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Open Access Publications from the University of California

Scholarly Works (71 results)

  • Article
  • Peer Reviewed
Proceedings of the Annual Meeting of the Cognitive Science Society, Volume 13 (1991)
A set of tasks developed in accordance with Kosslyn. Van Kleeck. & Kirby's (1990b) neurologically plausible model of visual mental imagery was used to explore effects of aging on specific component processes involved in image generation and maintenance. Contrary to the widely held belief that age differences in cognition are attributable to a single mechanism of global effect (e.g., a reduction in critical processing resources, Salthouse, 1988), results indicate that processes involved in visual mental imagery are differentially age-sensitive. More precisely, components required to actively maintain images are particularly sensitive to effects of aging, while those that access visual information from memory are not especially affected. Advantages of a componential approach to understanding age differences in cognitive processing are disscussed, as well as the potential for such agerelated changes to be a readily exploitable source of information regarding the functional architecture of cognition.
    Cover page: Adult Age Differences in Visual Mental Imagery: Evidence for Differentially Age-Sensitive Components
    • Article
    • Peer Reviewed
    Proceedings of the Annual Meeting of the Cognitive Science Society, Volume 15 (1993)
    Can observers recognize novel views of three-dimensional (3-D) objects, created by rotations in depth from a single familiar view? Three experiments using 3-D model objects are reported demonstrating that: (a) subjects can indeed recognize novel views under these circumstances, and (b) recognition accuracy depends on the types of objects employed. More precisely, subjects successfully recognized geometricallyregular and irregular objects rotated by 180 degrees about the vertical ^ ) axis. However, only geometricallyregular objects w o e recognized w h e n rotated similarly by 9 0 degrees. Thesefindingscannot be easily accommodated by contemporary object-centered or viewer-centered theories of shape-based object recognition, which m a k e no provisions for rqnesenting different types of objects uniquely. Alternatively, thesefindings support a theory in which inferences about objects' 3-D shapes are generated from information implicit in their two- dimensional (2-D) bounding contours, or silhouettes (Johnson, 1993). Such inferences m a y be premised on rules that C2q)ture importantregularities between 2- D bounding contours and 3-D surface geometry (e.g., Beusmans, Hofiman, & Bennett, 1987; Richards, Koenderink, & Hoffinan. 1987).
      Cover page: Effects of Object Structure on Recognizing Novel Views of Three-Dimensional Objects
      • Thesis
      • Peer Reviewed
      UC San Diego Electronic Theses and Dissertations (2024)

      Teacher retention is a critical issue for the American education system and society as awhole. Much research has focused on teacher recruitment, pathways to teacher credentialing, and factors that support teacher retention, including positive organizational conditions and administrative support. Teachers of Color make up a numerical minority in America’s classrooms despite student demographics shifting to an increasingly diverse composition. Research supports the importance of Teachers of Color for students, both minority and non- minority. Despite this understanding, numerous barriers exist for Teachers of Color in America’s classrooms. Recent research has shown that increased attention to organizational conditions and how teachers experience their workplace influences their employment decisions.

      Focusing on a suburban school district in Southern California, this mixed methodsresearch study examines how Teachers of Color experience their workplace, and how experiences of belonging and othering influence their desire to stay or depart. Drawing upon Bronfenbrenner’s (1999) Ecological Systems Theory, the study puts forth an original framework placing the Teacher of Color in the center of four contexts; self, school, district and community. Findings show that school context most influences belonging, that positive relationships with colleagues and administrators are positively associated with belonging, and that a teacher’s individual purpose is central to this theme. District equity policies are also positively associated with belonging in Teachers of Color. The implications for administrators and educational leaders hold promise in fostering belonging and increasing retention for Teachers of Color in suburban school settings.

