I urval från Stockholms universitets publikationsdatabas

• A three-factor benefits framework for understanding consumer preference for scented household products

  2022. Rachel S. Herz (et al.). Cognitive Research Principles and Implications 7 (1)

  Artikel

  Humans have deliberately scented their environment for purpose or pleasure for millennia. In the contemporary marketplace most consumers prefer and purchase scented versions of common household products. However, the drivers of this consumer preference have not been elucidated. To explain the attraction to scent in household products we propose a novel three-factor framework, comprising functional benefits (malodor mitigation, base odor coverage, freshening), in-use experience benefits (cleanliness, efficacy, pleasure), and emotional benefits (increasing in confidence, mood and nostalgia). To support this framework, we present new data from a market research survey on US consumer purchasing habits and attitudes towards home cleaning, laundry, and air freshening products. Further substantiating our framework, a focused review of olfactory psychological science illustrating the central role of scent in cognition, wellbeing, motivated behavior, and social behavior, as well as sensory marketing research highlights the benefits and implications of scent in consumer household products. Based on our three-factor framework we go on to discuss the potential for scent to influence health and raise issues to consider (such as potential negative responding to fragranced products). We conclude by showcasing new opportunities for future research in olfactory science and on scented household products that can advance the positive impacts of scent.

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• A Method for Computerized Olfactory Assessment and Training Outside of Laboratory or Clinical Settings

  2021. Simon Niedenthal (et al.). i-Perception 12 (3), 1-12

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  There are currently few ways to reliably and objectively assess olfaction outside of the research laboratory or clinic. The COVID-19 pandemic has highlighted the need for remote olfactory assessment; in particular, smell training at home is a promising method for olfactory rehabilitation, but further methodological advances might enhance its effectiveness and range of use. Here, we present Exerscent, a portable, low-cost olfactory display designed primarily for uses outside of the laboratory and that can be operated with a personal computer. Exerscent includes Radio Frequency Identification (RFID) tags that are attached to odor stimuli and read with a MFRC522 module RFID reader/antenna that encodes the odor in order to provide adaptive challenges for the user (e.g., an odor identification task). Hardware parts are commercially available or 3D printed. Instructions and code for building the Exerscent are freely available online (https://osf.io/kwftm/). As a proof of concept, we present a case study in which a participant trained daily to identify 54 odors, improving from 81% to 96% accuracy over 16 consecutive days. In addition, results from a laboratory experiment with 11 volunteers indicated a very high level of perceived usability and engagement. Exerscent may be used for olfactory skills development (e.g., perfumery, enology), and rehabilitation purposes (e.g., postviral olfactory loss), but it also allows for other forms of technological interactions such as olfactory-based recreational interactions.

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• Odor Recognition Memory in Parkinson's Disease

  2021. Tom Eek, Maria Larsson, Nil Dizdar. Frontiers in Aging Neuroscience 13

  Artikel

  Olfactory impairment is a central non-motor symptom in Parkinson's disease (PD). Previous studies have demonstrated that olfactory dysfunction is associated with mental illness and impaired cognition. The frequently investigated olfactory functions are odor detection, discrimination, and identification. However, few studies have focused on odor recognition memory (ORM). ORM tasks involves episodic memory which therefore can facilitate the detection of dementia among patients with PD and consequently adjust their treatment. Thus, the aim of this systematic review is to summarize the existing research on ORM in PD. Databases and reference lists were used for data collection. Studies were included in the review if they met the eligibility criteria derived from the PICOS-framework. Quality evaluation of the studies was based on the STROBE-statement. Six studies with small samples were included in the analysis which demonstrated the scarce research on the subject. The studies targeting ORM were heterogenous and involved two main tasks: odor recognition and odor matching. The synthesis of the data demonstrated that PD patients performed significantly lower than controls on both tasks, especially on odor matching task. Only the odor recognition task exhibited a difference between patients with PD vs. Alzheimer's disease (AD). PD patients performed significantly better than AD patients. The findings based on the available limited data support the notion that odor recognition task can be of importance in identifying Parkinson's disease dementia (PDD). To investigate this hypothesis, future research needs to include larger samples of PD, PDD and AD patients executing the same odor recognition task.

