924 resultados para Cognition and Perception


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How do signals from the 2 eyes combine and interact? Our recent work has challenged earlier schemes in which monocular contrast signals are subject to square-law transduction followed by summation across eyes and binocular gain control. Much more successful was a new 'two-stage' model in which the initial transducer was almost linear and contrast gain control occurred both pre- and post-binocular summation. Here we extend that work by: (i) exploring the two-dimensional stimulus space (defined by left- and right-eye contrasts) more thoroughly, and (ii) performing contrast discrimination and contrast matching tasks for the same stimuli. Twenty-five base-stimuli made from 1 c/deg patches of horizontal grating, were defined by the factorial combination of 5 contrasts for the left eye (0.3-32%) with five contrasts for the right eye (0.3-32%). Other than in contrast, the gratings in the two eyes were identical. In a 2IFC discrimination task, the base-stimuli were masks (pedestals), where the contrast increment was presented to one eye only. In a matching task, the base-stimuli were standards to which observers matched the contrast of either a monocular or binocular test grating. In the model, discrimination depends on the local gradient of the observer's internal contrast-response function, while matching equates the magnitude (rather than gradient) of response to the test and standard. With all model parameters fixed by previous work, the two-stage model successfully predicted both the discrimination and the matching data and was much more successful than linear or quadratic binocular summation models. These results show that performance measures and perception (contrast discrimination and contrast matching) can be understood in the same theoretical framework for binocular contrast vision. © 2007 VSP.

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Recent functional magnetic resonance imaging (fMRI) investigations of the interaction between cognition and reward processing have found that the lateral prefrontal cortex (PFC) areas are preferentially activated to both increasing cognitive demand and reward level. Conversely, ventromedial PFC (VMPFC) areas show decreased activation to the same conditions, indicating a possible reciprocal relationship between cognitive and emotional processing regions. We report an fMRI study of a rewarded working memory task, in which we further explore how the relationship between reward and cognitive processing is mediated. We not only assess the integrity of reciprocal neural connections between the lateral PFC and VMPFC brain regions in different experimental contexts but also test whether additional cortical and subcortical regions influence this relationship. Psychophysiological interaction analyses were used as a measure of functional connectivity in order to characterize the influence of both cognitive and motivational variables on connectivity between the lateral PFC and the VMPFC. Psychophysiological interactions revealed negative functional connectivity between the lateral PFC and the VMPFC in the context of high memory load, and high memory load in tandem with a highly motivating context, but not in the context of reward alone. Physiophysiological interactions further indicated that the dorsal anterior cingulate and the caudate nucleus modulate this pathway. These findings provide evidence for a dynamic interplay between lateral PFC and VMPFC regions and are consistent with an emotional gating role for the VMPFC during cognitively demanding tasks. Our findings also support neuropsychological theories of mood disorders, which have long emphasized a dysfunctional relationship between emotion/motivational and cognitive processes in depression.

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Pregnancy provides a very public, visual confirmation of femininity. It is a time of rapid physical and psychological adjustment for women and is surrounded by stereotyping, taboos and social expectations. This book seeks to examine these popular attitudes towards pregnancy and to consider how they influence women’s experiences of being pregnant. Sanctioning Pregnancy offers a unique critique of sociocultural constructions of pregnancy and the ways in which it is represented in contemporary culture, and examines the common myths which exist about diet, exercise and work in pregnancy, alongside notions of risk and media portrayals of pregnant women. Topics covered include: •Do pregnant women change their diet and why? •Is memory really impaired in pregnancy? •How risky behaviour is defined from exercise to employment •The biomedical domination of pregnancy research. Different theoretical standpoints are critically examined, including a medico-scientific model, feminist perspectives and bio-psychosocial and psychodynamic approaches. Table of Contents: Introduction. Cognition and Cognitive Dysfunction. Working and Employment. Dietary Change and Eating. Exercise and Activity. Pregnancy and Risk. Pregnancy Under Surveillance. Concluding Remarks. References/Bibliography. Index.

