UC Research Repository

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The UC Research Repository collects, stores and makes available original research from postgraduate students, researchers and academics based at the University of Canterbury.

 

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ItemOpen Access
The biofactory : implementing a life cycle sustainability assessment decision making tool for quantifying integral sustainability benefits of the wastewater circular economy in Chile.
(2023) Furness, Madeline
The “Biofactory” is a circular economy-based concept for wastewater treatment that improves water quality, promotes efficient use of materials and energy, recovering resources, generating stakeholder collaboration, and decreasing both emissions and costs. This proposes a solution for the global challenge of integrated water and sanitation management. Due to socio-economic bottlenecks, such as typical high costs and low public acceptance of novel resource recovery scenarios in wastewater treatment, realizing the Biofactory goals becomes a difficult task. Decision makers are currently unable to appreciate the environmental and social benefits of the Biofactory, as most decision-making tools focus on mainly technical and economic aspects. This research is the first to quantify integral sustainability benefits of co-product recovery of treated effluent, biosolids, biogas and nutrient in two full-scale “Biofactory” wastewater circular economies in Chile. Life Cycle Sustainability Assessment (LCSA) was implemented, combining Life Cycle Assessment (LCA), Social Life Cycle Assessment (SLCA) and Life Cycle Costing (LCC) with a Multi-criteria Decision Making (MCDM) model to quantify integral environmental, socio-cultural, and economic sustainability impacts of two Plants, A and B. Three scenarios for each plant were considered, discharge of wastewater without treatment, conventional wastewater treatment with no resource recovery, and biofactory wastewater circular economy configurations, to determine if each plant decrease impacts and determine which had better performance. LCA results showed Plant A decreased overall environmental impact by -37 % compared to baseline conventional scenarios, while Plant B -31 %. SLCA results showed Plant A decreased social impacts – 56 %, while Plant B – 18 %, therefore, Plant A had better overall environmental and social performance. However, Plant B decreased economic impacts by -48 % compared to an increase of 20 % in Plant A. Therefore, when combining scores using a MCDM model, Plant A decreased total sustainability impacts by -30 % and Plant B by -58 %, therefore, the resource recovery systems implemented in Plant B had better overall sustainability performance. These results were discussed across process contributions to environmental, social, and economic benefits. Model limitations were discussed, and recommendations were made for future applications of this research. The investigation demonstrated that the transition to WW-CEs improved integral sustainability according to the LCSAMCDM model implemented in both Plants. The urgent need to adopt sustainable decision-making models was highlighted and discussed, to not only improve sanitation coverage, but also improve sustainability performance of the sanitation industry across the globe.
ItemOpen Access
Does a dimensionally-gated reselection process restrict the entry of visual features into working memory?
(2023) Williamson, Kieran James
Visual working memory (VWM) is a limited-capacity cognitive system that allows us to maintain and manipulate visual information over a brief period of time. It plays a critical role in many cognitive functions, including visual search, problem-solving, and decisionmaking. While the importance of VWM is not disputed, a critical issue addressed in research is whether visual objects bind all their component features during VWM entry or if task-relevant features are prioritised for representation. In a recent study, Zhu et al. (2022) proposed that attended sensory information does not automatically enter VWM, but instead is subject to an additional reselection process that determines whether items are selected for VWM entry. Furthermore, they suggested that reselection operates using a dimensional memory filter, such that when an individual feature value (e.g., red) is selected for entry into VWM, all attended feature values within the same feature dimension (e.g., all colours) automatically enter VWM. Across three experiments, we systematically investigated these hypotheses by conceptually replicating two of Zhu et al.’s experiments, while incorporating modifications to address our concerns about their methodology. In Experiment 1, we investigated Zhu et al.’s proposal that a reselection process operates to restrict the entry of features into VWM. We assessed whether the irrelevant colour of a target object captured more attention than a new colour when it appeared as a distractor singleton in an orthogonal visual search task. We found that this was the case, indicating that the irrelevant colour of the target object was held in VWM, contrary to the key