HCI practitioners are increasingly interested in designing interactive technologies to support the body. At the CHI conference, research around health in particular has grown over the past decade. Once consisting of a session or two on health-related papers, it has since become one of the largest dedicated tracks in the conference. That said, few of us in HCI are experts in how the body works as a complex suite of physiological, interacting systems. Understandably so: Such expertise takes years of study in, for example, body-oriented fields like medicine or sports science. It is not a huge stretch, however, to expect that having more expertise about the body's complex systems would enable us to design better tools. For example, a screwdriver can be effective for working on some parts of a car, but if we wish to ensure that the engine under the hood is running well, we need additional, specific tools like timing lights and spark-gap slides. Understanding how to use these tools, of course, is an essential requirement for ensuring the optimal performance of that machine.
Few of us in HCI have the time or resources to devote ourselves to further years of study in medicine or sports performance, though we do wish to create better tools that can improve quality of life for all (or #makeNormalBetter ). We propose inbodied interaction as a frame through which to engage the complexity of the body to make its internal processes accessible to designers. Inbodied interaction is designed to respect the Einstein-attributed requirement to make such explanations "as simple as possible, but not simpler."
All body-based discussions have a particular way of framing the body. In the medical model, the body is framed as the site of disease, and its focus is for interventions to prevent or treat disease (see the article on tuning in this section). Much HCI work in health is based on this illness-centric framing. Another frame, less well known in HCI, is from sports science. Here, the body is the enabler of physical performance, and from that, cognitive performance . Philosophy also has a long history of the body, usually framed within a mind-body dichotomy. Since work such as Paul Dourish's Where the Action Is, embodied interaction researchers, drawing from 20th-century thinkers like Heidegger and Merleau-Ponty, have used this framing to situate the role of the body as a fundamental mediator of social and tangible interaction in making. Here, the body, while fundamental, remains largely a black box, with certain inputs and outputs that respond to contexts. More recently, somaesthetic design, as framed by Kristina Höök and colleagues , privileges the body as the fundamental material and site of design, focusing on sensory-motor experience (as per the somato-sensory cortex). Here, the physical sensations of rest, breathing, movement, and play are crucial design sites. In transhuman contexts, the body is often referred to as meat and meat space, imagining 1) that consciousness can be separated from the body and 2) that in that separation, a consciousness without the body would still be the same person, the body's material being seen as immaterial to the self.
To date, HCI has largely taken and used these various frames for understanding the body as a kind of black box: The body somehow processes certain inputs and delivers certain outputs. The how of that process, internally, has been of less interest. For those in HCI interested in working with the body as a locus for intervention, there is a cost to this limited knowledge of or integration with sciences of the inbodied regarding its complex, interconnected, internal systems and processes. Without such a frame, grounded in and extending from these inbodied systems, the ways in which HCI engages with the body and health can suffer from advancing unintentionally contradictory goals and needs. This lack of deeper familiarity with inbodied sciences is understandable: There is only so much time in the day to develop skills for one domain such as HCI—how are we to meaningfully develop inbodied knowledge too? To address this gap, we propose inbodied interaction as a framing of the body specifically for HCI researchers, to make the inbodied more familiar, to create a map of the territory, and to propose some journeys that will enrich our area's body-focused research.
In the articles that follow, we will show how inbodied interaction both foregrounds and respects the complexity of the body, and provides lenses through which to access that complexity. In particular, while sports science frames the body as the site of performance, and medicine the site of disease, inbodied interaction frames the body as the site of adaptation. Adaptation is the locus of inbodied interaction design. We show in this Special Topic section that this orientation for inbodied adaptation enables HCI practitioners to leverage our skills and methods to create interventions to support measurable, enduring, inbodied "better-ness," from individual to infrastructure—be it better health, quality of life, play, joy, meaning, access to food, other people, skills development, or other life realms.
A key principle is that our fundamental state is nonstop, always-on adaptation: The human body constantly responds and adapts to everything around it and within it, all the time.
A key principle of inbodied interaction is that as physiological, organic living systems, our fundamental state is nonstop, always-on adaptation: The human body constantly responds and adapts to everything around it and within it, all the time. In sports science, one framing of this constant responsiveness is the SAID principle: specific adaptation to imposed demand. In other words, the body is always responding exactly and immediately to what it experiences, physically encoding these experiences with, through, and of course, in, our bodies. Examples of adaptivity include gaining or losing weight, building muscle, learning skills, tanning, and being energized, fatigued, or stressed. Habit formation itself is an adaptation. These experiences can be large and immediate: A traumatic event creates a very rapid and intense adaptation. Adaptations are also developed incrementally with smaller doses over time, like learning an instrument. The intensity and frequency of doses to create adaptations are a subject of research in motor learning, neurophysiology, psychology, and cultural and medical anthropology.