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Modern managers are under tremendous pressure in attempting to fulfil a profoundly complex managerial task, that of handling information resources. Information management, an intricate process requiring a high measure of human cognition and discernment, involves matching a manager's lack of information processing capacity against his information needs, with voluminous information at his disposal. The nature of the task will undoubtedly become more complex in the case of a large organisation. Management of large-scale organisations is therefore an exceedingly challenging prospect for any manager to be faced with. A system that supports executive information needs will help reduce managerial and informational mismatches. In the context of the Malaysian public sector, the task of overall management lies with the Prime Minister and the Cabinet. The Prime Minister's Office is presently supporting the Prime Minister's information and managerial needs, although not without various shortcomings. The rigid formalised structure predominant of the Malaysian public sector, so opposed to dynamic treatment of problematic issues as faced by that sector, further escalates the managerial and organisational problem of coping with a state of complexity. The principal features of the research are twofold: the development of a methodology for diagnosing the problem organisation' and the design of an office system. The methodological development is done in the context of the Malaysian public sector, and aims at understanding the complexity of its communication and control situation. The outcome is a viable model of the public sector. `Design', on the other hand, is developing a syntax or language for office systems which provides an alternative to current views on office systems. The design is done with reference to, rather than for, the Prime Minister's Office. The desirable outcome will be an office model called Office Communication and Information System (OCIS).

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Neuroimaging studies of cortical activation during image transformation tasks have shown that mental rotation may rely on similar brain regions as those underlying visual perceptual mechanisms. The V5 complex, which is specialised for visual motion, is one region that has been implicated. We used functional magnetic resonance imaging (fMRI) to investigate rotational and linear transformation of stimuli. Areas of significant brain activation were identified for each of the primary mental transformation tasks in contrast to its own perceptual reference task which was cognitively matched in all respects except for the variable of interest. Analysis of group data for perception of rotational and linear motion showed activation in areas corresponding to V5 as defined in earlier studies. Both rotational and linear mental transformations activated Brodman Area (BA) 19 but did not activate V5. An area within the inferior temporal gyrus, representing an inferior satellite area of V5, was activated by both the rotational perception and rotational transformation tasks, but showed no activation in response to linear motion perception or transformation. The findings demonstrate the extent to which neural substrates for image transformation and perception overlap and are distinct as well as revealing functional specialisation within perception and transformation processing systems.

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This chapter explores the relationship between changes in strategy and environmental pressures within the UK Pharmaceutical Industry during a ten- year period. Two stable strategic time periods (SSTPs) were identified each of five years duration. Within each time period seven strategic groups were found but 11 out of 29 firms (37.9%) changed strategic groups membership during the period studied. The break between these two SSTPs was found to coincide with a sharp increase in the substitution of branded pharmaceuticals by cheaper parallel imports. A significant relationship was found between firms that changed groups and both their continent of origin and nationality. Firms whose home markets are more vulnerable to substitution were more likely to switch strategic groups. © 2011 Nova Science Publishers, Inc. All rights reserved.

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Background: There is substantial evidence that cognitive deficits and brain structural abnormalities are present in patients with Bipolar Disorder (BD) and in their first-degree relatives. Previous studies have demonstrated associations between cognition and functional outcome in BD patients but have not examined the role of brain morphological changes. Similarly, the functional impact of either cognition or brain morphology in relatives remains unknown. Therefore we focused on delineating the relationship between psychosocial functioning, cognition and brain structure, in relation to disease expression and genetic risk for BD. Methods: Clinical, cognitive and brain structural measures were obtained from 41 euthymic BD patients and 50 of their unaffected first-degree relatives. Psychosocial function was evaluated using the General Assessment of Functioning (GAF) scale. We examined the relationship between level of functioning and general intellectual ability (IQ), memory, attention, executive functioning, symptomatology, illness course and total gray matter, white matter and cerebrospinal fluid volumes. Limitations: Cross-sectional design. Results: Multiple regression analyses revealed that IQ, total white matter volume and a predominantly depressive illness course were independently associated with functional outcome in BD patients, but not in their relatives, and accounted for a substantial proportion (53%) of the variance in patients' GAF scores. There were no significant domain-specific associations between cognition and outcome after consideration of IQ. Conclusions: Our results emphasise the role of IQ and white matter integrity in relation to outcome in BD and carry significant implications for treatment interventions. © 2010 Elsevier B.V.

