Interactive fisheye views use distortion to show both local detail and global context in the same display space. Although fisheyes allow the presentation and inspection of large data sets, the distortion effects can cause problems for users. One such problem is lack of memorability the ability to find and go back to objects and features in the data. This thesis examines the possibility of improving the memorability of fisheye views by adding historical information to the visualization. The historical information is added visually through visit wear, an extension of the concepts of edit wear and read wear. This will answer the question Where have I been? through visual instead of cognitive processing by overlaying new visual information on the data to indicate a users recent interaction history. This thesis describes general principles of visibility in a space that is distorted by a fisheye lens and defines some parameters of the design space of visit wear. Finally, a test system that applied the principles was evaluated, and showed that adding visit wear to a fisheye system improved the memorability of the information space.

Studies of spatial memory provide valuable insight into more general mnemonic functions, for by observing the activity of cells such as place cells, one can follow a subject’s dynamic representation of a changing environment. I investigate how place cells resolve conflicting neuronal input signals by developing computational models that integrate synaptic inputs on two scales. First, I construct reduced models of morphologically accurate neurons that preserve neuronal structure and the spatial specificity of inputs. Second, I use a parallel implementation to examine the dynamics among a network of interconnected place cells. Both models elucidate possible roles for the inputs and mechanisms involved in spatial memory.

Sex differences in spatial cognition have been reported for many species ranging from voles to humans. The range size hypothesis predicts that sex differences in spatial ability will only occur in species in which the mating system selects for differential range size. Consistent with this prediction, we observed sex differences in spatial ability in giant pandas, a promiscuous species in which males inhabit larger ranges than females, but did not observe sex differences in Asian small-clawed otters, a related monogamous species in which males and females share home ranges. Furthermore, the sex difference in giant pandas was observed during the period of male range expansion and outside female estrus, thus the potentially confounding influence of decreased female ability was avoided. Finally, all subjects in this study were raised in captivity and never actually inhabited different range sizes. Therefore these findings emphasize the importance of biological rather than experiential factors underlying sex differences in spatial cognition. These results are the first evidence of sex differences in spatial ability in the order Carnivora, and provide support for the range size hypothesis.

<p>Primates in the wild face complex foraging decisions where they must assess the most valuable of different potential resources to exploit, as well recall the location of options that can be widely distributed. While differences in diet and ecology have long been thought to be an important factor influencing brain evolution in primates, it is less well understood what psychological abilities animals actually use when making foraging decisions. This dissertation examines cognitive domains that play a crucial role in supporting foraging behaviors--spatial memory and decision-making--by integrating both psychological and biological approaches to behavior. In particular, the research presented here examines multiple species of primates to address the cognitive skills that different animals use to solve foraging problems (at the proximate level of analysis), as well as why some species appear to solve such problems differently than other species (at the ultimate level of analysis).</p><p>The first goal of the dissertation is to compare closely-related species that vary in ecological characteristics, in order to illuminate how evolution shapes the cognitive skills used in foraging contexts. This component focuses on comparisons between chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), humans' closest extant relatives. In addition, this component reports comparisons amongst strepsirrhines (Lemur catta, Eulemur mongoz, Propithecus coquereli, and Varecia subsp.) to model cognitive evolution in a taxonomic group with greater ecological diversity than Pan. The first two chapters test the hypothesis that more frugivorous species exhibit more accurate spatial memory skills, first by comparing apes' spatial memory abilities (Chapter 2), and then by comparing four species of lemurs on a related set of spatial memory tasks (Chapter 3). In subsequent chapters, I examine apes' decision-making strategies to test the hypothesis that chimpanzees are more willing to pay decision-making costs than are bonobos, due to differences in their feeding ecology. I focus on preferences about the timing of payoffs (Chapter 4); preferences about risk, or the variability in payoffs (Chapters 4 and 5); and preferences about ambiguity, or knowledge about available options (Chapter 6). </p><p>The second goal of the dissertation is to compare the psychological mechanisms that human and nonhuman great apes use for foraging, in order to identify potentially human-unique cognitive abilities. In terms of spatial memory, I examine whether other apes also exhibit human-like patterns of spatial memory development (Chapter 2). In terms of decision-making, I examine whether apes exhibit a suite of human-like biases when making value-based choices. In particular, I test whether emotional and motivational processes, which are critical components of human decision-making, also play a role in apes' choices (Chapters 4); whether apes are sensitive to social context when making economic decisions (Chapter 5); and whether apes are sensitive to their degree of knowledge when making choices under uncertainty (Chapter 6). Finally, I directly compare human and ape preferences on a matched task to assess whether humans use any unique psychological abilities when making decisions about risk (Chapter 7). In sum, this dissertation links studies of mechanism with hypotheses about function in order to illuminate the evolutionary roots of human's unique cognitive phenotype.</p> / Dissertation

