Yes / We investigated the role of the human right Supra-Marginal Gyrus (SMG) in the generation of learned eye movement sequences. Using MRI-guided transcranial magnetic stimulation (TMS) we disrupted neural activity in the SMG whilst human observers performed saccadic eye movements to multiple presentations of either predictable or random target sequences. For the predictable sequences we observed shorter saccadic latencies from the second presentation of the sequence. However, these anticipatory improvements in performance were significantly reduced when TMS was delivered to the right SMG during the inter-trial retention periods. No deficits were induced when TMS was delivered concurrently with the onset of the target visual stimuli. For the random version of the task, neither delivery of TMS to the SMG during the inter-trial period nor during the presentation of the target visual stimuli produced any deficit in performance that was significantly different from the no-TMS or control conditions. These findings demonstrate that neural activity within the right SMG is causally linked to the ability to perform short latency predictive saccades resulting from sequence learning. We conclude that neural activity in rSMG constitutes an instruction set with spatial and temporal directives that are retained and subsequently released for predictive motor planning and responses.

Yes / Background: Soft contact lenses have been developed and licensed for reducing myopia progression. These lenses have different designs, such as extended depth of focus (EDOF) and dual focus (DF). In this prospective, doublemasked, cross-over study, different lens designs were investigated to see whether these had impact on accommodative microfluctuations and eye movements during reading. Methods: Participants were fitted with three lenses in a randomised order; a single vision (SV) design (Omafilcon A2; Proclear), a DF design (Omafilcon A2; MiSight), and an EDOF lens design (Etafilcon A; NaturalVue),. Accommodative microfluctuations were measured at 25 cm for at least 60s in each lens, using a Shin-Nippon SRW-5000 autorefractor adapted to continuously record accommodation at 22Hz. Eye movement data was collected with the Thomson Clinical Eye Tracker incorporating a Tobii Eye bar. Eye movements include fixations per row, fixations per minute, mean regressions per row, total number of regressions, and total rightward saccades. Accommodation data was analysed using power spectrum analysis. Differences between the lenses were compared using a related sample two-way Friedman test. Results: Twenty-three participants (18–29 years) were recruited to take part. The average mean spherical error was − 2.65D ± 1.42DS, with an average age of 23.4 ± 3.5 years. No significant difference for accommodative microfluctuations was found. Significant differences were found for fixations per row (P = 0.03), fixations per minute (P = 0.008), mean regressions per row (P = 0.002), and total number of regressions (P = 0.002), but not total rightward saccades (P = 0.10). Post-hoc analysis indicated the EDOF lens results were significantly different from the other lenses, with more regressive eye movements observed. Conclusions: Regressive saccades appear to increase when wearing EDOF lens designs, which may impact visual comfort. Further studies in children, over a longer period of adaptation are necessary to assess the potential impact of this finding on daily reading activities in children. / This project was supported by the British Contact Lens Association Summer Studentship Award (recipient Muskaan Hussain).

Many studies on feature-based search have found that color is preferentially used as a guiding feature. Most of these studies have utilized simple stimuli and the several studies that utilized real-world objects have been limited by the subjective color classification of objects. The current set of studies examined how search was guided by color and color proportions in real-world objects using color histograms to objectively classify color. To bridge the gap between simple stimuli and real-world objects, the first experiment examined how different color compositions in color conjunctions affected search. In the second experiment, real-world objects were objectively classified according to their primary color as determined by a color histogram, which was used to predict behavior. Finally, in the third experiment, real-world objects were classified by both their primary and secondary colors, which again, was used to predict behavior. Across three experiments the results demonstrated that search was guided by both colors of the target and there was more guidance to objects that matched the target's primary color than the target's secondary color. The results showed that theories derived from studying simple stimuli can be applied to more complex stimuli and tools developed in computer vision research can be used as an objective measure.

