Multiple chemical sensitivity, a test of the olfactory-limbic model

by Brown-DeGagne, Anne-Marie

Thus far, three published studies have examined cognitive hctioning in persons with Multiple Chernical Sensitivity (MCS). Cognitive impairments to substantiatethe subjective complaints of individuals with MCS have not been found. No study, however, has yet examined the cognitive profile of MCS within the hework of Bell's OLfactory-Limbic Model. It predicts that cognitive weaknesses WU be associated more with limbic (Le., fkontal andor temporal lobe) regions of the brain than with non-lirnbic regions (Le., posterior cortex). Matched MCS (N = 21 ), asthma (N= 21 ), and healthy control (N = 21) groups were tested on measures of cognitive fhctioning that have locaiizing value. Between-group comparisons showed that the MCS group performed as well as controls on al1 cognitive tasks. However, between-test comparisons showed that both the MCS and asthma groups performed signincantly more poorly on tasks sensitive to fiontal and temporal regions than to posterior regions. Subjective memory complaints were not related to memory task performance, but were related to anxiety and depression. Additional research is needed before concluding that the Olfactory-Limbic Model adequately describes the cognitive strengths and wealaesses of MCS. Confounding factors such as medication use, chronic illness, and environmental reactivity need to be considered. There is no evidence on nom-based cognitive measures that brain damage, per se, has occurred in MCS patients. List of Abbreviations and Symbols Used BAI = Beck Anxiety Inventory BDI = Beck Depression Inventory BFRT = Benton Facial Recognition Test COWA = Controiled Oral Word Association CNS = Central Nervous System EI = Environmental Ihess MCS = Multiple Chemical Sensitmty MOQ = Memory Observation Questionnaire RMF = Recognition Memory Test For Faces SOP = Self-Ordered Pointing Test WAIS-R = Wechsler Adult Intelligence Sde-Revised WMS = Wechsler Memory Sale