MA, University of Cincinnati, 2023, Arts and Sciences: Psychology

Attention is a cognitive process that, when stable, allows the mind to focus on relevant information. While attention can shift and fluctuate nonlinearly, research shows that a two-factor model can be used to capture the stability of selective sustained attention. Nevertheless, nonlinear dynamics of attention remain elusive under this two-factor model of attention. Hence, a one-sided focus on attentional stability undermines ways to control the processes of focusing and ignoring. To shed light on non-linear shifting in attention, I applied ideas from complexity science, a framework that anticipates such nonlinear phenomena. Specifically, I sought to apply a cusp model of selective sustained attention to explore the extent to which complexity science could be a useful approach to attention. The following demonstrates how a cusp model anticipates the presence of two orthogonal factors that align with those already identified in extant research on selective sustained attention. I also found that the empirical findings of selective sustained attention are conducive of fitting data to a cusp model. This research provides the first step in establishing a consistent framework for taking a dynamical complexity approach to the study of attention that inherently changes.

Committee: Heidi Kloos Ph.D. (Committee Chair); John Holden Ph.D. (Committee Member); Anthony Chemero Ph.D. (Committee Member) Subjects: Cognitive Therapy

Doctor of Philosophy, The Ohio State University, 2019, Anthropology

Beginning with Homo erectus, inferred changes in diet appear to be associated with dental reduction (Wrangham et al., 1999). With Homo sapiens, further reduction in crown size is associated with simplified trait expression (Bailey and Hublin, 2013). Trait simplification, particularly following the adoption of agriculture, may be an adaptive response to consuming soft, carbohydrate-rich foods that promote cavities and dental disease (Calcagno and Gibson, 1988; Meiklejohn et al., 1992). In contrast to the general trend of dental reduction and trait simplification, increases in the number and size of molar cusps in modern humans have been documented in the presence of developmental stress (Riga et al., 2014) and at least in one case, during the adoption of agriculture (Coppa et al., 2007). The question this dissertation addresses is how these different patterns of morphological change can be understood in terms of our current understanding of dental crown morphogenesis. The Patterning Cascade Model (PCM) has emerged as a developmental framework through which to predict patterns of dental morphological variability in terms of the size and placement of earlier forming cusps and the duration and rate of crown growth (Jernvall, 2000). These developmental events can be tracked by examining characteristics of the completed crown, assuming that distances among principal cusps reflect the original location of cusp-initiating centers (enamel-knots) and that the final size of the crown reflects the duration and rate of crown growth (Jernvall, 2000; Hunter et al., 2010; Skinner and Gunz, 2010; Morrmann et al., 2013; Ortiz et al., 2018). This dissertation is the first to investigate the extent to which the PCM can explain changes in dental morphology associated with both developmental stress and the shift to agriculture. For this research, three individual studies (presented as data chapters within the dissertation) were undertaken, each with a different sample or method to add (open full item for complete abstract)

Committee: Debbie Guatelli-Steinberg (Advisor); Mark Hubbe (Committee Member); John Hunter (Committee Member); Robert Cook (Committee Member) Subjects: Archaeology; Developmental Biology; Physical Anthropology