Maintaining a cognitive map in darkness : the need to fuse boundary knowledge with path integration

Spatial navigation requires the processing of complex, disparate and often ambiguous sensory data. The neurocomputations underpinning this vital ability remain poorly understood. Controversy remains as to whether multimodal sensory information must be combined into a unified representation, consistent with Tolman's "cognitive map", or whether differential activation of independent navigation modules suffice to explain observed navigation behaviour. Here we demonstrate that key neural correlates of spatial navigation in darkness cannot be explained if the path integration system acted independently of boundary (landmark) information. In vivo recordings demonstrate that the rodent head direction (HD) system becomes unstable within three minutes without vision. In contrast, rodents maintain stable place fields and grid fields for over half an hour without vision. Using a simple HD error model, we show analytically that idiothetic path integration (iPI) alone cannot be used to maintain any stable place representation beyond two to three minutes. We then use a measure of place stability based on information theoretic principles to prove that featureless boundaries alone cannot be used to improve localization above chance level. Having shown that neither iPI nor boundaries alone are sufficient, we then address the question of whether their combination is sufficient and - we conjecture - necessary to maintain place stability for prolonged periods without vision. We addressed this question in simulations and robot experiments using a navigation model comprising of a particle filter and boundary map. The model replicates published experimental results on place field and grid field stability without vision, and makes testable predictions including place field splitting and grid field rescaling if the true arena geometry differs from the acquired boundary map. We discuss our findings in light of current theories of animal navigation and neuronal computation, and elaborate on their implications and significance for the design, analysis and interpretation of experiments.

Towards an integration of the theory of planned behaviour and cognitive behavioural strategies : an example from a school-based injury prevention programme

Adolescent risk-taking behavior has potentially serious injury consequences and school-based behavior change programs provide potential for reducing such harm. A well-designed program is likely to be theory-based and ecologically valid however it is rare that the operationalisation process of theories is described. The aim of this paper is to outline how the Theory of Planned Behavior and Cognitive Behavioral Therapy informed intervention design in a school setting. Teacher interviews provided insights into strategies that might be implemented within the curriculum and provided detail used to operationalise theory constructs. Benefits and challenges in applying both theories are described with examples from an injury prevention program, Skills for Preventing Injury in Youth.

Transport injury risks in Queensland adolescents of Pacific Islander descent

Ethnicity is rarely considered in the development of injury prevention programs, despite its known impact on participation in risk behaviour. This study sought to understand engagement in transport related risk behaviours, patterns of injury and perceptions of risk among early adolescents who self-identify as being from a Pacific Islander background. In total 5 high schools throughout Queensland, Australia were recruited, of which 498 Year 9 students (13-14 years) completed questionnaires relating to their perceptions of risk and recent injury experience (specifically those transport behaviours that were medically treated and those that were not medically treated). The transport related risk behaviours captured in the survey were bicycle use, motorcycle use and passenger safety (riding with a drink driver and riding with a dangerous driver). The results are explored in terms of the prevalence of engagement in risky transport related behaviour among adolescents’ of Pacific Islander background compared to others of the same age. The results of this study provide an initial insight into the target participants’ perspective of risk in a road safety context as well as their experience of such behaviour and related injuries. This information may benefit future intervention programs specific to adolescents’ of Pacific Islander background.

Spectrum sensing, detection and optimisation in cognitive radio for non-stationary primary user signals

Cognitive radio is an emerging technology proposing the concept of dynamic spec- trum access as a solution to the looming problem of spectrum scarcity caused by the growth in wireless communication systems. Under the proposed concept, non- licensed, secondary users (SU) can access spectrum owned by licensed, primary users (PU) so long as interference to PU are kept minimal. Spectrum sensing is a crucial task in cognitive radio whereby the SU senses the spectrum to detect the presence or absence of any PU signal. Conventional spectrum sensing assumes the PU signal as ‘stationary’ and remains in the same activity state during the sensing cycle, while an emerging trend models PU as ‘non-stationary’ and undergoes state changes. Existing studies have focused on non-stationary PU during the transmission period, however very little research considered the impact on spectrum sensing when the PU is non-stationary during the sensing period. The concept of PU duty cycle is developed as a tool to analyse the performance of spectrum sensing detectors when detecting non-stationary PU signals. New detectors are also proposed to optimise detection with respect to duty cycle ex- hibited by the PU. This research consists of two major investigations. The first stage investigates the impact of duty cycle on the performance of existing detec- tors and the extent of the problem in existing studies. The second stage develops new detection models and frameworks to ensure the integrity of spectrum sensing when detecting non-stationary PU signals. The first investigation demonstrates that conventional signal model formulated for stationary PU does not accurately reflect the behaviour of a non-stationary PU. Therefore the performance calculated and assumed to be achievable by the conventional detector does not reflect actual performance achieved. Through analysing the statistical properties of duty cycle, performance degradation is proved to be a problem that cannot be easily neglected in existing sensing studies when PU is modelled as non-stationary. The second investigation presents detectors that are aware of the duty cycle ex- hibited by a non-stationary PU. A two stage detection model is proposed to improve the detection performance and robustness to changes in duty cycle. This detector is most suitable for applications that require long sensing periods. A second detector, the duty cycle based energy detector is formulated by integrat- ing the distribution of duty cycle into the test statistic of the energy detector and suitable for short sensing periods. The decision threshold is optimised with respect to the traffic model of the PU, hence the proposed detector can calculate average detection performance that reflect realistic results. A detection framework for the application of spectrum sensing optimisation is proposed to provide clear guidance on the constraints on sensing and detection model. Following this framework will ensure the signal model accurately reflects practical behaviour while the detection model implemented is also suitable for the desired detection assumption. Based on this framework, a spectrum sensing optimisation algorithm is further developed to maximise the sensing efficiency for non-stationary PU. New optimisation constraints are derived to account for any PU state changes within the sensing cycle while implementing the proposed duty cycle based detector.