To help design within this adaptation frame, we propose several inbodied lenses, described below. These include: complexity, nonvolitional and volitional processes, efficiency, plasticity, homeostasis and hedonics, balance, and what we call circumbodiedness.
Complex, always on. The foundation of the body's adaptivity is its awesome complexity.
Our complex body is composed of 11 organ systems that are themselves incredibly complex (Figure 1). These 11 organ systems include the enteric (gut), integumentary (skin, hair, fascia, adipose tissue), skeletal, muscular, circulatory (heart/blood flow), reproductive, urinary, respiratory (lungs), lymphatic (clearance/recirculation), nervous, and endocrine (hormones) systems.
|Figure 1. The 11 organ systems of the body.|
A critical fact about these systems that cannot be overemphasized is that they are always on, even in sleep. They are also always interacting with each other in response to their current state, and thus adapting/responding/processing/metabolizing (Figure 2) relative to the inputs they receive. These systems, working together throughout the body, become integrated in the brain, enabling responses such as proprioception, auditory and visual perception, balance, pain, and interoception, to name a few. The state of the body's adaptation affects the accuracy of these responses. For example, fatigue affects balance; stress affects vision; digestion affects emotion and decision making.
Nonvolitional to volitional. In inbodied interaction, we frame these 11 internal, responsive (inbodied) systems collectively as nonvolitional—they work without any conscious engagement. Our heart beats and our gut digests, for example, without our conscious control. Still, our behaviors and experiences do moderate these processes, with physical, social, or other contextual inputs interacting: Receiving good or bad news, for example, may cause our hearts to race (cardiovascular system) and our endorphins to pump (endocrine system), each affecting the rate of digestion (enteric system) in turn.
With inbodied interaction, a goal is to look at how to design interactive systems to help support our nonvolitional, always-on systems to perform optimally across diverse contexts. In the in5 model (discussed in the article on tuning), we show how we can deliberately use five essential volitional processes to support and influence our nonvolitional responses. This relationship between volitional and nonvolitional processes is a key pathway for inbodied interaction adaptivity design.
Efficiency (use it or lose it). Human bodies' adaptations are biased, over the long or short term, toward efficiency. Every cell in the body costs energy to sustain: If we do not demonstrate regularly that we need or use those cells, they are pruned. We can see this efficiency in images of astronauts coming back from spending time in space, shown being carried from their capsules. Their muscles have atrophied: Unused muscle tissue has been shed (Figure 3).
|Figure 3. Astronauts returning from space often have atrophied muscles.|
We counteract such atrophy simply by creating a demand. When we need to move loads in gravity—including our own bodies—our physiology responds by building tissue and movement patterns to support that specific effort. We see this adaptation in the different muscular profiles of athletes in different sports: the cyclist with larger legs and leaner upper body; the marathoner with a very lean but muscular body; the power lifter with a more muscularly massive body (Figure 4).
|Figure 4. Different types of athletes have different muscular profiles.|
In the article on insourcing and measurement, we consider how we can assess and use our efficiency to support positive, inbodied adaptation.
Plasticity. Related to efficiency is the body's plasticity. Plastic materials can be reformed—sometimes repeatedly—to hold a new shape or perform new actions. For example, Matt Stutzman was born without arms; despite this, he currently holds the world record for the longest accurately shot arrow from a bow—which he shot with his feet . Learning to play an instrument demonstrates inbodied systems plasticity: It is a combination of building physical and cognitive skills such as understanding musical structure, transcribing and reading musical data as scores, and translating that intellectual content into physical musical performance. Internally, our inbodied systems, from nervous to muscle tissue, change to support these processes as efficiently as possible. Patterns of muscular activation are developed, refined, stored, and reused; nerves connecting these processes are reinforced.
Every cell in the body costs energy to sustain: If we do not demonstrate regularly that we need or use those cells, they are pruned.
Our bodies are constantly responding to contexts, always adjusting/adapting to those stimuli. The more these pathways are stimulated, the more they are refined and reinforced. Physically, we see this reinforcement in nervous tissue becoming myelinated—a kind of fat-based organic insulation that enables the electrical impulses of a pattern to pass more quickly through its paths (Figure 5). Once myelinated, most of these pathways will remain, even without frequent stimulation, but they will rarely be as efficient or effective without that regular stimulation. Anyone who played an instrument or spoke a second language at one point in life knows the experience of feeling rusty after a period of inactivity; but they may also know that it takes far less time to regain their proficiency having had a solid prior practice than it did to initially acquire the skills for the first time. This experience is what is often referred to as muscle memory in physical practices. Muscle memory is less about the muscles than the nerves from the muscles developing patterns in the brain of how to fire a muscle for efficient execution of a movement. A deep strand of research in both learning and physical development is focused on determining the quantity and quality of repetitions, at sufficient intensity, with sufficient nutrients and recovery, necessary to create and sustain these adaptations. In the article on discomfort design, we explore adaptation experiences for new design opportunities.