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• Olfaction and Aging

  2021. Jonas K. Olofsson (et al.). i-Perception 12 (3), 1-24

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  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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• A Prospective Study on Risk Factors for Olfactory Dysfunction in Aging

  2020. Eva Palmquist (et al.). The journals of gerontology. Series A, Biological sciences and medical sciences 75 (3), 603-610

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  Background: Olfactory dysfunction (OD) refers to a reduced or absent ability to smell. OD negatively impacts health and quality of life and its prevalence increases with advancing age. Since OD may be an early marker of dementia and impending death, more knowledge regarding risk factors of OD in aging is warranted. The objective was therefore to explore longitudinally which demographic, genetic, clinical, lifestyle, and cognitive factors predict the development of OD.

  Methods: The study included participants aged 60–90 years from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K), who did not have OD at baseline and were reassessed with an odor identification task at a 6-year follow-up (n = 1,004). Risk factors of OD were assessed with multivariable logistic regression analyses.

  Results: The percentage of incident OD cases was 14.2% over 6 years in the total sample and this number increased monotonically with age. Increasing age, carrying the ε4 allele of the APOE gene, atrial fibrillation, cerebrovascular disease, and current smoking were found to be risk factors for the development of OD, whereas better olfactory identification and verbal episodic memory proficiency at baseline were identified as protective factors.

  Conclusions: In addition to nonmodifiable factors (age and genetic risk), several modifiable risk factors of OD were identified. This suggests that it might be possible to reduce OD incidence through the management of vascular risk factors and maintenance of a healthy lifestyle.

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• An Overprotective Nose? Implicit Bias Is Positively Related to Individual Differences in Body Odor Disgust Sensitivity

  2020. Marta Zuzanna Zakrzewska (et al.). Frontiers in Psychology 11

  Artikel

  Body odors are universal elicitors of disgust, a core emotion that plays a key role in the behavioral immune system (BIS) - a set of psychological functions working to avoid disease. Recent studies showed that body odor disgust sensitivity (BODS) is associated with explicit xenophobia and authoritarianism. In the current experimental pre-registered study (), we investigated the association between olfactory pathogen cues, BODS and implicit bias toward an outgroup (tested by an implicit association test). Results show that BODS is positively related to implicit bias toward an outgroup, suggesting that social attitudes may be linked to basic chemosensory processes. These attitudes were not influenced by background odors. Additionally, BODS was related to social, but not economic conservatism. This study extends the BIS framework to an experimental context by focusing on the role of disgust and body odors in shaping implicit bias.

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• Consequences of undetected olfactory loss for human chemosensory communication and well-being

  2020. A. Oleszkiewicz (et al.). Philosophical Transactions of the Royal Society of London. Biological Sciences 375 (1800)

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  Olfactory perception has implications for human chemosensory communication and in a broader context, it affects well-being. However, most of the studies investigating the consequences of olfactory loss have recruited patients who have already been categorized as having a dysfunctional sense of smell and sought help in an ENT clinic. We revisit these findings by distinguishing subjects with olfactory impairment from a group of subjects who all declared a normal sense of smell when enrolling for this study. In the initial sample of 203 individuals, we found 59 to have impaired olfaction and four with marginal olfactory performance, not useful in daily life. Interestingly, we found a significant between-group difference in cognitive functioning, further supporting the notion of the relationship between cognition and olfactory performance. However, their chemosensory communication and well-being appeared not to be different from subjects with normosmia. Impaired olfactory function certainly has a severe impact on daily life but more so in individuals who are bothered with it and decide to seek treatment. The limited-to-no olfactory perception in the fraction of subjects who neither complain about it nor seek help in ENT clinics does not seem to have a major effect on their social, cognitive, emotional and health functioning. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.