Reaching high-risk adolescents : a process evaluation of a school based injury prevention program

High-risk adolescents are a population most vulnerable to harm from injury due to increased engagement in risk taking behaviour. There is a gap in the literature regarding how universal school based injury prevention programs apply to high-risk adolescents. This study involves a component of the process evaluation of a school based injury prevention program, as it relates to high-risk adolescents (13-14 years)...

Reducing road related injuries for young adolescents : an investigation of truancy as a risk factor

Truancy is recognised as an indicator of engagement in high-risk behaviours for adolescents. Injuries from road related risk behaviours continue to be a leading cause of death and disability for early adolescents (13-14 years). The aim of this research is to determine the extent to which truancy relates to increased risk of road related injuries for early adolescents. Four hundred and twenty-seven Year 9 students (13-14 years) from five high schools in Queensland, Australia, completed a questionnaire about their perceptions of risk and recent injury experience. Self-reported injuries were assessed by the Extended Adolescent Injury Checklist (E-AIC). Injuries resulting from motorcycle use, bicycle use, vehicle use (as passenger or driver), and as a pedestrian were measured for the preceding three months. Students were also asked to indicate whether they sought medical attention for their injuries. Truancy rates were assessed from self-reported skipping class or wagging school over the same three month period. The findings explore the relationship between early adolescent truancy and road related injuries. The relationship between road related injuries and truancy was analysed separately for males and females. Results of this study revealed that road related injuries and reports of associated medical treatment are higher for young people who engage in truancy when compared with non-truant adolescents. The results of this study contribute knowledge about truancy as a risk factor for engagement in road related risks. The findings have the potential to enhance school policies and injury prevention programs if emphasis is placed on increasing school attendance as a safety measure to decrease road related injuries for young adolescents.

Development and review of vignettes representing older people with cognitive impairment

This paper describes a process undertaken to develop and review five clinical vignettes to be used in geriatric nursing educational research. The purpose of this process was to provide valid depictions of delirium and its subtypes and distinguish delirium from dementia. Five vignettes depicting hospital bedside interactions between nursing staff, family, and an older patient who displayed signs of one of the following conditions: delirium (hyper and hypo-active types respectively), dementia, or delirium (both types) superimposed on dementia were constructed. Vignette accuracy and reliability was established using a multistage process that culminated in formal review by a group of ten international nursing and medical delirium experts. The final five vignettes accurately depicted the given scenario as agreed by the experts and were at an appropriate level of simplicity and clarity. Given the increased interest in vignettes for both nursing research and educational purposes, the described method of vignette development and review has the ability to assist other vignette developers in creating reliable representations of their desired clinical scenarios.

Developing authentic professional knowledge through transformative community engagement in an interdisciplinary service learning project

This showcase presents a preliminary analysis of a community service learning project designed to align more authentically with contemporary society and emerging constructs of professional knowledge. As described in the paper, the project involves a multidisciplinary group of students working collaboratively with a community organisation to find creative presponses to challenging issues concerning the organisation's identity, how it interfaces with stakeholders, and how it evidences its inclusive practice. Of particular interest is how the interdisciplinary practice of the students within a service learning context encouraged reconsideration of their world0view and their rols as future professionals. Also highlighted is the need for greater congruence between the goals of the project and the structural elements of the curriculum.

First year industrial design studio-based teaching pedagogies and students’ engagement

Student engagement tends to be viewed as a reflection of learning processes, and in the context of first year university studies, it is a crucial means of an educational process that establishes the foundations for successful later year studies (Krausse and Coates, 2008). In the context of first year design studio teaching in higher education, fostering students’ positive engagement poses challenges to design educators as current trends set these design studios to be large size classes that makes difficult to manage and follow up students’ individual learning experiences. At QUT’s first year industrial design studio classes we engage in a variety of teaching pedagogies from which we identify two of them as instrumental vehicles to foster positive student engagement. Concept bombs and the field trip experience provide such platform as shown in student responses through a learning experience survey.