        Cover page: The Impact of Belonging on Retention Rates of Teachers of Color in Suburban School Districts
        • Thesis
        • Peer Reviewed
        UCLA Electronic Theses and Dissertations (2023)

        This case study focuses on the implementation and analysis of critical algorithmic literacy (CAL) lessons in two grade 3/4 combination classes. The study involves one elementary school teacher and 36 students from a K-6 school in Southern California. By analyzing various data sources, I identified trends that could be helpful for future researchers and educators looking to introduce CAL in elementary education.The data indicate that merging computer science and Kellner and Share’s (2019) Critical Media Literacy Framework represents a promising method for teaching contextualized algorithmic literacy models, like CAL, to elementary students. The study examines the importance of clear instructional examples for helping students grasp the concept of algorithms and their societal effects. It also highlights that a student’s understanding of bias and basic computer science concepts can enhance their understanding of algorithmic bias and its societal impacts. This study also illustrates how lessons designed for older students can be successfully modified for elementary students. It examines both the challenges and potential for the CAL framework’s design. Furthermore, it uncovers various obstacles and effective practices for integrating CAL instruction with third and fourth graders. Future research aiming to foster CAL in classrooms should investigate how teachers evaluate student learning and the role of general computer science knowledge in enabling critical examination of algorithmically driven media.

          Cover page: Critical Algorithmic Literacy: Explorations of Algorithmic Bias in Elementary School
          • Article
          • Peer Reviewed
          UC San Francisco Previously Published Works (2016)

          Background

          Biological mechanisms underlying symptom and prognostic heterogeneity in Attention-Deficit/Hyperactivity Disorder (ADHD) are unclear. Sleep impacts neurocognition and daytime functioning and is disrupted in ADHD, yet little is known about sleep in ADHD during adolescence, a period characterized by alterations in sleep, brain structure, and environmental demands as well as diverging ADHD trajectories.

          Methods

          A systematic review identified studies published prior to August 2016 assessing sleep in adolescents (aged 10-19years) with ADHD or participating in population-based studies measuring ADHD symptoms.

          Results

          Twenty-five studies were identified (19 subjective report, 6 using actigraphy/polysomnography). Findings are mixed but overall suggest associations between sleep disturbances and 1) ADHD symptoms in the population and 2) poorer clinical, neurocognitive, and functional outcomes among adolescents with ADHD. Common limitations of studies included small or non-representative samples, non-standardized sleep measures, and cross-sectional methodology.

          Conclusions

          Current data on sleep in adolescent ADHD are sparse and limited by methodological concerns. Future studies are critical for clarifying a potential role of sleep in contributing to heterogeneity of ADHD presentation and prognosis. Potential mechanisms by which sleep disturbances during adolescence may contribute to worsened symptom severity and persistence of ADHD into adulthood and an agenda to guide future research are discussed.
            Cover page: Sleep disturbances in adolescents with ADHD: A systematic review and framework for future research
            • Article
            • Peer Reviewed
            Western Journal of Emergency Medicine: Integrating Emergency Care with Population Health, Volume 11, Issue 2 (2010)

            Background: Brief alcohol intervention may improve outcomes for injury patients with hazardous drinking but is less effective with increased severity of alcohol involvement. This study evaluated a brief method for detecting problem drinking in minor trauma patients and differentiating hazardous drinkers from those with more severe alcohol problems.

            Methods: Subjects included 60 minor trauma patients in an academic urban emergency department (ED) who had consumed any amount of alcohol in the prior month. Screening and risk stratification involved the use of a heavy-drinking-day screening item and the Rapid Alcohol Problems Screen (RAPS). We compared the heavy-drinking-day item to past-month alcohol use, as obtained by validated self-reporting methods, and measured the percentage of carbohydrate-deficient transferrin (%CDT) to assess the accuracy of self-reporting. The Alcohol Dependence Scale (ADS) was administered to gauge the severity of alcohol involvement and compared to the RAPS.

