Omer Van den Bergh Research Group on Health Psychology University of Leuven, Belgium
SOME BACKGROUND
Healthy students N=1.549; no disease, no medication Symptoms and Negative Affectivity (NA) Correlation: r = .42671 130 (without anxiety symptoms) 110 Total Symptom Score 90 70 50 30 5 15 25 35 45 55 NA PANAS Controlled for content overlap Van Diest et al., SS&M, 2005
Symptoms – Negative Affectivity: Pervasive relation psychiatric functional Secondary care co-morbidity syndromes Negative Symptoms frequent anxious/ Primary care Affectivity consulters depressive high NA nonconsulting Normal population
Trait negative affectivity (NA) Broad, stable disposition to appraise situations as more threatening and to experience negative mood states and emotions (Watson & Clark, 1984) • Genetic basis • Over-reactive evaluative system • Distinct brain circuit function • Poor emotion regulation – Less reappraisal, more suppression • Distinct neurotransmitter activity • Attentional and interpretational biases towards threatening stimuli • Cognitive facets like worrying, rumination, catastrophizing,.. Hariri, 2009; Posner & Rothbart, 2000. Davidson, 2000;Yiend, 2010; Moberly & Watkins, 2008; De Peuter et al., 2008; Gross & John, 2003 …
Medically unexplained symptoms (MUS) CREATING MUS IN THE LAB
Creating MUS in the lab Odor-CO 2 inhalation paradigm Predictive cues CO 2 inhalation trials • odors • fast breathing • mental images • smothering sensations • chest tightness • feelings of choking • pounding heart • sweating • hot flushes • lump in throat • headache • tension, anxious feelings
Methods valve Odors Subject CO 2 air
Odor CSs ACQUISITION 2 min breathing trials • Ventilation (f, V T , V E ) CS+ Odor 1+ 7.5 % CO 2 • FETCO 2 • HR • Subjective symptoms CS- Odor 2+ room air TEST • Ventilation (f, V T , V E ) Odor 1+ room air CS+ • FETCO 2 • HR • Subjective symptoms CS- Odor 2+ room air
Acquired symptoms to harmless odors symptoms 24 CS+ 23 CS- 22 21 20 19 18 17 Ammon CS+ Niaouli CS+ • Symptom learning to unpleasant odor only! • No difference in contingency awareness Van den Bergh et al., 1995, 1997, 1999
More elevated in high NA and in clinical MUS patients symptoms CS+ 28 CS+ symptoms CS- CS- 22 26 20 24 22 18 20 16 Normals Patients High NA Low NA Van den Bergh et al., 1998, 1999
Generalizes to new odors symptoms 23 Condit. Ss 22 Not cond. Ss 21 20 19 18 17 Butyric Acid Acetic Acid Citric Aroma • Generalization follows gradient of unpleasantness Devriese et al., 2000
Can be “extinguished” Repeated presentations of odor only Symptoms 21 20.5 Extinct Wait 20 19.5 19 18.5 18 17.5 17 16.5 16 CS+1 E1 E2 E3 E4 E5 CS+7 Test trial after learning Test trial after extinction
20% CO 2 hampers extinction 6 5 4 CS+ 3 CS- 2 1 0 Ext1 Ext2 Ext3 Meulders et al., 2009
Thoughts as CSs: imagery scripts FEAR (example 1) You are alone in an elevator. It is very small and has no ventilation. You start feeling short of breath. It slowly becomes unbearable. You want to leave this place as soon as possible, but when the elevator stops the door is stuck. You are sweating and your heart pounds wildly. In despair, you start pushing all the buttons, but nothing helps. You perspire heavily and gasp for breath. It appears that there is almost no air available anymore in this little place. Your heart leaps into your mouth, while you pull on the door with all your strength. It remains jammed shut. Everything becomes black. Neutral (example 1) You are sitting in your living room reading on a Sunday afternoon. Sitting back, relaxed, you look out of the window. It's a sunny autumn day outside. Red and brown leaves drift slowly down from the trees and several cars and a truck go by in the street. Wind from the cars blows leaves which are lying in the street. They scatter onto the pavement and the thick green lawn. (Based on Lang, Kozak, Miller, Levin & McLean, 1980).