Yes / Adults with amblyopia ('lazy eye'), long-standing strabismus (ocular misalignment) or both typically do not experience visual symptoms because the signal from weaker eye is given less weight than the signal from its fellow. Here we examine the contribution of the weaker eye of individuals with strabismus and amblyopia with both eyes open and with the deviating eye in its anomalous motor position. The task consisted of a blue-on-yellow detection task along a horizontal line across the central 50 degrees of the visual field. We compare the results obtained in ten individuals with strabismic amblyopia with ten visual normals. At each field location in each participant, we examined how the sensitivity exhibited under binocular conditions compared with sensitivity from four predictions, (i) a model of binocular summation, (ii) the average of the monocular sensitivities, (iii) dominant-eye sensitivity or (iv) non-dominant-eye sensitivity. The proportion of field locations for which the binocular summation model provided the best description of binocular sensitivity was similar in normals (50.6%) and amblyopes (48.2%). Average monocular sensitivity matched binocular sensitivity in 14.1% of amblyopes' field locations compared to 8.8% of normals'. Dominant-eye sensitivity explained sensitivity at 27.1% of field locations in amblyopes but 21.2% in normals. Non-dominant-eye sensitivity explained sensitivity at 10.6% of field locations in amblyopes but 19.4% in normals. Binocular summation provided the best description of the sensitivity profile in 6/10 amblyopes compared to 7/10 of normals. In three amblyopes, dominant-eye sensitivity most closely reflected binocular sensitivity (compared to two normals) and in the remaining amblyope, binocular sensitivity approximated to an average of the monocular sensitivities. Our results suggest a strong positive contribution in habitual viewing from the non-dominant eye in strabismic amblyopes. This is consistent with evidence from other sources that binocular mechanisms are frequently intact in strabismic and amblyopic individuals.

L'étude de la lecture s'intéresse, entre autres, aux facteurs déterminant la visibilité de lettres et les mouvements oculaires. Néanmoins, l'approche de ces mécanismes reste différente selon qu'elle concerne la vision centrale ou périphérique. Cette thèse proposait, au contraire, une approche conjointe dans le but (1) de mettre en évidence les effets des facteurs visuels limitant la reconnaissance de mots, (2) de mieux comprendre le comportement oculomoteur lors de la lecture en vision centrale et (3) d'étudier le rôle des facteurs oculomoteurs spécifiques à la lecture en vision périphérique. Trois expériences ont été menées. La première axée sur l'étude des facteurs visuels, a mis en évidence que l'effet OVP était moins important pour des mots présentés dans le champ visuel inférieur. Ce résultat pouvant s'expliquer par la géométrie de l'acuité visuelle et de l'encombrement, suggère que la lecture en périphérie est limitée par les mêmes facteurs qu'en vision centrale. La deuxième étude, concernant la stabilité de fixation durant la lecture en présence d'un scotome artificiel, a révélé que la vitesse de lecture pouvait être améliorée en présence d'une stimulation fovéale stable. Enfin, nous avons montré que les mouvements oculaires variaient selon la taille des lettres, et ce, différemment selon la position du regard par rapport au centre des mots. Ce résultat, nouveau, est vraisemblablement attribuable à l'effet de processus visuomoteurs précoces. En conclusion, l'étude conjointe de la lecture en vision centrale et périphérique est prometteuse, non seulement d'un point de vue fondamental, mais aussi pour l'aide aux patients atteints de DMLA. / Reading is a large research field, which investigates for a great part the variables influencing letter visibility and eye movements. However, its study in central and peripheral vision has been conducted in parallel and with different approaches. Our work relied, on the contrary, on a joint approach in order (1) to uncover the visual factors limiting word recognition, (2) to better determine how the eyes move during reading in central vision, and (3) to study the role of oculomotor factors that might affect reading in peripheral vision. Three experiments were conducted. The first study focused on the role of visual factors in word identification. It showed that the OVP effect is reduced for words displayed in the lower visual field. This result, which can be explained by the geometry of visual acuity andl crowding, suggests that reading in peripheral vision is limited by the same visual factors as in central vision. Then we investigated the influence of fixation stability on sentence reading using an artificial scotoma. It revealed that reading speed could be improved with a stable foveal stimulation. The third experiment re-examined the possible influence of character size on eye movements in central vision. It revealed that eye movements varied depending on letter size, and differently as a function of the location of the eye relative to the center of words. This novel finding was very likely the effect of early visuomotor processes. In conclusion, the joint study of reading in central and peripheral vision is promising, not only at a fundamental level, but also for a better understanding of retinal visual deficits, such as AMD.