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• Interaction Between Odor Identification Deficit and APOE4 Predicts 6-Year Cognitive Decline in Elderly Individuals

  2020. Jonas K. Olofsson (et al.). Behavior Genetics 50 (1), 3-13

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  Olfactory identification impairment might indicate future cognitive decline in elderly individuals. An unresolved question is to what extent this effect is dependent on the ApoE-epsilon 4, a genotype associated with risk of Alzheimer's Disease (AD). Given the current concern about reproducibility in empirical research, we assessed this issue in a large sample (n = 1637) of older adults (60 - 96 years) from the population-based longitudinal Swedish National Study on Aging and Care in Kungsholmen (SNAC-K). A hierarchical regression analysis was carried out to determine if a low score on an odor identification test, and the presence of ApoE-epsilon 4, would predict the magnitude of a prospective 6-year change in the Mini-Mental State Examination (MMSE) after controlling for demographic, health-related, and cognitive variables. We found that overall, lower odor identification performance was predictive of cognitive decline, and, as hypothesized, we found that the effect was most pronounced among ApoE-epsilon 4 carriers. Our results from this high-powered sample suggest that in elderly carriers of the ApoE-epsilon 4 allele, odor identification impairment provides an indication of future cognitive decline, which has relevance for the prognosis of AD.

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• Neural processing of odor-associated words

  2020. Pengfei Han (et al.). Brain Imaging and Behavior 14, 1164-1174

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  Perception of olfactory information is mediated by both bottom-up (from molecules to perception) and top-down (e.g. cross-modal associative learning) processes. Acquired olfactory loss is a frequent disorder which is typically due to alterations in the bottom-up pathway. However, it is unclear how the top-down modulation of olfactory processing is affected by olfactory impairment. Our study aimed to investigate the top-down olfactory processing in patients with acquired olfactory loss and participants with normal olfaction. Using functional MRI, brain responses from 14 patients and 16 healthy controls were assessed during a task of expectation and reading of words with strong olfactory associations (OW) (e.g. “Rose”) and control words with little to no olfactory associations (CW) (e.g. “Door”). The expectation but not reading of the OW was associated with stronger neural activation in the angular gyrus and the inferior frontal gyrus extending to insula in the group of patients. During OW reading, the brain activation in the left OFC and right putamen was negatively correlated with odor identification score in patient and control groups, respectively. In addition, the duration of olfactory loss among patients was positively associated with activation in the left putamen during OW expectation. Taken together, these findings suggest an enhanced top-down olfactory modulation in patients with olfactory loss.

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• Neural processing of olfactory-related words in subjects with congenital and acquired olfactory dysfunction

  2020. Akshita Joshi (et al.). Scientific Reports 10 (1)

  Artikel

  Olfactory loss can be acquired (patients with a history of olfactory experiences), or inborn (patients without olfactory experiences/life-long inability to smell). Inborn olfactory loss, or congenital anosmia (CA), is relatively rare and there is a knowledge gap regarding the compensatory neural mechanisms involved in this condition. The study aimed to investigate the top-down olfactory processing in patients with CA or idiopathic acquired anosmia (IA) in comparison to normosmia controls (NC) during expectancy and reading of odor-associated words. Functional magnetic resonance imaging was used to assess brain activations in 14 patients with CA, 8 patients with IA, and 16 NC healthy participants during an expectancy and reading task. Words with strong olfactory associations (OW) (e.g. “banana”) or with little or no olfactory associations (CW) (e.g. “chair”) were used as stimuli and were presented with a block design Analyses were conducted to explore the brain activation in response to OW expectancy or OW reading between groups (CW as baseline). During the expectancy condition of OW, IA and NC groups showed stronger activation in posterior OFC extending to right insula, caudate region and frontal medial OFC respectively. Whereas during the reading condition of OW, CA patients showed stronger activation in posterior OFC extending to the insula. Increased activation of higher-order brain regions related to multisensory integration among CA patients suggests a compensatory mechanism for processing semantic olfactory cues.