result that Zhu et al. cited to support reselection. In Experiments 2 and 3, we investigated Zhu et al.’s claim that VWM consolidation operates via a dimensional memory filter. Specifically, we assessed whether memorising the colour of a fixation cross would cause the task-irrelevant colour of a target object to enter VWM. To determine whether this colour entered VWM, we measured its interference in an orthogonal shape change detection task. Experiment 2 used a 700 ms ISI, while in Experiment 3, we reduced the ISI to 100 ms. Unlike Zhu et al., who only reported trials where shape was consistent between displays, we included trials where shape changed between displays in our analysis and included trials in which the shape probe matched the memorised fixation colour. In Experiments 2 and 3, we found evidence that the target colour had entered VWM, consistent with a dimensional memory filter. However, we also found that the fixation colour had a stronger impact on shape change detection than the target colour, a finding that was not explicitly predicted by Zhu et al. Overall, our results align more closely with predictions from object-file theory (Kahneman et al., 1992) and event-file theory (Hommel, 1998, 2004), which propose object-specific binding occurs during encoding, and objectspecific benefits and costs emerge during object retrieval and review. The facilitation we observed when features were consistent between displays could reflect objectspecific repetition benefits, while the interference we observed when features partially changed between displays may indicate partial repetition costs.
ItemOpen Access
‘Akarongo, ‘Āpi‘i, Arataki Listen, Learn, Lead. Exploring the lived experiences and perspectives of Pacific peoples within climate change spaces : an Aotearoa context.
(2023) Timoteo, MahMah
Complex, nuanced, and devastating, the impacts of climate change are being felt on levels never experienced before in human history. Whilst many parts of the world are slowly, yet painfully becoming more exposed and familiar to the harmful and ever more destructive realities of the climate crisis, Pacific peoples and their communities have continued to be at the forefront of this global issue. Although much research has investigated the impact of climate change on Pacific Island nations, there is a lack of research that considers the multifaceted and intersectional lived experiences and voices of Pacific peoples and their navigation of the climate emergency, specifically within climate change spaces throughout Aotearoa New Zealand. This research aimed to explore the lived experiences of Pacific peoples in climate spaces within Aotearoa New Zealand and sought to identify the challenges Pacific peoples face whilst navigating these spaces. In doing so, this research sought to address such challenges by suggesting potential ways forward that can be implemented to aid the amplification and safety of Pacific peoples and their communities. An intersectional postcolonial approach was employed which provided a lens in which systemic and institutional oppression, marginalisation, and discrimination could be identified and understood. It is through the analysis of power dynamics and roles within climate spaces and discussions that we revealed the significance of decentring whiteness, dismantling of Eurocentrism, and colonial domination within such climate spaces. The following research involved ten Pacific participants throughout Aotearoa New Zealand. Guiding the research was the implementation of the Cook Island ‘Tivaevae Methodology’. The ‘akaruru (data collection) method carried out was an interweaving of semi-structured interviews, participant-observations, and talanoa. Stitched throughout the key stages of Tivaevae were five core values of the tivaevae model: taokotai (collaboration), tu akangateitei (respect), uriuri kite (reciprocity), tu inangaro (relationships), and akairi kite (shared vision). These values laid the foundation for how this research was carried out, centering the prosperity and wellbeing of those involved in this research and nurturing the vā between us. The key findings indicated that Pacific peoples and their community’s experiences of climate change spaces and discussions within Aotearoa New Zealand are dynamic, multifaceted, and complex. The talanoa sessions revealed that some Pacific peoples face various forms of discrimination and challenges within these spaces, with varying degrees of hardships brought about by oppressive systems and institutions upheld within Aotearoa New Zealand, which in turn negatively impacts their current livelihoods and futures. Informed by the lived experiences and perspectives shared by the participants involved, this research emphasises the imperative need for Pacific voices to be centred and amplified within climate change spaces and discussion. Furthermore, possible ways forward involve the decolonisation and indigenisation of systems and institutions that directly influence and impact climate spaces and beyond. Ways forward must be led by Pacific people and their communities to ensure the protection of their mana, safety, and future generations.
