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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.
31

The Effect of Spatial Frequency and Orientation on Configural Face Discriminations in Adults with Synaesthesia

Ghloum, Julian January 2016 (has links)
The structural and functional differences observed in the brains of adults with synaesthesia is thought to arise, at least in part, from less-than-normal neural pruning of the exuberant connections present within and among sensory cortical areas in infancy (reviewed in Maurer, Gibson, & Spector, 2013). This hypothesis is supported by previous work that has demonstrated that synaesthetes are superior at processing foreign speech sounds and inverted faces (Maurer et al., in prep). The present study investigated a link between spatial frequency and face processing in adults with synaesthesia by testing synaesthetes and non-synaesthetes on their ability to discriminate upright and inverted faces filtered at high and low spatial frequencies. As predicted, synaesthetes (n=20) were significantly more accurate than non-synaesthetes (n=20) at discriminating among inverted full spectrum faces (p=0.0235), with no differences in upright faces, replicating previous findings that support the hypothesis that synaesthetes undergo less perceptual attunement (Ghloum et al., 2013). Unexpectedly, synaesthetes were faster at responding across all face conditions. Faster reaction times with no sacrifice to accuracy suggest that synaesthetes may be processing faces more efficiently. In addition, no significant differences in accuracy were observed for high and low filtered faces at any orientation between synaesthetes and non-synaesthetes. Future studies could further explore the basis of synaesthete’s face processing advantages by using eye movements and a narrow-band noise-masking paradigm. / Thesis / Master of Science (MSc)
32

A CROSS SYNDROME STUDY OF FACIAL DISCRIMINATION SKILLS AND THEIR RELATIONSHIP TO SOCIALIZATION SKILLS IN PRADER-WILLI SYNDROME AND AUTISM

Feldman, Benjamin H. 24 August 2012 (has links)
No description available.
33

Face Processing in the Broad Autism Phenotype: Exploring Face Processing as an Endophenotype of Autism Spectrum Disorder

Feldman, Benjamin H. 03 June 2015 (has links)
No description available.
34

Effects of Propranolol on Cognition and Eye Contact in Autism Spectrum Disorder (ASD)

Saklayen, Sanjida Shoma 25 August 2010 (has links)
No description available.
35

The Neural Representations of Social Status: An MVPA Study

Koski, Jessica Elizabeth January 2015 (has links)
Status is a salient social cue, to the extent that it shapes our attention, judgment, and memory for other people, and it guides our social interactions. While prior work has addressed the traits associated with status, as well as its effects on cognition and behavior, research on the neural mechanisms of status perception is still relatively sparse and predominantly focused on neural activity during explicit status judgments. Further, there is no research looking at the involvement of person-processing networks in status perception, or how we embed status information in our representations of others. In the present study I asked whether person-specific representations in ventral face-processing regions (occipital face area (OFA), fusiform face area (FFA)) as well as more anterior regions (anterior temporal lobe (ATL) and orbitofrontal cortex (OFC)) contain information about a person’s status, and whether regions involved in affective processing and reward (amygdala, ventral striatum) decode status information as well. Participants learned to associate names, career titles, and reputational status information (high versus low ratings) with objects and faces over a two-day training regimen. Object status served as a nonsocial comparison. Trained stimuli were presented in an fMRI experiment, where participants performed a target detection task unrelated to status. MVPA revealed that face and object sensitive regions in the ATLs and lateral OFC decoded face and object status, respectively. These data suggest that regions sensitive to abstract person knowledge and valuation interact during the perception of social status, potentially contributing to the effects of status on social perception. / Psychology
36

Neural bases of emotional face processing in infancy : a funcional near-infrared spectroscopy study

