| 221. |
- Olofsson, Jonas, et al.
(författare)
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Comparison of chemosensory, auditory and visual event-related potential amplitudes
- 2008
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Ingår i: Scandinavian Journal of Psychology. - : Wiley-Blackwell. - 0036-5564 .- 1467-9450. ; 49, s. 2231-237
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Tidskriftsartikel (refereegranskat)abstract
- To enhance understanding of neuropsychological processing underlying chemosensory event‐related potentials (CSERPs), the objective of the present study was to compare CSERPs with auditory (AERPs) and visual event‐related potentials (VERPs), and to approach the question of similarities in neuropsychological processing by means of correlation and cluster analyses. A multisensory ERP protocol was used, in which olfactory/chemosomatosensory (pyridine), auditory (1000‐Hz tone) and visual (white circle) stimuli were presented in a pseudo‐randomized sequence to 18 young, healthy adults. The results show (1) a morphological relation between P2 and P3 components that is different for the chemosensory than for the auditory and visual modalities, (2) a relatively weak association between the chemosensory and auditory/visual modalities for P3 in terms of both correlation and cluster, and (3) a P2/P3 cluster for the chemosensory but not auditory or visual modality. This supports the claim that the chemosensory P2 and P3 components reflect similar neuropsychological processes.
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| 222. |
- Olofsson, Jonas, 1978-
(författare)
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Gender differences in chemosensory function
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis consists of two studies, in which gender differences in nasal chemosensory function are investigated. The first study assesses odor identification ability in a populationbased sample, varying from 45 to 90 yrs, screened for cognitive impairment and severe olfactory dysfunction. Results show that women are generally better than men at identifying odors, but there is no significant interaction of gender by age. Although odoridentification is influenced by semantic memory and cognitive speed, these cognitivefactors are unlikely to cause the observed gender difference in odor identification. The second study investigates chemosensory perception in men and women by assessing eventrelatedbrain potentials, and perceptual ratings for an odorant, which varies inconcentration and olfactory/irritating properties. The results display a generally larger cortical response in women than in men, beginning from about 350 ms after stimulus onset. Women report higher perceived intensity and npleasantness at the highest stimulus concentration, and a steeper psychophysical function, than do men. The results indicatethat stronger cortical responses of nasal chemosensory stimuli provide a neural basis for stronger supra-threshold perception in women than in men, which might enhance odor identification performance. The nature and causes of these gender-differences in nasal chemosensory function are discussed. This thesis for the licenciate degree is based on the following studies:Larsson, M., Nilsson, L-G., Olofsson, J.K., & Nordin, S. (2004). Demographic and cognitive predictors of odor identification: Evidence from a population-based study.Chemical Senses, 29, 547-554.Olofsson, J.K., & Nordin, S. (2004). Gender differences in chemosensory perception andevent-related potentials. Chemical Senses, 29, 629-637.
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| 223. |
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| 224. |
- Olofsson, Jonas K., et al.
(författare)
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Odor Identification Deficit as a Predictor of Five-Year Global Cognitive Change : Interactive Effects with Age and ApoE-ε4
- 2009
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Ingår i: Behavior Genetics. - : Springer Netherlands. - 0001-8244 .- 1573-3297. ; 39:5, s. 496-503
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Tidskriftsartikel (refereegranskat)abstract
- Olfactory impairments are present in common neurodegenerative disorders and predict conversion to dementia in non-demented individuals with cognitive impairment. In cognitively intact elderly, evidence is sparse regarding the role of olfactory deficits in predicting cognitive impairment. The present study investigated predictors of 5-year prospective decline in the Mini-Mental State Examination (MMSE) in a large (n = 501), population-based sample of elderly (65–90 years) individuals. All participants were genotyped for the ApoE gene, assessed for health factors, and were non-demented at the baseline assessment. After partialling out the influences of demographic and health-factors at baseline and dementia at follow-up, poor odor identification ability in combination with older age and the ApoE-ε4 allele predicted larger prospective global cognitive decline. This effect could not be produced by a vocabulary test. In sum, the findings suggest that an olfactory deficit can dissociate between benign and malign global cognitive development in non-demented, very old ε4-carriers, who are at high risk of developing dementia.
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| 225. |
- Olofsson, Jonas K, 1965-, et al.
(författare)
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Odor identification impairment in carriers of ApoE-ε4 is independent of clinical dementia
- 2010
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Ingår i: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 31:4, s. 567-577
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Tidskriftsartikel (refereegranskat)abstract
- The ApoE gene is expressed in olfactory brain structures and is believed to play a role in neuronal regenerative processes as well as in development of Alzheimer's disease (AD), the most common form of dementia. The ε4 allele has been reported to be associated with compromised odor identification ability in the elderly, and this deficit has been interpreted as a sign of pre-diagnostic AD. However, because it has not been demonstrated that the relationship between the ε4 allele and odor identification is mediated by dementia, it is possible that the ε4 allele may have an effect on odor identification over and above any effects of dementia. The present study investigated effects of ApoE-status on odor identification in a large, population-based sample (n = 1236) of adults (45–80 years), who were assessed for dementia at time of testing and 5 years later. The results showed that the ε4 allele was associated with an odor identification deficit among elderly participants (75–80). Critically, this effect remained after current and pre-diagnostic dementia, vocabulary, global cognitive status and health variables were partialled out. The present results suggest that the ApoE gene plays a role in olfactory functioning that is independent of dementia conversion within 5 years.
