Syftet med föreliggande studie var att ta fram ett svenskt material för att undersöka mottagligheten för semantiska illusioner vid bearbetning av auditivt språkligt meddelande hos vuxna individer utan kommunikationsstörning. Utöver detta syftade även studien till att undersöka om mottaglighet för den semantiska illusionseffekten är relaterad till lexikal åtkomst och arbetsminneskapacitet. I studiens initiala skede utformades det nya testmaterialet Auditivt test av mottaglighet för semantiska illusioner (ATSI). ATSI består av tre deltest, varje deltest innefattar 40 påståenden med en jämn fördelning av sanna påståenden, falska påståenden och illusoriska påståenden. Deltagarna i studien bestod av 30 vuxna individer utan kommunikationsstörning. Deltagarnas uppgift var att avgöra om påståendena i ATSI var sanna eller falska. Utöver ATSI utförde även deltagarna test gällande lexikal åtkomst och arbetsminneskapacitet. Effekten av semantiska illusioner analyserades genom t-test och visade att illusionseffekten var statistiskt signifikant. Resultaten från ATSI korrelerades med deltagarnas prestation gällande lexikal åtkomst och arbetsminneskapacitet. Hur lurade deltagarna blev av den semantiska illusionseffekten korrelerade med lexikal åtkomst. I föreliggande studie kunde inget samband observeras mellan hur lurade deltagarna blev och arbetsminneskapacitet. I diskussionen förs i föreliggande studie resonemang kring varierande metodologiska aspekter likväl som resultatens implikationer för den språkliga bearbetningsprocessen. Slutsatsen i föreliggande studie är att den semantiska illusionen är ett stabilt fenomen som har effekt vid bearbetning av språkligt meddelande auditivt. / The aim of this study was to construct a Swedish test material in order to examine the susceptibility for semantic illusions in adults without any communication disorders when processing verbal input of language. Furthermore the study aimed to investigate if the susceptibility for semantic illusions relates to the individual’s lexical access speed and working memory capacity. In order to accomplish the aim of the study, a new auditory test material called Auditivt Test av mottaglighet för Semantiska Illusioner (ATSI) was created. ATSI consists of three separate test sections, each containing 40 statements with an even distribution of true statements, false statements and statements containing the semantic illusion. The participants had to decide whether each statement was true or false. The participants in this study consisted of 30 adult individuals without communication disorders. Furthermore the participants performed test regarding lexical access speed and working memory capacity. The effects of semantic illusions were analyzed trough t-tests and found to be statistically significant. Correlation analysis were made between result from ATSI and lexical access speed as well as between results from ATSI and working memory capacity. How tricked the participants were by the semantic illusions was related to lexical access, but not working memory capacity. Methodological aspects are discussed in this study as well as the result’s implication for language processing. The conclusion is that semantic illusions is a stabile phenomenon, and it occurs when processing spoken sentences.

La désorganisation du discours est couramment observée en phase maniaque du trouble bipolaire. Elle peut se manifester par un langage incompréhensible, des idées décousues ou illogiques. Les premières études qui ont exploré les processus cognitifs sous-tendant ces perturbations du langage et du cours de la pensée dans le trouble bipolaire semblent en faveur de perturbations sémantiques. Pour déterminer la nature de ces perturbations, nous avons réalisé plusieurs études portant sur deux processus spécifiques : la propagation automatique de l’activation sémantique et l’inhibition sémantique. Pour évaluer ces processus nous avons construit deux tâches de décision lexicale basées sur l’amorçage sémantique. Celles-ci sont proposées à 17 patients bipolaires euthymiques ainsi qu’à un groupe de 61 personnes issues de la population générale pour lesquelles les traits de personnalité hypomaniaque et les tempéraments affectifs sont évalués. Les résultats montrent une moindre efficacité pour les deux processus dans le trouble bipolaire. Ces perturbations sont associées aux troubles du cours de la pensée. Dans la population générale, les résultats montrent que seule l’atteinte de la propagation automatique de l’activation est associée aux tempéraments hyperthymique et irritable. Cette association n’est pas retrouvée pour le processus d’inhibition sémantique, suggérant la mise en place de stratégies cognitives compensatoires lorsque les processus sont contrôlés. Nos résultats, associés à ceux de la littérature, semblent en faveur d’une approche dimensionnelle du trouble bipolaire et soulignent l’intérêt d’investiguer davantage la cognition dans les formes atténuées du trouble. / Disorganization of speech is commonly observed in the manic phase of bipolar disorder as incomprehensible language, disjointed or illogical ideas. Recent studies had explored the cognitive processes that underlie these disturbances of language and formal thought disorders in bipolar trouble. These studies appear to be in favor of semantic abnormalities. To determine the nature of these disturbances, we carried out studies which focus on two specific processes: the automatic spreading activation and the semantic inhibition. To assess these processes, two lexical decision tasks based on semantic priming were built. These tasks are proposed to 17 euthymic bipolar patients as well as to a group of 61 people from the general population for whom hypomanic personality traits and affective temperaments are evaluated. The results show lower efficacy for both processes in bipolar disorder. These disturbances are associated with the disturbances of formal thought disorders. In the general population, the results show that only the dysfunction of the automatic spreading activation is associated with hyperthymic and irritable temperaments. This association is not found for semantic inhibition, suggesting the intervention of compensatory cognitive strategies when the processes are controlled. Our results, combined with those of the literature, seem to be in favor of a dimensional approach to bipolar disorder and underline the interest of investigating cognition in the attenuated forms of the disorder.