The giant panda (Ailuropoda melanoleuca) is an endangered species and many efforts are being made to ensure its survival, including numerous research studies. However, there has been little investigation of spatial memory in the giant panda. Spatial memory is an important mechanism for survival in the wild, allowing an animal to find and remember the location of food, mates, den sites and avoid predators. Memory assessment in non-human species typically involves the use of recognition, as opposed to recall tasks. The current study tested spatial memory recall in 1.1 giant pandas using a delayed response memory task. The design required a delayed response to a previously lighted location, with varying lengths of delay between the observation phase and the test phase. The male subject reached criterion at 2-, 3-, 4-, 5-, 6-, and 10-second delays. The female subject reached criterion at 2-, 3-, 4-, 5-, 6-, 10-, and 15-second delays. The results support the hypothesis that giant pandas have working memory recall ability for spatial location.

Thesis (Ph. D.)--Miami University, Dept. of Psychology, 2009. / Title from second page of PDF document. Includes bibliographical references (p. 42-49).

abstract: Women are exposed to numerous endogenous and exogenous hormones across the lifespan. In the last several decades, the prescription of novel hormonal contraceptives and hormone therapies (HTs) have resulted in aging women that have a unique hormone exposure history; little is known about the impact of these hormone exposures on short- and long- term brain health. The goal of my dissertation was to understand how lifetime hormone exposures shape the female cognitive phenotype using several innovative approaches, including a new human spatial working memory task, the human radial arm maze (HRAM), and several rodent menopause models with variants of clinically used hormone treatments. Using the HRAM (chapter 2) and established human neuropsychological tests, I determined males outperformed females with high endogenous or exogenous estrogen levels on visuospatial tasks and the spatial working memory HRAM (chapter 3). Evaluating the synthetic estrogen in contraceptives, ethinyl estradiol (EE), I found a high EE dose impaired spatial working memory in ovariectomized (Ovx) rats, medium and high EE doses reduced choline-acetyltransferace-immunoreactive neuron population estimates in the basal forebrain following Ovx (chapter 4), and low EE impaired spatial cognition in ovary-intact rats (chapter 5). Assessing the impact of several clinically-used HTs, I identified a window of opportunity around ovarian follicular depletion outside of which the HT conjugated equine estrogens (CEE) was detrimental to spatial memory (chapter 6), as well as therapeutic potentials for synthetic contraceptive hormones (chapter 9) and bioidentical estradiol (chapter 7) during and after the transition to menopause. Chapter 6 and 7 findings, that estradiol and Ovx benefitted cognition after the menopause transition, but CEE did not, are perhaps due to the negative impact of ovarian-produced, androstenedione-derived estrone; indeed, blocking androstenedione’s conversion to estrone prevented its cognitive impairments (chapter 8). Finally, I determined that EE combined with the popular progestin levonorgestrel benefited spatial memory during the transition to menopause, a profile not seen with estradiol, levonorgestrel, or EE alone (chapter 9). This work identifies several cognitively safe, and enhancing, hormonal treatment options at different time points throughout female aging, revealing promising avenues toward optimizing female health. / Dissertation/Thesis / Doctoral Dissertation Psychology 2015

