Sociocultural & Biobehavioral Influences on Pain Expression and Assessment

Objective

The current proposal investigates behavioral, psychophysiological, and social processes that
may help explain biases and disparate outcomes in pain. Health disparities, or health
outcomes that adversely affect disadvantaged populations, are pervasive and apparent in many
diseases and symptoms, including pain. Pain is the number one reason individuals seek medical
treatment. Health disparities in pain encompass both differences in pain experience and
treatment for pain. For instance, research indicates that Black individuals report increased
pain and have reduced pain tolerance relative to White individuals, yet doctors are less
likely to treat minority patients pain and underestimate their pain experience. This project
aims to address this systemic discrepancy by focusing on interpersonal processes that may
contribute to these disparities, including socially-relevant responses to pain (i.e. pain
expression) and pain assessment (e.g. visual attention). The proposed research aims to
determine whether the study of pain expressions and their assessment can yield insights on
how social factors shape pain and its treatment. Further, we test the efficacy of potential
interventions designed to improve accuracy and reduce biases in pain assessment. If
successful, this work will form the foundation of a new research program that will link the
field of pain research with the field of social neuroscience, and forge new insights on the
critical problem of health disparities in pain.

Study population

We will accrue up to 320 total healthy volunteers to target 257 completers.

Design

Our overall aim is to understand how social factors influence the assessment and management
of pain, and to gain insight into psychosocial processes that may underlie health disparities
in pain. We propose a series of studies designed to test these links. First, we will measure
pain perception and physiological responses to painful stimuli in a diverse group of
individuals to test for sociocultural and biological influences on pain and pain-related
responses. In subsequent studies, new participants ( perceivers ) will view images of these
initial participants ( targets ) and will provide estimates of targets pain experience. We
will measure a) whether perceivers can accurately estimate targets pain experience; b)
whether accuracy and directed attention differ as a function of similarity between target and
perceiver (ingroup vs outgroup) for both healthcare providers and non-medical volunteers; and
c) whether individuals can improve accuracy through feedback and/or instruction.

Outcome measures

Primary outcome measures for all experiments will be decisions about pain (experienced by
self or other) measured with visual analogue scales, reaction time, and/or categorical
judgments (pain/no pain). We will also measure physiological responses (e.g., facial muscle
response, skin conductance, pupil dilation) as secondary outcome measures. We will test
whether pain and pain-related responses varies as a function of sociocultural/demographic
factors (e.g. race, ethnicity, gender) and whether accuracy in assessing others pain is
influenced by group similarity (i.e. ingroup vs. outgroup) and training (e.g. health
practitioners versus na(SqrRoot) ve volunteers; performance-related feedback).

- INCLUSION CRITERIA:

All Sub-Studies:

- Healthy

- Between 18 and 60 years old

- Fluent in English

- Able to provide written informed consent

EXCLUSION CRITERIA:

All Sub-Studies:

- Unable to comply with study procedures

- Has a major-medical condition or medical history that in a clinician's assessment
could affect ability to comply with study procedures, including neurological or
psychiatric conditions (including stroke and blindness or deafness, a history of brain
damage, substance or alcohol dependence or abuse or psychosis)

- Used recreational drugs within the past month

- NCCIH employee or fellow

- NIH employee who is a subordinate/relative/co-worker of any investigator on the
protocol

Sub-study 1:

- NIH employee, fellow, or contractor (including those who are not
subordinates/relatives/co-workers of any investigators)

- Has a major-medical condition or medical history that in a clinician's assessment
could affect heat sensitivity or pain thresholds. This may include cardiovascular,
autonomic, neurological or psychiatric conditions (including stroke and blindness or
deafness, a history of brain damage, substance or alcohol dependence or abuse or
psychosis) or a chronic systemic disease (e.g., diabetes)

- Has a medical condition that in a clinician's assessment might affect somatosensation
(e.g., Raynaud s disease, peripheral neuropathy, or circulatory disorder)

- Has a current chronic pain condition or has had chronic pain in the past (painful
condition lasting more than six months)

- Has a dermatological condition such as scars or burns in the testing region, or has
had a tattoo in the testing region within the previous 4 weeks that might influence
cutaneous sensibility

- Regular use of prescription medication that has a significant effect on pain or heat
perception. Excluded medications include central-acting agents such as opiates
(morphine, tramadol), antidepressants (amitriptyline, duloxetine, milnacipran),
anticonvulsants (gabapentin, pregabalin), anxiolytics (barbituates, benzodiazepines),
hypnotics (zolpidem, sodium oxybate), antipsychotics (valproate, lithium, olanzapine),
antimigraine agents (sumatriptan, ergotamine), and muscle relaxants (cyclobenzaprine,
carisoprodol). Use of analgesic medications, such as non-steroidal
anti-inflammatories, salicylates, and acetaminophen, taken on an "as needed" basis is
acceptable as long as the last dose was not taken was within 5 half-lives of testing.

- Is pregnant

- Is left handed

- Is born outside of the states or territories of the United States of America

- Does not currently reside in a state or territory of the United States of America

Sub-study 2, Medical Providers:

-Use of bi-focal lenses and any uncorrected atypical eye movement or refraction symptoms
(e.g., astigmatism)

Sub-studies 2-3, Healthy Volunteers:

- Use of bi-focal lenses and any uncorrected atypical eye movement or refraction
symptoms (e.g., astigmatism)

- Is born outside of the states or territories of the United States of America

- Does not currently reside in a state or territory of the United States of America