Health Psychology 2007, Vol. 26, No. 2, 165–173
Copyright 2007 by the American Psychological Association 0278-6133/07/$12.00 DOI: 10.1037/0278-6133.26.2.165
Does Priming a Specific Illness Schema Result in an Attentional Information-Processing Bias for Specific Illnesses? Caroline J. Henderson
Martin S. Hagger
University of Essex
University of Nottingham
Sheina Orbell University of Essex Objective: To test a hypothesis derived from H. Leventhal, D. Meyer, and D. Nerenz’s (1980) commonsense model that people possess implicit schemas for specific illnesses. Design: A 2 (illness vs. neutral shopping prime) ⫻ 2 (illness-related vs. control word) mixed design with repeated measures on the second factor. Participants primed for the common cold (Experiment 1) and cardiovascular disease (Experiment 2) were compared with participants receiving a neutral shopping prime on a modified Stroop color naming task. Main Outcome Measures: Attentional bias to illness related words was calculated as the difference between response latencies to illness words and neutral words under the prime conditions. Results: In Experiment 1, participants primed with common cold showed a response bias to words related to the common cold but not to words related to cardiovascular disease. Attentional bias among participants primed for common cold was significantly correlated with explicit illness representations assessed by the Revised Illness Perception Questionnaire. Experiment 2 replicated the findings in a different illness domain. Conclusion: Illness-specific illness schemas can be activated. Keywords: illness representations, illness perceptions, attentional bias, self-regulation theory
Leventhal, Meyer, and Nerenz (1980) proposed the common sense model (CSM) of illness representations to understand the processes by which people make sense of illnesses. The model hypothesizes that people form commonsense or lay representations when confronted with illness-related information that constitutes a threat to health. If an individual’s representation of the illness is interpreted as being sufficiently threatening, it is expected that he or she will adopt a coping strategy or procedure to manage the threat. Tests of the model across a range of chronic illnesses have provided some support for the CSM, particularly for the dimensional structure and content of illness representations (Hagger & Orbell, 2005; Heijmans & de Ridder, 1998) and for relations between illness representations with coping procedures and illness outcomes (Hagger & Orbell, 2003). The present research concerns a further aspect of illness representations, namely their schematic organization, and activation of specific illness schemas.
of that illness as a critical first step prior to the mobilization of coping resources to manage the health threat. Leventhal et al. defined illness representations as patients’ own implicit commonsense beliefs about their illnesses: “These belief structures may be implicit rather than explicit . . . the cognitive structures comprising the representation may be nonverbal perceptual memories that are difficult (or impossible) to represent verbally” (p. 17). The representation is viewed as a schema that is formed, activated, and modified in response to stimulus information about the illness. This information may be symptoms, lay information such as prior knowledge, and expert information from sources like general practitioners. Illness representations are typically considered to be multidimensional, comprising five main components: identity, perceived consequences, timeline, perceived cause, and cure or control (Hagger & Orbell, 2003). Identity includes the label and symptoms of the illness, such as a sore throat and cough in the case of a common cold. Consequences are beliefs about the level of impact the illness will have on everyday life or normal functioning. Timeline is the individual’s representation of the length of time the illness is expected to last. Cause is the biological, emotional, environmental, or psychological cause to which the illness is attributed. Cure or control is the perceived ability to cure or control the illness, especially by using certain coping strategies such as taking medication or resting. Recent extensions of the model have expanded the original dimensions to include acute or chronic and cyclical dimensions of timeline; two control subcomponents, treatment control and personal control; and two additional measures—illness coherence, which reflects the perceived clarity of understanding of the illness, and emotional representa-
The CSM Leventhal et al. (1980) viewed the process by which information about an illness leads to the formation of a cognitive representation Caroline J. Henderson and Sheina Orbell, Department of Psychology, University of Essex, Colchester, United Kingdom; Martin S. Hagger, School of Psychology, University of Nottingham, Nottingham, United Kingdom. We thank Kate Crawford, Sarah Croucher, and Sarah McLachlan for their help with data collection. Correspondence concerning this article should be addressed to Caroline J. Henderson, Department of Psychology, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom. E-mail:
[email protected] 165
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tions, which reflects distress and anger responses to the illness (Moss-Morris et al., 2002).
