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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Orthographic Representations and Working Memory Properties in the Spelling Process: A Neuropsychological Analysis

Costa, Vanessa January 2010 (has links)
The present thesis investigates the graphemic stage of the spelling process. Aim of thesis is to study the sub-processes occurring at the orthographic working memory level and the interaction between graphemic representations and working memory that holds these representations active during spelling. Chapter 1, after a brief description of the two-routes spelling model adopted in this research, deals with, presenting neuropsychological evidences, some of the most important issues about the relations between the different levels of elaboration that are engaged in the spelling process. Final part of this chapter is dedicated to the review of the neuropsychological researches regarding the structural organization and the processing of the orthographic representation. Chapter 2 reports the cases of GSI and CRI, two dysgraphic subjects with a selective deficit for consonants and a graphemic buffer disorder (GBD), whose spelling patterns are consistent with the hypothesis that their deficits affect different properties of orthographic working memory: temporal stability for GSI and representational distinctiveness for CRI. Their performance on spelling task demonstrate two things: first, GBD is not a homogeneous deficit because different sub-processes, involved in graphemic buffering, can be selectively affected by cerebral damage; second, different patterns of GSI and CRI arise from interaction of consonant representation and WM properties, both impaired in these subjects. Chapter 3 reports the case of a third dysgraphic subject, PPO, with a selective disorder for consonants but whose spelling picture was not identifiable as a clear GBD. Spelling pattern of this subject, quite different from those of both subjects of Chapter 2, demonstrates that the internal structure of orthographic representation, holding at working memory level, can be selectively impaired in the absence of working memory deficit. Moreover, PPO’s results on spelling task confirm the role of temporal stability and representational distinctiveness in the spelling and the interaction between representations and WM. Finally, Chapter 4 summarizes all the presented results and discusses the implications.
142

The smell of altruism: Incidental pleasant odors and chemosignal as prosocial decisions moderators

Perrotta, Valentina January 2012 (has links)
The study of the interactions between olfaction and the decision making processes has mainly focused on the investigation of what is considered the most useful odor to disperse in the air to drive the consumers' choices to prefer a product rather than another one. Despite the fact that some studies showed the existence of associations between odors and prosocial behavior, much less data are available on the links between olfaction and donation in favor of public goods. Thus, the main purpose of the series of experiments described in this thesis is precisely that to shed some light on the investigation of the nature of pleasant odor-decision and on the chemosignal-decision associations. In order to achieve this, the presence of an odor and the congruence between odor and decision task has been manipulated, and the decision to donate has been tested in different domains. Therefore, in the first series of experiments, we manipulated the presence of an ambient pleasant odor, expecting that the congruent stimuli sharing the more stable association odor-concept, would have resulted in an overall increase in the WTC (willingness to contribute) and WTP (willingness to pay) in the decision to donate in favor of a public good. The results confirmed the existence of an association between the olfactory stimulus congruence and the amount donated in favor of a public good. Interestingly, this effect is confirmed in both hypothetical and real decision settings. Moreover, the stimulus modality was manipulated presenting congruent olfactory or visual stimuli. Our findings confirmed the preferential link between olfaction and cognitive processes and showed higher donations in the olfactory setting (compared to the visual one). The existence of associations between odors and words are examined to know if the odors could semantically drive cognitive processes different from decision making. The results confirmed the existence of an association between the olfactory stimulus pleasantness and the performance in a lexical decision task (LDT). Thus, this effect is mediated by the presence of a pleasant odor and not by the semantic congruence between odor and the presented words. Moreover, the visual modality tend to worsen the LDT performance even if the visual stimulus was semantically congruent with the word presented. Finally, even though the semantic link appears to be crucial for cognitive processes such as decision, it seems not so important for memory and linguistic processes involved in the LDT. The second series of studies involved the presence of chemosignal, expecting that the congruity between stimulus and decision (the chemosignal used is AND, known as the best candidate to be considered a human chemosignal) would have resulted in an overall increase in amount of money donate to unknown persons during Dictator and Trust Game. The results confirmed the existence of an association between the chemosignal stimulus presence (and its olfactory experience) and the amount donated, and a mediation effect due to the positive mood (in presence of AND) especially in females and with high AND concentration.
143

