Smell plays a vital role in our daily lives and influences the way we perceive the world around us. People have the excellent ability to detect and distinguish odors, but they usually have difficulty in identifying individual odors. Olfactory abilities (olfactory identification, olfactory detection and olfactory discrimination) also differ significantly interindividually. In general, however, women achieve better results. While a number of studies point to sex differences in olfactory perception, especially in the identification of odors, we need to understand sex only as an overarching concept that includes specific factors such as hormonal influences or different odor experiences that can actually influence olfactory abilities. One of them could be verbal fluency, which allows us to recall information from memory, as there are studies showing the link between the ability to identify odors and verbal fluency. The main aim of the thesis was to test whether the difference between males and females in the identification of odors is mediated by a sex difference in verbal fluency. The secondary aim of the thesis was to explore whether the connection of odor identification and verbal fluency varies according to which form of verbal fluency is tested (phonetic or semantic), and whether these tests can be...

<p>In this thesis lateralization of olfactory functions was investigated by both behavioral and electrophysiological assessment, the latter with the olfactory event-related potential (OERP) technique. The olfactory sense is primarily ipsilateral in that a stimulus that is presented to one nostril is initially processed in the same hemisphere. This makes it possible to observe differences between stimulated nostrils as an indication of hemispheric difference. Study I explored differences in olfactory cognitive functions with respect to side of rhinal stimulation and demonstrated that familiarity ratings are higher at right- compared to left-nostril stimulation. No differences were found in episodic recognition memory or free identification, possibly reflecting inter-hemispheric interactions in higher cognitive functions. Effects of repetition priming were present in odor identification and tended to be more pronounced when tested via left nostril. Study II further investigated the effect of previous exposure in odor identification by a different experimental set-up, and demonstrated effects of repetition priming when tested via left- but not right-nostril stimulation. This finding indicates the importance of reconsidering possible sequential effects in olfactory research. Study III examined methodological aspects of an OERP protocol with respect to stimulus duration, which was used in Study IV. No differences in amplitudes or latencies where found between the stimulus durations of 150, 200 and 250 ms, suggesting the commonly used duration of 200 ms in a standard protocol. Study IV investigated laterality effects in OERPs with respect to side of stimulation and electrode site. The results showed consistent amplitudes and latencies regardless of rhinal side of stimulation. Larger amplitudes were demonstrated on left hemisphere and midline compared to right hemisphere, possibly explained by smaller N1/P2 amplitudes at the right-hemisphere sites at left-nostril stimulation. Apart from a proposed OERP protocol, the findings support the notions of a right-hemisphere predominance in processes related to olfactory perception and indicate, in accordance with other findings, a left-side advantage in conceptual repetition priming.</p>

In this thesis lateralization of olfactory functions was investigated by both behavioral and electrophysiological assessment, the latter with the olfactory event-related potential (OERP) technique. The olfactory sense is primarily ipsilateral in that a stimulus that is presented to one nostril is initially processed in the same hemisphere. This makes it possible to observe differences between stimulated nostrils as an indication of hemispheric difference. Study I explored differences in olfactory cognitive functions with respect to side of rhinal stimulation and demonstrated that familiarity ratings are higher at right- compared to left-nostril stimulation. No differences were found in episodic recognition memory or free identification, possibly reflecting inter-hemispheric interactions in higher cognitive functions. Effects of repetition priming were present in odor identification and tended to be more pronounced when tested via left nostril. Study II further investigated the effect of previous exposure in odor identification by a different experimental set-up, and demonstrated effects of repetition priming when tested via left- but not right-nostril stimulation. This finding indicates the importance of reconsidering possible sequential effects in olfactory research. Study III examined methodological aspects of an OERP protocol with respect to stimulus duration, which was used in Study IV. No differences in amplitudes or latencies where found between the stimulus durations of 150, 200 and 250 ms, suggesting the commonly used duration of 200 ms in a standard protocol. Study IV investigated laterality effects in OERPs with respect to side of stimulation and electrode site. The results showed consistent amplitudes and latencies regardless of rhinal side of stimulation. Larger amplitudes were demonstrated on left hemisphere and midline compared to right hemisphere, possibly explained by smaller N1/P2 amplitudes at the right-hemisphere sites at left-nostril stimulation. Apart from a proposed OERP protocol, the findings support the notions of a right-hemisphere predominance in processes related to olfactory perception and indicate, in accordance with other findings, a left-side advantage in conceptual repetition priming.