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• Olfactory Influences on Visual Categorization

  2020. Thomas Hörberg (et al.). Cerebral Cortex 30 (7), 4220-4237

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  Visual stimuli often dominate nonvisual stimuli during multisensory perception. Evidence suggests higher cognitive processes prioritize visual over nonvisual stimuli during divided attention. Visual stimuli should thus be disproportionally distracting when processing incongruent cross-sensory stimulus pairs. We tested this assumption by comparing visual processing with olfaction, a “primitive” sensory channel that detects potentially hazardous chemicals by alerting attention. Behavioral and event-related brain potentials (ERPs) were assessed in a bimodal object categorization task with congruent or incongruent odor–picture pairings and a delayed auditory target that indicated whether olfactory or visual cues should be categorized. For congruent pairings, accuracy was higher for visual compared to olfactory decisions. However, for incongruent pairings, reaction times (RTs) were faster for olfactory decisions. Behavioral results suggested that incongruent odors interfered more with visual decisions, thereby providing evidence for an “olfactory dominance” effect. Categorization of incongruent pairings engendered a late “slow wave” ERP effect. Importantly, this effect had a later amplitude peak and longer latency during visual decisions, likely reflecting additional categorization effort for visual stimuli in the presence of incongruent odors. In sum, contrary to what might be inferred from theories of “visual dominance,” incongruent odors may in fact uniquely attract mental processing resources during perceptual incongruence.

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• Predictors of Olfactory Decline in Aging

  2020. Ingrid Ekström (et al.). The journals of gerontology. Series A, Biological sciences and medical sciences 75 (12), 2441-2449

  Artikel

  Background: Olfactory dysfunction is common in aging and associated with dementia and mortality. However, longitudinal studies tracking change in olfactory ability are scarce. We sought to identify predictors of interindividual differences in rate of olfactory identification change in aging.

  Method: Participants were 1780 individuals, without dementia at baseline and with at least 2 olfactory assessments over 12 years of follow-up (mean age = 70.5 years; 61.9% female), from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K). Odor identification was assessed with the Sniffin’ Sticks. We estimated the impact of demographic, health, and genetic factors on rate of olfactory change with linear mixed effect models.

  Results: Advancing age, manufacturing profession, history of cerebrovascular disease, higher cardiovascular disease burden, diabetes, slower walking speed, higher number of medications, and the APOE ε4 allele were associated with accelerated odor identification decline (ps < .014). Multi-adjusted analyses showed unique associations of age, diabetes, and ε4 to olfactory decline (ps < .017). In 1531 participants who remained free of dementia (DSM IV criteria) during follow-up, age, cardiovascular disease burden, and diabetes were associated with accelerated decline (ps < .011). Of these, age and diabetes remained statistically significant in the multi-adjusted model (ps < .001).

  Conclusion: Demographic, vascular, and genetic factors are linked to rate of decline in odor identification in aging. Although some olfactory loss may be an inevitable part of aging, our results highlight the importance of vascular factors for the integrity of the olfactory system, even in the absence of dementia.

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• Smell-Based Memory Training

  2020. Jonas K. Olofsson (et al.). Chemical Senses 45 (7), 593-600

  Artikel

  Human and non-human animal research converge to suggest that the sense of smell, olfaction, has a high level of plasticity and is intimately associated with visual-spatial orientation and memory encoding networks. We investigated whether olfactory memory (OM) training would lead to transfer to an untrained visual memory (VM) task, as well as untrained olfactory tasks. We devised a memory intervention to compare transfer effects generated by olfactory and non-olfactory (visual) memory training. Adult participants were randomly assigned to daily memory training for about 40 days with either olfactory or visual tasks that had a similar difficulty level. Results showed that while visual training did not produce transfer to the OM task, olfactory training produced transfer to the untrained VM task. Olfactory training also improved participants’ performance on odor discrimination and naming tasks, such that they reached the same performance level as a high-performing group of wine professionals. Our results indicate that the olfactory system is highly responsive to training, and we speculate that the sense of smell may facilitate transfer of learning to other sensory domains. Further research is however needed in order to replicate and extend our findings.