A neurogênese hipocampal é modulada por muitos fatores que incluem envelhecimento, estresse, enriquecimento ambiental, atividade física e aprendizado. Atividade física voluntária (espontânea) estimula a proliferação celular no giro denteado e facilita a aquisição e/ou retenção de tarefas dependentes do hipocampo, incluindo o Labirinto Aquático de Morris. Embora seja bem estabelecido que o exercício físico regular melhore o desempenho em tarefas de memória e aprendizado, não está claro qual a duração desses benefícios após o final da atividade física. Neste estudo investigamos a relação temporal entre os efeitos benéficos da atividade física associado ao aprendizado de tarefa dependente da função hipocampal, e sua relação com a neurogênese, levando em consideração também o tempo decorrido desde o término da atividade física. Grupos independentes de ratos tiveram acesso a roda de atividade ao longo de 7 dias (Grupo EXE) ou roda bloqueada (Grupo Ñ-EXE) e receberam injeções de BrdU nos últimos 3 dias de exposição roda. Após um INTERVALO de 1, 3 ou 6 semanas após o final da exposição a roda de atividade após o final da exposição a roda de atividade, os animais foram testados no labirinto aquático de Morris, sendo uma parte deles expostos a tarefa de memória operacional espacial, dependente da função hipocampal (H), e outra parte a uma tarefa de busca por uma plataforma visível, independente da função hipocampal (ÑH). Em ambos os casos, o intervalo entre as tentativas (ITI) foi de 10 minutos durante as sessões 1-6 e (virtualmente) zero minutos durante as sessões 7-10. Concluída a tarefa os cérebros foram processados para imuno-histoquímica. Foram feitas imunoistoquímicas para a detecção de Ki-67 (proliferação celular), BrdU, NeuN (para identificar neurónios maduros), e DCX (para identificar imaturo neurônios). Nossos dados suportam a ideia que atividade física voluntária induz um aumento na proliferação celular e na diferenciação neuronal (neurogênese) no giro denteado. A introdução de um período de intervalo entre o final do exercício e a execução da tarefa comportamental causa uma redução significativa na sobrevivência dos novos neurônios, como observado com 1 semana de intervalo em comparação com os animais testados com 6 semanas de intervalo. Em contraste, entretanto, o presente resultado não confirma que esse aumento da neurogênese é acompanhado por melhora na memória espacial, como avaliado por meio da versão que envolve memória operacional no labirinto aquático de Morris. O aprendizado da tarefa do labirinto aquático de Morris, na versão de memória operacional que é dependente do hipocampo, leva a um aumento da sobrevivência dos novos neurônios que foram produzidos no período de exercício, ao passo que o aprendizado da versão independente da tarefa leva a uma redução do número absoluto de novos neurônios / Hippocampal adult neurogenesis is modulated by many factors including age, stress, environmental enrichment, physical exercise and learning. Spontaneous exercise in a running wheel stimulates cell proliferation in the adult dentate gyrus and facilitates acquisition and/or retention of hippocampal-dependent tasks including the Morris water maze. While it is well established that regular physical exercise improves cognitive performance, it is unclear for how long these benefits last after its interruption. In this study, we investigate the temporal relation between exercise-induced benefits associated with learning of a hippocampal-dependent task, this relationship with neurogenesis, considering the time after exercise has ended. Independent groups of rats were given free access to either unlocked (EXE Group) or locked (No-EXE Group) running wheels for 7 days, having received daily injections of BrdU for the last 3 days. The animals were then transferred to standard home cages. After a time period of either 1, 3 or 6 weeks, the animals were tested in the Morris water maze, one of them being exposed to the spatial working memory task dependent on hippocampal function (H) and partly to a task search for a visible platform, independent of hippocampal function (NH). In both cases, the interval between trials (ITI) was 10 minutes during sessions and 1-6 and (virtually) zero minute during the sessions 7-10. After the task brains were processed for immunohistochemistry. Cell proliferation and net neurogenesis were assessed in hippocampal sections using antibodies against BrdU, NeuN (to identify mature neurons), and DCX (to identify immature neurons). Data of the present study confirm that exposure of rats to 7 days of spontaneous wheel running increases cell proliferation and neurogenesis. In contrast, however, the present results did not confirm that this neurogenesis is accompanied by a significant improvement in spatial learning, as evaluated using the working memory version of the Morris&rsquo; water maze task. The introduction of a delay period between the end of exercise and cognitive training on the Morris water maze reduces cell survival; the number of new neurons was higher in the EXE1 week delay group as compared to the EXE6 week delay. We showed that learning the Morris water maze in the working memory task dependent on hippocampal function (H) increases the new neurons survival, in contrast, learning hippocampal-independent version of the task decreases number of new neurons

abstract: Chronic restraint stress impairs hippocampal-mediated spatial learning and memory, which improves following a post-stress recovery period. Here, we investigated whether brain derived neurotrophic factor (BDNF), a protein important for hippocampal function, would alter the recovery from chronic stress-induced spatial memory deficits. Adult male Sprague-Dawley rats were infused into the hippocampus with adeno- associated viral vectors containing the coding sequence for short interfering (si)RNA directed against BDNF or a scrambled sequence (Scr), with both containing the coding information for green fluorescent protein to aid in anatomical localization. Rats were then chronically restrained (wire mesh, 6h/d/21d) and assessed for spatial learning and memory using a radial arm water maze (RAWM) either immediately after stressor cessation (Str-Imm) or following a 21-day post-stress recovery period (Str-Rec). All groups learned the RAWM task similarly, but differed on the memory retention trial. Rats in the Str-Imm group, regardless of viral vector contents, committed more errors in the spatial reference memory domain than did non-stressed controls. Importantly, the typical improvement in spatial memory following recovery from chronic stress was blocked with the siRNA against BDNF, as Str-Rec-siRNA performed worse on the RAWM compared to the non-stressed controls or Str-Rec-Scr. These effects were specific for the reference memory domain as repeated entry errors that reflect spatial working memory were unaffected by stress condition or viral vector contents. These results demonstrate that hippocampal BDNF is necessary for the recovery from stress-induced hippocampal dependent spatial memory deficits in the reference memory domain. / Dissertation/Thesis / M.A. Psychology 2013