            Results: Eighty percent of the subjects endorsed at least one heavy drinking day in the past year, and all patients who exceeded recommended weekly drinking limits endorsed at least one heavy drinking day. Among those with at least one heavy drinking day, 58% had a positive RAPS result. Persons with no heavy drinking days (n=12) had a median ADS of 0.5 (range 0 to 3). RAPS-negative persons with heavy drinking days (n=20) had a median ADS of 2 (range 0 to 8). RAPS-positive persons with heavy drinking days (n=28) had a median ADS of 8 (range 1 to 43).

            Conclusion: A heavy-drinking-day item is useful for detecting hazardous drinking patterns, and the RAPS is useful for differentiating more problematic drinkers who may benefit from referral from those more likely to respond to a brief intervention. This represents a time-sensitive approach for risk-stratifying non-abstinent injury patients prior to ED discharge. [West J Emerg Med. 2010; 11(2):133-137.]

              Cover page: Identification and Risk-Stratification of Problem Alcohol Drinkers with Minor Trauma in the Emergency DepartmentCreative Commons 'BY-NC' version 4.0 license
              • Article
              • Peer Reviewed
              Proceedings of the Annual Meeting of the Cognitive Science Society, Volume 41 (2019)
              This study investigated how beat gesture and contrastive pitchaccenting affect online contrastive reference resolution duringspoken discourse comprehension. Evidence from gazefixations indicated that beat gesture encouraged fixations totarget referents of contrastive referring expressions and thatcontrastive accenting encouraged fixations to competitorreferents of non-contrastive referring expressions. Notably,beat gesture and contrastive accenting acted independently,indicating that their effects are additive rather than interactive.Moreover, neither beat gesture nor contrastive accentingaffected an observed tendency to anticipate contrastivereferring expressions. Together, these results provide the firstevidence that beat gesture, like contrastive accenting, isinterpreted as a cue to contrast during online referenceresolution in spoken discourse comprehension.
                Cover page: Eye See What You’re Saying: Beat Gesture Facilitates Online Resolution ofContrastive Referring Expressions in Spoken Discourse
                • Article
                • Peer Reviewed
                UC Santa Cruz Previously Published Works (2015)
                The ability to critically evaluate neuroscientific findings is a skill that is rapidly becoming important in non-science professions. As neuroscience research is increasingly being used in law, business, education, and politics, it becomes imperative to educate future leaders in all areas of society about the brain. Undergraduate general education courses are an ideal way to expose students to issues of critical importance, but non-science students may avoid taking a neuroscience course because of the perception that neuroscience is more challenging than other science courses. A recently developed general education cluster course at UCLA aims to make neuroscience more palatable to undergraduates by pairing neuroscientific concepts with philosophy and history, and by building a learning community that supports the development of core academic skills and intellectual growth over the course of a year. This study examined the extent to which the course was successful in delivering neuroscience education to a broader undergraduate community. The results indicate that a majority of students in the course mastered the basics of the discipline regardless of their major. Furthermore, 77% of the non-life science majors (approximately two-thirds of students in the course) indicated that they would not have taken an undergraduate neuroscience course if this one was not offered. The findings also demonstrate that the course helped students develop core academic skills and improved their ability to think critically about current events in neuroscience. Faculty reported that teaching the course was highly rewarding and did not require an inordinate amount of time.
                  Cover page: Brain literate: making neuroscience accessible to a wider audience of undergraduates.Creative Commons 'BY' version 4.0 license
                  • Article
                  • Peer Reviewed
                  UC Irvine Previously Published Works (2009)

                  Background

                  Lisdexamfetamine dimesylate (LDX) is indicated for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children 6 to 12 years of age and in adults. In a previous laboratory school study, LDX demonstrated efficacy 2 hours postdose with duration of efficacy through 12 hours. The current study further characterizes the time course of effect of LDX.