The Arousing Risk: Influences of positive and negative arousal on preferences for economic risk

Galentino, Andrea January 2015 (has links)
Standard economic models explain decision making under risk as a utility maximization process. Developments in cognitive psychology and neuroeconomics showed the volatility of such conceptualization highlighting human bounded rationality and discussing the role of decision maker’s affective state (basic reactions to any emotionally charged event) in cognitive evaluation of risk (risk as feeling). In particular, an affective-based evaluation of choice options may determine whether decision maker’s behavior will be risk averse or risk seeking. Evidence indicates that affective reactions carry over significant information about the goodness of certain choice options directly influencing risk taking behavior. Affective influences on decisions may be directly associated with the evaluation of the choice options and the anticipation of future outcomes (integral affect) or may be associated with stimuli or event unrelated to the decision at hand, for example contextual factors or environmental cues (incidental affect). A classic advertisement strategy, such as a smiling face presented in association with a good, is an example of contextual affective manipulation. Research shows that experiencing a positive affective state may lead to risk aversion behavior while negative affect may lead to risk seeking. However, previous studies mostly adopted a valence-based approach to the study of affect ignoring its multidimensional nature. In particular, the role of arousal has been largely neglected. Recent studies showed that emotional states with the same valence may have opposite consequences on risk taking. Therefore, the main purpose of the series of studies described in this dissertation was to investigate the effect of inducing incidental affective states at high and low levels of negative arousal or positive arousal on preferences for monetary options varying in risk. Research shows that elevated arousal is associated with cognitive depletion, increased sensitivity to rewards, immediate gratification, less resistance to temptation. Therefore, we hypothesized that affective states characterized by high levels of arousal might increase preferences for the riskier option. We further predicted that including arousing stimuli as contextual factor of a decision scenario would capture individual attention interfering with information processing of risk. In order to achieve this goal, in a first series of experiments we asked participants to make choices between couples of two-outcomes lotteries with the same expected value but different risk. Arousal was manipulated by presenting participants with visual stimuli (IAPS pictures) varying in the level of arousal (high or low) keeping the valence unvaried (negative or positive). By adopting the technique of contextual priming, participants were simultaneously exposed to stimuli (the lotteries) and the contextual factor (the arousing/unarousing image). An effect of arousal on predicting risky choice was found. Probability of selecting the riskier lottery was higher when an arousing stimuli (unpleasant or pleasant) was included as part of the decision context. In some cases, positive arousal was found to interact with gender: risk taking was higher in males than females when a pleasant arousing cue was presented. In a second series of studies, participants performed the same task and, by using an eye tracker, eye fixations and looking times were recorded. The predicted effect of arousal on attention was found. Participants spent more time looking at the arousing image (unpleasant or pleasant). This result is in line with arousal theories which correlate the level of arousal to attention allocated to the arousing stimuli. Furthermore, participants seemed to process less risky information (as indicated by decreased looking times toward the riskier option) when the arousing stimuli was contextually presented, as opposed to when the unarousing stimuli was presented.
144

The Talking Hands?: The Relation between Gesture and Language in Aphasic Patients