Porto, Juliana Antola 31 October 2017 (has links)
Submitted by PPG Medicina e Ci?ncias da Sa?de (medicina-pg@pucrs.br) on 2018-02-23T19:15:10Z No. of bitstreams: 1 JULIANA_ANTOLA_PORTO_TES.pdf: 4776720 bytes, checksum: 1995f76f1de8d24f63bbbf990ed7083c (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-02-26T19:46:38Z (GMT) No. of bitstreams: 1 JULIANA_ANTOLA_PORTO_TES.pdf: 4776720 bytes, checksum: 1995f76f1de8d24f63bbbf990ed7083c (MD5) / Made available in DSpace on 2018-02-26T19:51:08Z (GMT). No. of bitstreams: 1 JULIANA_ANTOLA_PORTO_TES.pdf: 4776720 bytes, checksum: 1995f76f1de8d24f63bbbf990ed7083c (MD5) Previous issue date: 2017-10-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / As bases neurais do processamento da emo??o facial na inf?ncia s?o amplamente desconhecidas. Os fatores ambientais que podem afetar o processamento facial e o reconhecimento emocional ao longo do curso de desenvolvimento tamb?m s?o pouco compreendidos. No entanto, acredita-se que as experi?ncias iniciais, particularmente envolvendo exposi??o repetida a faces emocionais dos cuidadores, influenciem esse curso. O objetivo deste estudo foi investigar os correlatos neurais do processamento de faces emocionais em lactentes usando a espectroscopia funcional no infravermelho pr?ximo (fNIRS), e examinar a poss?vel influ?ncia das experi?ncias emocionais iniciais dos lactentes, indiretamente medida pela investiga??o de sintomas de ansiedade materna. Foram avaliadas 29 crian?as de 5 meses de idade e suas m?es, recrutadas de uma amostra da comunidade de Boston, EUA. A ansiedade materna foi avaliada usando o componente tra?o do Invent?rio de Ansiedade Tra?o-Estado (STAI-T). Os lactentes observaram imagens visuais est?ticas de faces femininas retratando express?es de alegria e medo, enquanto as respostas hemodin?micas corticais foram medidas usando fNIRS. As respostas de oxihemoglobina (oxiHb) e deoxihemoglobina (deoxiHb) nas ?reas frontais, parietais e temporais foram comparadas entre as faces emocionais, e entre filhos de m?es com n?veis altos e baixos de sintomas de ansiedade. Os resultados demonstraram efeito principal significativo da emo??o (p=0,022), evidenciado pelo aumento na concentra??o de oxiHb para faces de alegria em compara??o a faces de medo. Ademais, observou-se efeito principal significativo da regi?o (p=0,013), induzido por maior concentra??o de oxiHb nas regi?es corticais temporais em rela??o ?s regi?es corticais frontais (p=0,031). Al?m disso, houve uma intera??o significativa entre emo??o, hemisf?rio e ansiedade (p=0,037). As an?lises revelaram que filhos de m?es com alta ansiedade demonstraram uma resposta hemodin?mica significativamente elevada no hemisf?rio esquerdo para faces de alegria, em compara??o com faces de medo no hemisf?rio direito (p=0,040) e esquerdo (p=0,033). Os resultados indicam que lactentes de 5 meses discriminaram faces de alegria em compara??o com faces de medo, evidenciado pela maior ativa??o para a primeira. A maior ativa??o nas regi?es temporais em rela??o ?s ?reas frontais foi discutida em rela??o ? ontog?nese do processamento facial e ?s redes neurais de reconhecimento emocional. A resposta mais acentuada, comparando faces de alegria e medo observada nos filhos de m?es com alta ansiedade, pode estar relacionada a altera??es no ambiente emocional dessas crian?as em compara??o com os filhos de m?es com baixa ansiedade. Assim, os n?veis de ansiedade materna parecem moderar as respostas cerebrais hemodin?micas das crian?as ?s faces emocionais. / The neural bases of facial emotion processing in infancy are largely unknown. The environmental factors that may impact facial processing and emotion recognition along the developmental course are also not clearly understood. However, early experiences, particularly involving consistent exposure to familiar caregiver faces, are believed to influence this course. The aim of this study was to investigate the neural correlates of infants? emotional face processing using functional near-infrared spectroscopy (fNIRS), and examine the potential influence of infants? early emotional experiences, indirectly measured by investigating maternal anxiety symptoms. Participants were 29 typically developing 5-monthold infants and their mothers, recruited from a community sample from the Boston greater area, MA, USA. Maternal anxiety was assessed using the trait component of the State-Trait Anxiety Inventory. Infants observed static visual images of a female model portraying happy and fearful expressions, while hemodynamic brain responses were measured using fNIRS. The oxyhemoglobin (oxyHb) and deoxyhemoglobin (deoxyHb) responses over frontal, parietal and temporal areas were compared for the emotional expressions in infants of mothers reporting low and high levels of anxiety symptoms. Results revealed a significant main effect of emotion (p=.022), driven by greater oxyHb concentration responses for happy compared to fearful faces. There was also a main effect of region (p=.013) induced by a significantly greater oxyHb concentration in temporal compared to frontal cortical regions (p=.031). Additionally, a significant three-way interaction between emotion, hemisphere and anxiety was observed (p=.037). Planned comparisons revealed that infants of high-anxious mothers showed significantly greater left hemispheric activation of oxyHb to happy faces when compared with right (p=.040) and left (p=.033) hemispheric activation of oxyHb to fearful faces. These findings possibly indicate that 5-month-olds can discriminate happy from fearful faces, evinced by the greater activation for the former. The greater activation in temporal as compared to frontal areas was discussed in relation to the ontogenesis of face processing and emotion recognition neural networks. The enhanced response to happy versus fearful faces observed in infants of high-anxious mothers can be related to the presumed altered emotional environment experienced by these infants, compared to that of infants of low-anxious mothers. Therefore, maternal anxiety levels appeared to moderate infants? hemodynamic brain responses to emotional faces.
37

