abstract: Current theoretical debate, crossing the bounds of memory theory and mental imagery, surrounds the role of eye movements in successful encoding and retrieval. Although the eyes have been shown to revisit previously-viewed locations during retrieval, the functional role of these saccades is not known. Understanding the potential role of eye movements may help address classic questions in recognition memory. Specifically, are episodic traces rich and detailed, characterized by a single strength-driven recognition process, or are they better described by two separate processes, one for vague information and one for the retrieval of detail? Three experiments are reported, in which participants encoded audio-visual information while completing controlled patterns of eye movements. By presenting information in four sources (i.e., voices), assessments of specific and partial source memory were measured at retrieval. Across experiments, participants' eye movements at test were manipulated. Experiment 1 allowed free viewing, Experiment 2 required externally-cued fixations to previously-relevant (or irrelevant) screen locations, and Experiment 3 required externally-cued new or familiar oculomotor patterns to multiple screen locations in succession. Although eye movements were spontaneously reinstated when gaze was unconstrained during retrieval (Experiment 1), externally-cueing participants to re-engage in fixations or oculomotor patterns from encoding (Experiments 2 and 3) did not enhance retrieval. Across all experiments, participants' memories were well-described by signal-detection models of memory. Source retrieval was characterized by a continuous process, with evidence that source retrieval occurred following item memory failures, and additional evidence that participants partially recollected source, in the absence of specific item retrieval. Pupillometry provided an unbiased metric by which to compute receiver operating characteristic (ROC) curves, which were consistently curvilinear (but linear in z-space), supporting signal-detection predictions over those from dual-process theories. Implications for theoretical views of memory representations are discussed. / Dissertation/Thesis / Ph.D. Psychology 2012

Many individuals with autism spectrum disorder (ASD) have atypical sensory processing and behaviors including sensory sensitivity and low registration of sensory stimuli as well as sensory seeking and avoiding behaviors. Additionally, many individuals with ASD have clinically distressing levels of anxiety. Previous research suggests that there is a link between abnormal sensory processing, anxiety, and ASD. The purpose of this study was to experimentally observe auditory sensory processing using pupillometry methods, between ASD, control, and high-anxious control groups. While a difference in tonic pupil size was observed, there were no reactivity or habituation differences between the groups. There were no significant correlations between the pupillometry measures and behavioral measures of emotional distress and anxiety. These results do not indicate a relationship between anxiety and unimodal auditory response in ASD. Implications and directions for future research are discussed.

Novel sounds in the auditory oddball paradigm elicit a biphasic dilation of the pupil (PDR) and P3a as well as novelty P3 event-related potentials (ERPs). The biphasic PDR has been hypothesized to reflect the relaxation of the iris sphincter muscle due to parasympathetic inhibition and the constriction of the iris dilator muscle due to sympathetic activation. We measured the PDR and the P3 to neutral and to emotionally arousing negative novels in dark and moderate lighting conditions. By means of principal component analysis (PCA) of the PDR data we extracted two components: the early one was absent in darkness and, thus, presumably reflects parasympathetic inhibition, whereas the late component occurred in darkness and light and presumably reflects sympathetic activation. Importantly, only this sympathetic late component was enhanced for emotionally arousing (as compared to neutral) sounds supporting the hypothesis that emotional arousal specifically activates the sympathetic nervous system. In the ERPs we observed P3a and novelty P3 in response to novel sounds. Both components were enhanced for emotionally arousing (as compared to neutral) novels. Our results demonstrate that sympathetic and parasympathetic contributions to the PDR can be separated and link emotional arousal to sympathetic nervous system activation.