In dieser Dissertation zeige ich anhand einer Reihe von Beispielen, wie das Langzeitgedächtnis die perzeptuelle Verarbeitung beeinflussen kann. Anhand einer Aufgabe zur visuellen Aufmerksamkeit verdeutliche ich, inwiefern episodische Erinnerungen perzeptuelle Distrakoreffekte reduzieren können. In Experiment 1 sollten Versuchspersonen zuvor gelernte Worte entweder ins Gedächtnis zu rufen oder die Erinnerung an die Worte zu unterdrücken. Anschließend mussten sie unter Zeitdruck neue, bisher nicht präsentierte Worte semantisch einordnen, wobei die Zielworte von den zuvor abgerufenen oder unterdrückten Worten flankiert waren. Da die flankierenden Worte für die semantische Entscheidungsaufgabe irrelevant und die Versuchspersonen instruiert worden waren, diese zu ignorieren, kann von einem perzeptuellen Distraktoreffekt ausgegangen werden. Distraktoreffekte waren für zuvor unterdrückte Gedächtnisinhalte im Vergleich zur abgerufenen Gedächtnisinhalten deutlich reduziert, was nahelegt, dass episodische Gedächtnisinhalte die Wahrnehmung beeinflussen. Auf dieser Erkenntnis aufbauend zeige ich in Experiment 2, wie die suppressionsinduzierte Reduktion der Verarbeitung von Distraktorreizen durch individuelle Differenzen maskiert werden kann. Schließlich wurden den Versuchspersonen in Experiment 3 in einer „Attentional-Blink“-Aufgabe unbekannte Objekte als zweites von zwei aufeinander folgenden Zielobjekten dargeboten. Versuchspersonen konnten Objekte, die mit einer neu gelernten semantischen Information assoziiert waren, besser erkennen als Objekte, die mit minimaler Information assoziiert waren. Dieser Effekt ging mit einer Modulation der ereigniskorrelierten Potenziale 100ms nach Erscheinen des Reizes einher. Diese Ergebnisse zeigen, dass Inhalte aus dem Langzeitgedächtnis Wahrnehmungsprozesse beeinflussen können und leisten damit einen weiteren Beitrag zur Erkenntnis, dass die Wahrnehmung gegenüber höheren Kognitionen nicht unabhängig ist. / Numerous studies are emerging which suggest that long-term memories can influence early perceptual processing. Notwithstanding, these finding have come under fire from critics who view perceptual processing as independent of cognition. In this dissertation I demonstrate novel instances of long-term memory effects on perceptual processing, both in the context of an attentional task where I look at the extent to which episodic memory can reduce perceptual distraction and in a conscious detection task where I assess the effect of semantic knowledge on peoples ability to consciously detect briefly presented objects. In experiment one, participants retrieved or suppressed previously memorised words. Following this task, participants made speeded semantic judgments on novel target words that were flanked by the words that had previously undergone suppression or retrieval. Because the flanking words were irrelevant to the semantic judgment and were supposed to be ignored, any influence of their presence on semantic judgment speed can be taken as a marker of perceptual distraction. Results showed that the tendency for flankers to distract from target processing was markedly reduced if those flankers had undergone suppression. In experiment two, I expanded upon this finding by showing how this suppression-induced reduction in distractor processing can be masked by individual differences. Finally, in experiment three, I presented pictures of novel objects to participants as the second of two targets in an attentional blink paradigm. Results showed that participants were able to perceive objects associated with newly acquired semantic knowledge better than objects associated with minimal knowledge, a finding that was associated with a modulation of event-related brain potentials 100 msec after stimulus onset. Taken together, these experiments contribute to the growing body of evidence showing that information from long-term memory can influence perceptual processing.

