Browsing by Subject "Cognition"
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Item Open Access Aviation risk perception: a comparison between experts and novices(Wiley-Blackwell Publishing, 2004) Thomson, M. E.; Önkal D.; Avcioǧlu, A.; Goodwin, P.This article describes an exploratory investigation of the risk perceptions of experts and novices in relation to helicopter operations, under conditions where the participants are matched on various characteristics previously found to affect perceptions, such as demographic, gender, and background factors. The study reports considerable evidence of perceptual differences between the two participant groups (i.e., expert pilots and candidate pilots). We find that the experts' perceptions of relative risks are more veridical, in terms of their higher correlation with the true relative frequencies. A significant positive correlation between the flight hours and the contextual risk-taking tendency is also shown, leading the experienced pilots' choices toward risky alternatives in scenarios - a potential result of their overconfidence based on superior task performance. Possible explanations are offered for the findings and potential avenues for future research are identified.Item Open Access Cognitive and emotional representations of terror attacks: a cross-cultural exploration(Wiley-Blackwell Publishing, 2007) Shiloh, S.; Güvenç, G.; Önkal D.A questionnaire measuring cognitive and affective representations of terror risk was developed and tested in Turkey and Israel. Participants in the study were university students from the two countries (n = 351). Four equivalent factors explained terror risk cognitions in each sample: costs, vulnerability, trust, and control. A single negative emotionality factor explained the affective component of terror risk representations in both samples. All factors except control could be measured reliably. Results supported the validity of the questionnaire by showing expected associations between cognitions and emotions, as well as indicating gender differences and cultural variations. Current findings are discussed in relation to previous results, theoretical approaches, and practical implications.Item Open Access Cognitive individualism and the child as scientist program(2011) Wringe, B.In this paper, I examine the charge that Gopnik and Meltzoff's 'Child as Scientist' program, outlined and defended in their 1997 book Words, Thoughts and Theories is vitiated by a form of 'cognitive individualism' about science. Although this charge has often been leveled at Gopnik and Meltzoff's work, it has rarely been developed in any detail.I suggest that we should distinguish between two forms of cognitive individualism which I refer to as 'ontic' and 'epistemic' cognitive individualism (OCI and ECI respectively). I then argue - contra Ronald Giere - that Gopnik and Meltzoff's commitment to OCI is relatively unproblematic, since it is an easily detachable part of their view. By contrast, and despite their explicit discussion of the issue, their commitment to ECI is much more problematic.Item Open Access Colour contribution to children's wayfinding in school environments(Elsevier, 2011) Helvacioglu, E.; Olgunturk, N.The purpose of this study was to explore the contribution of colour to children's wayfinding ability in school environments and to examine the differences between colours in terms of their remembrance and usability in route learning process. The experiment was conducted with three different sample groups for each of three experiment sets differentiated by their colour arrangement. The participants totalled 100 primary school children aged seven and eight years old. The study was conducted in four phases. In the first phase, the participants were tested for familiarity with the experiment site and also for colour vision deficiencies by using Ishihara's tests for colour-blindness. In the second phase, they were escorted on the experiment route by the tester one by one, from one starting point to one end point and were asked to lead the tester to the end point by the same route. In the third phase, they were asked to describe verbally the route. In the final phase, they were asked to remember the specific colours at their correct locations. It was found that colour has a significant effect on children's wayfinding performances in school environments. However, there were no differences between different colours in terms of their remembrances in route finding tasks. In addition, the correct identifications of specific colours and landmarks were dependent on their specific locations. Contrary to the literature, gender differences were not found to be significant in the accuracy of route learning performances.Item Open Access Complexity of socio-spatial transformations through tourism: a Mediterranean Village, Kaleköy(Routledge, 2004) Incirlioğlu, E. O.; Çulcuoğlu, G.This article reflects on the complex consequences of tourism development in the isolated Mediterranean village of Kaleko¨y. Built on the antique