Remembering to complete some future intention (i.e., prospective remembering) is a frequent requirement of everyday activities. Prospective memory failures (e.g., forgetting to take one’s medication) can have devastating consequences. Cognitive psychologists have sought to understand how individuals can successfully fulfill their prospective memory intentions. Unfortunately, it has been difficult to find evidence for specific cognitive mechanisms that could feasibly account for prospective memory behaviors. In part, this is because many theories of prospective memory stipulate that prospective remembering is accomplished through discrete/covert mental processes. In the current set of experiments, eye-tracking technology was used to test these various mechanistic explanations. Using an eye-tracking computer to measure pupillary responses to prospective memory task characteristics allowed for the observation of changes in discrete mental activity during the course of a prospective memory task scenario. Across two experiments, I observed elevated pupil dilation when participants were given additional prospective memory demands. Furthermore, when participants correctly recognized the presentation of a prospective memory target, it appeared that their pupil dilation increased dramatically, and elevated dilation persisted for several trials. This pattern of pupil dilation is consistent with an account of prospective remembering that suggests individuals sometimes engage in actively monitoring for an opportunity to<br>11<br>complete their prospective memory intention, and that at other times, individuals will reduce or discontinue monitoring activity until some cue brings the prospective memory intention back into mind. Consistent with such an account, individual differences in working memory were positively associated with pupil size only when the prospective memory task afforded monitoring. This was in line with recent research implicating the working memory system in facilitating active monitoring during certain prospective memory contexts. Finally, the current set of experiments demonstrated the utility of pupillometric methods for measuring active monitoring in a prospective memory scenario.

O mercúrio é um metal tóxico, que pode causar diversas alterações no organismo humano. O presente estudo teve como objetivo investigar a ocorrência de disfunções neuropsicológicas em ex-trabalhadores de fábricas de lâmpadas fluorescentes que foram expostos a vapor de mercúrio, anos após a interrupção da exposição, além de investigar os efeitos dessa exposição sobre o Sistema Nervoso Autônomo a partir do método não-invasivo da pupilometria dinâmica. A avaliação neuropsicológica foi realizada através do Inventário Beck de Depressão e da bateria neuropsicológica computadorizada CANTABeclipse, utilizando-se subtestes que avaliam memória operacional (Spatial Span), memória espacial (Spatial Recognition Memory), memória visual (Pattern Recognition Memory), percepção visual (Delayed Matching to Sample), planejamento de ações (Stockings of Cambridge) e tomada de decisão (Information Sampling Task). A avaliação do Sistema Nervoso Autônomo, por sua vez, foi realizada através da pupilometria dinâmica, que provê informações acerca do funcionamento de ambas as funções simpática e parassimpática. Foram utilizados flashes de 631nm (luz vermelha) com 1 s de duração, com luminância de 1, 10 e 100 cd/m². Os escores de depressão foram significativamente mais altos entre os indivíduos com histórico de exposição em comparação aos sujeitos do grupo controle (p=0,025). Os pacientes expostos ao vapor de mercúrio apresentaram desempenho significativamente inferior à média do grupo controle nos testes: SSP direto (p=0,004), SRM (p=0,039), PRM (p=0,001), IST latência para abertura das caixas (p=0,001), IST latência para tomada de decisão (p=0,014), IST número de caixas abertas (p=0,045), DMS com intervalo (p=0,001) e DMS total (p=0,001). Portanto, foram encontrados prejuízos em: span atencional, memória espacial, memória visual de longa duração, memória visual de curta duração e tomada de decisão. No exame de pupilometria dinâmica, no parâmetro tempo em 75% de recuperação do diâmetro pupilar, em 10cd/m² de luminância, os sujeitos com histórico de exposição apresentaram resposta significativamente mais lenta do que os indivíduos do grupo controle (p=0,025). Os altos escores de depressão, além das perdas cognitivas em domínios variados, fazem parte do quadro de mercurialismo crônico e os achados do presente estudo são corroborados por pesquisas anteriores. O exame de pupilometria indicou perdas na função simpática do SNA. Estes últimos resultados já foram alcançados por algumas pesquisas anteriores, mas não foram encontrados registros de uso do exame de pupilometria dinâmica como forma de avaliação do SNA em pacientes com histórico de intoxicação por mercúrio / Mercury is a toxic metal which can cause several changes in the human body. The present study aimed to investigate the occurrence of neuropsychological dysfunction in former workers of fluorescent lamps factories that were exposed to mercury vapor (years after cessation of exposure), and to investigate the effects of such exposure on the Autonomic Nervous System using the non-invasive test of dynamic pupillometry. Neuropsychological evaluation was performed using the Beck Depression Inventory and the computerized neuropsychological battery CANTABeclipse, using subtests that assess working memory (Spatial Span), spatial memory (Spatial Recognition Memory), visual memory (Pattern Recognition Memory), visual perception (Delayed Matching to Sample), planning (Stockings of Cambridge) and decision making (Information Sampling Task). The Autonomic Nervous System assessment, in turn, was performed using dynamic pupillometry, which provides information on the operation on both the sympathetic and parasympathetic functions. We used flashes of red light (631nm) with 1 second duration and luminance of 1, 10 and 100cd/m². The depression scores were significantly higher among the former workers when compared with the control group (p=0,025). They also had significantly worse performance than the control group in the following tests: SSP direct (p=0,004), SRM (p=0,039), PRM (p=0,001), IST latency for opening the boxes (p=0,001), IST latency for decision making (p=0,014), IST number of boxes opened (p=0,045), DMS interval (p=0,001) e DMS complete (p=0,001). Therefore, deficits were found in: attentional spam, spatial memory, short term visual memory, long term visual memory, and decision making. In the dynamic pupillometry test, former workers had significantly lower response than the control group (p=0,025) in parameter time by 75% recovery of the pupil diameter, in 10cd/m² luminance. The high depression scores, in addition to cognitive impairments in several functions are expected in chronic mercurialism and our findings are supported by previous studies. The dynamic pupilllometry test indicated sympathetic function deficits. This latest result have already been achieved by some previous research, but we did not find any records of the dynamic pupillometry usage as a tool for assessing the Autonomic Nervous System in patients with previous mercury exposure