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• TOM-32-An extended test for the assessment of olfactory memory

  2020. Agnieszka Sorokowska, Agnieszka Sabiniewicz, Maria Larsson. Journal of Neuroscience Methods 344

  Artikel

  Background: Olfactory memory testing is a promising way to explore different aspects of smell-related abilities in healthy subjects as well as to diagnose various diseases associated with disorders of this type of memory. Despite the obvious value of olfactory memory assessments, few available methods enable its diagnosis.

  New method: The aim of our study was to create a standardized research tool designed for olfactory memory studies: an extended, 32-item version of an available Test for Odor Memory.

  Results: The study involving 222 subjects revealed satisfactory psychometric qualifies of TOM-32, and - as hypothesized - subjects with depression scored significantly lower than healthy participants. We additionally showed that TOM-32 scores was associated with sex, age and olfactory awareness. Women performed significantly better than men, young people tended to have lower false alarm rate than older subjects and olfactory awareness was positively associated with olfactory memory.

  Comparison with existing method(s): TOM-32 could expand the possibilities of testing olfactory memory. It may offer additional information about cognitive and sensory abilities relative to existing research tools, and the large number of included test items may facilitate repeated and longitudinal testing. Wide range of applied odors increases the possibility to detect subtle differences between, as well as changes within, individuals.

  Conclusions: We present an extensive olfactory memory test with satisfactory psychometric qualifies - a test that is comprehensive enough to show significant inter- and intra-individual differences, but time-efficient enough to be comfortable in daily research and clinical usage.

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• Temporolimbic cortical volume is associated with semantic odor memory performance in aging

  2020. Janina Seubert (et al.). NeuroImage 211

  Artikel

  Olfactory function, and specifically semantic olfactory memory (i.e., odor identification), has frequently been shown to predict cognitive functioning across multiple domains in old age. This observation suggests that olfactory function can serve as a marker for the integrity of temporolimbic cortical networks, but a clear delineation of this association is still missing. To address this issue, the present study employed voxel-based morphometry in a region of interest-based design to determine the extent to which gray matter volumes of core olfactory and memory areas are associated with olfactory memory performance in an aging population free from neurodegenerative disease. We further aimed to determine potential overlap in structural anatomical correlates, and differences in association strength, for semantic and episodic olfactory memory. Structural magnetic resonance imaging (MRI), episodic and semantic odor memory and episodic and semantic verbal memory data were collected in 422 participants from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K), all aged >= 60 years. Controlling for age and education, semantic, but not episodic, olfactory memory was positively related to gray matter volume in a cluster extending from the anterior hippocampus and amygdala into the posterior piriform cortex. The observed associations remained even when verbal memory performance was controlled for, supporting a link between the olfactory memory domain and cortical volume over and above more generalized memory abilities. As such, our data provide evidence for distinct functionalstructural associations for semantic odor memory, supporting the idea of temporolimbic integrity as a neurobiological substrate linking olfactory function to cognitive health in old age.

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• The reminiscence bump is blind to blindness

  2020. Stina Cornell Kärnekull (et al.). Consciousness and Cognition 78

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  The reminiscence bump is the disproportionally high reporting of autobiographical memories from adolescence and early adulthood and is typically observed when memories are evoked by cues, such as words, pictures, and sounds. However, when odors are used the bump shifts to early childhood. Although these findings indicate that sensory modality affects the bump, the influence of the individual's sensory function on the reminiscence bumps is unknown. We examined the reminiscence bumps of sound- and odor-evoked autobiographical memories of early blind and sighted individuals, since early blindness implies considerable effects on sensory experience. Despite differences in sensory experience between blind and sighted individuals, the groups displayed similar age distributions of both sound- and odor-evoked memories. The auditory bump spanned the first two decades of life, whereas the olfactory bump was once again found in early childhood. These results demonstrate that the reminiscence bumps are robust to fundamental differences in sensory experience.

