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Open Access Publications from the University of California

Scholarly Works (10 results)

  • Article
  • Peer Reviewed
Comitatus: A Journal of Medieval and Renaissance Studies, Volume 31, Issue 1 (2000)
    Cover page: Peter Martyr: The Inquisitor as Saint
    • Article
    • Peer Reviewed
    UCLA Previously Published Works (2013)
    Because decision-making in situations of potential conflict hinges on assessing many features of the self and the foe, this process can be facilitated by summarizing diverse attributes in a single heuristic representation. Physical size and strength are evolutionarily ancient determinants of victory in conflict, and their relevance is reinforced during development. Accordingly, size and muscularity constitute ready dimensions for a summary representation of relative formidability, a perspective paralleled by the notion that social power is represented using envisioned relative size. Physical incapacitation constitutes a significant tactical disadvantage, hence temporary incapacitation should increase the envisioned size and strength of an antagonist. In Study 1, being bound to a chair increased men's estimates of the size of an angry man and decreased estimates of their own height. Study 2 conceptually replicated these effects: among men for whom standing on a balance board was challenging, the attendant experience of postural instability increased estimates of an angry man's size and muscularity, with similar patterns occurring at a reduced level among all but those whose equilibrium was apparently unaffected by this task.
      Cover page: Bound to Lose: Physical Incapacitation Increases the Conceptualized Size of an Antagonist in Men
      • Article
      • Peer Reviewed
      Proceedings of the Annual Meeting of the Cognitive Science Society, Volume 42 (2020)
      Using an experimental transmission design, we investigated the extent to which intentional information-sending creates anaccumulation of beneficial information, relative to transmission via inadvertent information.A small subset of an information providers search was transmitted to an information receiver, either selected by theinformation provider themselves (Intentional), or randomly sampled from their full search history (Inadvertent). A thirdcondition where information receivers were shown all of the information providers search attempts was included as acontrol.Intentional information-sending led to cumulative improvements that were comparable to receiving full information froma previous participants search, demonstrating that intentional information-sending had promoted cumulative cultural evo-lution. A follow-up study manipulated whether the sender also received feedback from the receiver which provided infor-mation about locations which had not been searched. No difference was found between these conditions, indicating thatfor this task, bidirectional communication did not further boost the effects of unidirectional intentional communication.
        Cover page: Intentional information sharing promotes cumulative culture relative toinadvertent behavioural cues: an experimental demonstrationCreative Commons 'BY' version 4.0 license
        • Article
        • Peer Reviewed
        Proceedings of the Annual Meeting of the Cognitive Science Society, Volume 42 (2020)
        Some theories propose that human cumulative culture is dependent on System 2 cognitive processes. We aimed to restrictaccess to adults executive functions via a dual-task paradigm, to assess whether this reduced their ability to improveupon information provided by a computer model. 206 participants completed a grid-search task in conjunction with aworking-memory task and a matched control, with the aim of outperforming an example attempt observed vicariously,presented on the computer. Participants behaviour was then used to simulate the outcome if the task was iterated overmultiple generations. Simulations run using the data showed that, across all conditions, participant behaviour would leadto cumulatively increasing scores over successive generations. However, scores plateaued without reaching the maximum.Overall, the task did not provide clear evidence that working-memory directly facilitates cumulative cultural evolution.However, differences between conditions may have been masked by offloading task demands to the concurrent working-memory task.
          Cover page: Restricted Access to Working Memory Does Not Prevent CumulativeImprovement in a Cultural Evolution Task.Creative Commons 'BY' version 4.0 license
          • Article
          • Peer Reviewed
          Proceedings of the Annual Meeting of the Cognitive Science Society, Volume 42 (2020)
          Population size has been proposed to promote cumulative culture in humans. Experimental evidence from adult humanssuggests that this may be due to the potential for combining beneficial information from multiple models. However, it ispossible that such combinatory social learning requires cognitive capacities restricted to adult humans. In our task, childrenaged 5-10 years watched two models consecutively search a 3x3 grid for rewards. Models revealed different correct andincorrect reward locations. This information could be used by the child to maximise their own score on the same task. Wewere interested in childrens ability to select rewarded locations, and avoid unrewarded ones, revealed by both models. Wealso manipulated the spatial and temporal displacement of the information available. Childrens performance on the taskimproved with age. Most children could outperform the mean score of the two models, but outperforming the combinedscore occurred in only limited circumstances.
            Cover page: Children combine information from multiple models in a grid search taskCreative Commons 'BY' version 4.0 license
            • Article
            • Peer Reviewed
            UC Davis Previously Published Works (2007)