|Figure 5. Illustration of the myelination process.|
Homeostatic/hedonic. Our bodies are homeostatic systems. There is a range of values within core physical processes that our bodies need to maintain to be able to function. If one of its systems fall outside those values, the body crashes. Blood sugar, blood pressure, temperature, inflammation, pH, and fluid levels—these are all attributes that have narrow ranges of acceptable values that enable the body to maintain a constant functional internal state, despite external environmental changes. Hence, on hot days, we sweat to maintain our internal temperature; our heart rate and breathing varies to maintain blood pressure to enable blood to circulate. Homeostasis is the key to our resilience: As long as we can maintain homeostasis, we remain alive. Consequently, we can abuse our bodies to an incredible degree, which connects to hedonic signaling. Hedonic signals are reward based. For example, in eating, homeostasis normally controls energy balance. In the presence of food, however, the reward feedback from eating for pleasure can outweigh the homeostatic cue, allowing us to eat beyond what we require to maintain optimal inbodied function. The literature is rich with examples in which, if we are depressed or stressed, we use food as a fast hedonic fix to help us experience something positive in that moment. Our ability to action a hedonic cue is related to the abundance of our environments and, indeed, is likewise an adaptation. Our systematic bias toward efficiency invites us to conserve energy; thus we build contexts that allow us to conserve. We can skip walking if our vehicles can take us from one doorway to another. Designing to balance homeostatic and hedonic signals and its interaction to context is part of tuning and the in5 model.
Balanced/ratioed. Inbodied systems' processes are neither bad nor good. For example, cholesterol, often demonized as "bad cholesterol," is a necessary fat produced by the body and used in all our cells. Optimal inbodied performance reflects a ratio of the three types of cholesterol. That ratio is influenced by the ratios of the types of foods that we eat and the demands upon our body that manifest from context. How we design to support this nuanced approach of balancing external resources (e.g., food) for internal processes (ratios of fat types) is dynamic: A sprinter has different energy requirements from a drummer or a chess player.
Circumbodied is a lens we developed to capture our physiological, essential connection to the environment. Every cell in our body is affected by at least three physical properties of our environment: light, air, and bacteria (more specifically, the microbiome). Our metabolism—the process of inbodied anabolism and catabolism—is fundamentally dependent on the circumbodied. The diversity of the bacteria in our gut affects our capacity to digest food and create nutrients like vitamin K. The air quality affects our ventilation and circulation, and from there has knock-on effects to all the other systems. The quality of darkness during sleep affects our capacity to learn and build new tissue. In this section's article on chronobiological rhythms that result from an interaction of endogenous and exogenous factors, we look at one example of the effect of circumbodied contexts on our adaptations.
Inbodied interaction is proposed as a way to make the essential complexity of our inbodied selves both more apparent and more accessible to the HCI community. It enumerates and foregrounds the interconnectedness of the inbodied's complex, always on, plastic, efficient, circumbodied, nonvolitional homeostatic systems.
Inbodied interaction also frames the body, fundamentally, as the site of adaptation. We propose that this framing enables HCI to engage with the body in new ways. We can ask what specific adaptation(s) we wish to support in our designs. We can align our measures of success and modes of evaluation with the quality of that adaptation. Inbodied interaction also foregrounds the phasic and cyclic nature of our constant adaptations. We can therefore deliberately target where in the temporal cycle of these adaptations we may wish to intervene. The lenses of inbodied interaction can further help us identify nonvolitional and volitional pathway interactions as options for exploring an adaptation. By targeting a specific phase of an adaptation, we have an opportunity to design studies that can evaluate the dynamics of that adaptation in what we call tuning. Our designs can focus on supporting practices that help people explore, initiate, maintain, or change such practices. Fundamentally, inbodied interaction and its associated lenses are navigation tools to help us in HCI engage with the awesome complexity of the inbodied, design new kinds of interventions opened up by this model, and, in turn, help make life better, at scale, for all.
Thank you to Aaron Tabor, Elizabeth Murnane, Ian Smith, Marion Lean, Tom Gayler, Scott Bateman, and Eric Hekler for your contributions to this article. This work is supported by EPRSC Health Resilience Interactive Technologies, GetAMoveOn, ReFresh (EP/T007656/1, EP/K021907/1, EP/N027299/1).
2. schraefel, m.c., #MakeNormalBetter. Interactions 24, 5 (Sept.–Oct. 2017), 24–26; https://doi.org/10.1145/3125393
m.c. schraefel is a professor of computer science and human performance at the University of Southampton, U.K. She also directs the WellthLab, whose vision is to help make normal better for all. The lab's mission is to develop the science, engineering, and design of human-centered, human-systems interaction, from individual to infrastructure, that empowers people to explore, define, build, and own their own healthful cultures. firstname.lastname@example.org
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