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• Achieving Olfactory Expertise

  2019. Paulina Morquecho-Campos (et al.). Chemical Senses 44 (3), 197-203

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  Human olfactory function requires the identification of everyday odors. A characteristic feature of olfaction is that most people find it hard to identify and name common odors, and when odors are presented simultaneously in mixtures, performance is even further compromised. Few studies have systematically assessed how training might enhance identification of single odors and mixtures. This study compared how odor identification training with either single odors or binary mixtures affected identification performance, as well as transfer effects to untrained tasks and odors. Twenty- seven healthy participants (22 F; 28.0 +/- 4.7 years old) completed identification training of 8 odors using a list of 16 veridical names. The study included 8 training sessions, as well as pretest and posttest evaluations. Results suggest notable effects of learning, as well as transfer to novel tasks and odors. Overall, training with single odors led to slightly better results than the binary mixture condition, suggesting that in novices, odor identification may be facilitated via consolidation of single odor objects, before learning to dissociate binary mixtures. Overall, odor identification may be trained to generate transfer of learning, although transfer effects were observed in both training methods. Our work suggests that odor identification abilities, while often limited, are highly trainable.

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• Body odor disgust scale (BODS)

  2019. Jonas Olofsson (et al.). Chemical Senses 44 (3), e8-e8

  Artikel

  Body odors provide important social and health-related cues in many species. While human body odor perception often triggers feelings of disgust, few studies have investigated body odor disgust in a systematic way. We have developed the body odor disgust scale (BODS), a brief 12-item scale to assess the extent to which individuals are disgusted by common body odors such as sweat and urine. The scale development included both internal and external validation tests. We used the BODS in conjunction with scales measuring social attitudes and biases, and found consistent associations between high body odor disgust and stronger authoritarian attitudes, as well as more pronounced outgroup biases. Our work is consistent with the “behavioral immune system” framework, wherein social attitudes and political ideologies are shaped by perceived pathogen risk and disease avoidance via feelings of disgust. Body odor perception may thus not only be important for personal interactions, but may also be linked to social attitudes and political ideologies.

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• Incongruent odors suppress perceptual categorization of visual objects

  2019. Jonas K. Olofsson (et al.).

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  During multisensory experiences, visual stimuli typically suppress non-visual stimuli. Such ”visual dominance” effects might stem from inhibition across sensory systems. Does visual dominance generalize to odor-visual pairings? We developed a categorization task (fruits vs flowers) with congruent and incongruent odor-picture pairings and a delayed auditory response target that informed about categorization modality (olfactory vs visual). We investigated behavioral and cortical (ERP) responses. For congruent pairings, we found better accuracy for visual decisions. However, for incongruent pairings, we insteadobserved faster RTs for olfactory decisions. Incongruent olfactory stimuli thus interfere more with visualdecisions than vice versa. Our ERP results from auditory targets on incongruent trials gave supporting evidence of olfactory suppression over visual perception; higher P300 amplitudes were more strongly correlated with faster RTs during visual categorization. A late “slow wave” ERP effect had later onset andlonger latency during visual vs olfactory decisions. This indicates that in order to rapidly and successfully categorize visual stimuli (and ignore incongruent odors), participants need to allocate additional attentional and working memory resources. In sum, both behavioral and ERP effects suggest a higher level of interference from incongruent olfactory, compared to visual, input. These findings suggest that asymmetric inhibition across sensory systems is a fruitful way of studying sensory dominance, and that olfactory stimuli can dominate visual stimuli, refuting the general notion of ”visual dominance”.

