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Age-Related Aspects Of Mirror-Use By Bottlenose Dolphins (Tursiops Truncatus), Rachel A. Morrison

Dissertations, Theses, and Capstone Projects

Bottlenose dolphins are neuroanatomically different and evolutionarily divergent from primates yet they exhibit mirror self-recognition (MSR), a rare cognitive ability in non-human animals. This research investigated the developmental and age-related aspects of MSR in this species. During a longitudinal study, a social group of bottlenose dolphins at the National Aquarium, Baltimore, MD were exposed to a mirror and their behavioral responses were recorded to: 1) further confirm the presence of MSR in this species, 2) determine the age of emergence of MSR and 3) draw comparisons with data documenting the emergence of this ability in humans and great ape species. …

Attention Shapes Our Expectations And Perceptions: The Neural Mechanisms Of Top-Down Attention During Adulthood And Development, Snigdha Banerjee

Dissertations, Theses, and Capstone Projects

Top-down attention is the focusing of attention at one's will through knowledge regarding a current task. There is evidence that top-down attention involves the modulation of sensory cortices by higher order regions. However, the mechanisms of top-down attention across sensory modalities, its influence on early sensory inputs, as well as interactions with motivational systems remain unclear. We performed the following set of electrophysiological experiments in typically developed adults and adolescents to examine these areas. 1) The supramodal attentional theory holds that parietally-based attentional mechanisms are shared across sensory modalities. We tested the supramodal theory by examining if lateralized parieto-occipital alpha-band …

Biological Motion Processing In Typical Development And In The Autism Spectrum, Aaron Krakowski

Dissertations, Theses, and Capstone Projects

Biological motion (BM) analysis and interpretation is a fundamental process of human neurocognition that has been only minimally explored neurophysiologically. In addition to its importance in understanding the underlying roots and development of social cognition, BM processing is a prime candidate domain for exploring the underlying etiology of social cognitive disorders such as the autism spectrum.

In an initial experiment, typical adults observed BM point-light displays of a human actor (UM) as well as their spatially scrambled counterparts (SM), in both an unattended distractor task as well as an explicit attention task. Results showed a neurophysiological response manifested as three …

Phylogeny And Population Genetics Of The Endangered Dwarf Bear-Poppy, Arctomecon Humilis Coville (Papaveraceae) Using Microsatellite Markers, Joshua Simpson

Dissertations, Theses, and Capstone Projects

The genus Arctomecon (Papaveraceae) is comprised of three narrowly endemic rare species that are largely restricted to gypsum soils of the eastern Mojave Desert. The small, remaining populations of these species have become increasingly isolated by urban development and habitat fragmentation. Arctomecon humilis is federally listed as endangered due to its limited distribution within a ~15 km radius of an actively expanding city. Organizations involved with land management and conservation have called for greater insight into the genetic variation and population structure of the remaining subpopulations as they make important decisions regarding where to focus their efforts and resources.

The …