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We re-analysed visuo-spatial perspective taking data from Kessler and Thomson (2010) plus a previously unpublished pilot with respect to individual- and sex differences in embodied processing (defined as body-posture congruence effects). We found that so-called 'systemisers' (males/low-social-skills) showed weaker embodiment than so-called 'embodiers' (females/high-social-skills). We conclude that 'systemisers' either have difficulties with embodied processing or, alternatively, they have a strategic advantage in selecting different mechanisms or the appropriate level of embodiment. In contrast, 'embodiers' have an advantageous strategy of "deep" embodied processing reflecting their urge to empathise or, alternatively, less flexibility in fine-tuning the involvement of bodily representations. © 2012 Copyright Taylor and Francis Group, LLC.

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In-Motes is a mobile agent middleware that generates an intelligent framework for deploying applications in Wireless Sensor Networks (WSNs). In-Motes is based on the injection of mobile agents into the network that can migrate or clone following specific rules and performing application specific tasks. By doing so, each mote is given a certain degree of perception, cognition and control, forming the basis for its intelligence. Our middleware incorporates technologies such as Linda-like tuplespaces and federated system architecture in order to obtain a high degree of collaboration and coordination for the agent society. A set of behavioral rules inspired by a community of bacterial strains is also generated as the means for robustness of the WSN. In this paper, we present In-Motes and provide a detailed evaluation of its implementation for MICA2 motes.

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This article reflects on context effects in the study of behavioral ethics and organizational justice. After a general overview, we review three key challenges confronting research in these two domains. First, we consider social scientific versus normative approaches to inquiry. The former aims for a scientific description, while the latter aims to provide prescriptive advice for moral conduct. We argue that the social scientific view can be enriched by considering normative paradigms. The next challenge we consider, involves the duality of morally upright versus morally inappropriate behavior. We observe that there is a long tradition of categorizing behavior dichotomously (e.g., good vs. bad) rather than continuously. We conclude by observing that more research is needed to compare the dichotomous versus continuous perspectives. Third, we examine the role of “cold” cognitions and “hot” affect in making judgments of ethicality. Historically speaking, research has empathized cognition, though recent work has begun to add greater balance to affective reactions. We argue that both cognition and affect are important, but more research is needed to determine how they work together. After considering these three challenges, we then turn to our special issue, providing short reviews of each contribution and how they help in better addressing the three challenges we have identified.

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An estimated 30% of individuals with autism spectrum disorders (ASD) remain minimally verbal into late childhood, but research on cognition and brain function in ASD focuses almost exclusively on those with good or only moderately impaired language. Here we present a case study investigating auditory processing of GM, a nonverbal child with ASD and cerebral palsy. At the age of 8 years, GM was tested using magnetoencephalography (MEG) whilst passively listening to speech sounds and complex tones. Where typically developing children and verbal autistic children all demonstrated similar brain responses to speech and nonspeech sounds, GM produced much stronger responses to nonspeech than speech, particularly in the 65–165 ms (M50/M100) time window post-stimulus onset. GM was retested aged 10 years using electroencephalography (EEG) whilst passively listening to pure tone stimuli. Consistent with her MEG response to complex tones, GM showed an unusually early and strong response to pure tones in her EEG responses. The consistency of the MEG and EEG data in this single case study demonstrate both the potential and the feasibility of these methods in the study of minimally verbal children with ASD. Further research is required to determine whether GM's atypical auditory responses are characteristic of other minimally verbal children with ASD or of other individuals with cerebral palsy.