Ovarian steroid hormones are neuroactive steroids with widespread actions in the brain, and are thus able to influence mood, behavior and cognition. In this thesis the effects of progesterone withdrawal and the direct effects of the progesterone metabolite allopregnanolone are evaluated. Allopregnanolone, through binding to the GABAA receptor complex, enhances inhibitory neurotransmission, thus exerting anxiolytic, sedative and antiepileptic effects. The acoustic startle response (ASR) is a withdrawal reflex evoked by sudden or noxious auditory stimuli, and can be measured in humans as an eye blink. ASR is significantly increased in several anxiety disorders, and notably also during progesterone withdrawal. Sensorimotor gating can be assessed by measuring prepulse inhibition of the startle response (PPI). The CNS circuits regulating PPI are sensitive to hormone fluctuations. GABAergic drugs are involved in cognitive impairment and animal studies have indicated that allopregnanolone may inhibit learning. The main purpose of this research was to evaluate the behavioral effects of progesterone withdrawal on the startle response and sensorimotor gating in PMDD patients and healthy controls, in healthy third trimester pregnant women and healthy postpartum women. A second aim was to evaluate allopregnanolone effects on memory and cognition in healthy women and also on the startle response and PPI. We found that PMDD patients have an increased startle response across the menstrual cycle and a deficiency in sensorimotor gating during the late luteal phase. Ovarian steroids affect sensorimotor gating; pregnant women have lower levels of PPI than late postpartum women. Acutely administered allopregnanolone did not affect the ASR or PPI. Allopregnanolone impairs episodic memory in healthy women. In conclusion, our studies suggest that ovarian steroids, including allopregnanolone, do not influence the startle response. Ovarian steroids affect sensorimotor gating; pregnancy, a condition with high levels of ovarian steroids, suppresses PPI. Theoretically, the variability in PPI across reproductive events is due to effects mediated by the progesterone or estradiol receptors but is not mediated by allopregnanolone. PMDD patients display decreased PPI during the late luteal phase, suggesting underlying pathophysiology in common with other anxiety disorders. The most vulnerable memory system, the episodic memory, is impaired by the allopregnanolone in healthy women.

The aim of the present thesis was twofold, first to map the semantic memory decline in Alzheimer patients over time, second to take the patient’s perspective and create a multifaceted picture of the individual with Alzheimer’s disease through the study of memory, awareness, central coherence and emotions. Further issues concerned how Alzheimer individuals handled their cognitive erosion in everyday life and if they were well calibrated with their spouse in disease related matters. Two studies were performed, the first involved a longitudinal study of sematic deterioration, the second had a mixed methods design involving both quantitative and qualitative measures as in neuropsychological assessment and interviews. Through the longitudinal study it could be concluded that the nature of semantic deterioration is best described as loss of memory information rather than problems in accessing the information. It was further concluded that semantic concepts gradually lose their specific features during course of illness. The results from the second study revealed that the Alzheimer individuals were aware of their disease although they could not foresee the implications of their cognitive shortcomings in their everyday life. They evidenced weak central coherence, in that they were unable to infer details into a meaningful whole. This implies that they perceive their surrounding world in a fragmented way as consisting of separate objects rather than a comprehensible context. Concerning emotions it was found that they responded to negatively valenced words in the same way as normal ageing individuals, although being impaired in their response to positively and neutral words. Finally, the Alzheimer individuals and their spouses were not well calibrated regarding disease related issues. The findings of the present thesis have important clinical implications and gives valuable input to the understanding of the individual with Alzheimer’s disease. / Föreliggande avhandling hade två huvudsyften; dels att kartlägga försämringen av semantiskt minne hos Alzheimerpatienter över tid; dels att ta patientens perspektiv och skapa en mångfacetterad bild av individen med Alzheimers sjukdom. Fyra begrepp studerades i relation till detta, nämligen minne, medvetande, central koherens och emotioner. Ytterligare aspekter som studerades var hur Alzheimerindivider hanterar sina kognitiva tillkortakommanden i sin vardag samt hur väl kalibrerade de är med sin make/maka angående sjukdomsrelaterade frågor. Två studier genomfördes varav den första var en longitudinell studie av semantisk minnesförsämring och den andra hade en ’mixed methods’ design, inkluderande både kvantitativa (neuropsykologiska tester) och kvalitativa (intervjuer) metoder. Resultaten från den longitudinella studien avslöjade att semantiska begrepp som inte längre är välrepresenterade hos individen har gått förlorade snarare än att det skulle vara från om att individerna inte kan plocka fram informationen. Vidare kunde konstateras att semantiska begrepp gradvis tappar sina nyanser i takt med att sjukdomen fortskrider. Den andra studien visade att Alzheimerindividerna var medvetna om sin sjukdom och sina minnesproblem men att de inte kunde förutsäga vilka problem deras kognitiva tillkortakommanden skapade i deras vardag. De konstaterades ha svag central koherens vilket innebär att de ser sin omgivning på ett fragmentariskt sätt utan att kunna få ihop de olika objekten runt omkring sig till en meningsfull kontext. Vad gäller emotioner så kunde konstateras att Alzheimerindivider reagerar likadant som normalt åldrande individer på negativt laddade ord men att de är signifikant försämrade i förmågan att känna igen positiva och neutrala ord. Alzheimerindividerna och deras make/maka var inte väl kalibrerade vad gäller sjukdomsrelaterade frågor. Avhandlingens resultat har viktiga kliniska implikationer och ger ett värdefullt bidrag till förståelsen av en individ med Alzheimers sjukdom.