            Previous research has proposed that genomic instability contributes to cancer progression, with its initiation linked to tetraploid cell formation (Duesberg, P., and R. Li. 2003. Cell Cycle. 2: 202-210; Ganem, N.J., Z. Storchova, and D. Pellman. 2007. Curr. Opin. Genet. Dev. 17: 157-162). However, there is little direct evidence linking cancer-causing mutations with such events, and it remains controversial whether genomic instability is a cause or an effect of cancer. In this study, we show that adenomatous polyposis coli (APC) mutations found in human colorectal cancers dominantly inhibit cytokinesis by preventing mitotic spindle anchoring at the anaphase cortex and, thus, blocking initiation of the cytokinetic furrow. We find that dividing crypt cells in the small intestines of APC(Min/+) mice exhibit similar mitotic defects, including misoriented spindles and misaligned chromosomes. These defects are observed in normal crypt cells with wild-type levels of beta-catenin and, importantly, are associated with tetraploid genotypes. We provide direct evidence that the dominant activity of APC mutants induces aneuploidy in vivo. Our data support a model whereby tetraploid cells represent a first step in the onset of genomic instability and colorectal cancer.

              Cover page: APC mutations lead to cytokinetic failures in vitro and tetraploid genotypes in Min mice
              • Article
              • Peer Reviewed
              Proceedings of the Annual Meeting of the Cognitive Science Society, Volume 42 (2020)
              We investigated whether capuchin monkeys could use information about rewarded and unrewarded stimuli such that chain-ing of their response patterns would in principle generate increasingly successful performances, indicative of potential forcumulative culture. Two populations of tufted capuchin monkeys were tested using a touchscreen stimulus-selection taskrequiring subjects to learn the strategy of repeating rewarded, and avoiding unrewarded selections following demonstra-tions of varying success. Although capuchins outperformed demonstrations of chance-level performance (simulating per-formance of a nave individual), they did not consistently outperform demonstrations of above-chance-level success. Thissuggests that, in a social transmission scenario, the accumulation of beneficial information over successive transmissionevents would be relatively limited. Despite mastering the task contingencies, the capuchins did not use the informationoptimally, limiting the potential for cumulative culture. Our data may provide insights into factors constraining cumulativeculture in the natural behaviour of non-humans.
                Cover page: Potential for cumulative culture in capuchin monkeys (Sapajus apella) in asimulated transmission chain study.Creative Commons 'BY' version 4.0 license
                • Article
                • Peer Reviewed
                Proceedings of the Annual Meeting of the Cognitive Science Society, Volume 42 (2020)
                Human cognition is routinely challenged by today’s multitasking demands which require continuous attentional deployment to multiple task components in parallel. While practice-based multitasking training has been shown to improve multitasking performance, little is known about how attention should be best deployed for optimal training. To this end, we leveraged a large-scale dataset from an online cognitive-training platform to investigate individual differences in task learning across long-term training. We developed an index of attentional deployment that specifies the temporal dynamics of learning for each component of the multitask and calculate distance maps between clusters of users to specify distinct learning styles. While long-term practice improved the multitasking performance of all participant groups, participants who focused on learning one task component earlier and more emphatically, benefited from superior learning gains throughout the entirety of training.
                  Cover page: A Large-Scale Analysis of Attentional Deployment across One Hundred Sessions of Adaptive Multitask TrainingCreative Commons 'BY' version 4.0 license
                  • Article
                  • Peer Reviewed
                  Proceedings of the Annual Meeting of the Cognitive Science Society, Volume 38 (2016)
                    Cover page: The cultural evolution of cognition
                    • Article
                    • Peer Reviewed
                    UC Davis Previously Published Works (2017)
                    An international summit focusing on the difficult challenge of providing adequate nutrition for adolescent girls and young women in low- and middle-income countries was held in Portland, Oregon in 2015. Sixty-seven delegates from 17 countries agreed on a series of recommendations that would make progress toward improving the nutritional status of girls and young women in countries where their access to nutrition is compromised. Delegate recommendations include: (1) elevate the urgency of nutrition for girls and young women to a high international priority, (2) raise the social status of girls and young women in all regions of the world, (3) identify major knowledge gaps in the biology of adolescence that could be filled by robust research efforts, (4) and improve access to nutrient-rich foods for girls and young women. Attention to these recommendations would improve the health of young women in all nations of the world.
                      Cover page: International summit on the nutrition of adolescent girls and young women: consensus statement
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