                  Methods

                  Children aged 6 to 12 years with ADHD were enrolled in a laboratory school study. The multicenter study consisted of open-label, dose-optimization of LDX (30, 50, 70 mg/d, 4 weeks) followed by a randomized, placebo-controlled, 2-way crossover phase (1 week each). Efficacy measures included the SKAMP (deportment [primary] and attention [secondary]) and PERMP (attempted/correct) scales (secondary) measured at predose and at 1.5, 2.5, 5, 7.5, 10, 12, and 13 hours postdose. Safety measures included treatment-emergent adverse events (AEs), physical examination, vital signs, and ECGs.

                  Results

                  A total of 117 subjects were randomized and 111 completed the study. Compared with placebo, LDX demonstrated significantly greater efficacy at each postdose time point (1.5 hours to 13.0 hours), as measured by SKAMP deportment and attention scales and PERMP (P < .005). The most common treatment-emergent AEs during dose optimization were decreased appetite (47%), insomnia (27%), headache (17%), irritability (16%), upper abdominal pain (16%), and affect lability (10%), which were less frequent in the crossover phase (6%, 4%, 5%, 1%, 2%, and 0% respectively).

                  Conclusion

                  In school-aged children (6 to 12 years) with ADHD, efficacy of LDX was maintained from the first time point (1.5 hours) up to the last time point assessed (13.0 hours). LDX was generally well tolerated, resulting in typical stimulant AEs.

                  Trial registration

                  Official Title: A Phase IIIb, Randomized, Double-Blind, Multi-Center, Placebo-Controlled, Dose-Optimization, Cross-Over, Analog Classroom Study to Assess the Time of Onset of Vyvanse (Lisdexamfetamine Dimesylate) in Pediatric Subjects Aged 6-12 With Attention-Deficit/Hyperactivity Disorder. ClinicalTrials.gov Identifier: NCT00500149 http://clinicaltrials.gov/ct2/show/NCT00500149.
                    Cover page: A 13-hour laboratory school study of lisdexamfetamine dimesylate in school-aged children with attention-deficit/hyperactivity disorder
                    • Article
                    • Peer Reviewed
                    UC San Francisco Previously Published Works (2009)
                    Demographic models built from genetic data play important roles in illuminating prehistorical events and serving as null models in genome scans for selection. We introduce an inference method based on the joint frequency spectrum of genetic variants within and between populations. For candidate models we numerically compute the expected spectrum using a diffusion approximation to the one-locus, two-allele Wright-Fisher process, involving up to three simultaneous populations. Our approach is a composite likelihood scheme, since linkage between neutral loci alters the variance but not the expectation of the frequency spectrum. We thus use bootstraps incorporating linkage to estimate uncertainties for parameters and significance values for hypothesis tests. Our method can also incorporate selection on single sites, predicting the joint distribution of selected alleles among populations experiencing a bevy of evolutionary forces, including expansions, contractions, migrations, and admixture. We model human expansion out of Africa and the settlement of the New World, using 5 Mb of noncoding DNA resequenced in 68 individuals from 4 populations (YRI, CHB, CEU, and MXL) by the Environmental Genome Project. We infer divergence between West African and Eurasian populations 140 thousand years ago (95% confidence interval: 40-270 kya). This is earlier than other genetic studies, in part because we incorporate migration. We estimate the European (CEU) and East Asian (CHB) divergence time to be 23 kya (95% c.i.: 17-43 kya), long after archeological evidence places modern humans in Europe. Finally, we estimate divergence between East Asians (CHB) and Mexican-Americans (MXL) of 22 kya (95% c.i.: 16.3-26.9 kya), and our analysis yields no evidence for subsequent migration. Furthermore, combining our demographic model with a previously estimated distribution of selective effects among newly arising amino acid mutations accurately predicts the frequency spectrum of nonsynonymous variants across three continental populations (YRI, CHB, CEU).
                      Cover page: Inferring the Joint Demographic History of Multiple Populations from Multidimensional SNP Frequency Data
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