Symptoms Provide a Window into the Intuitive Mind: New Insights from Fatigue Research

I wrote previously about my colleague Dr. Mustafa Ozkaynak's study of fatigue among emergency-room nurses, which showed how fatigue impairs decision-making, especially at the level of the Narrative Mind. In a new paper that we published from the same dataset, Dr. Ozkaynak's team examined psychometric properties of the Swedish Occupational Fatigue Inventory (SOFI). We found that the emergency-room nurses' experience of fatigue was a good fit with what people have reported in other occupational contexts, with 4 different aspects of fatigue: (a) lack of motivation, (b) physical discomfort, (c) sleepiness, and (d) an overall "lack of energy" scale that both encompasses the other 3 elements of fatigue and also has some unique items associated only with lack of energy. We tested whether 2 additional items from another tool, which are generally understood to measure (e) mental fatigue, would be a meaningful addition to the SOFI, but in this case they were not -- either the nurses didn't experience their fatigue in that way, or else the mental fatigue concept is subsumed into the overall concept of lack of energy. Similarly, another subscale from the original SOFI, measuring (f) physical exertion, did not add meaningfully to the measurement of fatigue among ED nurses.

Our new article has technical utility for other researchers who want to measure nurses' occupational fatigue, which is its primary value for the literature. But looking at which measures did and didn't characterize nurses' fatigue also tells us something about the way our participants experienced the feeling of fatigue, and that experiential dimension has implications for Two Minds Theory. When people talk about "energy," they also mean things like motivation, sleepiness, and bodily discomfort. The fact that "energy" served as an umbrella term is interesting, because it seems to have both physical and mental dimensions. The fact that adding "mental fatigue" or "physical exertion" to the mix didn't help to characterize nurses' fatigue means that they see "energy" as a sufficient concept to describe these experiences as well. But if we hear the word "energy" and think it means physical energy only, we are likely to miss the important mental components of what nurses mean by this term -- and our other research with this group shows that they do have mental changes with fatigue that could potentially impact the quality of their work! 

In a third analysis from the same dataset, this team found that various dimensions of the SOFI probably capture unique aspects of nurses' fatigue experience. For example, nurses reported the most change in physical discomfort, sleepiness, and lack of energy from the start to the end of their shift, with lack of energy showing the greatest amount of increase as they worked. Those changes were most pronounced for nurses working the evening shift, with overnight second, and day shift reporting some but less dramatic increases in fatigue as they worked. (The evening shift is probably hardest because it goes most strongly against circadian rhythms -- the body and mind are attempting to power down for the night right at the time when work is the most intense. Overnight there's a general level of tiredness but not the same transition effect). Although lack of energy and sleepiness were important aspects of fatigue for both men and women, male nurses reported greater increases in the lack of motivation dimension of fatigue during their shift, while female nurses reported more change in physical discomfort, an aspect of fatigue that men were more likely to minimize. Again, we see how people's subjective experiences can vary even within a concept like "fatigue" that might initially seem straightforward.

What does all of this have to do with Two Minds Theory? Symptom studies of this type are useful because they help us gain access to someone's inner world. A symptom is, by definition, a subjective or phenomenological experience -- something that we can only know about because someone tells us what they are feeling. Symptoms include phenomena like fatigue, pain, mood, cognitive slowness, or the feeling of craving for an addictive substance. (Note that these are different from "signs" like sleep, which are objectively measurable physical processes or behaviors). Symptoms are Intuitive-Mind experiences at their core, arising spontaneously in the course of daily life. When we paste a Narrative-Mind label on them, like "fatigue," we might think that everyone means the same thing by that label. But subtle differences in the dimensions of people's experience might be obscured, like the greater motivational changes reported by men versus the greater physical discomfort reported by women after a long shift in the emergency department. 

The largest compilation of validated symptom measures is PROMIS (NIH's patient-reported outcome measurement information system). The Symptom Interpretation Model (developed by former CU faculty member Dr. Paula Meek among others) describes some common ways in which symptoms are experienced by patients: in terms of their frequency, their severity, and their level of interference with daily activities. People then interpret their symptoms' potential meaning -- e.g., "should I do something about this symptom? How urgently? What might happen if I don't? How might it be treated if I do? Can I manage it on my own, or do I need a doctor? Many symptoms such as fatigue are seen as normal daily experiences that might not require any special management, although even in the case of our ED nurse participants, people are likely to have their own preferred ways to decompress after a tiring day of work. Finally, the Symptom Interpretation Model suggests that people put a label on their experiences, such as "fatigue." This is the Narrative-Mind stage of the process, and it's where some of the rich detail of people's symptom experiences can be obscured.

To get beyond the initial label and gain a better understanding of what's really going on at the level of the Intuitive Mind, here are some questions about symptoms that might help:

• Timing - when did this symptom start? Has it changed over time (e.g., gotten better or worse)?
• Triggers - is this symptom better or worse in some specific situations?
• Treatment - what helps when you have this symptom? or what makes it worse?
• Severity - how strong is this symptom (e.g., on a scale from 0 to 10)? When was it worst? When was it least severe? Has it ever been a 10, and if so, what was happening then? Since it started, has it ever been completely absent (a level of 0), and if so, what was happening then? 
• Frequency - how often do you have this symptom? Is it ongoing, or intermittent? If ongoing, are there some times when it is worse than others or better than others?
• Interference - to what extent does this symptom interfere with your work? With your home or family life? With your social life or recreation? With other aspects of your life? 
• Distress - how upset or concerned are you about this symptom? What does it mean to you?
• Plans - what do you plan to do about this symptom, if anything? How satisfied are you with that plan? What else have you considered?

Understanding symptoms in depth can help to predict their effect on health outcomes or behavior, in a way that a simple Narrative-Mind label like "fatigue" doesn't permit.