city of Simena of the 4th century BC and having remnants also from Hellenistic, Byzantine and Ottoman periods, Kaleko¨y’s main source of livelihood since the 1980s has been tourism. Multiple changes that take place simultaneously at the local level, in relation to or as a consequence of tourism, are conceptualised as interrelated transformations that may fall under the four major headings of economy, demography, spatial organisation and cognition. Defining culture as ‘everything learned’, these transformations amount to a radical change in the local culture, which now includes a culture of tourism. Based on ethnographic research, the article aims to demonstrate the complexity of changes in physical, as well as economic and social structures as they pertain to tourism.Item Open Access Default mode network connectivity is linked to cognitive functioning and CSF Aβ1-42 levels in Alzheimer's disease(Elsevier Ireland Ltd, 2016) Celebi, O.; Uzdogan, A.; Oguz, K. K.; Has, A. C.; Dolgun A.; Cakmakli, G. Y.; Akbiyik, F.; Elibol, B.; Saka, E.Background: Changes in the default mode network (DMN) activity are early features of Alzheimer's disease (AD) and may be linked to AD-specific Aβ pathology. Methods: Cognitive profiles; DMN connectivity alterations; and cerebrospinal fluid (CSF) amyloid beta (Aβ)1-42, total tau, phosphorylated tau 181, and α-synuclein levels were studied in 21 patients with AD and 10 controls. Results: DMN activity is altered in AD. Posterior cingulate cortex (PCC) functional connectivity with other parts of DMN was related to cognitive function scores. The reduction of connectivity of the dorsal PCC with the retrosplenial cortex on the right side was closely related to decreased CSF Aβ1-42 levels in patients with AD. Conclusions: The dorsal PCC and retrosplenial cortex may have special importance in the pathogenesis and cognitive findings of AD. © 2015 Elsevier Ireland Ltd.Item Open Access A game theoretical model of traffic with multiple interacting drivers for use in autonomous vehicle development(IEEE, 2016) Oyler, D. W.; Yıldız, Yıldıray; Girard, A. R.; Li, N. I.; Kolmanovsky, İ. V.This paper describes a game theoretical model of traffic where multiple drivers interact with each other. The model is developed using hierarchical reasoning, a game theoretical model of human behavior, and reinforcement learning. It is assumed that the drivers can observe only a partial state of the traffic they are in and therefore although the environment satisfies the Markov property, it appears as non-Markovian to the drivers. Hence, each driver implicitly has to find a policy, i.e. a mapping from observations to actions, for a Partially Observable Markov Decision Process. In this paper, a computationally tractable solution to this problem is provided by employing hierarchical reasoning together with a suitable reinforcement learning algorithm. Simulation results are reported, which demonstrate that the resulting driver models provide reasonable behavior for the given traffic scenarios.Item Open Access The Genetics of Endophenotypes of Neurofunction to Understand Schizophrenia (GENUS) consortium: a collaborative cognitive and neuroimaging genetics project(Elsevier, 2018) Blokland, G. A. M.; Del Re, E. C.; Mesholam-Gately, R. I.; Jovicich, J.; Trampush, J. W.; Keshavan, M. S.; DeLisi, L. E.; Walters, J. T. R.; Turner, J. A.; Malhotra, A. K.; Lencz, T.; Shenton, M. E.; Voineskos, A. N.; Rujescu, D.; Giegling, I.; Kahn, R. S.; Roffman, J. L.; Holt, D. J.; Ehrlich, S.; Kikinis, Z.; Dazzan, P.; Murray, R. M.; Di Forti, M.; Lee, J.; Sim, K.; Lam, M.; Wolthusen, R. P. F.; De Zwarte, S. M. C.; Walton, E.; Cosgrove, D.; Kelly, S.; Maleki, N.; Osiecki, L.; Picchioni, M. M.; Bramon, E.; Russo, M.; David, A. S.; Mondelli, V.; Reinders, A. A. T. S.; Falcone, M. A.; Hartmann, A. M.; Konte, B.; Morris, D. W.; Gill, M.; Corvin, A. P.; Cahn, W.; Ho, N. F.; Liu, J. J.; Keefe, R. S. E.; Gollub, R. L.; Manoach, D. S.; Calhoun, V. D.; Schulz, S. C.; Sponheim, S. R.; Goff, D. C.; Buka, S. L.; Cherkerzian, S.; Thermenos, H. W.; Kubicki, M.; Nestor, P. G.; Dickie, E. W.; Vassos, E.; Ciufolini, S.; Marques, T. R.; Crossley, N. A.; Purcell, S. M.; Smoller, J. W.; Van Haren, N. E. M.; Toulopoulou, Timothea; Donohoe, G.; Goldstein, J. M.; Seidman, L. J.; McCarley, R. W.; Petryshen, T. L.Background: Schizophrenia has a large genetic component, and the pathways from genes to illness manifestation are beginning to be identified. The Genetics of Endophenotypes of Neurofunction to Understand Schizophrenia (GENUS) Consortium aims to clarify the role of genetic variation in brain abnormalities underlying schizophrenia. This article describes the GENUS Consortium sample collection. Methods: We identified existing samples collected for schizophrenia studies consisting of patients, controls, and/or individuals at familial high-risk (FHR) for schizophrenia. Samples had single nucleotide polymorphism (SNP) array data or genomic DNA, clinical and demographic data, and neuropsychological and/or brain magnetic resonance