Olfactory function is affected by demographic, cognitive, and genetic factors. In the present thesis, three empirical studies investigated individual differences in olfactory ability. Study I explored demographic and cognitive correlates in common olfactory tasks; odor detection, odor discrimination, and odor identification. The results indicated that old age influenced performance negatively in all tasks, and that semantic memory proficiency and executive functioning were related to odor discrimination and odor identification performance. No cognitive influence was observed for measurements of olfactory threshold. Using population-based data, Study II investigated a potential influence of the ApoE gene on olfactory identification after controlling for health status, semantic memory, and preclinical and clinical dementia. The main finding was that the ApoE- ɛ4 allele interacted with age, such that older ɛ4-carriers had an impaired odor identification performance relative to older non-carriers. Importantly, the negative ApoE- ɛ4 effect on olfactory proficiency was independent of clinical dementia conversion within five years. Study III investigated the effects of the BDNF val66met polymorphism on olfactory change over a five-year interval, in a community dwelling sample of young and old age cohorts. The results showed that age-related decline in olfactory identification was influenced by the BDNF val66met. In middle-aged subjects, no effect of BDNF val66met was observed although older val homozygote carriers showed a selectively larger olfactory decline than the older met carriers. Overall, results suggest that the relative influence of demographic and cognitive factors vary across different olfactory tasks and that two genes (ApoE and BDNF) impact age-related deficits in odor identification. Potential theoretical and practical implications of the findings are discussed as well as potential limitations of association studies in genomics research.

Episodic memory for olfactory information is still relatively uncharted. The overall purpose of this thesis is to investigate the sensory and cognitive causes of the well-established age-related decline in olfactory episodic odor memory and of the age-independent sex difference in olfactory episodic memory. The purpose of Study I was to investigate the causes of the sex difference in olfactory episodic memory. The results show that the female advantage in episodic recognition memory seems to be explained by women´s higher aptitude in odor identification for familiar odors. With this background, the purpose of Study II was to investigate the age-related decline in olfactory episodic memory, with a particular eye to the role of odor identification. When controlling for the sensory variables olfactory threshold and odor quality discrimination, and the cognitive factor mental speed, the age-related deterioration in odor identification was eliminated. This suggests that changes in basic sensory and cognitive abilities underlie the age-related impairment in odor identification. The purpose of Study III was to investigate the role of recollective experience and intention to memorize for age-related and sex-related differences in episodic odor memory. Younger adults reported more experiences of remembering, and the elderly adults more experiences of feeling of knowing. The participants benefited from intentionality at encoding when the odors were unfamiliar, but intentionality did not affect memory for the familiar odors. The purpose of Study IV was to investigate the role of subjectively perceived qualities of the encoded odors for episodic memory across age and sex. Odors perceived as unpleasant, intense, and irritable were more easily remembered throughout the adult life span. The oldest adults selectively recognized the odors they rated as highly irritable indicating compensatory use of trigeminal activation. Overall, the result suggests that episodic odor memory rely heavily on both sensory and cognitive abilities, but in a different manner depending on demographic factors. The age-related decline appears to be driven by a sensory flattening disabling adequate cognitive processing. The age-independent sex difference on the other hand, is mainly cognitively mediated and driven by cognitive factors such as the ability to verbalize olfactory information.