Does the addition of integrated cognitive behaviour therapy and motivational interviewing improve the outcomes of standard care for young people with comorbid depression and substance misuse?

Background: The high rates of comorbid depression and substance use in young people have been associated with a range of adverse outcomes. Yet, few treatment studies have been conducted with this population. Objective: To determine if the addition of Motivational Interviewing and Cognitive Behaviour Therapy (MI/CBT) to standard alcohol and other drug (AOD) care improves the outcomes of young people with comorbid depression and substance use. Participants and Setting: Participants comprised 88 young people with comorbid depression (Kessler 10 score of > 17) and substance use (mainly alcohol/cannabis) seeking treatment at two youth AOD services in Melbourne, Australia. Sixty young people received MI/CBT in addition to standard care (SC) and 28 received SC alone. Outcomes Measures: Primary outcome measures were depressive symptoms and drug and alcohol use in the past month. Assessments were conducted at baseline, 3 and 6 months follow up. Results and Conclusions: The addition of MI/CBT to SC was associated with a significantly greater rate of change in depression, cannabis use, motivation to change substance use and social contact in the first 3 months. However, those who received SC had achieved similar improvements on these variables by 6 months follow up. All young people achieved significant improvements in functioning and quality of life variables over time, regardless of the treatment group. No changes in alcohol or other drug use were found in either group. The delivery of MI/CBT in addition to standard AOD care may offer accelerated treatment gains in the short-term.

Social cognitive mediators of the effect of the MobileMums intervention on physical activity

Objective To explore whether improvements in physical activity following the MobileMums intervention were mediated by changes in Social Cognitive Theory (SCT) constructs targeted in the intervention (barrier self efficacy, goal setting skills, outcome expectancy, social support, and perceived environmental opportunity for exercise). This paper also examined if the mediating constructs differed between initial (baseline to 6 weeks) and overall (baseline to 13 weeks) changes in physical activity. Methods Secondary analysis of data from a randomized controlled trial involving 88 postnatal women (<12 months postpartum). Participants were randomized to receive either the 12-week MobileMums intervention or a minimal-contact control condition. Physical activity and proposed mediators were assessed by self-report at baseline, 6 weeks, and 13 weeks. Walking for Exercise frequency was assessed using the Australian Women's Activity Survey and frequency of moderate-to-vigorous physical activity (MVPA) was assessed using a single-item question. Results Initial improvements in goal-setting skills mediated the relationship between experimental condition and initial changes in MVPA, αβ (95% CI) = 0.23(0.01, 0.59), and Walking for Exercise, αβ (95% CI) = 0.34(0.06, 0.73). Initial improvements in barrier self efficacy mediated the relationship between experimental condition and initial change in MVPA, αβ (95% CI) = 0.36(0.12, 0.65), but not Walking for Exercise. None of the SCT outcomes significantly mediated the relationship between experimental condition and overall (baseline to 13 weeks) change in frequency of MVPA or Walking for Exercise. Conclusion Future interventions with postnatal women using SCT should target barrier self-efficacy and goal setting skills in order to increase physical activity. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

How do older adults respond to Active Australia physical activity questions? Lessons from cognitive interviews

The aim of this study was to examine older adults’ understanding and interpretation of a validated questionnaire for physical activity surveillance, the Active Australia Survey (AAS). To address this aim, cognitive interviewing techniques were used during face-to-face semi-structured interviews with 44 adults aged 65-89 years. Qualitative data analysis revealed that participants were confused with questionnaire phrasing, misunderstood the scope of activities to include in answers, and misunderstood the time frame of activities to report. They also struggled to accurately estimate the frequency and duration of their activities. Our findings suggest that AAS questions may be interpreted differently by older adults than intended by survey developers. Findings also suggest that older adults use a range of methods for calculating PA frequency and duration. The issues revealed in this study may be useful for adapting AAS for use in older community-dwelling adults.

Sensory imagery in craving : from cognitive psychology to new treatments for addiction

Sensory imagery is a powerful tool for inducing craving because it is a key component of the cognitive system that underpins human motivation. The role of sensory imagery in motivation is explained by Elaborated Intrusion (EI) theory. Imagery plays an important role in motivation because it conveys the emotional qualities of the desired event, mimicking anticipated pleasure or relief, and continual elaboration of the imagery ensures that the target stays in mind. We argue that craving is a conscious state, intervening between unconscious triggers and consumption, and summarise evidence that interfering with sensory imagery can weaken cravings. We argue that treatments for addiction can be enhanced by the application of EI theory to maintain motivation, and assist in the management of craving in high-risk situations.