imaging (MRI) data. Data were subjected to quality control procedures at a central site. Results: Sixteen research groups contributed data from 5199 psychosis patients, 4877 controls, and 725 FHR individuals. All participants have relevant demographic data and all patients have relevant clinical data. The sex ratio is 56.5% male and 43.5% female. Significant differences exist between diagnostic groups for premorbid and current IQ (both p < 1 × 10− 10). Data from a diversity of neuropsychological tests are available for 92% of participants, and 30% have structural MRI scans (half also have diffusion-weighted MRI scans). SNP data are available for 76% of participants. The ancestry composition is 70% European, 20% East Asian, 7% African, and 3% other. Conclusions: The Consortium is investigating the genetic contribution to brain phenotypes in a schizophrenia sample collection of > 10,000 participants. The breadth of data across clinical, genetic, neuropsychological, and MRI modalities provides an important opportunity for elucidating the genetic basis of neural processes underlying schizophrenia.Item Open Access Heritability of neuropsychological measures in schizophrenia and nonpsychiatric populations: a systematic review and meta-analysis(Oxford University Press, 2017) Blokland, G. A. M.; Mesholam-Gately, R. I.; Toulopoulou, T.; Del Re, E. C.; Lam, M.; Delisi, L. E.; Donohoe, G.; Walters, J. T. R.; Seidman, L. J.; Petryshen, T. L.Schizophrenia is characterized by neuropsychological deficits across many cognitive domains. Cognitive phenotypes with high heritability and genetic overlap with schizophrenia liability can help elucidate the mechanisms leading from genes to psychopathology. We performed a meta-analysis of 170 published twin and family heritability studies of >800 000 nonpsychiatric and schizophrenia subjects to accurately estimate heritability across many neuropsychological tests and cognitive domains. The proportion of total variance of each phenotype due to additive genetic effects (A), shared environment (C), and unshared environment and error (E), was calculated by averaging A, C, and E estimates across studies and weighting by sample size. Heritability ranged across phenotypes, likely due to differences in genetic and environmental effects, with the highest heritability for General Cognitive Ability (32%-67%), Verbal Ability (43%-72%), Visuospatial Ability (20%-80%), and Attention/Processing Speed (28%-74%), while the lowest heritability was observed for Executive Function (20%-40%). These results confirm that many cognitive phenotypes are under strong genetic influences. Heritability estimates were comparable in nonpsychiatric and schizophrenia samples, suggesting that environmental factors and illness-related moderators (eg, medication) do not substantially decrease heritability in schizophrenia samples, and that genetic studies in schizophrenia samples are informative for elucidating the genetic basis of cognitive deficits. Substantial genetic overlap between cognitive phenotypes and schizophrenia liability (average r g = '.58) in twin studies supports partially shared genetic etiology. It will be important to conduct comparative studies in well-powered samples to determine whether the same or different genes and genetic variants influence cognition in schizophrenia patients and the general population.Item Restricted Introduction; The second cognitive revolution(1992) Harre, RomItem Restricted Mental models in narrative comprehension(1990) Bower, Gordon H.Item Open Access No evidence for a common factor underlying visual abilities in healthy older people(American Psychological Association, 2019) Shaqiri, A.; Pilz, K. S.; Cretenoud, A. F.; Neumann, K.; Clarke, Aaron; Kunchulia, M.; Herzog, M. H.The world’s population is aging at an increasing rate. Even in the absence of neurodegenerative disorders, healthy aging affects perception and cognition. In the context of cognition, common factors are well established. Much less is known about common factors for vision. Here, we tested 92 healthy older and 104 healthy younger participants in 19 visual tests (including visual search and contrast sensitivity) and three cognitive tests (including verbal fluency and digit span). Unsurprisingly, younger participants performed better than older participants in almost all tests. Surprisingly, however, the performance of older participants was mostly uncorrelated between visual tests, and we found no evidence for a common factor.Item Open Access A polygenic risk score analysis of psychosis endophenotypes across brain functional, structural, and cognitive domains(John Wiley & Sons, Inc., 2018) Ranlund, S.; Calafato, S.; Thygesen, J. H.; Lin, K.; Cahn, W.; Crespo-Facorro, B.; Díez, A.; Forti, M. D.; Iyegbe, C.; Jablensky, A.; Jones, R.; Hall, M.; Kahn, R.; Kalaydjieva, L.; Kravariti, E.; McDonald, C.; McIntosh, A. M.; McQuillin, A.; Picchioni, M.; Prata, D. P.; Rujescu, D.; Schulze, K.; Shaikh, M.; Toulopoulou, Timothea; Haren, N.; Zwarte, S. M. C.; Os, J.; Vassos, E.; Walshe, M.; Lewis, C.; Murray, R. M.; Powell, J.; Bramon, E.This