<p>Robotic-assisted surgery (RAS) is one of the most significant advancements in surgical techniques in the past three decades. It provides benefits of reduced infection risks and shortened recovery time over open surgery as well as improved dexterity, stereoscopic vision, and ergonomic console over laparoscopic surgery. The prevalence of RAS systems has increased over years and is expected to grow even larger. However, the major concerns of RAS are the technical difficulty and the system complexity, which can result in long learning time and impose extra cognitive workload and stress on the operating room. Human Factor and Ergonomics (HFE) perspective is critical to patient safety and relevant researches have long provided methods to improve surgical outcomes. Yet, limited studies especially using objective measurements, have been done in the RAS environment. </p> <p> </p> <p>With advances in wearable sensing technology and data analytics, the applications of physiological measures in HFE have been ever increasing. Physiological measures are objective and real-time, free of some main limitations in subjective measures. Eye tracker as a minimally-intrusive and continuous measuring device can provide both physiological and behavioral metrics. These metrics have been found sensitive to changes in workload in various domains. Meanwhile, electroencephalography (EEG) signals capture electrical activity in the cerebral cortex and can reflect cognitive processes that are difficult to assess with other objective measures. Both techniques have the potential to help address some of the challenges in RAS.</p> <p> </p> <p>In this study, eight RAS trainees participated in a 3-month long experiment. In total, they completed 26 robotic skills simulation sessions. In each session, participants performed up to 12 simulated RAS exercises with varying levels of difficulty. For Research Question I, correlation and mixed effect analyses were conducted to explore the relationships between eye tracking metrics and workload. Machine learning classifiers were used to determine the sensitivity of differentiating low and high workload with eye tracking metrics. For Research Question II, two eye tracking metrics and one EEG metric were used to explain participants’ performance changes between consecutive sessions. Correlation and ANOVA analyses were conducted to examine whether variations in performance had significant relationships with variations in objective metrics. Classification models were built to examine the capability of objective metrics in predicting improvement during RAS training. </p> <p> </p> <p>In Research Question I, pupil diameter and gaze entropy distinguished between different task difficulty levels, and both metrics increased as the level of difficulty increased. Yet only gaze entropy was correlated with subjective workload measurement. The classification model achieved an average accuracy of 89.3% in predicting workload levels. In Research Question II, variations in gaze entropy and engagement index were negatively correlated with variations in task performance. Both metrics tended to decrease when performance increased. The classification model achieved an average accuracy of 68.5% in predicting improvements.</p> <p> </p> <p>Eye tracking metrics can measure both task workload and perceived workload during simulated RAS training. It can potentially be used for real-time monitoring of workload in RAS procedure to identify task contributors to high workload and provide insights for training. When combined with EEG, the objective metrics can explain the performance changes during RAS training, and help estimate room for improvements.</p>

A agenda de pesquisa da discriminacao condicional e composta por diversos procedimentos que investigaram a formacao de classes de equivalencia. Dentre eles: o procedimento Go/Nogo com estimulos compostos; o procedimento Yes/No; o procedimento Respondent-type; o procedimento de pareamento de estimulos envolvendo uma resposta (Stimulus Pairing Response); e o procedimento de pareamento de estimulos envolvendo uma resposta de orientacao (Stimulus pairing Orientation Response). No Respondent-type a condicionalidade entre os estimulos nao foi demonstrada em treino, mas sim por meio do desempenho dos participantes em condicoes de testes das relacoes emergentes. A condicionalidade nao poderia ser demonstrada por respostas diferenciais aos pares de estimulos relacionados em condicoes de treino, uma vez