Illness Schemas and Illness Representations The CSM was originally proposed as a model of illness danger; that is, at the moment of illness threat, the representation will be borne out of symptoms and lay knowledge, which would be schematic in nature and located subconsciously as an illness prototype (Bishop & Converse, 1986). Leventhal et al. (1980) stated that illness representations contain both abstract and concrete information about an illness, allowing them to be accessed implicitly. The difference between the abstract and concrete levels is that the abstract reflects a general frame of reference, whereas the concrete reflects a comprehensive lay theory of that illness. Therefore, illness representations may include general information common to all illnesses as well as illness-specific information for particular illnesses. Given that sufficient specific information may be represented in an individual’s illness schemas for particular illnesses, it may be possible to activate such specific schemas, given sufficient specific information about that illness, without activating schemas for other illnesses. An implicit awareness of health information would suggest that there is an implicit understanding of the illness that would be activated when specific illness-related stimuli are presented. In addition, sufferers of a specific illness and those familiar with that illness, such as caregivers, would be expected to hold more concrete and elaborate schemas or representations of that illness compared with non-illness-sufferers and would thus have greater implicit knowledge of such illnesses. There is some evidence to support the proposition that a general illness representation or schema can be activated implicitly. Williams, Wasserman, and Lotto (2003) demonstrated that participants who rated themselves as having low levels of general health would show response latencies to illness-related words on a modified Stroop color-naming task. Participants’ general illness schema was activated by asking them to write about their last illness episode. Participants who gave a poorer rating of their general health showed greater color-naming latencies on the Stroop task for illness versus nonillness words. Moss-Morris and Petrie (2003) also examined whether current illness sufferers demonstrated a processing bias. Patients with chronic fatigue syndrome (CFS) and control participants were presented with a Stroop task containing somatic words and words relating to depression. There was no evidence that patients were more attentive to CFS-related words than to neutral words. However, additional analyses revealed that CFS patients were more likely to interpret ambiguous words in a health-related manner than were the control participants. In summary, Williams et al.’s (2003) findings suggest that it is possible to activate a general illness schema that results in an attentional bias to information about illnesses. There is also some evidence from Moss-Morris and Petrie (2003) to suggest that individuals who are currently experiencing an illness show heightened attention to illness-related information. However, to date, these studies have not directly investigated the possibility that individuals possess schemas with sufficient specific information to be activated in isolation and independent from schemas for other illnesses. Because Williams et al. demonstrated that a general illness schema can be activated using an illness activation task, we expected that it would be possible to activate a specific illness schema.
The Present Study The current study investigated whether individuals possess specific illness-related schemas for common illnesses. We expected that this would be indicated by an attentional informationprocessing bias to illness stimuli related to those schemas. We aimed to extend Williams et al.’s (2003) research by presenting participants with an illness activation task to prime a specific illness schema to test whether this activation results in an implicit response bias to information regarding that specific illness. We hypothesized that participants primed for a specific illness would exhibit an attentional information-processing bias for illnessrelated words specific to the primed illness but not for words related to illnesses that were not primed (Hypothesis 1). In addition, we expected that the information-processing bias demonstrated by participants primed for that specific illness would be associated with an explicit illness representation of the same illness (Hypothesis 2). This was tested by examining the relationship between an index representing the response bias and an explicit psychometric measure of illness representations for the primed illness.
Experiment 1 Method Participants. Participants were 88 undergraduate students (men ⫽ 27, women ⫽ 61; mean age ⫽ 22.0 years, SD ⫽ 4.62) who volunteered to participate in the experiment. The participants were native English language speakers and gained course credits for their participation. Participants were randomly assigned to either the experimental or control condition. Materials. The modified Stroop (1935) color-naming task was controlled by computer and presented on a 14-in. color monitor. Ten common cold-related words, 10 cardiovascular disease-related words, and 10 neutral words were each presented in three colors: blue, green, and red (see the Appendix). The word lists were all matched for frequency and length through use of the CELEX database (Baayen, Piepenbrock, & van Rijn, 1993). Each word was presented in capital letters 8 mm high on the screen and was presented until the participant responded (Munafo & Stevenson, 2003). A 160-ms interstimulus interval was used and is considered the most appropriate interval for a good effect with the least number of errors (Sharma & McKenna, 2001). Latency in color naming was recorded via the participant pushing red, blue, and green colored buttons on a keyboard. Response latency was measured in milliseconds from the presentation of the stimulus to the response. The number of correct responses was also collected. Stimulus words. The cardiovascular disease-related words were taken from Erblich, Montgomery, Valdimarsdottir, Cloitre, and Bovbjerg (2003), and their frequencies were certified through use of the CELEX database (Baayen et al., 1993). The common cold-related words were selected from a pilot study in which 127 undergraduate psychology students were asked to write down all single symptom or non-symptom words they could think of relating to the common cold. This generated a list of 433 words. Many words were discarded from this list as they were not single words (e.g., “runny nose”) or they were not specifically associated with the common cold (e.g., “hospital”). Of the remaining words, the 20 most frequently occurring were then rated by an independent sample of 20 undergraduate students as to how strongly the words were associated with the common cold on 4-point rating scales (e.g., “I think this word is very strongly associated with the common cold and no other illnesses or conditions”). The 10 words rated as most strongly associated with the common cold on this scale were then used in the experiment, and the frequencies of these