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• Olfaction Dominates Visual Perception

  2019. Jonas K. Olofsson (et al.). Chemical Senses 44 (7), E32-E32

  Artikel

  During multisensory experiences, visual stimuli typically override non-visual stimuli. Such “visual dominance” effects might stem from inhibition across sensory systems. Does visual dominance generalize to odor-visual pairings? We developed a binary categorization task (fruits vs flowers) with congruent and incongruent odor-picture pairings and a delayed auditory target probe that informed about categorization modality (olfactory vs visual). We investigated behavioral and cortical (ERP) responses.For congruent pairings, we found better accuracy for visual decisions. However, for incongruent pairings, we instead observed faster RTs for olfactory decisions. Incongruent olfactory stimuli thus interfere more with visual decisions than vice versa.Our ERP results from auditory targets on incongruent trials gave supporting evidence for olfactory dominance over visual perception; higher P300 amplitudes were more strongly correlated with faster RTs during visual categorization. A late “slow wave” ERP effect had later onset and longer latency during visual vs olfactory decisions. This indicates that in order to rapidly and successfully categorize visual stimuli (and ignore incongruent odors), participants need to allocate additional attentional and working memory resources. In sum, both behavioral and ERP effects suggest a higher level of interference from incongruent olfactory, compared to visual, input.These findings suggest that asymmetric inhibition across sensory systems is a fruitful way of studying perceptual dominance, and that olfactory stimuli can dominate visual perception, refuting the general notion of “visual dominance”.

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• Olfaction Dominates Visual Perception

  2019. Jonas Olofsson (et al.).

  Konferens

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• Olfactory perception and blindness

  2019. Agnieszka Sorokowska (et al.). Psychological Research 83 (8), 1595-1611

  Artikel

  Anecdotal reports suggest that blind people might develop supra-normal olfactory abilities. However, scientific evidence shows a mixed pattern of findings. Inconsistent observations are reported for both sensory-driven olfactory tasks (e.g., odor threshold) and higher-order olfactory functions (e.g., odor identification). To quantify the evidence systematically, we conducted a review and meta-analysis. Studies were included if they examined olfactory function (i.e., odor threshold, odor discrimination, free odor identification, or cued odor identification) in blind compared with a sighted control group. Articles were identified through computerized literature search. A total of 18 studies focused on olfactory threshold (n = 1227: 590 blind and 637 sighted individuals), 14 studies targeted discrimination (n = 940: 455 blind and 485 sighted), 14 studies measured cued identification (n = 968: 468 blind and 500 sighted), and 7 studies (n = 443: 224 blind and 219 sighted individuals) assessed free identification. Overall, there were no differences in effect sizes between the blind and sighted individuals after correcting the results for publication bias. We additionally conducted an exploratory analysis targeting the role played by three moderators of interests: participants' age, the proportion of women versus men in each of the studies included into meta-analysis and onset of blindness (early blind vs. late-blind). However, none of the moderators affected the observed results. To conclude, blindness seems not to affect cued/free odor identification, odor discrimination or odor thresholds.

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• Subjective Olfactory Loss in Older Adults Concurs with Long-Term Odor Identification Decline

  2019. Ingrid Ekström (et al.). Chemical Senses 44 (2), 105-112

  Artikel

  Olfactory impairments may provide early indications of future health outcomes in older adults. Thus, an important question concerns whether these impairments can be self-assessed. Previous findings of cross-sectional studies indicate low correlations between self-reported olfactory function and objective olfactory performance. On the other hand, subjective olfactory impairments predict future dementia and mortality in longitudinal settings. No previous study has assessed the relationship between subjectively and objectively measured decline in olfaction over time. Based on data for 903 older adults derived from the Betula Study, a Swedish population-based prospective study, we tested whether rate-of-change in odor identification could be predicted from subjective olfactory decline over a time span of 10 years during which subjective and objective odor functions were assessed on 2 or 3 test occasions. Indeed, we found that participants who experienced subjective olfactory decline over the study period also had significantly steeper rates of decline in odor identification, even after adjusting for demographic, cognitive, and genetic factors that previously have been associated with performance in odor identification. This association was, however, not present in a subsample with baseline cognitive impairment. We interpret these results as evidence that when asked about whether they have an olfactory impairment or not, older persons are assessing intraindividual olfactory changes, rather than interindividual differences. Our results indicate that subjective olfactory loss reflects objective olfactory decline in cognitively intact older adults. This association might be harnessed to predict health outcomes and highlights the need to develop effective olfactory self-assessments.