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Background: Anticholinergic medications may be associated with adverse clinical outcomes, including acute impairments in cognition and anticholinergic side effects, the risk of adverse outcomes increasing with increasing anticholinergic exposure. Older people with intellectual disability may be at increased risk of exposure to anticholinergic medicines due to their higher prevalence of comorbidities. We sought to determine anticholinergic burden in ageing people with intellectual disability. Methods: Medication data (self-report/proxy-report) was drawn from Wave 1 of the Intellectual Disability Supplement to the Irish Longitudinal Study on Ageing (IDS-TILDA), a study on the ageing of 753nationally representative people with an IDC40 years randomly selected from the National Intellectual Disability Database. Each individual’s cumulative exposure to anticholinergic medications was calculated using the Anticholinergic Cognitive Burden Scale (ACB) amended by a multi-disciplinary group with independent advice to account for the range of medicines in use in this population. Results: Overall, 70.1 % (527) reported taking medications with possible or definite anticholinergic properties (ACBC1), with a mean (±SD) ACB score of 4.5 (±3.0) (maximum 16). Of those reporting anticholinergic exposure (n=527), 41.3 % (217) reported an ACB score o fC5. Antipsychotics accounted for 36.4 % of the total cumulative ACB score followed by anticholinergics (16 %) and antidepressants (10.8 %). The most frequently reported medicine with anticholinergic activity was carbamazepine 16.8 % (127). The most frequently reported medicine with high anticholinergic activity (ACB 3) was olanzapine13.4 % (101). There was a significant association between higher anti-cholinergic exposure and multimorbidity, particularly mental health morbidity, and some anticholinergic adverse effects such as constipation and day-time drowsiness but not self-rated health. Conclusion: Using simple cumulative measures proved an effective means to capture total burden and helped establish that anticholinergic exposure in the study population was high. The finding highlights the need for comprehensive reviews of medications.

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This article provides a narrative review of psychology of entrepreneurship research published in leading psychology journals, based on which we develop an organising framework for future psychological contributions to this field. Furthermore, we introduce the manuscripts collected in this special issue. Our review identified five research areas, broadly corresponding with basic psychological domains, namely personal differences; careers; health and well-being; cognition and behaviour; and leadership; as well as three cross-cutting themes: gender issues; genetic and biological foundations; and context. With the aim to stimulate integration across different approaches and disciplines, we propose a framework to understand how psychologists can offer innovative contributions to the multi-disciplinary entrepreneurship literature. This includes a focus on the entrepreneur embedded in and in interaction with his or her immediate and wider context; attention to different types of entrepreneurs; and a focus on dynamic within-person processes evolving over time.

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The objective was to identify evidence to support use of specific harms for the development of a children and young people's safety thermometer (CYPST). We searched PubMed, Web of Knowledge, and Cochrane Library post-1999 for studies in pediatric settings about pain, skin integrity, extravasation injury, and use of pediatric early warning scores (PEWS). Following screening, nine relevant articles were included. Convergent synthesis methods were used drawing on thematic analysis to combine findings from studies using a range of methods (qualitative, quantitative, and mixed methods). A review of PEWS was identified so other studies on this issue were excluded. No relevant studies about extravasation injury were identified. The synthesized results therefore focused on pain and skin integrity. Measurement and perception of pain were complex and not always carried out according to best practice. Skin abrasions were common and mostly associated with device related injuries. The findings demonstrate a need for further work on perceptions of pain and effective communication of concerns about pain between parents and nursing staff. Strategies for reducing device-related injuries warrant further research focusing on prevention. Together with the review of PEWS, these synthesized findings support the inclusion of pain, skin integrity, and PEWS in the CYPST.

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It is well documented that facial disfigurements can generate avoidance responses in observers towards the afflicted person, yet less is known about the effect of a facial disfigurement on attention to and perception of faces. In two experiments we studied overt and covert attention to laterally presented face stimuli when these contained a unilateral disfiguring feature (a simulated portwine stain), an occluding feature, or no salient feature. In Experiment 1, observers’ eye movements were tracked while they explored laterally presented faces which they had to rate for attractiveness. Overt attention, as measured by the patterns of fixations on the face, was found to be significantly affected by the presence of a facial disfigurement or an occluder. In Experiment2, we used a covert orienting task with bilaterally presented target and distractor to measure the interference effect induced by a distractor face (disfigured, occluded, or normal) on a non facetarget discrimination task. The presence of a face increased response times to the target stimulus,but this interference was not modulated by the presence of a salient feature (disfigurement or occluder). Together, these results suggest that the presence of salient features affect overt but not the covert processing of faces.