ItemOpen Access
Freedom from exposure to intimate partner violence in early childhood and emotional regulation during middle childhood, among pacific childhood growing up in Aotearoa/New Zealand.
(2023) Hakeemi, Humaira
Background: Studies have consistently demonstrated that children exposed to intimate partner violence (IPV) are at a higher risk of experiencing behavioural, physical, and emotional problems. Recent findings from a longitudinal study revealed that within the Pacific Islands Families (PIF) cohort, 41% of mothers identified themselves as either victims or perpetrators of IPV, highlighting the prevalence of such violence in the lives of children. Emotional regulation plays a critical in a child's development and well-being, emphasising the importance of investigating early childhood experiences to understand the factors that shape emotional health and identify protective measures. This study significantly contributes to a deeper understanding of the unique needs and experiences of Pacific children, thereby facilitating the development of targeted interventions tailored to this specific population. Given that PIF communities often contend higher rates of IPV compared to other demographic groups, this study aims to illuminate the distinct challenges they confront. Research Aim: The purpose of this study was to examine the relationship between freedom from exposure to IPV during early childhood (2-years) and emotional regulation during middle childhood (9-years), among Pacific children growing up in Aotearoa/New Zealand. Methods: This study utilized the PIF study, a longitudinal birth cohort study providing comprehensive data on the development of Pacific children in New Zealand. The study’s participants consisted of Pacific infants born at Middlemore Hospital in Auckland between March 15 to December 17, 2000. A total of participants completed both the IPV questionnaire and the internalising problems questionnaire. IPV exposure in children was assessed using mothers' reports at the 2-year measurement wave, while internalising problems were evaluated based on reports from mothers, teachers, and children at the 9- year measurement wave. Additionally, the study examined a child's report at the 9-year measurement wave to explore potential factors, such as substance exposure and bullying, in the relationship between IPV exposure and internalising problems. Result: While the study did not find a direct association between mother-reported IPV exposure and subsequent internalising problems, it did yield several significant findings. Children self-reported significantly higher rates of internalising problems than anticipated, with the severity of violence exposure notably impacting these rates. Specifically, children who reported symptoms were 2.2 times more prevalent among those whose mothers reported severe violence. Furthermore, mothers reported higher rates of internalising problems compared to children in a US-based standardization sample. This study also identified that children who had experienced bullying were at a 1.45 times increased risk of internalising problems, a pattern consistently reported by the children themselves. Additionally, the findings from this study indicated that children with access to any form of substance were found to be at a 3.27 times higher risk for internalising problems when compared to children without substance use. Despite the sample’s diversity, this study did not reveal any influences of cultural orientation on the relationships between preschool physical IPV exposure and middle childhood internalising problems. Implication: It is important to interpret these results within the existing literature and acknowledge the study’s limitations. The recruitment strategy used in the PIF study may restrict the generalizability of the results, given that the study’s participants were restricted to infants born at Middlemore Hospital and within the PIF study regions. It is possible that individuals from other regions in New Zealand may experience internalising problems differently. The relatively small sample size of 623 participants in this study could also affect the generalizability of the results, potentially yielded different outcomes with a larger sample. Previous research has produced varied results concerning the association between IPV exposure and children’s internalising problems, with some studies demonstrating significant associations and others showing no significant effects. This complexity underscores the necessity for further investigation to gain a more profound understanding of the underlying mechanisms and potential moderating factors involved.
ItemOpen Access
Response biases in visual processing: the effect of similarity and attention on judgments of sameness.
(2023) Humphries, Ailsa M.
