Generalization of Acquired Somatic Symptoms in Response to Odors: A Pavlovian Perspective on Multiple Chemical Sensitivity

  title={Generalization of Acquired Somatic Symptoms in Response to Odors: A Pavlovian Perspective on Multiple Chemical Sensitivity},
  author={Stephan Devriese and Winnie Winters and Kris Stegen and Ilse Van Diest and Hendrik Veulemans and Benoit Nemery and Paul Eelen and Karel P. van de Woestijne and Omer Van den Bergh},
  journal={Psychosomatic Medicine},
Objective Somatic symptoms that occur in response to odors can be acquired in a pavlovian conditioning paradigm. The present study investigated 1) whether learned symptoms can generalize to new odors, 2) whether the generalization gradient is linked to the affective or irritant quality of the new odors, and 3) whether the delay between acquisition and testing modulates generalization. Methods Conditional odor stimuli (CS) were (diluted) ammonia and niaouli. One odor was mixed with 7.4% CO2… 

Acquiring Symptoms in Response to Odors: A Learning Perspective on Multiple Chemical Sensitivity

In this chapter, a learning account is discussed as a potential explanation for the symptoms in multiple chemical sensitivity, and cognitive‐behavioral treatment techniques appear to produce beneficial results in clinical cases.

Media Warnings About Environmental Pollution Facilitate the Acquisition of Symptoms in Response to Chemical Substances

Only participants who had been given warnings about environmental pollution reported more symptoms to the odor that had previously been associated with CO2, compared with the control odor, for both the foul- and the pleasant-smelling odor.

Perceived relation between odors and a negative event determines learning of symptoms in response to chemicals

Believing that a specific odor cue was associated with a symptom episode was more important than the actual association in order to provoke symptoms in response to harmless odor cues.

Modeling the development of panic disorder with interoceptive conditioning

Exploratory Investigation of a Brief Cognitive Behavioral Intervention and Transcranial Direct Current Stimulation on Odor Sensitivity

Results suggest that CBT techniques for somatic processes may show promise in treating conditions characterized by increased sensitivity to odors (e.g., MCS), given the connection between anxiety and MCS.



Acquisition and extinction of somatic symptoms in response to odours: a Pavlovian paradigm relevant to multiple chemical sensitivity.

Subjects can acquire somatic symptoms and altered respiratory behaviour in response to harmless, but odorous chemical substances, if these odours have been associated with a physiological challenge that originally had caused these symptoms.

Memory effects on symptom reporting in a respiratory learning paradigm.

Attention manipulation showed that the learned complaints during the test phase were based on memory of the acquisition complaints and not on physiological responses during the tests, suggesting that physiological conditioning effects were not found.

Learning to have Psychosomatic Complaints: Conditioning of Respiratory Behavior and Somatic Complaints in Psychosomatic Patients

Respiratory responses and psychosomatic complaints can be elicited by conditioned stimuli in a highly specific way and are relevant for disorders in which respiratory abnormalities and/or psychosodic complaints may play a role and for multiple chemical sensitivity.

Fear-relevant images as conditioned stimuli for somatic complaints, respiratory behavior, and reduced end-tidal pCO2.

The type of imagery had strong effects on symptoms and physiological responses, and a selective conditioning effect was also observed: CS+ imagery produced more symptoms and altered respiratory behavior compared with CS- imagery, but only in the fear-relevant script condition.

Olfaction and Multiple Chemical Sensitivity

  • R. Doty
  • Psychology
    Toxicology and industrial health
  • 1994
This study suggests that MCS is associated with increased nasal airflow resistance, respiration rate, heart rate, and scores on the Beck Depression Inventory, but not with significant changes in odor detection threshold sensitivity to phenyl ethyl alcohol and methyl ethyl ketone, the two target stimuli evaluated.

Time-dependent sensitization of heart rate and blood pressure over multiple laboratory sessions in elderly individuals with chemical odor intolerance.

The data suggest that elderly individuals with a high degree of chemical odor intolerance evidence of increased sympathetic tone in the cardiovascular system at rest over multiple measurements and greater sensitizability and/or lesser habituation of heart rate and diastolic blood pressure over time as a function of repeated environmental stressor exposures.

Preparedness and phobias: Specific evolved associations or a generalized expectancy bias?

  • G. Davey
  • Psychology, Biology
    Behavioral and Brain Sciences
  • 1995
It is suggested that the readiness with which such stimuli become associated with aversive outcomes arises from biases in the processing of information about threatening stimuli rather than from phylogenetically based associative predispositions or “biological preparedness".