large multi‐center study investigates the relationships between genetic risk for schizophrenia and bipolar disorder, and multi‐modal endophenotypes for psychosis. The sample included 4,242 individuals; 1,087 patients with psychosis, 822 unaffected first‐degree relatives of patients, and 2,333 controls. Endophenotypes included the P300 event‐related potential (N = 515), lateral ventricular volume (N = 798), and the cognitive measures block design (N = 3,089), digit span (N = 1,437), and the Ray Auditory Verbal Learning Task (N = 2,406). Data were collected across 11 sites in Europe and Australia; all genotyping and genetic analyses were done at the same laboratory in the United Kingdom. We calculated polygenic risk scores for schizophrenia and bipolar disorder separately, and used linear regression to test whether polygenic scores influenced the endophenotypes. Results showed that higher polygenic scores for schizophrenia were associated with poorer performance on the block design task and explained 0.2% (p = 0.009) of the variance. Associations in the same direction were found for bipolar disorder scores, but this was not statistically significant at the 1% level (p = 0.02). The schizophrenia score explained 0.4% of variance in lateral ventricular volumes, the largest across all phenotypes examined, although this was not significant (p = 0.063). None of the remaining associations reached significance after correction for multiple testing (with alpha at 1%). These results indicate that common genetic variants associated with schizophrenia predict performance in spatial visualization, providing additional evidence that this measure is an endophenotype for the disorder with shared genetic risk variants. The use of endophenotypes such as this will help to characterize the effects of common genetic variation in psychosis.Item Open Access Polygenic risk score increases schizophrenia liability through cognition-relevant pathways(Oxford University Press, 2019) Toulopoulou, Timothea; Zhang, X.; Cherny, S.; Dickinson, D.; Berman, K. F.; Straub, R. E.; Sham, P.; Weinberger, D. R.Cognitive deficit is thought to represent, at least in part, genetic mechanisms of risk for schizophrenia, with recent evidence from statistical modelling of twin data suggesting direct causality from the former to the latter. However, earlier evidence was based on inferences from twin not molecular genetic data and it is unclear how much genetic influence ‘passes through’ cognition on the way to diagnosis. Thus, we included direct measurements of genetic risk (e.g. schizophrenia polygenic risk scores) in causation models to assess the extent to which cognitive deficit mediates some of the effect of polygenic risk scores on the disorder. Causal models of family data tested relationships among key variables and allowed parsing of genetic variance components. Polygenic risk scores were calculated from summary statistics from the current largest genome-wide association study of schizophrenia and were represented as a latent trait. Cognition was also modelled as a latent trait. Participants were 1313 members of 1078 families: 416 patients with schizophrenia, 290 unaffected siblings, and 607 controls. Modelling supported earlier findings that cognitive deficit has a putatively causal role in schizophrenia. In total, polygenic risk score explained 8.07% [confidence interval (CI) 5.45–10.74%] of schizophrenia risk in our sample. Of this, more than a third (2.71%, CI 2.41–3.85%) of the polygenic risk score influence was mediated through cognition paths, exceeding the direct influence of polygenic risk score on schizophrenia risk (1.43%, CI 0.46–3.08%). The remainder of the polygenic risk score influence (3.93%, CI 2.37–4.48%) reflected reciprocal causation between schizophrenia liability and cognition (e.g. mutual influences in a cyclical manner). Analysis of genetic variance components of schizophrenia liability indicated that 26.87% (CI 21.45–32.57%) was associated with cognition-related pathways not captured by polygenic risk score. The remaining variance in schizophrenia was through pathways other than cognition-related and polygenic risk score. Although our results are based on inference through statistical modelling and do not provide an absolute proof of causality, we find that cognition pathways mediate a significant part of the influence of cumulative genetic risk on schizophrenia. We estimate from our model that 33.51% (CI 27.34–43.82%) of overall genetic risk is mediated through influences on cognition, but this requires further studies and analyses as the genetics of schizophrenia becomes better characterized.Item Open Access Prediction as the basis of low level cognitive organization(Bilkent University, 1998) Yavuz, ArmağanI suggest that the brain’s low-level sensory-motor systems are organized on the basis of prediction. This suggestion differs radically from existing theories of sensory-motor systems, and can be summarized as follows. Certain simple