It is well known that humans exhibit biased behaviours. Research suggests that both perceptual and cognitive biases arise from adaptive solutions to situations in which decisions must be made in the absence of complete information. These biases result from the operation of heuristics, or mental shortcuts, that evolved to keep us safe; to orient us towards friend and away from foe. While some biases are considered negative, leading to prejudice and discrimination, many are not; they are simply interesting tendencies that are worth studying to better understand information processing. Research in visual comparison tasks has identified two key biases. The spatial congruency bias (SCB) is a relative bias, with a greater tendency to judge objects as “same” if they are presented at the same location compared with a different location; and the overall bias (OB) is the average bias across all trials, that varies with overall display similarity and the degree to which analytic processing is required. Studying these biases will help with understanding the visual processing mechanisms that underlie object comparison, a fundamental task in our everyday activities. In two studies, signal detection theory was used to measure response bias and calculate the SCB and OB in visual comparison tasks that required judging whether two objects were the same or different. Each trial consisted of two sequential displays (S1 and S2). Each display contained a 3x3 grid with a target object in the middle row and two distractor objects, one in the top row and one in the bottom row. Participants judged whether the shape and/or position of a target object was the same or different in S1 and S2. There were two key manipulations common to both studies. Firstly, within every experiment the relative location of the grid between S1 and S2 was manipulated to assess the SCB. The grid was in the same location from S1 to S2 on half the trials and a different location on the remaining trials. Secondly, between experiments, the similarity of the distractor objects was manipulated with respect to the task relevant feature (i.e., their shape in the shape judgement task and their position in the position judgment task). The distractor objects either remained the same from S1 to S2 on most trials (high similarity) or they changed from S1 to S2 on all trials (low similarity). Study 1 was designed to investigate how location and display similarity affect response biases, and how those effects differ for position judgements versus shape judgements. Previous research has focused on investigating the SCB in judgments of object features such as shape and colour. In the first two experiments the task moved beyond feature comparisons, requiring comparison of the local position of the target (a black dot) with displays that had high similarity (Experiment 1) or low similarity (Experiment 2). The next two experiments directly compared the SCB and OB in position judgments versus shape judgments in within-subjects designs using letter stimuli; again, displays had high similarity (Experiment 3) or low similarity (Experiment 4). Together, the results of these experiments revealed that the SCB is a general phenomenon that applies to both position and shape comparisons, and is consistent regardless of stimulus type (dot or letter). Further, the SCB was weakened and the OB shifted more towards “different” when similarity was low, and the OB was shifted more towards “same” in position versus shape comparisons. The pattern of results suggests the SCB indexes the operation of a visual heuristic that is linked to the privileged nature of location and is evoked more often when similarity is high. Furthermore, as attentional selection requirements increase, due to the nature of the task and/or differences between displays, the tendency for “different” response increases. Study 2 was designed to determine whether an attentional mechanisms account, in which bias is modulated via adjustments to attentional zoom, or an overlap measure account, in which bias is modulated via an interaction between the number of differences and the threshold for a “different” response, is more parsimonious as an explanation for the effect of similarity on response bias. Previous research has indicated that the extent of attentional focus is adjusted to optimise target selection when the position of the target is predictable. In four experiments the position of the target letter was manipulated in the shape comparison task: it either remained in the same position from S1 to S2 or changed position, and this manipulation was either predictable (Experiments 5 and 7) or unpredictable (Experiment 6 and 8). Further, distractor similarity again varied from high (Experiments 5 and 6) to low (Experiments 7 and 8). The results revealed that reduced similarity affects response bias when either distractor shape or target position changes, and the predictability of target position only modulates bias when distractor similarity is low. The pattern of results suggests that mechanisms inherent in the overlap measure account provide a sufficient explanation for variation in response bias when holistic processing is possible, and that attentional mechanisms play an important role when analytic processing is required. In summary, a complex interaction between multiple factors influences response bias in visual comparisons. The SCB manifests as a result of the privileged nature of location which underpins a key heuristic, “same-location = same-object”, and the strength with which this heuristic is evoked varies with overall display similarity and attentional zoom settings. Visual similarity influences both the operation of the heuristic and the overall tendency for a “different” response via an interaction between the overlap measure, a “difference count” from the direct comparison of two displays, and the threshold for a “different” response, that develops on the basis of the heterogeneity of differences across multiple trials. Both biases are further modulated by attentional mechanisms that operate to adjust attentional zoom settings when experience with the task and/or displays indicates that analytic processing is optimal.