Orientador: Maria Aparecida Azevedo Pereira da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T19:30:51Z (GMT). No. of bitstreams: 1 Natalicio_MariaAngelica_D.pdf: 1137447 bytes, checksum: bf1a6d401d0100649213c09ece37f7f9 (MD5) Previous issue date: 2012 / Resumo: Testes sensoriais para a avaliação da função olfatória de indivíduos têm sido validados e utilizados em diagnósticos da população em geral, e em portadores de desordens cerebrais e pesquisas em neurociência em particular. No Brasil, testes para serem utilizados com segurança e eficiência para a avaliação da capacidade de identificação e discriminação de odores de indivíduos ainda não foram adequadamente desenvolvidos e validados. Assim, os objetivos da presente pesquisa foram: i) desenvolver, testar e validar testes de identificação e discriminação de odores para avaliar a função olfatória de indivíduos brasileiros, ii) avaliar a potencialidade das metodologias desenvolvidas para uso em pré-diagnóstico clínico de indivíduos da terceira idade e pacientes portadores de epilepsia, iii) verificar o desempenho, em portadores de epilepsia, de uma metodologia já validada e utilizada mundialmente para avaliar a capacidade de identificação de odores de indivíduos e, iv) avaliar em portadores de epilepsia, funções que são processadas por substratos neurais comuns à função olfatória, neste caso, a capacidade de reconhecimento de emoção facial e vocal. Para o teste de identificação de odores, foi desenvolvido um instrumento intitulado &quot;Pastilhas de Odor¿ contendo em pastilhas individuais, 36 odores familiares aos brasileiros. Os odores foram caracterizados quanto à intensidade, aceitação, pungência, refrescância e familiaridade, sendo considerados adequados para comporem um teste de avaliação da função olfatória. A identificação dos odores de &quot;Pastilhas de Odor¿ foi realizada através de um teste de múltipla escolha contendo quatro alternativas, das quais apenas uma é a correta. Para o desenvolvimento do teste de discriminação de odores, 24 voláteis odoríferos puros (P.A.), associados a 6 diferentes categorias de odor - doce, verde, frutal, cítrico, floral e desagradável - foram selecionados e diluídos em propilenoglicol. Com essas amostras, 36 testes de comparação pareada foram construídos, onde em cada categoria de odor, uma amostra alvo foi selecionada para ser comparada com as demais da mesma categoria. O desempenho de cada indivíduo neste teste é analisado utilizando-se a teoria &quot;signaldetection¿, através dos seguintes parâmetros: taxa de acertos (HR), taxa de falsos alarmes (FR), poder discriminativo (d¿L) e vício de resposta (CL). Os dois testes desenvolvidos - &quot;Pastilhas de Odor¿ e teste de discriminação - foram validados com a participação de três grupos de indivíduos: grupo controle, grupo da terceira idade e grupo de indivíduos portadores de epilepsia do lobo temporal (ELT). A capacidade de identificação de odores, de pacientes norte-americanos portadores de ELT foi também avaliada, utilizando-se com esse fim, o teste já validado, denominado &quot;University of Pennsylvania Smell Identification Test¿ (UPSIT), o qual consiste em um teste de múltipla escolha, composto por 40 estímulos odoríferos microencapsulados. Adicionalmente, avaliou-se nesses pacientes, a capacidade de reconhecimento de emoção facial e vocal, utilizando-se uma nova ferramenta intitulada &quot;Comprehensive Affect Testing System¿ (CATS). Com relação à capacidade de identificação de odores dos indivíduos brasileiros, os resultados obtidos através do teste &quot;Pastilhas de Odor¿ revelaram significância estatística tanto para o efeito &quot;sexo¿ (p=0,0003), como para o efeito &quot;idade¿ (p<0,001). O teste também permitiu identificar que os portadores de ELT, sem cirurgia e após ressecção do lobo temporal, apresentavam menor capacidade de identificação de odores comparativamente ao grupo controle (p= 0,05); este mesmo resultado foi observado ao aplicar o UPSIT em portadores de ELT norte-americanos, antes e após os mesmos terem sido submetidos à mencionada cirurgia. O teste &quot;Pastilhas de Odor¿ mostrou ser de fácil manuseio e aplicação em indivíduos adultos, apresentou alto coeficiente de confiabilidade no teste-reteste (r=0,87, p<0,001) e suas pastilhas apresentaram boa estabilidade ao armazenamento durante 3 meses. Por sua vez, os dados obtidos através do teste de discriminação de odores identificaram que tanto o grupo da terceira idade como o dos portadores de ELT apresentaram poder discriminativo e taxa de acertos inferiores (p=0.05) aos indivíduos do grupo controle. Os resultados obtidos pela aplicação do teste CATS em indivíduos norte-americanos, revelaram que pacientes ELT tanto pré- como póscirúrgicos apresentaram menor reconhecimento de emoção facial e vocal quando comparados com o grupo controle, principalmente para as emoções negativas. O fato dos testes &quot;Pastilhas de Odor¿ e de discriminação de odores desenvolvidos na presente pesquisa terem detectado deficiência olfatória nos indivíduos brasileiros da terceira idade e portadores de epilepsia, constrói validade para a utilização dos mesmos em diagnósticos clínicos associados a essas populações / Abstract: Sensory tests to evaluate olfactory function have been validated and used in the diagnosis of subjects, mainly in brain disorders patients, and in the neuroscience research. In Brazil, reliable tests of odor discrimination and identification have not been appropriately developed and validated. The aims of the present study were: i) to develop, test and validate odor discrimination and identification tests to assess olfactory function of Brazilian population; ii) to evaluate the methodologies performance in the diagnosis of elderly subjects and epilepsy patients. For odor identification test, the developed instrument was entitled &quot;Odor Tablets¿, with 36 different odors familiar to Brazilians; to verify the performance in patients with epilepsy, a methodology previously validated and used worldwide to evaluate the ability to identify odors of individuals, and iv) to evaluate in patients with epilepsy, functions that are processed by common neural substrates for olfactory function, in this case, the ability of recognition of voice and facial emotion. Odors were rated as to their intensity, pleasantness, pungency, coolness and familiarity and they were considered suitable for composing a test to assess olfactory function. &quot;Odor Tablets¿ proceeded through multiple-choice test with four alternatives which only one was correct. For the development of odor discrimination test, 24 pure odorants, associated with six different odor categories ¿ sweet, green, fruity, citric, floral and unpleasant - were selected and diluted in propylene glycol. With these samples, 36 paired comparison tests were constructed, where in each odor category, a target sample was selected to be compared with the others in the same category. The participant¿s performance in the odor discrimination test was analyzed using the &quot;signal-detection" theory through the following parameters: hit rate (HR), false-alarm rate (FR), discrimination measurement (d 'L) and bias response (CL). Both tests, &quot;Odor Tablets¿ and odor discrimination test, were validated with three groups of subjects: control group, elderly group and temporal lobe epilepsy patients group (TLE). The ability to identify odors from North American TLE patients was also measured, using for this purpose, the validated test "University of Pennsylvania Smell Identification Test" (UPSIT), a multiple choice test consisting of 40 microencapsulated odor stimuli. In addition, the ability of recognition of voice and facial emotion of TLE patients were evaluated using a new tool entitled "Comprehensive Affect Testing System" (CATS). For the subject¿s ability to identify odors, there were significant differences for gender (p=0.0003) and age (p<0.001). Also, for this test, the results showed that pre- and postsurgery epilepsy patients presented lower performance than the control group (p= 0.05); This same result was observed when applying the UPSIT in American TLE patients before and after surgery. &quot;Odor Tablets¿ proved to be easy to administer in adult subjects, showed a high coefficient of the test-retest reliability (r = 0.87, p<0.001), and the tablets presented a storage stability for 3 months. The discrimination test results showed that elderly and epilepsy patient groups presented lower performance in the discrimination measurement and hit rate parameters than the control group. The results obtained using the CATS test in American TLE patients revealed that both pre-and post-surgery showed deficits in the facial and vocal emotions when compared with the control group, especially for negative emotions. The fact that the &quot;Odor Tablets¿ and the discrimination odor test developed in the present study had detected olfactory dysfunction in elderly subjects and epilepsy patients, provides their validity for use in the diagnoses of these population / Doutorado / Consumo e Qualidade de Alimentos / Doutor em Alimentos e Nutrição

