someone far away feels just by reaching out your palm. A group of scientists led by University of Sussex interaction designer Marianna Obrist is testing a system that can stimulate the hand to convey human emotion without any sort of physical contact. In a study using Ultrahaptics, a system that creates tactile sensations in midair using ultrasound, they found that people can recognize different emotional states just from tactile clues on their hands.

To begin the study, researchers showed participants images representing different emotional states, like a nature scene, an image of whitewater rafting, a graveyard, and a car on fire. They asked 10 study subjects to come up with sensations that would communicate those feelings—serenity, happiness, anger, sadness—via the Ultrahaptics machine's ultrasonic waves.

Next, a different group of 10 participants evaluated these “haptic descriptions,” or the touches evoking each feeling, ranking them to determine which sensations invented by the other study subjects fit the stated emotions best. Finally, a third group of 10 people was brought in to try to match the selected haptic descriptions to the appropriate image. 

Overall, the researchers found that this last group was able to successfully match the top-ranked tactile sensations with the images that were supposed to represent those feelings.

Compared to the control image (a clock on the wall), the participants generally matched the correct tactile sensation with the corresponding emotional image. However, they tended to rate touches as equally appropriate for the two high arousal images—represented by white water rafting and a car on fire—indicating that it’s still challenging to distinguish between positive and negative emotions through touch. Yet they were able to distinguish between the different types of emotional arousal of the feelings (whether the feeling intended was calm serenity or excited happiness, for instance) on their hands. And the participants felt very confident that they had read the tactile sensations right. The subjects’ average rating of confidence in their answers was a 5.8 on a scale of one to seven (seven being the most confident).

So what kind of tactile sensations convey certain emotions? “Our findings suggest that for a positive emotion through haptic stimulation one might want to stimulate the area around the thumb, the index finger, and the middle part of the palm,” Obrist and her team write in their paper, presented earlier this week at the CHI 2015 conference on human-computer interaction in Seoul.

On the other hand, to elicit a negative response, it’s better to stimulate the area around the pinky and the outer part of the palm.

Though this initial study was quite small (just 30 people), the research is promising. Similar touch-based systems could eventually be incorporated into wearable technology that would alert you to the emotional states of the people close to you, the researchers write:

Imagine a couple that just had a fight in the morning before going to work. She is sitting in a meeting wearing her bracelet that transmits haptic emotional messages from her partner. When she receives a new stimulus, she pulls out the string from her bracelet and connects it to her ring finger…Her partner created a haptic stimulus using a combination of 16 and 32Hz frequencies with low intensity, so that she realizes he is not angry anymore.

Technology means never having to say you're sorry. Out loud, at least.

[h/t: Eurekalert]