O mercúrio é um metal tóxico, que pode causar diversas alterações no organismo humano. O presente estudo teve como objetivo investigar a ocorrência de disfunções neuropsicológicas em ex-trabalhadores de fábricas de lâmpadas fluorescentes que foram expostos a vapor de mercúrio, anos após a interrupção da exposição, além de investigar os efeitos dessa exposição sobre o Sistema Nervoso Autônomo a partir do método não-invasivo da pupilometria dinâmica. A avaliação neuropsicológica foi realizada através do Inventário Beck de Depressão e da bateria neuropsicológica computadorizada CANTABeclipse, utilizando-se subtestes que avaliam memória operacional (Spatial Span), memória espacial (Spatial Recognition Memory), memória visual (Pattern Recognition Memory), percepção visual (Delayed Matching to Sample), planejamento de ações (Stockings of Cambridge) e tomada de decisão (Information Sampling Task). A avaliação do Sistema Nervoso Autônomo, por sua vez, foi realizada através da pupilometria dinâmica, que provê informações acerca do funcionamento de ambas as funções simpática e parassimpática. Foram utilizados flashes de 631nm (luz vermelha) com 1 s de duração, com luminância de 1, 10 e 100 cd/m². Os escores de depressão foram significativamente mais altos entre os indivíduos com histórico de exposição em comparação aos sujeitos do grupo controle (p=0,025). Os pacientes expostos ao vapor de mercúrio apresentaram desempenho significativamente inferior à média do grupo controle nos testes: SSP direto (p=0,004), SRM (p=0,039), PRM (p=0,001), IST latência para abertura das caixas (p=0,001), IST latência para tomada de decisão (p=0,014), IST número de caixas abertas (p=0,045), DMS com intervalo (p=0,001) e DMS total (p=0,001). Portanto, foram encontrados prejuízos em: span atencional, memória espacial, memória visual de longa duração, memória visual de curta duração e tomada de decisão. No exame de pupilometria dinâmica, no parâmetro tempo em 75% de recuperação do diâmetro pupilar, em 10cd/m² de luminância, os sujeitos com histórico de exposição apresentaram resposta significativamente mais lenta do que os indivíduos do grupo controle (p=0,025). Os altos escores de depressão, além das perdas cognitivas em domínios variados, fazem parte do quadro de mercurialismo crônico e os achados do presente estudo são corroborados por pesquisas anteriores. O exame de pupilometria indicou perdas na função simpática do SNA. Estes últimos resultados já foram alcançados por algumas pesquisas anteriores, mas não foram encontrados registros de uso do exame de pupilometria dinâmica como forma de avaliação do SNA em pacientes com histórico de intoxicação por mercúrio / Mercury is a toxic metal which can cause several changes in the human body. The present study aimed to investigate the occurrence of neuropsychological dysfunction in former workers of fluorescent lamps factories that were exposed to mercury vapor (years after cessation of exposure), and to investigate the effects of such exposure on the Autonomic Nervous System using the non-invasive test of dynamic pupillometry. Neuropsychological evaluation was performed using the Beck Depression Inventory and the computerized neuropsychological battery CANTABeclipse, using subtests that assess working memory (Spatial Span), spatial memory (Spatial Recognition Memory), visual memory (Pattern Recognition Memory), visual perception (Delayed Matching to Sample), planning (Stockings of Cambridge) and decision making (Information Sampling Task). The Autonomic Nervous System assessment, in turn, was performed using dynamic pupillometry, which provides information on the operation on both the sympathetic and parasympathetic functions. We used flashes of red light (631nm) with 1 second duration and luminance of 1, 10 and 100cd/m². The depression scores were significantly higher among the former workers when compared with the control group (p=0,025). They also had significantly worse performance than the control group in the following tests: SSP direct (p=0,004), SRM (p=0,039), PRM (p=0,001), IST latency for opening the boxes (p=0,001), IST latency for decision making (p=0,014), IST number of boxes opened (p=0,045), DMS interval (p=0,001) e DMS complete (p=0,001). Therefore, deficits were found in: attentional spam, spatial memory, short term visual memory, long term visual memory, and decision making. In the dynamic pupillometry test, former workers had significantly lower response than the control group (p=0,025) in parameter time by 75% recovery of the pupil diameter, in 10cd/m² luminance. The high depression scores, in addition to cognitive impairments in several functions are expected in chronic mercurialism and our findings are supported by previous studies. The dynamic pupilllometry test indicated sympathetic function deficits. This latest result have already been achieved by some previous research, but we did not find any records of the dynamic pupillometry usage as a tool for assessing the Autonomic Nervous System in patients with previous mercury exposure