Acidentes ofídicos constituem um problema de saúde publica. Estudos prévios indicam que constituintes do veneno de Crotalus durissus terrificus injetados sistemicamente promovem, agudamente, aumento dos níveis de ansiedade em ratos; se injetados topicamente na formação hipocampal, região intimamente ligada a processos de memória espacial e ansiedade, induzem alterações citoestruturais. O objetivo deste trabalho foi avaliar, em ratos, efeitos comportamentais decorrentes da injeção sistêmica de veneno bruto de Crotalus durissus terrificus e a eficácia do soro anticrotálico em prevenir esses prejuízos quando administrado variáveis intervalos de tempo depois do envenenamento. Ratos submetidos a uma única injeção sistêmica de veneno bruto 7 dias antes do inicio dos testes foram avaliados nas tarefas de memória de referencia e de memória operacional no labirinto aquático de Morris, e também a uma tarefa envolvendo uma plataforma visível no mesmo aparelho. A seguir, os animais foram submetidos ao paradigma do teste-reteste no labirinto em cruz elevado. Os resultados mostraram que houve prejuízos de memória de referencia e de memória operacional; este último efeito ocorreu quando o intervalo entre as tentativas foi de 10 minutos, mas não quando foi de zero minutos. Potenciais efeitos sensoriais e motores foram excluídos. Alem disso, houve substancial aumento nos níveis de ansiedade. A administração de soro anti-crotálico preveniu os principais prejuízos de memória desde que realizada em ate 10 horas apos a injeção do veneno (foram testados intervalos de 0, 0,5, 2, 10 e 24 horas, em grupos independentes de animais)..O grupo tratado com soro anti-crotálico 24 horas depois do envenenamento apesar de prejudicado em relação aos grupos controle (um injetado com salina e o outro apenas com soro), exibiu desempenho melhor do que o grupo tratado apenas com veneno. Assim, o presente conjunto de resultados representam a primeira demonstração de que (1) uma única dose sistêmica do veneno crotálico produz prejuízos de memória espacial em ratos e aumenta os níveis de ansiedade avaliados 4 semanas apos a injeção, e (2) os prejuízos de memória podem ser prevenidos pela administração de soro anticrotálico desde que essa administração ocorra em ate 10 horas apos o envenenamento. / Snakebites constitute a serious public health problem in Brazil. Prior studies have shown that systemic injections of venom fractions of Crotalus durissus terrificus produce acute increase in anxiety levels in rats; when injected topically within the hippocampal formation, a brain region underlying processes of spatial memory and anxiety, induce damage. The aims of this study included to investigate, in rats, behavioral effects of a single systemic injection of crude venom on performance of spatial memory tasks and on anxiety, and the efficacy and time course of the antivenom administration to prevent memory disruption. Rats subjected to a single systemic injection of venom 7 days before the beginning of behavioral testing were evaluated in modified versions of the reference and working memory tasks in the water maze, and also to a version of the task in which the platform is visible. Then, the subjects were submitted to the test-retest paradigm in the elevated plus maze. Rats injected with the venom exhibited disruption of performance both in reference and working memory versions of the water maze task; in this latter task, however, disruption occurred when the intertrial interval was 10 minutes but not when the it was zero minutes. Anti-crotalic serum injection prevented memory disruptions when its administration occurred up to 10 hours after injection of the venom (time intervals evaluated included 0, 0.5, 2, 10 and 24 hours, in independent groups of rats). Subjects that received anti-crotalic serum 24 hours after venom injection exhibited disruption of memory relative to control groups (one of them treated with saline and the other with anti-crotalic serum only); however, performance of those animals was better when compared to subjects receiving only venom administration. These results show, to our knowledge for the first time, that (1) a single systemic injection of crotalic venom induces disruption of spatial memory and increases anxiety evaluated 4 weeks after injection, and (2) major spatial memory disruptions may be prevented by administration of the anti-crotalic serum up to 10 hours after the venom injection.