SPECIFICITY OF ILLNESS SCHEMAS words in the English language were verified through use of the CELEX database. A list of neutral words that matched the common cold words for frequency and length was also taken from the CELEX database. To ascertain that the three word lists were matched for frequency and length, we performed two one-way analyses of variance (ANOVAs) with the word lists (common cold-related, cardiovascular disease-related, and neutral words) as the independent variable and number of letters per word (word length) and word frequency serving as the dependent variables in each of the respective analyses. No significant differences were found between the word lists for word length or frequency. Procedure. Participants were shown into a testing booth in which there was a computer with blue, green, and red colored keys. The researcher asked them to complete a standard consent form and then explained the upcoming task. The researcher placed the questionnaire and the priming task sheet facedown on the desk next to the computer. The participant was told that after the researcher left the room, the participant was to turn over the top sheet of paper (printed with either the experimental or control prime) and complete the question; the participant could take as long on this task as he or she wished. The experimental prime instructed participants to write a short narrative about their most recent common cold, whereas the control prime required participants to write a short narrative about their most recent shopping experience. For the experimental prime, participants were presented with the following text: Please write a short narrative about your most recent common cold experience. Please think about how it felt to have the cold and what you did when you had the cold. You can be as descriptive and explanatory as you like. Participants assigned to the control condition received a control prime to maintain cognitive load prior to the Stroop task, which was identical to the experimental prime save that the word shopping was substituted for the word cold. The text read: Please write a short narrative about your most recent shopping experience. Please think about how it felt to go shopping and what you did when you were shopping. You can be as descriptive and explanatory as you like. Participants’ narratives were examined by the experimenter at the end of the experiment to ensure that participants had engaged in the task specified as required for the priming manipulation. No participants’ data were excluded on the basis of the inspection of the narratives. After completion of the priming task, participants were instructed to press a button on the computer to begin the modified Stroop task. At the end of the Stroop task, the final screen prompted them to complete a brief distraction task. The distraction task required participants to draw a map of the University campus on a blank sheet of paper. The purpose of the distraction task was to minimize the effect of the prime on responses to the questionnaire. Finally, participants were asked to complete a questionnaire comprising study measures, which was facedown on the desk next to the priming task sheet. Measures. The questionnaire was made up of a demographic section, which also contained questions relating to participants’ experiences with cardiovascular disease, and the Revised Illness Perception Questionnaire (IPQ-R; Moss-Morris et al., 2002) adapted for the common cold.1 Participants were asked to indicate whether they were currently suffering from a common cold, whether they were currently suffering or had ever suffered from cardiovascular disease, and whether any close relatives or friends had suffered from cardiovascular disease. If participants indicated that they or a friend or relative had suffered from this illness, they were asked to disclose the timescale of the illness, to judge how recently it had affected them or how serious it was, and if applicable, their relationship with the person, to ascertain the extent to which the illness sufferer was a close relative or friend. Data from 9 participants were excluded on the basis of family history; none were excluded because of personal history, as might be expected in a sample of this age. Participants
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could not be screened for a personal or family history of cardiovascular disease prior to recruitment to the study, because this would have made them aware of the nature of the study. No participants were excluded on the basis of currently suffering from a common cold. The IPQ-R was used to measure participants’ explicit illness representations of the common cold. The IPQ-R is a standardized psychometric measure of illness representations that has demonstrated adequate validity and reliability for a number of illnesses (Hagger & Orbell, 2005; MossMorris et al., 2002). The IPQ-R was modified according to standardized instructions to refer to the common cold (Moss-Morris et al., 2002), and participants were asked to complete this with respect to their most recent experience with the common cold by recalling how they feel when they do have a cold. The nine subscales of the IPQ-R include Identity, Timeline Acute/Chronic (␣ ⫽ .83), Timeline Cyclical (␣ ⫽ .79), Consequences (␣ ⫽ .76), Personal Control (␣ ⫽ .88), Treatment Control (␣ ⫽ .70), Illness Coherence (␣ ⫽ .92), Emotional Representations (␣ ⫽ .87), and Cause. With the exception of Identity and Cause, all illness representation dimensions were scored on 5-point scales with endpoints strongly disagree and strongly agree. Illness identity was measured by the sum of the number of symptoms the participant experienced. Participants were also asked to rate 18 possible causes of a common cold and list the three most important causes. The most frequent causes named were a germ or virus (28%), stress or worry (14%), lowered or altered immunity (12%), and bad weather (7%). These four causes were adopted as single-item measures of illness cause in subsequent analyses.