Yang, Fu Ju January 2011 (has links)
This thesis is composed of two individual but interconnected studies. The first study investigated the gestural ability of aphasic patients in comparison with healthy speakers, by analysing both qualitatively and quantitatively co-speech gestures during a story-retelling task. The objective was to understand the relation between language and gesture ability in the aphasic patient: whether impairments in language production influence gesture production, as suggested by the long existing notion “asymbolia†. If this is not the case, gesture then may play a very potential role in aphasic daily communication and rehabilitation, as suggested by researchers and clinicians (e.g., Marshall, 2006; Rodriguez et al., 2006) who proposed the use of gesture as a compensatory and facilitative means to assist aphasic individuals to communicate. In our first study, four aphasic patients and four age-matched healthy speakers were recruited. They were requested to retell stories after watching eight short films from the cartoon “Tweety and Silvester†. Both verbal and non-verbal production from the participant were video-taped for analyses. Group and individual analyses were performed to examine representational and non-representational gestures in per-100-word and per-minute measures. We found that in aphasic subjects, as a group, gestures were quantitatively indistinguishable from those produced by normal controls. Also, qualitative analyses demonstrated that the aphasic subjects tended to use representational gestures to cue or substitute for difficult-to-name words. This supports the notion that gesture may cue naming and may be a potential treatment approach in aphasia rehabilitation. The second study explored treatment efficacy of three approaches in aphasia rehabilitation – the Gesture-based, the Language-based, and the Combined approach, aiming to understand the effects elicited by these techniques in improving single word naming ability in aphasic patients. Previous research suggested that gesture training can facilitate word naming (see Rose, 2006 for review). Language-based treatment aiming to reconstruct concepts and restore phonological information on difficult-to-name words has been widely studied, but the therapeutic role played by gesture in language recovery has been rarely considered. Our second study recruited four chronic aphasic patients with word-finding difficulty to explore the effects of three types of treatment – Gesture-based, Language-based, and Combined, on the retrieval of nouns and verbs. It was hypothesized that gesture and language-based treatments alone would yield positive effects and that combined treatment would result in the largest improvement of single-word naming. In gesture-based treatment, patients were trained to produce a gesture that can be mapped onto a corresponding word. In language-based treatment, Semantic Feature Analysis and Phonological Component Analysis were used. The combined treatment includes the same materials used in the gesture-based and language-based treatments, but materials were alternated across sessions. Training materials included verbs of hand-related actions and nouns of manipulable objects. We found that all types of treatment, as hypothesized, led to significant item-specific improvement in both verb and noun naming. Three of four subjects showed the largest recovery following combined treatment, especially on verbs. This suggests that gesture, when combined with logopedic treatment, can boost naming skills.
145

Traits, States and Situations: Automatic Prediction of Personality and Situations from Actual Behavior

Kalimeri, Kyriaki January 2013 (has links)
Technology has a great impact on our everyday lives; computers, smart devices, sensors and digital technology in general, try to communicate with us to accomplish some task. Each step of the communication however, requires understanding of the future behavioral utterance, deciding on what is the circumstance and the social context, and finally predicting the individual’s needs. Even if computers are so deeply involved in our daily lives, they lack basic social skills that would allow for natural communication. We believe automatic personality recognition will provide computers with an essential social notion, improving the quality of services, such as in intelligent tutoring systems or information retrieval systems among many other uses. Over the past few years, researcher in social computing have shown that personality trait recognition from nonverbal behavior is feasible, yet, the accuracy rate never exceeds a certain level, due to a phenomenon called within-person variability. This means that individuals may vary their behavioral manifestation according to the situational context in which they are in. In this thesis, we propose a shift from the traditional personality trait theory, to an approach which incorporates the personality fluctuations. This new perspective defines personality as dynamic episodes, the so called personality states, which relate to situational factors. Based on this property, we define the notion of social situations and propose a fully data-driven approach based on the Topic Modeling theory. The active situational characteristics that emerge from the model are interpreted according to their interrelation to the personality states fluctuations. We also present an automatic framework based on topic modeling, which handles dynamic spatio-temporal patterns of behavior and aims to predict the semantic meaning of the situational patterns, in meaningful situations, without the need of expert annotators.
146

Shape-to-color associations in non-synesthetes: perceptual, emotional, and cognitive aspects

