A role for local mechanisms in perceived duration of brief visual events

Background: Spatially localized duration compression of a briefly presented moving stimulus following adaptation in the same location is taken as evidence for modality-specific neural timing mechanisms.

Aims: The present study used random dot motion stimuli to investigate where these mechanisms may be located.

Method: Experiment 1 measured duration compression of the test stimulus as a function of adaptor speed and revealed that duration compression is speed tuned. These data were then used to make predictions of duration compression responses for various models which were tested in experiment 2. Here a mixed-speed adaptor stimulus was used with duration compression being measured as a function of the adaptor’s ‘speed notch’ (the removal of a central band from the speed range).

Results: The results were consistent with a local-mean model.

Conclusions: Local-motion mechanisms are involved in duration perception of brief events.

How many bad apples are in a bunch? An experimental investigation of perceived pesticide residue risks

Subjective risks of having contaminated apples elicited via the Exchangeability Method (EM) are examined in this study. In particular, as the experimental design allows us to investigate the validity of elicited risk measures, we examine the magnitude of differences between valid and invalid observations. In addition, using an econometric model, we also explore the effect of consumers’ socioeconomic status and attitudes toward food safety on subjects’ perceptions of pesticide residues in apples. Results suggest first, that consumers do not expect an increase in the number of apples containing only one pesticide residue, but, rather, in the number of those apples with traces of multiple residues. Second, we find that valid subjective risk measures do not significantly diverge from invalid ones, indicative of little effect of internal validity on the actual magnitude of subjective risks. Finally, we show that subjective risks depend on age, education, a subject’s ties to the apple industry, and consumer association membership.

Individual factors and perceived community characteristics in relation to mental health and mental well-being

Background
It has been argued that though correlated with mental health, mental well-being is a distinct entity. Despite the wealth of literature on mental health, less is known about mental well-being. Mental health is something experienced by individuals, whereas mental well-being can be assessed at the population level. Accordingly it is important to differentiate the individual and population level factors (environmental and social) that could be associated with mental health and well-being, and as people living in deprived areas have a higher prevalence of poor mental health, these relationships should be compared across different levels of neighbourhood deprivation.

Methods
A cross-sectional representative random sample of 1,209 adults from 62 Super Output Areas (SOAs) in Belfast, Northern Ireland (Feb 2010 – Jan 2011) were recruited in the PARC Study. Interview-administered questionnaires recorded data on socio-demographic characteristics, health-related behaviours, individual social capital, self-rated health, mental health (SF-8) and mental well-being (WEMWBS). Multi-variable linear regression analyses, with inclusion of clustering by SOAs, were used to explore the associations between individual and perceived community characteristics and mental health and mental well-being, and to investigate how these associations differed by the level of neighbourhood deprivation.

Results
Thirty-eight and 30 % of variability in the measures of mental well-being and mental health, respectively, could be explained by individual factors and the perceived community characteristics. In the total sample and stratified by neighbourhood deprivation, age, marital status and self-rated health were associated with both mental health and well-being, with the ‘social connections’ and local area satisfaction elements of social capital also emerging as explanatory variables. An increase of +1 in EQ-5D-3 L was associated with +1SD of the population mean in both mental health and well-being. Similarly, a change from ‘very dissatisfied’ to ‘very satisfied’ for local area satisfaction would result in +8.75 for mental well-being, but only in the more affluent of areas.

Conclusions
Self-rated health was associated with both mental health and mental well-being. Of the individual social capital explanatory variables, ‘social connections’ was more important for mental well-being. Although similarities in the explanatory variables of mental health and mental well-being exist, socio-ecological interventions designed to improve them may not have equivalent impacts in rich and poor neighbourhoods.

Factors predicting the portion size and perceived fillingness of evening meals in Danish and Iris households

Purpose:
This study explored how meal-related variables, socio-demographics and psychological predispositions affect the portion
size and perceived fillingness of an evening meal in Danish and Irish households.
Methods:
Using survey data collected in 2115 respondents from Denmark (DK) and the Island of Ireland (IOI), we compared four
sets of predictors of the portion size chosen for four evening meals (i.e. pizza/soup/chicken salad/pork meal): Biological
variables (hunger, thirst), socio-demographic variables (gender, age, BMI); psychological predispositions (cognitive
restraint, uncontrolled eating, emotional eating, general health interest) and meal-related variables (expected fillingness,
perceived healthiness, liking, frequency of consumption). We also compared five sets of predictors (the previous
four plus portion size) of perceived portion fillingness.
Results:
Portion size selections were associated mainly with demographic variables (gender, BMI) and psychological predispositions
(cognitive restraint, uncontrolled eating). In addition, only liking and sometimes expected healthiness (mealrelated
variables) appeared as drivers. Conversely, perceived portion fillingness was mostly influenced by the selected
portion size as well as expected fillingness and liking. There were some differences between meals; e.g. GHI not a
predictor for Pizza but a predictor for Chicken salad. Also some country differences were observed; emotional eating
predicted portion selection in the IOI but not DK.
Conclusions:
When making portion size selections at home, psychological predispositions, restrained and uncontrolled eating as well
as meal-related variables, liking and healthiness explained the decisions. However, surprisingly, individuals’ expected
fillingness of a food did not influence their portion size selection but was a driver of fillingness of the selected portion.