que nenhuma relacao R-S r foi programada. Apesar de nenhuma resposta ser requerida nessas condicoes, existem respostas que naturalmente ocorrem frente ao ambiente programado (e.g respostas sensoriais) e que sao relevantes para o desempenho nas tarefas, no caso, os testes. Em contingencias de controle de estimulos, respostas sensoriais ou de orientacao sao necessarias, primeiramente, por colocarem os participantes em contato com as propriedades relevantes dos estimulos que compoe o ambiente programado. Alem da relevancia por colocar o organismo em contato com as propriedades relevantes dos estimulos, a agenda experimental demonstrou que as respostas de orientacao tambem influenciam na emergencia de relacoes transitivas. Tendo em vista a relevancia das respostas de orientacao, o presente estudo tem como objetivo rastrear medidas da resposta de orientacao por meio do rastreamento dos movimentos oculares de participantes expostos ao procedimento Respondent-type. Explorar medidas da resposta de orientacao em treino sem reforcamento diferencial e testes das relacoes emergentes pode ser uma maneira de contribuir com a investigacao das variaveis de controle dessas respostas e, com isso, permitir a manipulacao de propriedades espaco-temporais eficientes. Apesar das classes serem formadas a partir de treino Respondent-type (sem programacao de R S r), sua demonstracao, em condicao de teste, seria acompanhada pela demonstracao de observacao seletiva? De acordo com os resultados, nove de dez participantes demonstraram a emergencia de classes equivalentes. Assim, a replicacao foi bem-sucedida. Dados obtidos atraves do equipamento de rastreamento dos movimentos oculares permitiram a identificacao de observacao seletiva nos testes em MTS, mesmo nao havendo programacao de relacao R S r em treino. Por fim, a demonstracao de observacao seletiva permitiu a elaboracao de hipoteses baseadas em aspectos do procedimento que permitiram o estabelecimento de funcoes de estimulos corretos e incorretos na tarefa experimental (uma vez que o treino das relacoes condicionais nao era um treino discriminativo) / Conditional discrimination literature studies the formation of equivalent classes through several different procedures, such as: the Go/No-go procedure with compound stimuli; the Yes/No procedure; the Respondent-type procedure; the Stimulus Pairing Response procedure; and the Stimulus Pairing Orientation Response procedure. Regarding the Respondent-type procedure, the conditionality between stimuli was not demonstrated in training, but it was instead observed in the performance of participants in emergent relations test conditions. Conditionality could not be demonstrated by differential responding in training, since R-S relation was not programmed in this study. Even though no responses are required in these conditions, some responses that naturally occur in the programmed environment (i.e. sensorial responses) are relevant for the performance of tasks, which in this case are the tests. In stimuli control conditions, sensorial or orientation responses are needed, first, to put the participants in contact with the relevant properties of the stimulus that form the programmed environment; and second, to demonstrate that such responses also influence the creation of transitive relations. Considering how relevant orientation responses are, this study aims to track measurements for such responses through tracking the eye movements of participants exposed to Respondent-type procedure. Through the exploration of orientation responses in trainings that lack differential reinforcement, and of tests for emerging relationships, this study can contribute to research investigating the variables of orientation responses, and allow for a manipulation of their spatial-temporal properties. Although classes are formed through Respondent-type training (without an R-S response being programmed into it), would their establishment, in testing conditions, be accompanied by the establishment of selective observing? According to the results, nine in ten participants observed the establishment of equivalent classes, which indicate that our replication was successful. Data obtained through eye-movement tracking allowed us to identify selective observation in MTS training even through no R-S relationship was programmed. Lastly, the establishment of selective observation allowed us to formulate hypothesis based on certain aspects of the procedure, which allowed for the establishment of functions of correct and incorrect stimuli in the experimental task (because the training for conditional relationships was not a discriminative training)