mechanisms in the brain predict the current or future states of other brain mechanisms. These mechanisms can be established and disposed dynamically. Successful prediction acts as a kind of selection criteria .and new structures are formed and others are disposed according to their predictive powers. Simple mechanisms become connected to each other on the basis of their predictive power, possibly establishing hierarchical structures, and forming large complexes. The complexes so formed, can implement a number of functionalities including detecting interesting events, creating high-level representations, and helping with goal-directed activity. Faculties such as attention and memory contribute to such processes of internal predictions and they can be studied and understood within this setting. All of this does not rule out the existence of other mechanisms, but an organization driven by prediction serves as the backbone of low-level cognitive activity. I develop a computational model of a sensory-motor system that works on this basis. I also show how this model explains certain interesting aspects of human perception and how it can be related to general cognitive capabilities.Item Open Access Structural brain alterations of Down’s syndrome in early childhood evaluation by DTI and volumetric analyses(Springer Verlag, 2017) Gunbey, H. P.; Bilgici, M. C.; Aslan, K.; Has, A. C.; Ogur, M. G.; Alhan, A.; Incesu, L.Objectives: To provide an initial assessment of white matter (WM) integrity with diffusion tensor imaging (DTI) and the accompanying volumetric changes in WM and grey matter (GM) through volumetric analyses of young children with Down’s syndrome (DS). Methods: Ten children with DS and eight healthy control subjects were included in the study. Tract-based spatial statistics (TBSS) were used in the DTI study for whole-brain voxelwise analysis of fractional anisotropy (FA) and mean diffusivity (MD) of WM. Volumetric analyses were performed with an automated segmentation method to obtain regional measurements of cortical volumes. Results: Children with DS showed significantly reduced FA in association tracts of the fronto-temporo-occipital regions as well as the corpus callosum (CC) and anterior limb of the internal capsule (p < 0.05). Volumetric reductions included total cortical GM, cerebellar GM and WM volume, basal ganglia, thalamus, brainstem and CC in DS compared with controls (p < 0.05). Conclusion: These preliminary results suggest that DTI and volumetric analyses may reflect the earliest complementary changes of the neurodevelopmental delay in children with DS and can serve as surrogate biomarkers of the specific elements of WM and GM integrity for cognitive development. Key Points: • DS is the most common genetic cause of intellectual disability. • WM and GM structural alterations represent the neurological features of DS. • DTI may identify the earliest aging process changes. • DTI-volumetric analyses can serve as surrogate biomarkers of neurodevelopment in DS. © 2016, European Society of Radiology.Item Open Access Understanding the effects of cognition in creative decision-making : a creativity model for enhancing the design studio process(Bilkent University, 2005) Hasırcı, DenizThe demand for creativity is a significant concern in all educational environments, especially in institutions of design. Considering this, the study aspires to improve creativity in the design studio. Based on the theories and research addressing creativity in the design field, creative decision-making, and cognitive processes during creative activity, this study analyzes the creative process of design in depth by investigating the characteristics of the decisions made through the stages of the process, and means of supporting those decisions for the main purpose of enhancing academic and professional creativity. The study establishes its basic framework by combining two different models: ‘4P’s’ of creativity by Rhodes and the ‘Five Stages of the Sensational Thinking Model’ of O’Neill and Shallross (5R’s), and makes use of the methods of protocol analysis, observation, product assessment, and retrospective interviews. Implemented in the third year design studio in the Interior Architecture and Environmental Design Department, Bilkent University in Turkey, the study yielded significant results on preferred imagery and representation styles and quantity, time spent at different stages of the process, underdeveloped skills, behavior, in addition to student-student and student-instructor relations, and associations between creative processes and products. Moreover, constructive interaction between students was observed to be helpful in developing their ideas, and students who have used more imagery were detected as more creative. A model was proposed to understand the creative process and test the hypotheses, refined according to the study, and presented in a way to be readily utilized or adapted to various situations.Item Restricted Vygotsky's social theory of mind(1989) Williams, Meredith