May 20, 2013 in Neuroscience,
Writing, Thinking,
Simon van
Rysewyk, Science, Research,
Pain, Consciousness,
Mind-Brain
Identity Theory, phenomenal
consciousness, Brain, Type
Identity Theory, Mind, Type-token
Identity Theory, Token
Identity Theory, Clinical Pain,
Chronic Pain
| Tags: writing, neuroscience, brain,
mind, thinking, medicine, simon van rysewyk, science, research, pain, philosophy, consciousness, mind-brain identity theory, clinical pain, chronic pain | Leave a comment
Variations in response to pain have been reported in clinical settings
(e.g., Bates et al. 1996; Cherkin et al. 1994; Jensen et al. 1986; Unruh, 1996;
Wormslev et al. 1994). Patients with similar types and degrees of wounds vary
from showing no pain to showing severe and disabling pain. Many chronic pain
patients show disabling chronic pain despite showing no observable wound. Other
patients show severe wounds but do not show pain. Why is it that two persons
with identical lesions do not show the same pain or no pain at all? Why are all
pain patients unique?
I propose that mind-brain identity theory may offer an answer to
this difficult question. There are two main versions of identity theory: type
and token identity. A sample type identical property is to identify “Being in
pain” (X) with “Being the operation of the nervous-endocrine-immune mechanism”
(Y) (i.e., X iff Y) (Chapman et al. 2008; van Rysewyk, 2013). For any
person in pain the nervous-endocrine-immune mechanism (NEIM) must be active,
and when NEIM is active in a person, he or she is in pain. Thus, type identity
theory strongly limits the pattern of covariation across persons. According to
token identity theory, for a person in mental state X at time t, X is
identical to some neurophysiological state Y. However, in the same
person at time t1, the same mental state X may be identical to a
different neurophysiological state Y2. Token identity theory doesn’t limit the
pattern of covariation across persons; it only claims that, at any given time,
some mind-brain identity must be true.
In response to the topic question, I propose a hybrid version of
identity theory – ‘type-token mind-brain identity theory’. Accordingly, for
every person, there is a type identity between a mental state X and some
neurophysiological state Y. So, when I am in pain, I am in NEIM state Y (and
vice versa), but this NEIM state Y may be quite different across persons.
Type-token identity theory therefore proposes a type identity model at the
level of every person (i.e., it may vary across persons). A type-token identity
theory implies that group-level type identities (i.e., type-type) cannot fully
explain the pattern of covariation in pain responses across persons. Measuring
changes of a pattern of psychological and neurophysiological indicators over
time may then support a unidimensional model of chronic pain for each pain
patient. Thus, being in chronic pain for me is identical with a specific
pattern of NEIM activity (Chapman et al. 2008; van Rysewyk, 2013), but for a
different patient, the same state of pain may be identical to a different
pattern of NEIM activity. In preventing and alleviating chronic pain, it is
therefore essential to best fit the intervention to the type-token pain
identity profile of the patient.
References
Bates, M. S., Edwards, W. T., & Anderson, K. O. (1993).
Ethnocultural influences on variation in chronic pain perception. Pain, 52(1),
101-112.
Chapman, C. R., Tuckett, R. P., & Song, C. W. (2008). Pain and
stress in a systems perspective: reciprocal neural, endocrine, and immune
interactions. Journal of Pain 9: 122-145.
Cherkin, D. C., Deyo, R. A., Wheeler, K., & Ciol, M. A. (1994).
Physician variation in diagnostic testing for low back pain. Who you see is
what you get. Arthritis & Rheumatism, 37(1), 15-22.
Jensen, M. P., Karoly, P., & Braver, S. (1986). The measurement of
clinical pain intensity: a comparison of six methods. Pain, 27(1),
117-126.
Unruh, A. M. (1996). Gender variations in clinical pain experience. Pain,
65(2), 123-167.
van Rysewyk, S. (2013). Pain is Mechanism. Unpublished PhD
Thesis. University of Tasmania.
Wormslev, M., Juul, A. M., Marques, B., Minck, H., Bentzen, L., &
Hansen, T. M. (1994). Clinical examination of pelvic insufficiency during
pregnancy: an evaluation of the interobserver variation, the relation between
clinical signs and pain and the relation between clinical signs and physical
disability. Scandinavian journal of rheumatology, 23(2), 96-102.