Cognitive functioning is important for managing work and life in general. However, subjective cognitive complaints (SCC), involving self-perceived difficulties with concentration, memory, decision making, and clear thinking are common in the general and in the working population and can be coupled with both lowered well-being and work ability. The present thesis investigated the extent to which SCC among people in the work force can be explained by objective cognitive functioning (study I &amp; II) and working conditions (study III), utilizing samples from the working population. The potential roles of other common psychological problems which often co-occur with SCC were also investigated in studies I-III. In Study I, high levels of SCC were associated with significantly poorer episodic memory performance during high executive demands and a trend was found towards poorer episodic memory, while not being associated with semantic memory. In Study II, high levels of SCC were associated with significantly poorer executive cognitive performance on all three executive cognitive tests used. Symptoms of depression, chronic stress and sleeping problems were found to play an important role in the relations between SCC and episodic memory during divided attention in study I and executive cognitive functioning in study II. In Study III, in all cross-sectional data analyses, high quantitative demands, information and communication technology (ICT) demands, underqualification in the work situation and inter-personal conflicts were positively associated with SCC, whereas social support, good resources at work and overqualification in the work situation were negatively associated with SCC. In all prospective data analyses, quantitative job demands, ICT demands and underqualification were positively associated with future SCC, including when adjusted for baseline cognitive complaints. The findings may guide prevention of and interventions for SCC among people in the work force. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Submitted. Paper 2: Accepted.</p>

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We describe the automatic acquisition of a semantic network in which over 7,500 of the most frequently occurring nouns in the English language are linked to their semantically related concepts in the WordNet noun ontology. Relatedness between nouns is discovered automatically from lexical co-occurrence in Wikipedia texts using a novel adaptation of an information theoretic inspired measure. Our algorithm then capitalizes on salient sense clustering among these semantic associates to automatically disambiguate them to their corresponding WordNet noun senses (i.e., concepts). The resultant concept-to-concept associations, stemming from 7,593 target nouns, with 17,104 distinct senses among them, constitute a large-scale semantic network with 208,832 undirected edges between related concepts. Our work can thus be conceived of as augmenting the WordNet noun ontology with RelatedTo links. The network, which we refer to as the Szumlanski-Gomez Network (SGN), has been subjected to a variety of evaluative measures, including manual inspection by human judges and quantitative comparison to gold standard data for semantic relatedness measurements. We have also evaluated the network’s performance in an applied setting on a word sense disambiguation (WSD) task in which the network served as a knowledge source for established graph-based spreading activation algorithms, and have shown: a) the network is competitive with WordNet when used as a stand-alone knowledge source for WSD, b) combining our network with WordNet achieves disambiguation results that exceed the performance of either resource individually, and c) our network outperforms a similar resource, WordNet++ (Ponzetto & Navigli, 2010), that has been automatically derived from annotations in the Wikipedia corpus. iii Finally, we present a study on human perceptions of relatedness. In our study, we elicited quantitative evaluations of semantic relatedness from human subjects using a variation of the classical methodology that Rubenstein and Goodenough (1965) employed to investigate human perceptions of semantic similarity. Judgments from individual subjects in our study exhibit high average correlation to the elicited relatedness means using leave-one-out sampling (r = 0.77, σ = 0.09, N = 73), although not as high as average human correlation in previous studies of similarity judgments, for which Resnik (1995) established an upper bound of r = 0.90 (σ = 0.07, N = 10). These results suggest that human perceptions of relatedness are less strictly constrained than evaluations of similarity, and establish a clearer expectation for what constitutes human-like performance by a computational measure of semantic relatedness. We also contrast the performance of a variety of similarity and relatedness measures on our dataset to their performance on similarity norms and introduce our own dataset as a supplementary evaluative standard for relatedness measures.

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No description available.