Results Preliminary analyses. Response latency times to each word on the modified Stroop color-naming task were transformed with a natural logarithmic function because the reaction times were not normally distributed (Tabachnick & Fidell, 2001). The attentional bias dependent variable was a relative measure calculated as the mean difference between the response latencies for the illness-related words and those for the neutral words (i.e., neutral word mean latency subtracted from the illness word mean latency) for each participant. Few errors were recorded overall, and no significant differences were found in the number of errors made for the word list or prime condition (3.8% of responses were errors). Means and standard deviations of the attentional bias scores are given in Table 1. Word type and prime analysis. A 2 ⫻ 2 mixed-model ANOVA (Prime Condition ⫻ Attentional Bias for each word list) with repeated measures on the second factor revealed a significant main effect of the prime, F(1, 86) ⫽ 7.70, p ⬍ .05, 2p ⫽ .08. More important, we also obtained the hypothesized significant interaction between the prime and attentional bias for cold-related words, F(1, 86) ⫽ 4.66, p ⬍ .05, 2p ⫽ .05. Univariate post hoc simple-effects analyses indicated that participants receiving the common cold prime incurred a response bias, F(1, 86) ⫽ 10.50, p ⬍ .05, 2p ⫽ .11, for common cold-related words (mean response bias ⫽ 26.10, SD ⫽ 77.34) but not for cardiovascular diseaserelated words (mean response bias ⫽ 15.05, SD ⫽ 58.26). IPQ-R and attentional bias. Our second hypothesis related to the association between color-naming latency and explicit illness representations. There were no significant differences in the IPQ-R illness representation mean scores for the common cold across the 1 The versions of the IPQ-R adapted for the common cold and cardiovascular disease used in the present investigation are available from Caroline J. Henderson on request.
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Table 1 Descriptive Statistics of Attentional Bias for Common Cold-Related and Cardiovascular DiseaseRelated Words and IPQ-R Measures of Illness Representations: Experiment 1 Common cold prime
Control prime
Measure
M
SD
M
SD
Attentional bias for common cold-related words Attentional bias for CVD-related words Identity Timeline Chronic/Acute Consequences Personal Control Treatment Control Illness Coherence Timeline Cyclical Emotional Representations
26.10 15.05 6.80 2.05 2.06 3.41 3.37 3.37 2.74 2.20
77.34 58.26 2.50 0.71 0.60 0.66 0.75 1.15 0.65 0.60
⫺26.64 ⫺2.27 6.85 2.18 2.15 3.35 3.31 3.55 2.64 2.28
90.13 73.75 2.80 0.54 0.70 0.66 0.68 0.00 0.79 0.74
Note. Attentional bias statistics are expressed as differences between response times in milliseconds for common cold-related words and neutral words. IPQ-R ⫽ Revised Illness Perception Questionnaire; CVD ⫽ cardiovascular disease.
primed and control groups (see Table 1), suggesting that the primes themselves did not affect responses to the questionnaire. To test our hypothesis, we computed correlations between each of the illness representations and the measure of attentional bias (see Table 2). There were significant positive correlations between the attentional bias measure for common cold-related words and the Consequences (r ⫽ .382, p ⬍ .05) and Emotional Representations (r ⫽ .317, p ⬍ .05) scales for participants in the experimental prime condition but not the control condition.
Discussion Results of Experiment 1 suggest that participants show attentional bias to specific illness-related words compared with other illness words and neutral words when primed for that illness. Support for this
Table 2 Correlations Between Attentional Bias for Common ColdRelated Words and Measures of Illness Representations: Experiment 1 Illness representation
Common cold prime
Control prime
Identity Timeline Chronic/Acute Consequences Personal Control Treatment Control Illness Coherence Timeline Cyclical Emotional Representations Cause: Germ or virus Cause: Stress or worry Cause: Lowered or altered immunity Cause: Bad weather
⫺.033 ⫺.119 .382* ⫺.163 ⫺.219 ⫺.100 ⫺.186 .317* ⫺.167 .037 .004 ⫺.067
.023 ⫺.115 ⫺.047 ⫺.000 .071 .086 ⫺.013 ⫺.193 .250 .097 ⫺.116 ⫺.212
Note. Positive correlations indicate high scores on the attentional bias measure; that is, the greater the delay, the higher the level for that illness representation. The cause components were scored according to whether the cause was present (1 ⫽ yes) or absent (0 ⫽ no) in the participant’s list of causes. * p ⬍ .05.