O estudo das fixações e dos movimentos dos olhos pode trazer contribuições para o entendimento do estabelecimento do controle de estímulos discriminativos. O objetivo desta pesquisa foi verificar se análises mais moleculares das durações e frequências das fixações dos olhos de humanos em direção a estímulos antecedentes em diferentes treinos de discriminação fornecem resultados mais sistemáticos sobre estas fixações do que os resultados obtidos até o presente momento. Foram realizados 3 experimentos com 4 fases cada um. Os participantes foram jovens com idades entre 16 e 27 anos. Cada participante foi submetido a uma sessão experimental individual. Nos treinos de discriminação, 2 conjuntos de 80 imagens que não se repetiram ao longo do treino foram utilizados como estímulos antecedentes. As respostas a serem controladas discriminativamente foram pressões na barra de espaço de um teclado de computador e as consequências diferenciais programadas para estas respostas foram apresentação de um som (plim) e apresentação de pontos. O Experimento 1 contou com 4 participantes. Na 1ª fase, pressionar a barra de espaço diante de estímulos dos 2 conjuntos não teve consequências programadas. Na segunda fase, os sons foram apresentados contingentes a pressões na barra em esquema de intervalo variável de 3 s (VI-3 s) apenas diante dos estímulos de um dos conjuntos (componentes de reforço). Não houve consequências programadas para pressões na barra diante dos estímulos do segundo conjunto nessa fase (componentes de extinção). Na 3ª fase, as contingências de reforço e extinção foram revertidas em relação aos conjuntos de estímulos antecedentes. Na 4ª fase, pressões à barra diante de estímulos de ambos os conjuntos podiam produzir o som e os pontos em VI-3 s. Ao final da sessão, o participante foi informado de quantos pontos recebeu. No Experimento 2, com 4 participantes, o componente de extinção foi substituído por um componente em que pressões na barra tinham como consequência, em VI-3 s, um som diferente, indicativo de perda de pontos. O Experimento 3, com 3 participantes, foi análogo ao primeiro, com a exceção de que, durante a 2ª e 3ª fases, pressões na barra durante os últimos 2 segundos dos componentes de extinção postergaram a mudança para o próximo componente. Durante todo o experimento foram registrados os movimentos dos olhos dos participantes, as pressões na barra de espaço e recebimento de pontos. RESULTADOS: No Experimento 1, para os 4 participantes, nas 2ª e 3ª fases, as durações das primeiras fixações nos estímulos relacionados ao reforço foram mais longas do que as fixações nos estímulos relacionados à extinção. Este resultado não foram replicados nos Experimentos 2 e 3. Esta análise mais molecular apresentou sistematicidade maior de resultados que análises anteriores / Eye movements and fixation may contribute for understanding the establishment of discrimination learning. The present research investigated whether more molecular analysis than the ones made so far of frequency and duration of eye fixation to antecedent stimuli during discrimination training may result in systematic data. Three experiments were conducted, each one with 4 different phases. Participants were humans from 16 to 27 years old. Each participant was submitted to only one individual experimental session of about 12 minutes. On discrimination trainings, a set of 80, non-repeating, abstract images and a set of 80, non-repeating, figurative images were used as antecedent stimuli. Responses to be controlled were computer keyboard space-bar pressings and differential consequences were a sound (plin) presentation and delivery of points. Experiment 1 counted with 4 participants. On Phase 1 space-bar pressing had no differential consequences. On Phase 2 sound was presented contingent upon space-bar pressing on a variable interval of 3 s schedule (VI 3-s) during display of only one set of images (reinforcing components). No consequences were programmed for space-bar pressings during display of the alternative set (extinction components). On Phase 3 reinforcement and extinction contingencies were reversed in relation to antecedent stimuli sets. On Phase 4 space-bar pressing during display of both sets of stimuli were reinforced with sound and points on VI 3-s. The amount of points received was only