Perceived difficulty of various steps of manual small incision cataract surgery among trainees in rural China

Background: The perceived difficulty of steps of manual small incision cataract surgery among trainees in rural China was assessed. Design: Cohort study. Participants: Fifty-two trainees at the end of a manual small incision cataract surgery training programme. Methods: Participants rated the difficulty of 14 surgical steps using a 5-point scale, 1 (very easy) to 5 (very difficult). Demographic and professional information was recorded for trainees. Main Outcome Measure: Mean ratings for surgical steps. Results: Questionnaires were completed by 49 trainees (94.2%, median age 38 years, 8 [16.3%] women). Twenty six (53.1%) had performed ≤50 independent cataract surgeries prior to training. Trainees rated cortical aspiration (mean score±standard deviation=3.10±1.14) the most difficult step, followed by wound construction (2.76±1.08), nuclear prolapse into the anterior chamber (2.74±1.23) and lens delivery (2.51±1.08). Draping the surgical field (1.06±0.242), anaesthetic block administration (1.14±0.354) and thermal coagulation (1.18±0.441) were rated easiest. In regression models, the score for cortical aspiration was significantly inversely associated with performing >50 independent manual small incision cataract surgery surgeries during training (P=0.01), but not with age, gender, years of experience in an eye department or total number of cataract surgeries performed prior to training. Conclusions: Cortical aspiration, wound construction and nuclear prolapse pose the greatest challenge for trainees learning manual small incision cataract surgery, and should receive emphasis during training. Number of cases performed is the strongest predictor of perceived difficulty of key steps. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

The perceived impact of interprofessional information sharing on young people about their sexual health care

This article presents the results from an analysis of data from service providers and young adults who were formerly in state care about how information about the sexual health of young people in state care is managed. In particular, the analysis focuses on the perceived impact of information sharing between professionals on young people. Twenty-two service providers from a range of professions including social work, nursing and psychology, and 19 young people aged 18–22 years who were formerly in state care participated in the study. A qualitative approach was employed in which participants were interviewed in depth and data were analysed using modified analytical induction (Bogdan & Biklen, 2007). Findings suggest that within the care system in which service provider participants worked it was standard practice that sensitive information about a young person’s sexual health would be shared across team members, even where there appeared to be no child protection issues. However, the accounts of the young people indicated that they experienced the sharing of information in this way as an invasion of their privacy. An unintended outcome of a high level of information sharing within teams is that the privacy of the young person in care is compromised in a way that is not likely to arise in the case of young people who are not in care. This may deter young people from availing themselves of the sexual health services.

Strength of visual percept generated by famous faces perceived without awareness: effects of affective valence, response latency, and visual field

Participants who were unable to detect familiarity from masked 17 ms faces ([Stone and Valentine, 2004] and [Stone and Valentine, in press-b]) did report a vague, partial visual percept. Two experiments investigated the relative strength of the visual percept generated by famous and unfamiliar faces, using masked 17 ms exposure. Each trial presented simultaneously a famous and an unfamiliar face, one face in LVF and the other in RVF. In one task, participants responded according to which of the faces generated the stronger visual percept, and in the other task, they attempted an explicit familiarity decision. The relative strength of the visual percept of the famous face compared to the unfamiliar face was moderated by response latency and participants’ attitude towards the famous person. There was also an interaction of visual field with response latency, suggesting that the right hemisphere can generate a visual percept differentiating famous from unfamiliar faces more rapidly than the left hemisphere. Participants were at chance in the explicit familiarity decision, confirming the absence of awareness of facial familiarity.