effect is provided by the significant interaction between the attentional bias measure for common cold-related words and the prime condition. These results support Hypothesis 1 in that participants primed for a specific illness exhibited an attentional information-processing bias for illness-related words specific to the primed illness but not to illness-related words unrelated to the prime.2 According to the CSM, these results suggest the presentation of information about a specific illness activates the relevant illness schema and interferes with information processing when subsequent information relating to the activated illness is presented. It extends the research conducted by Williams et al. (2003) by indicating that the priming of an illness representation can be confined to a specific illness and does not generalize to schemas for other illnesses. Participants primed for the common cold did not exhibit any attentional bias when presented with words relating
2 To rule out a possible alternative interpretation of these findings, namely that the effects of the cold prime on subsequent color-naming latency were due simply to a semantic field effect, we conducted a supplementary study in which participants were primed by either the common cold or shopping. Color-naming latencies were examined in a modified Stroop color-naming task containing shopping words and common cold-related words. The dependent measure of attentional bias was the same as that for Experiments 1 and 2, calculated as the difference between the target words and neutral words (i.e., neutral words mean latency subtracted from the common cold-related words mean latency, and neutral words mean latency subtracted from the shopping-related words mean latency). A 2 ⫻ 2 mixed model ANOVA (Prime Condition ⫻ Attentional Bias for each word list) with repeated measures on the second factor revealed a significant interaction between the prime and attentional bias for common cold-related words, F(1, 35) ⫽ 5.00, p ⬍ . 05, 2p ⫽ . 13. Univariate post hoc simple-effects analyses indicated that participants receiving the common cold prime incurred a response bias, t(15) ⫽ 2.505, p ⬍ . 05, for common cold-related words (mean response bias ⫽ 34.83, SD ⫽ 140.21) but not for shopping-related words (mean response bias ⫽ ⫺13.62, SD ⫽ 36.26). When participants received the shopping prime, no significant effects were found for shopping-related words. These findings lend support to our contention that the present findings are evidence of a schema activation effect rather than the mere activation of a semantic field.
SPECIFICITY OF ILLNESS SCHEMAS
to another illness, namely cardiovascular disease. In addition, the Consequences and Emotional Representations dimensions from the IPQ-R were significantly correlated with the attentional bias scores for common cold words in the experimental prime condition but not in the control condition. Of importance, there were no significant differences in the reported levels of the illness representation dimensions from the IPQ-R across both groups. This supports Hypothesis 2 and provides some evidence that the attentional bias resulting from the experimental prime corresponds with explicit stored knowledge relating to that illness. The results suggest that it is possible to activate a specific illness schema for a common illness and that the attentional bias that activation produces is related to some aspects of explicit knowledge that the person holds about that illness. However, we hypothesized that additional corroborating evidence might be provided by priming another illness, perhaps one with which the participants have no direct experience, to establish whether the same specific attentional bias effect could be replicated.
Experiment 2 We conducted this experiment to replicate the findings of Experiment 1 using a similar experimental protocol. In Experiment 2, we primed a cardiovascular disease schema to demonstrate that this would result in attentional bias to cardiovascular diseaserelated but not common cold-related words. We hypothesized that participants presented with the cardiovascular disease prime would exhibit an attentional information-processing bias for cardiovascular disease-related words but not for the nonprimed illness, namely the common cold (Hypothesis 1). In addition, we expected that the degree of attentional information-processing bias exhibited by participants primed for cardiovascular disease would be associated with their explicit representations of the illness from the modified IPQ-R.
Method Participants. Seventy-one undergraduate students (men ⫽ 35, women ⫽ 36; mean age ⫽ 22.13 years, SD ⫽ 4.27) volunteered to participate in the experiment. All were native English language speakers and gained course credits for participation. Participants were randomly assigned to either the experimental or control condition. Of importance, participants were required to have had no direct experience with cardiovascular disease. This was to eliminate the possibility that prior experience may have been responsible for the attentional bias and not the schema activation as indicated in previous research (Erblich et al., 2003). Data from 6 participants were excluded on the basis of family history; none were excluded because of personal history, as might be expected in a sample with a mean age of 22 years. Participants could not be screened for a personal or family history of cardiovascular disease prior to recruitment as this would have made them aware of the nature of the study. No participants were excluded on the basis of currently suffering from a common cold. Materials. The modified Stroop color-naming task and stimulus words used were identical to those in Experiment 1. Procedure. The procedure was identical to that of Experiment 1, except the content of the experimental prime was for cardiovascular disease rather than the common cold. Given that it was assumed that participants had no direct experience with cardiovascular disease, the experimental prime presented a hypothetical scenario rather than a prompt about their most recent illness experience. Participants in the experimental
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group were initially presented with a definition of cardiovascular disease (World Health Organization, 2004). The prime comprised the following statement: Imagine you have just been diagnosed with cardiovascular disease (heart disease). Please write a short narrative about what you think you might encounter, and what your experiences would be. Please think about how it might feel to have cardiovascular disease (heart disease) and what you would do when you knew you had the illness. You can be as descriptive and explanatory as you like. This was designed to correspond closely with the common cold prime from Experiment 1 but also to induce thoughts as to how the participant would deal with the illness. The control prime referring to a control experience (shopping) was identical to that used in Experiment 1. Again, participants’ narratives were examined to ensure that they had engaged in the priming task. No participants’ data were excluded on the basis of inspection of the narratives. Measures. The demographic section of the questionnaire and questions regarding experiences with the common cold and cardiovascular disease were identical to those in Experiment 1, and the same definition for cardiovascular disease that was used in the experimental prime was given. The IPQ-R (Moss-Morris et al., 2002) was adapted for cardiovascular disease to measure the explicit illness representations as if the participant had just been diagnosed with cardiovascular disease (see Footnote 1). Heijmans, de Ridder, and Bensing (1999) used the IPQ-R for a similar purpose with caregivers of patients with chronic illness, providing evidence that this measure can be used in a hypothetical context. The Symptom scale probed participants’ beliefs about whether each symptom was related to cardiovascular disease. The remaining IPQ-R dimensions were identical to those listed in the procedure for Experiment 1 but reworded for cardiovascular disease: Timeline Acute/Chronic (␣ ⫽ .66), Timeline Cyclical (␣ ⫽ .73), Consequences (␣ ⫽ .74), Personal Control (␣ ⫽ .69), Treatment Control (␣ ⫽ .71), Illness Coherence (␣ ⫽ .92), and Emotional Representations (␣ ⫽ .75). A number of causes were listed as the three most important causes of cardiovascular disease. The four most frequently listed causes were diet (15%), smoking (14%), heredity (13%), and stress (10%). These single-item, dichotomous measures were used as measures of the Cause dimension.