Malfatti, Michela January 2014 (has links)
The study of cross-modal and cross-dimensional associations in non-synesthetes has become an increasingly hot topic in recent times (see Spence, 2011, for a review). Despite the many examples of associations between shape/color-stimuli on one hand and stimuli of different sensory nature on the other hand, little is known about the way shape and color are interrelated with each other. The purpose of our research was to test whether non-synesthetes also exhibit systematic associations between these two different dimensions of the visual domain, that is, shape and color. Furthermore, our study also relates to art, and in particular to Kandinsky’s theory on shape-color correspondences (1912, 1926), which could be tested indirectly. The project consisted of six experiments, some of them (Experiments 1-3 and 6) carried out in the Experimental Psychology Labs at the University of Trento under the supervision of Prof. Liliana Albertazzi, and the others (Experiments 4-5) carried out in the Visual Perception and Aesthetics Lab at the University of California Berkeley, under the supervision of Prof. Stephen E. Palmer. Experiment 1 provided the first evidence that people tend to match certain hues to certain simple geometric shapes. The strongest relations were found between the triangle and yellows, and the circle and square with reds, confirming only in part Kandinsky’s artistic findings. Experiment 2 replicated the results of Experiment 1 with a different group of participants and showed that the pattern of shape-color associations that previously emerged was independent of a shape’s size, area/perimeter, and stability. Experiment 3 examined the relation between parts of shapes (angles) and hues, also in order to assess if the choice of a hue to be matched with a given shape could be partly driven by its angles. In the remaining experiments (4-5), we extended the previous studies to color dimensions other than the hue, and to an even wider variety of shapes and shape-features. The shape-features studied included pointedness, intersections, symmetry-axes, concavities, and the number of generating-points. We found that specific shape-features of line-shapes (Experiment 4) or closed geometric shapes (Experiment 5) influence specific color attributes (saturation, lightness, redness/greenness, and yellowness/blueness) of the associated colors. Our results also suggested that shape-color associations may be mediated, in part, by emotions; indeed people tend to match colors and shapes that have similar emotional associations (e.g., angry colors are matched to angry shapes). Finally, Experiment 6 assessed in an exploratory way the association between words related to abstract concepts and hues. Altogether, additional examples of associations in the non-synesthetic population were reported. We suggest that this new trend of research, at large, could improve the study of human perception and cognition, guide the search for neural correlates, as well as find possible applications in a variety of disciplines, including ergonomics, art, and design.
147

Verbs and nouns in awake neurosurgery: needs and answers

Rofes, Adria January 2015 (has links)
Awake surgery is a surgical procedure applied to people with brain tumors. Patients are kept awake during surgery to perform language tasks during electrical stimulation of cortico-subcortical brain structures. When the application of electrical pulses to the brain repeatedly triggers errors, this is taken as an indication that the area is critically involved in the language skills probed by the task, and therefore should not be removed, as this would result in postoperative language deficits. In this thesis, we focused on the role of production tasks using finite verbs and the evaluation of their ability to assess language processing in comparison with the current gold standard (i.e., object naming). As a preliminary step in the development of novel, controlled object and verb production tasks, we critically reviewed the literature. We discussed published studies that proposed intraoperative tasks requiring the production of verbs in isolation and in sentences, and we graphically represented the stimulation sites and error types that were reported in each study. Subsequently, we discussed the advantages and disadvantages of each from a cognitive neuroscience and neurolinguistic perspective. With this information in mind, we constructed and validated two naming tasks for native speakers of Italian undergoing awake surgery – an object naming task and a finite verb production task. We administered the finite verb production task and other picture naming tasks to subjects with post-stroke aphasia, and established that a task that uses finite verbs shows a strong correlation with communicative abilities in daily life. Also, we introduced and compared our standardized finite verb task in the operating theater and compared it with an object naming task. Our tests are currently and successfully used in different surgery wards in Italy and overseas. This work can be extended to other neurological populations such as stroke, dementias, and epilepsy.
148

Cognitive determinants of infra-humanization: the role of illusory correlation and attentional processes

Prazienkova, Martina January 2013 (has links)
People commonly attribute more uniquely human characteristics to their in-group than to out-groups but do not differentially attribute the characteristics that we share with other animals. This process is called out-group de/infra-humanization. Up to now it has been conceptualized mainly as a motivated phenomenon serving many intergroup functions. Research so far has not investigated the possibility that animalistic de/infra-humanization might also have cognitive determinants. My research sought to fill this gap in the literature by suggesting that out-group infra-humanization can be conceived as an illusory correlation that people create between groups which represent (at least in one’s own experience) the majority and humanness, which is a quality unique to and shared by all human beings. Recent research on illusory correlation explains this phenomenon in terms of Kruschke’s (1996, 2001, 2003) Attention Theory of category learning (AT). AT proposes that, when learning about multiple groups, the features of the majority group are learned earlier than the features of the minority group. Once the features of the majority group are learned, attention is shifted to learn about the minority group. Impressions of the second-learned group form around those features that most clearly differentiate it from the first-learned group. Since the in-group often has a majority status and being uniquely human is a generally shared attribute, this model would suggest that we tend to associate humanness with the in-group. In turn, the association of humanness with the second-learned group (out-group) would be inhibited. Moreover, the out-group is more likely to be associated with the less common comparative attribute (i.e., non-uniquely human), strengthening out-group infra-humanization. Three experiments support this explanation of the infra-humanization effect as a result of associating humanity with the in-group. In Studies 1 and 2, we investigated whether out-group infra-humanization can result from the way people perceive and process information in case of illusory correlation where no real differences exist between the majority and minority groups. In Study 3, we investigated whether group identification modulates the basic illusory correlation effect. Implications for de/infra-humanization, illusory correlation, and stereotype formation are discussed.
149