informed for the participant at the end of the session. Experiment 2 counted with 4 participants and the same 4 phases. The extinction components were exchanged for components in which points indicated by a second kind of sound (bee) were withdraw contingent to space-bar pressing on a VI 3-s schedule. Experiment 3 counted with 3 participants and the same 4 phases. On this experiment termination of extinction components was contingent on 2 s without space-bar pressings. Eye fixation, space-bar pressing, and sound delivery were registered during the entire sessions for the 3 experiments. Duration of the first fixation on antecedent stimulus was longer for reinforcement components than for extinction components during Phases 2 and 3 for the 4 participants of Experiment 1. These results were not replicated for Experiments 2 and 3. The more molecular analysis resulted in a more systematic data of human eye fixation

O estudo do responder controlado por relações de seleção ou rejeição insere-se no âmbito de investigações sobre as condições necessárias e suficientes para a formação de classes de estímulos equivalentes. O presente projeto pretendeu investigar aspectos relacionados ao tema em experimentos conduzidos com humanos e pombos. O primeiro experimento teve por objetivo avaliar se o registro do comportamento de olhar, em termos do tempo de observação dos estímulos e padrões de rastreamento exibidos ao longo do treino de discriminações condicionais, poderia fornecer medidas auxiliares sobre o processo de aquisição dos controles por seleção e rejeição durante o treino de discriminações condicionais em participantes humanos. Para esta finalidade era importante preparar uma situação experimental que, previsivelmente, gerasse diferenças nos resultados da aprendizagem discriminativa. Desse modo, seria possível verificar se o olhar poderia fornecer dicas adicionais sobre o estabelecimento do responder controlado por relações de seleção ou rejeição. Estudos anteriores mostraram que, em procedimentos de MTS, utilizar o teclado ou o mouse produz diferentes resultados nos testes de formação de classes. Objetivou-se assim verificar se diferentes topografias de resposta gerariam resultados diferentes na aquisição das discriminações condicionais e nos testes de formação de classes e, adicionalmente, se gerariam padrões de rastreamento diferentes em termos do tempo de observação dos estímulos. Estudantes universitários foram submetidos aos treinos de discriminações condicionais envolvendo seis conjuntos de estímulos (treinos EF, DE, CD, BC e AB) enquanto utilizam um equipamento que registrava o comportamento de olhar. Os resultados sugerem que diferentes topografias de respostas dão origem a diferentes padrões de rastreamento dos estímulos, entretanto não foram encontradas evidências de que tais padrões estariam relacionados ao estabelecimento de relações controladas por seleção ou rejeição. O segundo experimento teve por objetivo verificar a existência de relações de transitividade a partir de um treino condicional envolvendo estímulos temporais. Foram utilizados 12 pombos (Columba lívia) experimentalmente ingênuos e mantidos a 80% do seu peso ad lib. O equipamento utilizado consistia em uma caixa experimental padrão contendo três discos de respostas dispostos horizontalmente. Uma tentativa de treino ocorria da seguinte forma: a luz ambiente e o disco central de respostas eram acesos ao mesmo tempo. Se, por exemplo, o estímulo temporal programado fosse de 4 s, uma luz branca no disco central permanecia ligada por esse período. Após 4 s, a luz do disco central era apagada e cores eram apresentadas nos discos laterais. Uma bicada em qualquer um dos discos laterais encerrava a tentativa. Respostas corretas eram seguidas por um curto período de acesso ao comedouro e um IET de 20 s. Respostas incorretas eram seguidas pelo IET e pela reapresentação da mesma tentativa (procedimento de correção). O procedimento era composto por três fases de treino: nas tentativas do Treino A, os sujeitos aprenderam a bicar o disco iluminado pela cor vermelha diante do modelo 1 s e a bicar o disco iluminado pela cor verde diante de 4 s. Nas tentativas do Treino B, eles aprenderam a bicar o disco iluminado pela cor azul diante de 4 s e a bicar o disco iluminado pela cor amarela diante de 16 s. Durante o Treino C, os sujeitos aprenderam a bicar o disco iluminado pela cor azul diante do modelo verde e a bicar o disco iluminado pela cor amarela diante do modelo