Results Preliminary analyses. As in Experiment 1, prior to analysis, response latency times to each word on the modified Stroop color-naming task were transformed with a natural logarithmic function (Tabachnick & Fidell, 2001). The calculations for the relative measure for attentional bias were the same as those in Experiment 1 (i.e., neutral words mean latency subtracted from illness words mean latency). Means and standard deviations for the response bias scores are given in Table 3. There were no significant differences in the number of errors made across word lists, and few errors were made overall (2.6%). Word type and prime analysis. A 2 ⫻ 2 mixed-model ANOVA (Prime Condition ⫻ Attentional Bias for each word list) with repeated measures on the second factor revealed a significant main effect of the prime, F(1, 69) ⫽ 4.29, p ⫽ .05, 2p ⫽ .06, and a significant main effect of word type, F(1, 69) ⫽ 5.85, p ⬍ .05, 2p ⫽ .08. Of importance, we also obtained the hypothesized significant interaction between the prime condition and attentional bias for the illness related words, F(1, 69) ⫽ 7.79, p ⬍ .05, 2p ⫽ .10. Univariate post hoc simple-effects analyses indicated that participants receiving the cardiovascular disease prime incurred a response bias, F(1, 69) ⫽ 6.75, p ⬍ .05, 2p ⫽ .09, for cardiovas-
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Table 3 Descriptive Statistics of Attentional Bias for Cardiovascular Disease-Related and Common ColdRelated Words and IPQ-R Measures of Illness Representations: Experiment 2 CVD prime
Control prime
Measure
M
SD
M
SD
Attentional bias for CVD-related words Attentional bias for common cold-related words Identity Timeline Chronic/Acute Consequences Personal Control Treatment Control Illness Coherence Timeline Cyclical Emotional Representations
89.76 1.06 7.69 3.90 3.69 3.60 3.22 3.10 3.26 3.86
207.59 49.21 1.95 0.76 0.60 0.77 0.59 0.91 0.65 0.72
3.34 0.92 6.63 3.59 3.46 3.79 3.67 3.10 3.17 3.47
55.68 54.69 2.03 0.66 0.66 0.70 0.50 0.87 0.52 0.66
Note. Attentional bias statistics are expressed as differences between response times in milliseconds for common cold-related words and neutral words. IPQ-R ⫽ Revised Illness Perception Questionnaire; CVD ⫽ cardiovascular disease.
cular disease-related words (mean response bias ⫽ 89.76, SD ⫽ 207.59) but not for common cold-related words (mean response bias ⫽ 1.06, SD ⫽ 49.21). IPQ-R and attentional bias. Table 3 shows means and standard deviations for the IPQ-R illness representation dimensions. Univariate tests for the IPQ-R measures of illness representations showed that there were no significant differences across the primed and control groups in the cardiovascular disease illness representation scores, confirming that the experimental condition per se did not influence IPQ-R scores. Correlations between the IPQ-R dimensions and attentional bias were computed to test our second hypothesis (see Table 4). In the primed group, significant positive correlations were found between the attentional bias meaTable 4 Correlations Between Attentional Bias for Cardiovascular Disease-Related Words and Measures of Illness Representations: Experiment 2 Illness representation
Cardiovascular disease prime
Control prime
Identity Timeline Chronic/Acute Consequences Personal Control Treatment Control Illness Coherence Timeline Cyclical Emotional Representations Cause: Diet Cause: Smoking Cause: Heredity Cause: Stress
⫺.136 ⫺.443** .508** ⫺.791** ⫺.697** ⫺.646** ⫺.138 .459** ⫺.566** .322 ⫺.157 .253
.221 ⫺.180 .162 .235 .294 .087 ⫺.184 .363* .121 ⫺.053 .265 .218
Note. Positive correlations indicate high scores on the attentional bias measure; that is, the greater the delay, the higher the level for that illness representation. The cause components were scored according to whether the cause was present (1 ⫽ yes) or absent (0 ⫽ no) in the participant’s list of causes. * p ⬍ .05. ** p ⬍ .01.
sure for cardiovascular disease-related words and the Consequences and Emotional Representations dimensions. Significant negative correlations were also observed between attentional bias and Timeline Chronic/Acute, Personal Control, Treatment Control, Illness Coherence, and Perceived Cause: Diet.