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| 226. |
- Olofsson, Jonas K., et al.
(författare)
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Olfaction and Aging : A Review of the Current State of Research and Future Directions
- 2021
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Ingår i: i-Perception. - : SAGE Publications. - 2041-6695. ; 12:3, s. 1-24
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Forskningsöversikt (refereegranskat)abstract
- Olfaction, the sense of smell, is characterized by a notable age-dependency such that aging individuals are more likely to have poor olfactory abilities. These impairments are considered to be mostly irreversible and as having potentially profound effects on quality of life and food behavior, as well as constituting warning signs of mortality, cognitive dysfunction, and dementia. Here, we review the current state of research on aging and olfaction, focusing on five topics which we regard to be of particular relevance for the field: nutrition and health, cognition and dementia, mortality, environment and genetics, and training-based enhancement. Under each of these headlines, we provide a state-of-the-art overview and discuss gaps in our knowledge which might be filled by further research. Understanding how olfactory abilities are diminished in aging, and how they may be alleviated or recovered, involves a set of challenging tasks for researchers in the years to come.
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| 227. |
- Olofsson, Jonas K., 1978-, et al.
(författare)
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Olfactory distortions in the general population
- 2022
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Parosmia, distorted smell sensations, is a common consequence of respiratory virus infections. The phenomenon is not well understood in terms of its impact and long-term outcomes. We examined self-reported experiences of parosmia in a population-based sample from the Betula study that was conducted in Umea in northern Sweden (baseline data collected in 1998-2000). We used a baseline sample of 2168 individuals aged 35-90 years and with no cognitive impairment at baseline. We investigated the prevalence of parosmia experiences and, using regression analyses, its relationship to other olfactory and cognitive variables and quality of life. Benefitting from the longitudinal study design, we also assessed the persistence of parosmia over 5 and 10 years prospectively. Parosmia experiences were prevalent in 4.8% of the population and it often co-occurred with phantosmia (olfactory hallucinations), but was not associated with lower self-rated overall quality of life or poor performance on olfactory or cognitive tests. For some individuals, parosmia was retained 5 years (17.0%) or even 10 years later (10.3%). Thus, parosmia experiences are commonly reported in the population, and can be persistent for some individuals, but might be mostly benign in nature. Our work complements research on clinical-level parosmia, which is typically more severe, and recent parosmia reports during the COVID-19 pandemic, where long-term outcomes are still unknown.
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| 228. |
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| 229. |
- Olofsson, Jonas, 1978-
(författare)
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Odor identification in aging and dementia : Influences of cognition and the ApoE gene
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Olfactory function is impaired in aging and dementia. The general aim of this thesis was to identify variables that predict olfactory function and dysfunction (assessed with an odor identification test) in middle-aged and elderly adults. The thesis investigated whether odor identification performance was associated with demographic variables, cognitive function, the ApoE gene, dementia, and other health-related variables. The ApoE-ε4 allele is associated with cognitive impairment and Alzheimer’s disease, the most common form of dementia. The studies included in this thesis used data from the Betula study, a large-scale, population-based prospective study on aging, memory, and health. Study 1 investigated demographic and cognitive predictors of odor identification ability in non-demented participants. The results showed that younger age, female sex, and high education contributed to better odor identification ability. Cognitive speed and vocabulary had a small additional influence. Study 2 included information about ApoE genotypes, dementia and other health-related variables. The results indicated that the ApoE-ε4 allele was associated with odor identification impairment among the elderly, but not middle-aged adults. Participants who were demented at the time of testing or became demented within five years after testing exhibited olfactory impairments. Interestingly, the age-related olfactory impairment in ε4-carriers was independent of clinical dementia within five years. In Study 3, decline in global cognitive status over a five-year test-retest interval was predicted in a sample of elderly participants. The major result was a three-way interaction reflecting that odor identification impairment, old age, in combination with the ε4 allele predicted a larger cognitive decline. However, odor identification impairment did not predict cognitive change in elderly who were non-carriers of the ε4 allele. Overall, the results indicate that odor identification impairment in elderly is related to ApoE-ε4, cognitive decline, and clinical and pre-clinical stages of dementia. Theoretical and practical implications of the results are discussed. Furthermore, it is proposed that in order to effectively predict clinical dementia or cognitive decline from olfactory assessment in the elderly, variables that mediate (e.g. neuropathology) or moderate (e.g. age) the associations between olfactory function, the ε4 allele, and dementia need to be further evaluated, preferably in studies using longitudinal assessment.
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| 230. |
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