Pain Perception Process - Article Example

The article by Donald D. Price explores the neurological process of pain and pain perception. It defines ‘pain’ and explains it as an ‘unpleasant emotional feeling’. This definition itself puts pain in the arena of psychology as this definition does not have any physiological angle. It further says that pain has two dimensions – affective and sensory. But as he proceeds to explain these terms, it remains in the arena of psychology only as it all revolves around pain as a feeling or emotion.

According to the medical dictionary, pain has both components – emotional and physical (MedicineNet.com). The physical pain is due to the stimulation of nerves. Price also comes to that point later in this article. He tries to explain the intricacies of the brain and the nervous system in relaying the feeling of pain. He calls it a serial interaction. But according to him, the feeling or sensation of pain is the foremost factor. He says that this sensation is ‘more intense than other type of somatic sensations’. He gives certain characteristics of pain as – slow adaptation, temporal summation, spatial spread, spatial summation and unique sensory qualities. This can be understood by the different words used to describe pain like burning sensation or stinging or aching. He reiterates pain as a neural and psychological process.

Then he proceeds to explain the intricacies of both these processes. The effect of pain gets contributions from other sensory processes that may be nociceptive, exteroceptive and interoceptive. He says that there are many ascending pathways to several brainstem and cortical regions. Some of them project directly to the brainstem and limbic system arenas from the spinal cord dorsal horn. Individual neurons many times project in multiple pathways. These pathways relay nociceptive information to somatosensory cortices. Since the cortices are physically linked with the cortico-limbic pathway, it is connected to other somatosensory input like seeing and hearing. This pathway converges with the same structure that is accessed by ascending spinal pathways. Due to this dual convergence, multiple neural sources can contribute to pain perception. According to Cass Barnes, pain is a matter of both mind and body. There is a controversy on this point on how much is it dependent on the mind and how much on the brain. The brain forms the physical or the ‘body’ part of pain whereas the mind forms the psychological part of the pain. The International Association for the Study of Pain defines pain as ‘an unpleasant sensory and emotional experience’. This definition makes pain like any other perception like sight or hearing. Cass explains that pain is processed in the brain and creates the perception of pain.

This is by Price who also explains the processing of pain in the brain in great detail. Cass cites a study done in 1997 where perception of pain was measured by PET scan. The pain was induced in the subjects by putting their hands in ice-cold water. The same was done when the subjects were hypnotized. PET scan results showed less pain in a hypnotized state. The somatosensory cortex was highly activated in the hypnotized subjects that show the perception of pain but the anterior cingulated cortex was less active in hypnotized subjects, showing less aversion to pain. Price also confirms that pain sensation and pain unpleasantness are two different things and the intensity is affected by various psychological factors. He also cites the example of the comparative perception of pain when the subjects are hypnotized. He concludes that some psychological factors have selective influence on pain unpleasantness and some of them can alter pain unpleasantness as there is a change in the pain sensation. Thus psychological factors have a very important role in pain and pain perception.

Then he explains the secondary pain effect. It has a more projected implication that is related to its future implications. The relation between pain unpleasantness and secondary effect is based on the perceived implications of present pain to future problems. He has cited Harkin's assessment of personality traits on pain sensation which is an authentic work cited by many authors and researchers in the field of psychosomatic research. He has concluded from the studies done by Harkins et al that neuroticism does not have so much effect on the pain sensory process as it has on a secondary effect.

Coming to the mind-body theory of pain, Ronald Melzack and Patrick Wall’s research says that pain transmission can be blocked or controlled and may not be allowed to reach the higher centres from where pain perception comes. This may explain the reduced pain perception of hypnotized people. If in a hypnotized state, the ascending and descending pain signals are blocked at the base of the spinal cord, then these signals do not reach the brain and there is no pain perception. But the study shows that the signals are reaching the brain and there is pain perception but there is no aversion or less aversion to pain. This indicated the involvement of psychological factors.

It seems that the points raised and the explanations provided by Price are logical and pain perception has a high level of psychological influence. He has discussed the structure of the brain and spinal cord in great detail to explain the relationship between stimuli and pain perception. This makes it a scientific study of pain perception. It gives minute details of how the signals travel through various neurons in various parts of the brain and how they are processed. These details provide an explanation of primary and secondary pain perception based on neuron networks in the brain.

This is a very strong and concrete explanation of pain perception by Price that analyzes and explains the pain perception process in a very intricate manner and supports it with 29 citations. The citations also cover both old and new publications ranging from 1948 to 1999. This improves the authenticity of the article and makes it an important document in the field of pain perception or psychosomatic studies.