Discussion Results of Experiment 2 suggest that participants exhibited an attentional information-processing bias to specific illness-related words compared with other illness words and control words when primed for that specific illness. This effect is illustrated by the significant Attentional Bias ⫻ Prime interaction. These results support Hypothesis 1, that cardiovascular disease-primed participants’ response latencies were significantly slower in response to primed illness-related words relative to response latencies for unrelated illness words and those for participants receiving a control prime. There is also evidence that whereas participants in the experimental prime and control groups exhibited no significant differences in their reporting of illness representations of cardiovascular disease on any IPQ-R construct, participants in the experimental prime group exhibited significant correlations between the attentional bias to cardiovascular disease-related words and the IPQ-R constructs, with the exception of the Timeline Cyclical and Identity dimensions. These results support Hypothesis 2, that the attentional bias produced by the activation of a specific illness schema is strongly associated with the explicit stored information regarding the primed illness.
General Discussion A key hypothesis of Leventhal et al.’s (1980) CSM is that when an individual is presented with information about an illness, a schema reflecting a lay representation of that illness is activated automatically. The present study examined whether priming an illness schema resulted in a specific attentional bias to information regarding the primed illness but not other illnesses (Hypothesis 1).
SPECIFICITY OF ILLNESS SCHEMAS
In addition, the present study also investigated whether the attentional bias measure for the primed illness was significantly related to explicit measures of the illness representations (Hypothesis 2). Findings from two experiments revealed that participants primed for a specific illness displayed greater attentional bias in color naming for illness-related words relating to the primed illness than to other illness-related words in a modified Stroop task. In addition, although there were no differences in reporting the illness representations for either illness across both primed and nonprimed groups, attentional bias to specific illness-related stimuli was related to two of the illness representation constructs in Experiment 1 and almost all illness representation constructs in Experiment 2. The purpose of this study was to explore one of the key hypotheses of the CSM and elaborate on the findings of Williams et al. (2003). The CSM suggests that an individual processes the available information about an illness and that this assists in the formation and modification of a commonsense representation of that illness. Traditionally, the CSM has been studied through the use of explicit measures of illness representations (e.g., IPQ-R) and has focused on the relationship between these representations and coping procedures and illness outcomes (Hagger & Orbell, 2003). However, few studies have given an appreciation of the processes involved in the formation and activation of these illness representations when information relating to that illness, in whatever form, is made available or salient. Results from the present study provide some preliminary evidence that the representation of knowledge regarding an illness can be activated in individuals if information regarding the illness is made salient and that the activation of that knowledge structure or schema results in a specific attentional bias to the subsequent implicit presentation of information about that illness. Of importance, this effect was illustrated for two illnesses, one acute and one chronic, and showed that knowledge about each illness could be primed. In addition, the resulting bias was significantly related to the explicit information an individual had about the illness. Once activated, individuals respond to implicit illness stimuli in line with their explicit illness representations, whereas when the specific illness is not activated, responses are unrelated to their explicit knowledge structure surrounding the illness. The present study also corroborates and extends the findings of Williams et al.’s (2003) study on the activation of health-related schemas. Williams et al. showed that priming a recent illness experience results in a subsequent attentional bias to illness-related words, which was attributed to the activation of generalized healthrelated schemas. The present study demonstrated that if the prime contains information of sufficient specificity regarding an illness, a specific attentional bias to information relating to that illness can occur. This was further supported by the relationship of the specific information-processing bias exhibited by the individual to the explicit knowledge or illness representation he or she possesses regarding that illness. Furthermore, it is important to highlight that neither the primed group nor the nonprimed group exhibited any differences in the levels of explicit knowledge to either illness, suggesting that tacit knowledge of an illness is isolated from the activated schema. In speculation, it may be that specificity in the activation of the schema may depend on the information made available in the prime as well as previous experience with the