Events that violate expectations are biologically significant and accordingly elicit various physiological responses. We investigated the functional relationship between three of these responses: the P300, the Novelty P3 and the pupil dilation response (PDR), with a particular focus on their co-variance with reaction time and measures of subsequent memory. In a modified Novelty P3 oddball paradigm, participants semantically categorized a sequence of stimuli including (1) words of a frequent category, (2) words of an infrequent category (14% of the trials) and (3) pictures of the frequent category (14% of the trials). The Novelty P3 oddball task was followed by a recall- and a recognition test. Larger amplitudes of the P300, identified by a spatial principal component analysis (PCA), were associated with enhanced subsequent recall as well as faster reaction times during the recognition test, suggesting a close relationship between the cognitive process indexed by the P300 and memory encoding. The PDR was larger for infrequents (which required a response switch) than both frequents and pictures (which did not require a switch). Furthermore, its latency was correlated with reaction time on the same trial and with reaction time on the immediately following trial. There was only weak evidence for a correlation with subsequent memory, suggesting that the cognitive process associated with the PDR might be a direct link in the stimulus-response stream. Larger Novelty P3 amplitudes were associated with both faster reaction times on the same trial and stronger memory traces, suggesting that its amplitude might index resource allocation. These findings suggest that each of the physiological responses carries a distinct functional significance in detecting, processing, or responding to novel events, and we discuss the findings in the light of the prevalent theories of the functional significance of each response.