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• The Allocation of Valenced Percepts Onto 3D Space

  2019. Fernando Marmolejo-Ramos (et al.). Frontiers in Psychology 10

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  Research on the metaphorical mapping of valenced concepts onto space indicates that positive, neutral, and negative concepts are mapped onto upward, midward, and downward locations, respectively. More recently, this type of research has been tested for the very first time in 3D physical space. The findings corroborate the mapping of valenced concepts onto the vertical space as described above but further show that positive and negative concepts are placed close to and away from the body; neutral concepts are placed midway. The current study aimed at investigating whether valenced perceptual stimuli are positioned onto 3D space akin to the way valenced concepts are positioned. By using a unique device known as the cognition cube, participants placed visual, auditory, tactile and olfactory stimuli on 3D space. The results mimicked the placing of valenced concepts onto 3D space; i.e., positive percepts were placed in upward and close-to-the-body locations and negative percepts were placed in downward and away-from-the-body locations; neutral percepts were placed midway. These pattern of results was more pronounced in the case of visual stimuli, followed by auditory, tactile, and olfactory stimuli. Significance Statement Just recently, a unique device called the cognition cube (CC) enabled to find that positive words are mapped onto upward and close-to-the-body locations and negative words are mapped onto downward and away-from-the-body locations; neutral words are placed midway. This way of placing words in relation to the body is consistent with an approach-avoidance effect such that good and bad things are kept close to and away from one's body. We demonstrate for the very first time that this same pattern emerges when visual, auditory, tactile, and olfactory perceptual stimuli are placed on 3D physical space. We believe these results are significant in that the CC can be used as a new tool to diagnose emotion-related disorders.

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• The semantic organization of the English odor vocabulary

  2019. Thomas Hörberg, Maria Larsson, Jonas K. Olofsson.

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  Most people find it difficult to name familiar odors. Many languages, including English, lack a vocabulary devoted to describing odor qualities (compared to, e.g., a color term vocabulary), and little is known about the vocabulary used to describe odors. Attempts to establish “primary odor descriptors” have been unsuccessful. To date, research on odor vocabulary has rarely been done from a data-driven, empirical perspective.

  We present a study on the semantic organization of odor vocabulary, based on the distribution of words in olfactory and gustatory contexts, using a three-billion-word corpus of written English. Using a data-driven, computational linguistic approach developed in our lab, we quantify terms with respect to the degree of olfactory-semantic content they convey. We then derive the semantic organization of the top 200 olfactory-related terms, using a distributional-semantic word vector model, which represent semantic distances as multidimensional vector distances. The model is trained on olfactory and gustatory contexts, using the word2vec neural network implementation. Based on the semantic distances, we then use dimensionality reduction and clustering techniques (i.e., PCA and hierarchical clustering) to derive a 3-dimensional, corpus-based semantic space, and six principal descriptor clusters.

  Using distances based on the Draveneiks odor-term ratings data set, we also derive a semantic space with six specific clusters for the Draveneiks terms. The organization and clustering of our corpus-based semantic space match with the ratings-based semantic space, thereby showing the viability of our corpus-based approach. Based on our corpus-based data, we finally propose a novel domain-general odor term taxonomy (i.e., a domain-general odor wheel) that captures the dimensions and clusters identified in our analyses.

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