This thesis examines information-processing in chronic pain. "Schematic"
processing is investigated selective memory for pain-related information is explored
in depressed and non-depressed chronic pain patients, depressed non pain-patients and
controls. A memory bias for sensory adjectives is found in the non depressed chronic
pain group, while a tendency to over-recall both sensory and affective compared to
neutral information is found in the depressed chronic pain group. No memory bias
is observed in an acute pain group, and the implications of this are discussed. A
possible cognitive avoidance mechanism is identified in depression.
A questionnaire assessing beliefs about pain ("conceptual" processing) is
developed and validated, and shown to differentiate between chronic pain patients
and controls. The impact of two interventions for chronic pain (surgery and
cognitive-behavioural management) on schematic and conceptual processing is
investigated prospectively. In general the endorsement of organic beliefs decreases
while the emphasis on psychological beliefs increases post-intervention. Evidence is
found to suggest that surgery, but not cognitive-behavioural treatment, reverses pain-related
memory biases. This is discussed in relation to changes in pain intensity.
Evidence is provided to suggest that beliefs are causally related to several pain-related
measures including anxiety, depression, health locus of control, cognitive
coping strategies and activity levels.
A word completion paradigm is employed to explore further the role of schematic
processing in chronic pain, and finally, a lexical decision task is used to assess the
role of word frequency effects in information-processing in chronic pain. These
results suggest that memory biases in chronic pain cannot be explained by frequency
effects, hence addressing the validity of the memory biases described earlier in the
thesis