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illness. One interesting aspect of the present study is that the illnesses featured in the study varied in terms of their severity and the level of experience that participants had with the illnesses. However, present findings illustrate that the illness schema could be activated for both types of illnesses and that the associated attentional bias was significantly related to explicit information the individuals possessed regarding the illnesses. Thus, the evidence from both experiments suggests that it may be possible for any individual to possess a schema specific to an illness, regardless of his or her level of personal experience and the illness chronicity. However, it is important to note that both illnesses were those for which people are likely to have a reasonable level of knowledge. It is unlikely that such a schema would exist for a relatively unknown illness unless the individual had professional knowledge about the illness or personal experience as a sufferer or knowing someone with the illness. Although both experiments demonstrated a similar pattern of results, there was some variation in the number of explicit illness representation dimensions from the IPQ-R that were correlated with the attentional bias measure across the experiments. Specifically, only two of the IPQ-R constructs—Consequences and Emotional Representations— exhibited significant correlations with the attentional bias measure in Experiment 1. However, all but two of the dimensions were related to the attentional bias measure in Experiment 2. These differences cannot be attributed to different levels of internal reliability in IPQ-R measures attenuating the size of correlations. It seems that the attentional information-processing bias for the common cold reflects only the consequences— cognitive and emotional— of that illness, probably because the effects of the illness on personal and emotional resources are the representations of actual consequences for this illness, as it is generally a given that it is controllable, coherent, and with shortlived symptoms. Of interest, the correlations for the attentional bias scores and the Consequences and Emotional Representations constructs were significant and positive in both experiments. Therefore, a high degree of attentional bias is associated with perceptions that the illness has serious cognitive and emotional consequences. However, the correlations between the Timeline Chronic/Acute, Timeline Cyclical, Personal Control, Treatment Control, Illness Coherence, and the Perceived Cause: Diet dimensions from the IPQ-R and the attentional bias scores in Experiment 2 were negative. Therefore, viewing the illness as uncontrollable, acute, incoherent, and unrelated to diet is associated with higher bias as well. The fact that these correlations show that attentional bias is greatest among people whose cognitive representations suggest that they view the illness as threatening is consistent with the idea that these IPQ-R dimensions mainly reflect anxiety or concern regarding the illness rather than anything more specific. It may be that both the attentional bias incurred as a result of the prime and the illness representations measured by the IPQ-R are mediated by anxiety. This is consistent with the pattern of associations between the IPQ-R dimensions and emotional outcomes reported in Hagger and Orbell’s (2003) meta-analysis. The present data cannot unequivocally rule out the notion that the relationship between the attentional bias from the Stroop task and cognitive representations from the IPQ-R in the present experiments could be explained as an anxiety or concern response.
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However, findings from Erblich et al.’s (2003) study have shown that color-naming latencies from Stroop tasks using cancer-related words among people with family histories of cancer are not mediated by perceived risk or elevated distress. Furthermore, MossMorris and Petrie (2003) showed no heightened attention to depression-related words among illness sufferers compared with attention to neutral words. In summary, although these data show that the attentional bias measure, an implicit measure of illness threat, corresponds to an explicit measure of that threat as suggested by Leventhal et al.’s (1980) model, present results cannot explicitly rule out the possibility that the link between the implicit bias incurred by priming an illness schema and the cognitive representations reflects a pattern of threat or concern regarding the illness. This may explain the more robust relationships between attentional bias and consequences and emotional representation in Experiment 2 compared with Experiment 1, as all participants had experienced a common cold; thus, there could be little variation in the data and clear knowledge that the threat of impact on everyday life was small and for a rather short period of time. Future studies may administer the IPQ-R for both the primed and nonprimed illnesses. This would rule out the alternative hypothesis that the attentional bias found in this study was related to explicit measures of consequences and emotional representations for the primed and nonprimed illnesses. In addition, we provide evidence to eliminate the alternative hypothesis that the attentional biases found in the present study were merely the result of the priming of semantically related categories; see Footnote 2.
Future Research Directions and Conclusions Present results provide evidence to support the existence of specific illness schemas and suggest that an illness schema can be activated with the presentation of information about an illness, that the activation results in an implicit attentional bias to illnessrelated information, and that such a bias is related to explicit representations of the illness. However, one limitation of the present experiments is that the participants received a prime that heavily activated the illness schema for both the common cold and cardiovascular disease. Future studies may aim to replicate these findings using a subliminal prime to support the implicit nature of the illness schema and the level of activation required. In addition, future research may examine other hypotheses of the CSM such as the relationships between illness representations and coping responses. According to the CSM, illness representations may compel the search for coping strategies to manage the illness threat. Leventhal et al. (1980) called these “if-then” rules. It would be
interesting to examine such a relationship by activating a specific illness schema and then evaluating sensitivity to common coping strategies associated with that illness.
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Appendix Stroop Stimulus Items Cardiovascular disease
Common cold
Neutral
BLOCKAGE BYPASS CARDIOLOGIST CHOLESTEROL CLOT CORONARY HEART HYPERTENSION PACEMAKER STROKE
COLD CONGESTION COUGHING INFLUENZA MENTHOL MUCUS NOSE PHLEGM SNEEZING TISSUES
AEROPLANES AMPHIBIAN CRUMBLE DINNERS JOURNEYS LEAD NECK STAIRS STINKING WAVES
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