Perceived positive and negative consequences after surviving cancer and their relation to quality of life

Surviving childhood cancer has multiple implications on both physical and psychological domains of the individual. However, its study and possible effects on health-related quality of life (HRQoL) outcomes of adolescent survivors has been understudied. The objective of this study was twofold; to assess positive and negative cancer-related consequences (psychosocial and physical) in a sample of adolescent cancer survivors and to explore their relationship with HRQoL outcomes. Forty-one participants answered two questions about positive and negative consequences in the aftermath of cancer and filled in the KIDSCREEN-52 self-reported version. Data were analysed using mixed methods approach. 87.8% of the sample identified positive consequences and 63.4% negative consequences in survivorship. Four positive categories and five negative categories with regard to cancer-related consequences were found. Changed perspectives in life narratives seem to be the positive consequence more related to HRQoL (physical well-being, mood & emotions, autonomy, social support & peers), followed by useful life experience (physical well-being, autonomy, social support & peers). Psychological impact was the most referred negative consequence with a significant detrimental effect on social support and peers HRQoL dimension. Even if the majority of survivors reported benefit finding in the aftermath of cancer, concomitant positive and negative consequences have been found. However, findings only reveal a significant relationship between positive narratives and HRQoL, and negative consequences do not seem to have a significant influence on overall HRQoL in survivorship.

Emotional Responses to Disfigured Faces: The Influences of Perceived Anonymity, Empathy, and Disgust Sensitivity

Two experiments investigated self-reported emotional reactions to photographs of people with attractive, unattractive or structurally disfigured faces. In Experiment 1 participants viewing disfigured faces reported raised levels of sorrow and curiosity but not raised levels of negative emotions. In Experiment 2 there was more negative emotion and less positive emotion reported under conditions of relatively high anonymity, compared to low anonymity, specific to disfigured faces, suggesting that self-reports are influenced by social desirability. Trait empathy was associated with sorrow and negative emotions when viewing disfigured faces. Disgust sensitivity was associated with negative emotions and inversely associated with positive emotions.

Perceived Social Pressures and the Internalization of the Mesomorphic Ideal: the Role of Drive for Muscularity and Autonomy in Physically Active Men

BACKGROUND: Researchers have tested the beliefs of sportspeople and sports medicine specialists that cognitive strategies influence strength performance. Few investigators have synthesised the literature. OBJECTIVES: The specific objectives were to review evidence regarding (a) the cognitive strategy-strength performance relationship; (b) participant skill level as a moderator; and (c) cognitive, motivational, biomechanical/physiological, and emotional mediators. METHOD: Studies were sourced via electronic databases, reference lists of retrieved articles, and manual searches of relevant journals. Studies had to be randomised or counterbalanced experiments with a control group or condition, repeated measures, and a quality control score above 0.5 (out of 1). Cognitive strategies included goal setting, imagery, self-talk, preparatory arousal, and free choice. Dependent variables included maximal strength, local muscular endurance, or muscular power. RESULTS: Globally, cognitive strategies were reliability associated with increased strength performance (results ranged from 61 to 65 %). Results were mixed when examining the effects of specific strategies on particular dependent variables, although no intervention had an overall negative influence. Indeterminate relationships emerged regarding hypothesised mediators (except cognitive variables) and participant skill level as a moderator. CONCLUSIONS: Although cognitive strategies influence strength performance, there are knowledge gaps regarding specific types of strength, especially muscular power. Cognitive variables, such as concentration, show promise as possible mediators.

Role Ambiguity and Perceived Organizational Politics in Wolf Recovery: Washington State Wildlife Agency Personnel Perspectives

Thesis (Master's)--University of Washington, 2015-12

Just noticeable differences in perceived image contrast with changes in displayed image size

An evaluation of the change in perceived image contrast with changes in displayed image size was carried out. This was achieved using data from four psychophysical investigations, which employed techniques to match the perceived contrast of displayed images of five different sizes. A total of twenty-four S-shape polynomial functions were created and applied to every original test image to produce images with different contrast levels. The objective contrast related to each function was evaluated from the gradient of the mid-section of the curve (gamma). The manipulation technique took into account published gamma differences that produced a just-noticeable-difference (JND) in perceived contrast. The filters were designed to achieve approximately half a JND, whilst keeping the mean image luminance unaltered. The processed images were then used as test series in a contrast matching experiment. Sixty-four natural scenes, with varying scene content acquired under various illumination conditions, were selected from a larger set captured for the purpose. Results showed that the degree of change in contrast between images of different sizes varied with scene content but was not as important as equivalent perceived changes in sharpness.

Understanding the internet banking adoption by Portuguese customers - a unified theory of acceptance and use of technology and perceived risk application.

Trabalho de Projeto apresentado como requisito parcial para obtenção do grau de Mestre em Estatística e Gestão de Informação