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<p>Although many aspects of odor naming have received attention during the years, the participants' own cognitions (metamemory) about their naming attempts have not. (i) We showed that feeling of knowing (FOK) judgments accompanying odor naming failures are predictive of later recognition (Study I) or retrieval (Study III) of the missing name, but to a lesser degree than equivalent judgments about names of persons. “Tip of the nose” (TON) experiences do predict later odor name recall (Study I), but are otherwise poorly related to any partial activation of other information associated with the odor. (ii) We evaluated two theories proposed to explain the underlying basis of FOK judgments. Correlational analysis showed that FOK judgments about odor names are related to the perceived familiarity of the cue triggering the FOK (cue familiarity theory; Study III). FOK judgments are based on the amount of available information about the sought-for memory (accessibility theory; Study I and III). (iii) We demonstrated that the participants are overconfident in their odor naming attempts (Study I and II). This may to some degree be due to the arousing properties of the odors (Study II), suggesting that emotional variables should be taken into account when researching metamemory. (iv) Our inability to correctly name odors are typically not due to an uniquely poor association between odors and their proper names, but rather due to failures to identify the odors (Study III), that is, failures to retrieve “what it is”. It was also found that TOT experiences are unusual for odor names and more so than for person names. (v) We discuss potential differences between olfactory metamemory and metamemory for other modalities. The TON experience differs from the tip of the tongue (TOT) experience and the predictive validity is lower for metamemory judgments about odor names compared to other modalities.</p>

Although many aspects of odor naming have received attention during the years, the participants' own cognitions (metamemory) about their naming attempts have not. (i) We showed that feeling of knowing (FOK) judgments accompanying odor naming failures are predictive of later recognition (Study I) or retrieval (Study III) of the missing name, but to a lesser degree than equivalent judgments about names of persons. “Tip of the nose” (TON) experiences do predict later odor name recall (Study I), but are otherwise poorly related to any partial activation of other information associated with the odor. (ii) We evaluated two theories proposed to explain the underlying basis of FOK judgments. Correlational analysis showed that FOK judgments about odor names are related to the perceived familiarity of the cue triggering the FOK (cue familiarity theory; Study III). FOK judgments are based on the amount of available information about the sought-for memory (accessibility theory; Study I and III). (iii) We demonstrated that the participants are overconfident in their odor naming attempts (Study I and II). This may to some degree be due to the arousing properties of the odors (Study II), suggesting that emotional variables should be taken into account when researching metamemory. (iv) Our inability to correctly name odors are typically not due to an uniquely poor association between odors and their proper names, but rather due to failures to identify the odors (Study III), that is, failures to retrieve “what it is”. It was also found that TOT experiences are unusual for odor names and more so than for person names. (v) We discuss potential differences between olfactory metamemory and metamemory for other modalities. The TON experience differs from the tip of the tongue (TOT) experience and the predictive validity is lower for metamemory judgments about odor names compared to other modalities.