A study on the representation of the arithmetic facts memory: cognitively speaking, is the commutativity a property of multiplications and additions?

Didino, Daniele January 2011 (has links)
In this thesis we deal with the role of the commutative property in the organization of the memory that encodes the knowledge about two arithmetic operations: multiplication and addition. Despite its relevance in arithmetic the commutative property has been largely neglected. This theoretical underestimation of the order of the operands and of the cognitive processing of commutative property is likely due to the lack of strong empirical evidences. In this thesis we provide new and clear empirical evidences of a operands-order effects. Five experiments were conducted by using various methodologies. Our results indicate that commutative pairs are processed differently for the two operations. For additions, we found an effect of the order of the operands. Namely, the problems in which the first operand is the larger (e.g., 7+4) were solved faster than the commuted problems (e.g., 4+7). For multiplication, we found an extremely surprising result that can not be predicted by any of the current models of arithmetical cognition, that is an interaction between the order of the operands and the size of the problem. Namely, for large multiplications (both operands larger than 5) the problems in which the first operand is the smaller (e.g., 7×8) were solved faster than the commuted problems (e.g., 8×7); for small multiplications (both operands smaller than 5) and medium multiplications (one operand smaller and the other larger than 5) the problems in which the first operands is the larger (e.g., 3×4, 7×3) were solved faster than the commuted problems (e.g., 4×3, 3×7). For both operations the relevant role of the order of the operands (and its interaction with size for multiplication) in the processing of the problems is also confirmed by a ERPs study. This results are interpreted as the evidence that the arithmetic facts memory is organized by the commutative property. More precisely, we propose to interpret the effects we found as due to the interaction of two factors that shape this memory according to the commutativity: (1) the order of acquisition of the commuted pairs and (2) a reorganization of the memory due to the use of non-retrieval procedures that privilege one of the two orders of the operands. Clearly, further researches are needed in order to better understand the relation between arithmetic facts memory and the commutative property. However, our result have showed a new effect that can usefully be used to investigate how the cognitive system encode, represent and process the arithmetical knowledge.
150

Audiotactile interactions: psychophysical and neuroimaging approaches

Leonardelli, Elisa January 2015 (has links)
In daily life, we are immersed in a continuous flow of stimuli targeting each of our different senses. Far from being independently processed, accumulating evidence has been widely documented by studies showing that stimuli from different modalities largely interact. However, despite the increasing interest, the interpretations of the results of experiments studying multisensory interaction are still controversial and the underlying mechanisms remain broadly unknown. The aim of this thesis is to investigate the interactions that occur between the senses of audition and touch. Audiotactile interactions have been far less studied than the ones existing between other modality pairings. Maybe because they go often unnoticed though being well present in many everyday life situations. This thesis focuses mainly on two aspects that concern interactions: understanding the impact of the relative saliency between the stimuli and investigating the mechanism behind perceptual integration. These questions are addressed respectively in two studies conducted by means of magnetoencephalography. The thesis is structured as following: in chapter 1, I provide the theoretical background to my scientific questions. A brief synthesis of the two main studies is presented in chapter 2. The two studies are entirely reported under the form of manuscripts in chapter 4. Finally, in appendix a behavioral study that investigates spatial aspects of AT interactions is reported. Although the results of this study are of pertinence of the project, given the preparatory character and the preliminary state of the study we decided to show them in the appendix rather than include them in the main body of the thesis.

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