Thoughts as CSs ACQUISITION 2 min breathing trials • Ventilation (f, V T , V E ) Imag 1 CS+ 5.5 % CO 2 • FETCO 2 • HR • Subjective symptoms CS- Imag 2 room air TEST • Ventilation (f, V T , V E ) Imag 1 room air CS+ • FETCO 2 • HR • Subjective symptoms CS- Imag 2 room air
Thoughts as CSs symptoms symptoms 28 24 CS+ CS+ CS- 27 CS- 23 26 22 25 21 20 24 19 23 18 22 Neutral Fear • symptoms are learned only with fearful thoughts • knowing the CS-US relationship is necessary but not sufficient J. Abnorm. Psychol., 1999
What is the basis for acquired MUS? What is learned? • Interoceptive hypervigilance for actual physiological arousal? • Cognitive interpretation biases towards actual physiological arousal? • Automatic activation of somatic memories of acquisition experiences?
Automatic memory activation No Distraction at Acquisition Distraction at Acquisition Symptoms Symptoms 20.5 20.5 CS+ CS+ 20 CS- 19.5 CS- 19.5 19 18.5 18.5 18 17.5 17.5 17 16.5 16.5 16 15.5 15.5 Amm. CS+ Nia CS+ Amm CS+ Nia CS+ • No diff in physiological responses at test • Pattern of learned symptoms reflect acquisition symptoms • RT : memory activation is automatic (nonconscious) process Van den Bergh et al., 1998
What needed to produce MUS … • Take a high NA person • Have this person experience symptom episodes • Induce expectancy • By unpleasant cues reliably associated with the symptom episodes • Some characteristics - MUS generalize to other cues following an unpleasantness gradient - Can be “extinguished” but hampered by intense aversive experiences • Engage the same central neurobiological structures as the sensations resulting from peripheral physiological stimulation
Electrosensitivity and sham radiation Subjects • Patients with electrosensitivity • healthy controls Exposure • heat • sham radiation from mobile phones Landgrebe et al., 2008
Anterior cingulate ACC cortex Landgrebe et al., 2008
Left and right insular cortex ACC Landgrebe et al., 2008
Role of unpleasant cues in persons with MUS? PLAYING “HIDE AND SEEK” WITH MUS
Interoception and emotion • Intricate relationship between interoception and emotion • Specific brain regions serve as an interface → How do affective cues influence “interoceptive accuracy” ? Bechara & Naqvi, 2004
“Fusing” Affect “invades” the perception of bodily states • Viewing fearful faces enhances sensations of oesophageal distention • Viewing negative IAPS-pictures enhances unpleasantness of dyspnea • Negative emotional states increase perceived dyspnea and pain Phillips et al., 2003 von Leupoldt et al., 2008 Leeuw et al., 2007 von Leupoldt and Dahme, 2007
Critical role of insula Craig, 2009
Body – symptom correspondence • within-subject correlation between a specific subjective report and a specific physiological response across a number of breathing trials - Minute ventilation - Faster/deeper breathing - PCO 2 - Breathlessness
Role of affective context “Test of quality of air on subjective well-being” High and low NA normals Negative frame Positive frame Unpleasant odor Pleasant odor “breathing this air may make you “ breathing this air may make you feel tensed like when being in feel tensed like when being love or looking out for anxious or expecting something really nice to something terrible to occur” happen”
Role of affective context Symptom Level Correspondence 19 17 15 13 11 9 7 5 Low NA Positive Negative High NA Van den Bergh et al., P&H, 2004
Semantic cues • within-subject correlation between a specific subjective report and a specific physiological response across a number of breathing trials neutral - Minute ventilation - Faster/deeper breathing - PCO 2 - Breathlessness
Semantic cues • within-subject correlation between a specific subjective report and a specific physiological response across a number of breathing trials - Minute ventilation - Faster/deeper breathing - PCO 2 - Breathlessness symptom
Semantic cues : Neutral vs Symptom rating High and low symptom reporters (normals) 1 Transformed correlation Low MUS 0,9 High MUS 0,8 p < .01 0,7 0,6 0,5 0,4 Neutral Symptom Bogaerts et al., JPR, 2008
Pictorial cues ( IAPS ) Series of 20 pics, 8 sec/pic Total symptom score State NA 25 60 55 20 50 15 45 40 10 35 5 30 POSITIVE NEUTRAL NEGATIVE SYMPTOM POSITIVE NEUTRAL NEGATIVE SYMPTOM Low MUS High MUS Low MUS High MUS • NA acts as a moderator, not as a mediator Bogaerts et al., 2010
Chronic Fatigue Patients Brief induction of negative affective state Imagery scripts (2 min) Typical CFS Symptoms Negative affect (state) 22 24 18 22 14 20 18 10 Bogaerts et al., 2007
Somatovisceral illusions Negative affective cue ?
More speculations ?? • Deficient prefrontal inhibitory control leading to somatovisceral illusions?
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