Metrics of the Mindscape: Arousal
Skin conductance is famous for being one of the biosignals used by lie detectors, aka polygraph, but it is much more than that. Skin conductance activity denotes the states of our central nervous system, in other word its state of arousal. Low arousal means we are in a calm state, most likely a bit slow in reaction time and under performant; Very high arousal means we are over-stimulated and likely shaky and chaotic in our reactions, but somewhere in between, there is a level of optimal arousal, where we are well awake and performant.
The Lie Detector Explanation
I think the lie detector offers a relatable example (let’s be honest, we all lied at least once) for how this biosignal works, while at the same time bringing the spotlight on the importance of experiment design.
The way the lie detector works is the following: skin conductance shows abrupt changes — called skin conductive responses (i.e. SCR; Fig. 1), whenever an unexpected, surprising or intense event happens. These events can be external stimuli (sounds, bright flashes, intense scent) or internal (a shocking idea or an intense emotion).
During the lie detector test, the technician asks questions to the volunteer. There are casual questions and there are questions related to the crime being investigated. If the volunteer is actually the author of the crime, the questions related to the crime in question are likely to trigger a stronger SCR, than the casual questions about his normal daily life. This is because questions about the crime are supposed to elicit strong emotional and cognitive responses as the volunteer is affected by the topic, but also because it triggers a process of deception, which involves lying, maintaining apparent composure and producing a coherent response, all of which require a higher level of arousal.
Therefore, it is not so much the signal that indicates the lies, but rather the experimental design that makes lies noticeable through the biosignal.
Now, there are various factors that can affect an individual’s skin conductance responses and because of that the polygraph is not admitted in court. In theory, the test works, but if an innocent person is genuinely stressed about the interview, it can trigger false positives. In contrast, a psychopath or a sociopath with a high level of detachment is likely to be able to ace the test, simply because creating deception is not as much of a challenge for these.
What does it brings to the Mindscape ?
Arousal emerged as a distinctive biosignal associated with emotions and excitement. It can also indicate that the environment is unpredictive and/or distracting.
The type of experience that are likely to be expressed in the dimension of arousal: fireworks, exciting sporting events, action scenes in movies.
Arousal is sought, whenever people are in the mood for a light-minded and exciting experience.
Arousal vs. engagement
One relationship that has emerged frequently in our data is the anti-correlation between arousal and engagement (Fig. 2).
It appears that whenever people get deeply engaged in an experience, the rate of SCRs decrease. I’m sharing my opinion on what might be an explanation for this effect below, but in the context of the Mindscape, this relationship shows that an exciting experience is generally incoherent with an engaging one. This insight should be considered by experience creators when comes the moment to make a choice as to what is the dominant feeling of various segments of the experience. Further, we are noticing that some personas are more enticed by engaging experiences, while other prefer exciting ones.
We still have a lot left to learn, about the relationship between engagement, arousal, personas and experience satisfaction. For instance, we recently sampled a video game called Overcooked 2. This video game is a chaotic couch party oriented toward cooperation and performance as a team. The game itself was very much appreciated by the play testers and had a high level of engagement, but what surprised us is that both engagement and arousal were increasing during an average level (Fig. 3). This shows that an experience can be exciting and engaging at the same time.
I’m separating this section as I will now express my professional opinion about arousal. Some of the statement I’m about to make are definitely contentious and many scientists are likely to disapprove my interpretation. Still, it is important to consider that the following represents what I believe at the moment and my opinion will certainly evolve as I gather more evidences.
Arousal is often presented as a metric related to emotional intensity and while this is not incorrect per se, I think it is an incomplete description. Arousal do go up, when emotions are expressed, but it also goes up when people are distracted by something, regardless of whether it triggers an emotional response or not.
As far as I’m concerned, I have come to formulate the hypothesis that arousal is an indication that an event, external stimuli or internal thought, has crossed the attentional barrier and reached consciousness, in an unexpected fashion. When people are deeply engaged, their attention is directed and will suppress external and non-pertinent stimuli before they reach consciousness and this is what explains our observation that arousal decreases when people are engaged.
In the specific case of the Overcooked 2 experience. My hypothesis is that the game is so chaotic, that players need to deploy extra attentional resources (increasing engagement) to filter the environment information, but the environment is so chaotic, that the mind can’t filter all events (thus, the increasing arousal).
As science goes, time and more results should help us determine if our model of arousal, in the context of psychophysiology, is defendable.
Interested in this kind of topics, join the Urban Mindscape Initiative: https://www.meetup.com/the-urban-mindscape-initiative/