The role of selective attention in perceptual switching

Stoesz, Brenda M. 12 September 2008 (has links)
When viewing ambiguous figures, individuals can exert selective attentional control over their perceptual reversibility behaviour (e.g., Strüber & Stadler, 1999). In the current study, we replicated this finding but we also found that ambiguous figures containing faces are processed quite differently from those containing objects. Furthermore, inverting an ambiguous figure containing faces (i.e., Rubin’s vase-face) resulted in an “inversion effect”. These findings highlight the importance of considering how we attend to faces in addition to how we perceive and process faces. Describing the perceptual reversal patterns of individuals in the general population allowed us to draw comparisons to behaviours exhibited by individuals with Asperger Syndrome (AS). The group data suggested that these individuals were less affected by figure type or stimulus inversion. Examination of individual scores, moreover, revealed that the majority of participants with AS showed an atypical reversal pattern, particularly with ambiguous figures containing faces, and an atypical inversion effect. Together, our results show that ambiguous figures can be a very valuable tool for examining face processing mechanisms in the general population and other distinct groups of individuals, particularly those diagnosed with AS. / October 2008
38

Eye-tracking explorations of attention to faces for communicative cues in Autism Spectrum Disorders

Gillespie-Smith, Karri Y. January 2011 (has links)
Background Individuals with Autism Spectrum Disorder (ASD) have been reported to show socio-communicative impairments which are associated with impaired face perception and atypical gaze behaviour. Attending to faces and interpreting the important socio-communicative cues presented allows us to understand other’s cognitive states, emotions, wants and desires. This information enables successful social encounters and interactions to take place. Children with ASD not attending to these important social cues on the face may cause some of the socio-communicative impairments observed within this population. Examining how children with ASD attend to faces will enhance our understanding of their communicative impairments. Aim The present thesis therefore aimed to use eye-tracking methodology to examine attention allocation to faces for communicative cues in children with ASD. Method The first line of enquiry examined how children with ASD (n = 21; age = 13y7m) attended to faces presented within their picture communication systems compared to typically developing children matched on chronological age, verbal ability age and visuo-spatial ability age. The next investigation was conducted on the same group of children and examined how children with ASD attended to faces of different familiarity including, familiar, unfamiliar and the child’s own face. These faces were also presented with direct gaze or averted gaze to investigate how this would impact on the children’s allocation of attention. The final exploration highlighted how children with ASD (n = 20; age = 12y3m) attended to socially salient information (faces) and non-socially salient information (objects) presented within social scenes of varying complexity, compared to typically developing controls. Again groups were matched based on chronological age, verbal ability age, and visuo-spatial ability age. Results Children with ASD were shown to allocate attention to faces presented within their picture communication symbols similarly compared to their typically developing counterparts. All children were shown to fixate significantly longer on the face images compared to the object images. The children with ASD fixated for similar amounts of time to the eye and mouth regions regardless of familiarity and gaze direction compared to their controlled matches. All groups looked significantly longer at the eye areas compared to the mouth areas of the faces across all familiarity types. The children also fixated longer on the eye and mouth regions of direct gazing faces compared to the regions presented on the averted gazing faces. The children with ASD fixated on the faces and objects presented within social scenes similar to their typically developing counterparts across all complexity conditions. The children were shown to fixate significantly longer on the objects compared to the faces. Conclusions Children with ASD showed typical allocation of attention to faces. This suggests that faces are not aversive to them and they are able to attend to the relevant areas such as eye and mouth regions. This may have been influenced by the inclusion of high functioning children with ASD. However these results may also suggest that attention allocation and gaze behaviour are not the only factors which contribute to the socio-communicative impairments observed in ASD.
39

The role of selective attention in perceptual switching

Stoesz, Brenda M. 12 September 2008 (has links)
When viewing ambiguous figures, individuals can exert selective attentional control over their perceptual reversibility behaviour (e.g., Strüber & Stadler, 1999). In the current study, we replicated this finding but we also found that ambiguous figures containing faces are processed quite differently from those containing objects. Furthermore, inverting an ambiguous figure containing faces (i.e., Rubin’s vase-face) resulted in an “inversion effect”. These findings highlight the importance of considering how we attend to faces in addition to how we perceive and process faces. Describing the perceptual reversal patterns of individuals in the general population allowed us to draw comparisons to behaviours exhibited by individuals with Asperger Syndrome (AS). The group data suggested that these individuals were less affected by figure type or stimulus inversion. Examination of individual scores, moreover, revealed that the majority of participants with AS showed an atypical reversal pattern, particularly with ambiguous figures containing faces, and an atypical inversion effect. Together, our results show that ambiguous figures can be a very valuable tool for examining face processing mechanisms in the general population and other distinct groups of individuals, particularly those diagnosed with AS.
40

The role of selective attention in perceptual switching

Stoesz, Brenda M. 12 September 2008 (has links)
When viewing ambiguous figures, individuals can exert selective attentional control over their perceptual reversibility behaviour (e.g., Strüber & Stadler, 1999). In the current study, we replicated this finding but we also found that ambiguous figures containing faces are processed quite differently from those containing objects. Furthermore, inverting an ambiguous figure containing faces (i.e., Rubin’s vase-face) resulted in an “inversion effect”. These findings highlight the importance of considering how we attend to faces in addition to how we perceive and process faces. Describing the perceptual reversal patterns of individuals in the general population allowed us to draw comparisons to behaviours exhibited by individuals with Asperger Syndrome (AS). The group data suggested that these individuals were less affected by figure type or stimulus inversion. Examination of individual scores, moreover, revealed that the majority of participants with AS showed an atypical reversal pattern, particularly with ambiguous figures containing faces, and an atypical inversion effect. Together, our results show that ambiguous figures can be a very valuable tool for examining face processing mechanisms in the general population and other distinct groups of individuals, particularly those diagnosed with AS.

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