Apathy or lack of motivation is increasingly recognized to be a major factor affecting quality of life and prognosis in many neurological conditions. It is particularly prevalent in Parkinson's disease, impacting on every disease stage, including de novo cases, and has been reported to affect up to 70% of cases. Despite the pervasiveness of apathy, challenges remain in its detection, clinical assessment and treatment. Several lines of evidence have implicated fronto-striatal reward related neural pathways in the genesis of apathy but the precise processes remain to be fully explained. This thesis examines the potential mechanisms of apathy using Parkinson's disease as a model to study the condition. Novel oculomotor tasks that used eye movement and pupillary responses were developed to help assess if insensitivity to incentives could be an underlying component of apathy. This was examined in healthy young and elderly participants as well as in patients with Parkinson's disease. Patients were tested both ON and OFF their normal dopaminergic medication so that the effect of dopamine could be assessed and the association with apathy determined. This was also performed in a pharmacological study in young participants with the use of Haloperidol, a dopaminergic D2-selective antagonist. Insensitivity to rewards modulated by dopamine was regarded to be a contributory mechanism of apathy in Parkinson's disease and also applicable to general mechanisms of motivation in healthy populations.

Typically developing humans innately place subjective value on social information and orient attention to it. This can be shown through eye tracking and pupillometry, a method used to show attentional engagement. Social brain development and social preference is present from infancy, and is thought to rely on a carefully balanced network of neurotransmitters and neural connections. Autism Spectrum Disorder (ASD) presents altered neural systems which cause individuals to perceive and process social information differently, but the neurophysiology of this difference remains unclear. Previous research shows atypical gaze patterns, hyperarousal, and lack of orienting to social stimuli in ASD. Since autism is highly comorbid and shares traits with other neurodevelopmental disorders, it is difficult to distinguish aspects of these social processing differences. This study used a group of 35 neuropsychiatric patients to investigate how individuals with autism process social and non-social scenes. Eye tracking and pupillometry measures were collected while participants observed images of natural scenes with or without a person. Participants with autism did not show a pupillary response to social images and were slower to fixate on the face  region than the other participants. Additionally there were correlations between clinical measures of social functioning and the length of time it took to fixate to faces. The results highlight important distinctions of social processing in autism. This thesis proposes a new perspective of looking at the social deficits present in autism spectrum disorder. It suggests reframing the current discussion from two leading hypotheses to a unified approach and formally considering the limitations of differing types of stimuli.

Many autistic adults experience debilitating anxiety that interferes with their daily functioning. Atypical sensory processing and intolerance of uncertainty are cognitive processes linked to atypical limbic system functioning and impaired fear conditioning as potential mediators of anxiety in autism. A previous fear conditioning study using fMRI found atypical amygdala functioning in autism when the threat stimulus was only partially reinforced. The first aim of this dissertation is a multimethod examination of brain and psychophysiological response in autistic and in neurotypical adults during a fear conditioning/extinction task with the threat stimulus reinforced 100% percent of the time. We were also interested in the responses of autistic and neurotypical adults during an auditory looming task that requires no learning contingencies. We used fMRI, pupillometry, and skin conductance response as the dependent measures. Results demonstrated a significant main effect for insula activation, but not amygdala activation, during the 100%-reinforcement fear conditioning task with no between-group differences or group x condition interactions. There were likewise no condition differences (Safe vs Threat) for amygdala in the auditory looming task. However, the autism group demonstrated increased insula response to both Threat and Safe auditory conditions of the looming task, suggesting the autism group utilized alternative cognitive resources than the neurotypical group. Results indicate intact fear conditioning and extinction in autism for more certain conditions and suggests that behavioral (exposure) anxiety treatments for phobias could be useful under certain conditions. Results of this study are inconsistent with the atypical/hyperactive amygdala hypotheses of anxiety with autism and inconsistent with the portion of the South & Rodgers (2017) anxiety model regarding the importance of intolerance of uncertainty in autism samples.