Effect of expectation on pain assessment of lower- and higher-intensity stimuli

Abstract

<jats:title>Abstract</jats:title><jats:sec id="j_j.sjpain.2016.09.013_s_008_w2aab2b8c36b1b7b1aab1c16b1Aa"><jats:title>Background and aims</jats:title><jats:p>Pain modulation via expectation is a well-documented phenomenon. So far it has been shown that expectations about effectiveness of a certain treatment enhance the effectiveness of different analgesics and of drug-free pain treatments. Also, studies demonstrate that people assess same-intensity stimuli differently, depending on the experimentally induced expectations regarding the characteristics of the stimuli. Prolonged effect of expectation on pain perception and possible symmetry in conditions of lower- and higher-intensity stimuli is yet to be studied. Aim of this study is to determine the effect of expectation on the perception of pain experimentally induced by the series of higher- and lower-intensity stimuli.</jats:p></jats:sec><jats:sec id="j_j.sjpain.2016.09.013_s_009_w2aab2b8c36b1b7b1aab1c16b2Aa"><jats:title>Methods</jats:title><jats:p>192 healthy participants were assigned to four experimental groups differing by expectations regarding the intensity of painful stimuli series. Expectations of two groups were congruent with actual stimuli; one group expected and received lower-intensity stimuli and the other expected and received higher-intensity stimuli. Expectations of the remaining two groups were not congruent with actual stimuli; one group expected higher-intensity stimuli, but actually received lower-intensity stimuli while the other group expected lower-intensity stimuli, but in fact received higher-intensity ones. Each group received a series of 24 varied-intensity electrical stimuli rated by the participants on a 30° intensity scale.</jats:p></jats:sec><jats:sec id="j_j.sjpain.2016.09.013_s_010_w2aab2b8c36b1b7b1aab1c16b3Aa"><jats:title>Results</jats:title><jats:p>Expectation manipulation had statistically significant effect on pain intensity assessment. When expecting lower-intensity stimuli, the participants underestimated pain intensity and when expecting higher-intensity stimuli, they overestimated pain intensity. The effect size of expectations upon pain intensity assessment was equal for both lower- and higher-intensity stimuli.</jats:p></jats:sec><jats:sec id="j_j.sjpain.2016.09.013_s_011_w2aab2b8c36b1b7b1aab1c16b4Aa"><jats:title>Conclusion</jats:title><jats:p>The obtained results imply that expectation manipulation can achieve the desired effect of decreasing or increasing both slight and more severe pain for a longer period of time. Manipulation via expectation before the stimuli series was proven to be effective for pain modulation in the entire series of stimuli which lasted around 10 min. The results suggest a potential benefit of manipulating expectations to alleviate emerging pain, since the obtained effects are moderate to large.</jats:p></jats:sec><jats:sec id="j_j.sjpain.2016.09.013_s_012_w2aab2b8c36b1b7b1aab1c16b5Aa"><jats:title>Implications</jats:title><jats:p>It seems that expectation effect is strong enough to “overcome” even the direct effect of stimulus intensity (at least in the low to moderate intensity range), which suggests potential benefits of verbal instructions even in rather painful stimuli.</jats:p></jats:sec>

Effects of Language Context and Cultural Identity on the Pain Experience of Spanish–English Bilinguals

“…Specifically, in prior experimental pain literature, intensity ratings have been associated with the sensorydiscriminative aspect of pain while unpleasantness ratings are used to assess pain's affective-motivational component (Auvray et al, 2010). As anxiety and expectations are both known to influence evaluations of experimentally induced pain (Ružić et al, 2017;Tang & Gibson, 2005), participants also provided anxiety and pain anticipation ratings, though these ratings are not considered in the present analyses. Open-ended verbal descriptions of the pain experience were collected to assess the presence of language-congruent differences in pain coping (Schulz et al, 2013).…”

“…As a key feature of Hispanic culture (Taylor et al, 2012), language usage may meaningfully contribute to pain experiences. Further study could examine how other cultural patterns, e.g., familismo (i.e., placing familial needs ahead of individual needs) or machismo (i.e., masculine aggression and strength) commonly expressed in Hispanic cultures (Ingoldsby, 1991) may influence factors, such as verbal suggestibility or coping strategies, which are known to alter pain responses (Jensen et al, 1991;Ružić et al, 2017).…”

Investigation of the neural basis of expectation-based analgesia in the human brainstem and spinal cord by means of functional magnetic resonance imaging

“…Pain perception is strongly influenced by cognitive factors such as the expected severity or intensity of impending pain, or expected changes in pain ( Villemure and Bushnell, 2002 , Rhudy et al, 2006 , Gollub et al, 2018 , Henderson et al, 2020 ). Expectation effects can also have a strong influence on experimentally-induced pain for research purposes, and on the effectiveness of pain treatments, such as when coupled with an inactive treatment to produce placebo or nocebo effects ( Ružić et al, 2017 , Evers et al, 2018 ). Behavioral studies have demonstrated that expectation of higher pain results in increased pain ratings, and expectation of lower pain results in lower pain ratings ( De Pascalis et al, 2002 , Ružić et al, 2017 ).…”

Biološke osnove placebo-učinka

“…94 Zdravstveni djelatnici mogu modulirati kako specifična očekivanja o efikasnosti lijeka tako šire psihološko sta-kako je samo manipulacija očekivanjima bez ikakvog tretmana učinkovita, primjerice, u smanjenju boli. [95][96][97][98] Posebno je pak zanimljiva i ilustrativna činjenica proizašla iz paradigme prikrivenog davanja lijekova za ublažavanje boli. [99][100][101]73 .…”