conditioning and cancer

Question 1

psychological side effects of cancer treatment

Answer 1

• lack/loss of appetite
• anticipatory nausea & vomiting (ANV)

Question 2

lack/loss of apetite

side effect

Answer 2

• reduced appetite, refusal of food
• particularly to protein rich food e.g. meat

Question 3

anticipatory nausea & vomiting

Answer 3

• nausea occurring during the hrs before scheduled drug infusion
• particularly when in or thinking about infuion setting
• possible sources of gastric distress in cancer patients: tumour growth, radiotherapy, chemotherapy

Question 4

taste aversion learning

Answer 4

• model for reduced appetite in patients
• animal is made ill after consuming a particular food or flavour
• food –> LiCl injection
• animal subsequently avoids that food - aversion developed
• successful in only 1 trial
• conditioning effective despite intervals of several hrs between food & illness

Question 5

smith & roll (1967)

taste aversion learning

Answer 5

• food as CS
• illness as US
• aversion as CR
• bought illness through x-ray
• saccharin as food which shouldn’t make feel ill without x-ray
• as interval increases between saccharin & x-ray, preference increases although this is still lower than control

Question 6

bernstein (1991)

lack/loss of appetite

Answer 6

• could be result of learned aversions to specific foods that were eaten during the period of tumour (or radiotherapy) induced nausea
• most patients learn aversions to numerous tastes, so anorexia appears general

Question 7

midkiff & bernstein (1985)

lack/loss of appetite

Answer 7

• questionnaire results suggest CT induced aversions more likely to high protein, stronger flavours
• less likely to weaker flavours

Question 8

bernstein & borson (1986)

lack/loss of appetite

Answer 8

• ev that rats learn aversion to specific novel foods during
• period of tumour or
• radiotherapy induced nausea

Question 9

rescorla (1968)

lack/loss of appetite

Answer 9

• if CS then only one US = good contingency
• more US cant any longer use CS to see if impact on US = bad contingency, bad learning
• the case in cancer patients as they always feel ill? possobility

Question 10

conditioned taste aversion in people

bovbjerg et al. (1992)

Answer 10

• conditioned taste aversion induced by CT
• informed that this was a study of CT side effects, no mention of taste aversion (reduce demand characteristics)
• experimental group: 150ml lemon-lime drink in distinctive cup before infusion (n=25)
• control group: not offered lemon-lime drink (n=22)
• pre/post questionnaires & home assessment of drink
• taste aversions can be learned whilst they are having their drink
• experimental corr of nausea response in relation to after drink & CT
• -ve corr rating to drink & nausea (like the drink low nausea & vice versa)

Question 11

potential treatments

andressen et al. (1990)

Answer 11

• scapegoat effect
• suggested novel tasting food eaten after “normal” food which precedes CT will acquire strong association to normal food
• given either novel or familiar food consumed 10-15mins before CT session
• novel group: more food increase in liking then decrease
• familiar group: more food decrease in liking then increase
• novel food can protect the dislike for normal food during CT
• using the process of overshadowing

Question 12

ANV

Answer 12

• occurs in 20-40% of CT patients
• more with most emetic drugs
• historically: not helped by anti-emetic meds, improved by more recent drugs

Question 13

garcia & koelling (1966)

nausea conditioned to contextual cues

Answer 13

• lavour & illness easy to learn about
• but flavour & shock or light & illness difficult to learn about
• contextual with illness (light –> illness)

Question 14

hall & symonds (2006) consumption test

Answer 14

• context A: rats made to feel ill
• context B: given saline condition
• how much sucrose consumed in each location?
• less sucrose in A then B
• feel ill so less sucrose - based on where they felt ill

Question 15

retrospective studies

Answer 15

• shown ANV associated with: increasing number of infusions, severity of PNV, younger patients who get strongly emetic drugs
• all consistent with conditioning
• but some effects could be artifacts (see in data but not due to conditioning)

Question 16

bovbjerg (2006)

Answer 16

• significant correlation between the intensity of AN in the clinic prior to their treatment infusion & subsequent past treatment nausea during the 24hr after the infusion
• provide support for the conditioned nausea may contribute to the severity of subsequent post treatment nausea in patients receiving repeated cycles of CT

Question 17

andrkowski et al. (1985)

Answer 17

• if ANV is classically conditioned, predict increased incidence of ANV with: more severe PNV, longer duration of infusion, should result in more successful conditioning, higher pre-infusion state anxiety
• before 1st CT infusion: Speilberger trait anxiety inventory (STAI)
• before 2nd: EPI
• before each infusion: rated PNV severity after last infusion, anxiety now & over past 24hrs, physical symptoms
• 37% showed ANV
• no association with type of drug, technique, diagnosis
• all who showed PNV also reported ANV
• without ANV: post-treatment nausea low, low length of infusion
• with ANV: post-treatment nausea high, high length of infusion
• PNV does sig predict ANV, +ve corr
• length of infusion does predict ANV, +ve corr

Question 18

kvale & hugdahl (1994)

Answer 18

• if ANV is classically conditioned, then it should co-vary with ind diffs known to affect classical conditioning
• ANV & autonomic conditionability
• looked at heart rate (HR) conditioning - like nausea this is controlled by parasympathetic ANS
• 2 CSs, 6s tones (1200 & 2000 Hz. US = 1s white noise burst)
• RTs to noise US - ANV group faster than n-ANV group
• ANV group show diff conditionability to CS
• ANV have change (increase) in HR but n-ANV don’t really show any change
• but could be due to noise being presented rather than the association that is being shown

Question 19

latent inhibition as a treatment

klosterhalfen et al. (2005)

Answer 19

• motion-induced sickness using body rotation procedure
• different groups: no pre-exposure before rotation, 1 pre-exposure day before rotation, 3 pre-exposure before rotation
• test day: sat on chair but didn’t rotate, fill out the questionnaire
• no pre-exposure: sickness rating highest, female show sig higher than males
• 1 & 3 pre-exposure statistically the same

Question 20

using overshadowing for potential treatments

Answer 20

• omidi et al. (2023)
• overshadowing using flavoured sweet
• no reduction in nausea severity
• children as ppts/patients in CT
• dont know if sweets were novel or familiar

Question 21

types of treatment that have been reported

carey & burish (1988); morrow & dobkin (1988)

Answer 21

• hypnosis to minimise PNV
• relaxation & guided imagery during infusion
• systematic desensitisation
• video game play during infusion
• seems to disrupt the association whilst having the treatment