vermelho. Considerando os treinos A e B, as cores azul e verde foram relacionadas ao mesmo estímulo temporal 4 s, enquanto que as cores vermelho e amarelo não partilharam qualquer estímulo comum durante o treino anterior. Os resultados sugerem que as relações entre azul e verde foram adquiridas mais rapidamente, fato de parece comprovar a formação de relações de transitividade em fases ix anteriores do treino / The study of responding controlled by selection or rejection relations is within the scope of research on the necessary and sufficient conditions for the formation of equivalent stimuli classes. This project sought to investigate aspects related to this subject by performing experiments with humans and pigeons. The first experiment evaluated whether the record of eye movement - in terms of stimuli observation time and tracking patterns exhibited throughout conditional discrimination training - could provide ancillary measures on the acquisition process of control by selection rejection during the conditional discrimination training on human participants. For this purpose it was important to prepare an experimental situation that predictably generate differences in the discriminative learning outcomes. Thus, it would be possible to verify if the eye movement could provide additional clues about the establishment of responding controlled by relations of selection or rejection. Previous studies have shown that using the keyboard or mouse, in MTS tasks, produces different results in class formation testing. The objective was, therefore, to check if different response topographies would generate different results in conditional discrimination acquisition and class formation tests and, furthermore, if it would generate different tracking patterns, in terms of stimuli observation time. College students were subjected to conditional discriminations training involving six sets of stimuli (training EF, DE, CD, BC and AB) while using a device that recorded eye movement. Results suggest that different response topographies originate different patterns of stimulus tracking, however there was no evidence that such patterns referred to the establishment of relations controlled by selection or rejection. The second experiment sought verifying the existence of transitivity relations from conditional training involving temporal stimuli. Subjects were 12 pigeons (Columba livia) experimentally naive and kept at 80% of their ad lib weight. The equipment used consisted of a box containing three standard experimental response keys horizontally arranged. A training attempt occurred as follows: house light and the central key were lit at the same time. If, for example, the programmed interval was 4 s, a white light in the central key remained on for that period. After 4 s, the light from the central key was turned off and colors were presented on the side keys. A peck on either of the side keys ended the attempt. Correct answers were followed by a short period of access to the feeder and an ITI of 20 s. Incorrect answers were followed by the ITI and the repetition of the same trial (correction procedure). The procedure consisted of three phases of training: in Training A attempts, the subjects learned to choose the red colored key when the 1 s model was presented, and to choose the green colored key when the 4 s model was presented. In Training B attempts, they learned to choose the blue colored key when the 4 s model was presented and to choose the yellow colored key when the 16 s model was presented. During Training C, subjects learned to choose the blue colored key when green color was presented and to choose yellow colored key when red color model was presented. Regarding A and B trainings, blue and green stimuli were related to the same temporal stimulus 4 s, while red and yellow ones did not share any common temporal stimulus during earlier training. Results suggest that relations between blue and green were acquired more quickly, a fact that seems to demonstrate formation of transitivity relations in earlier stages of training

Eye fixations of the face are normally directed towards either the eyes or the mouth, however the proportions of gaze to either of these regions are dependent on context. Previous studies of gaze behavior demonstrate a tendency to stare into a target’s eyes, however no studies investigate the differences between when participants believe they are engaging in a live interaction compared to knowingly watching a pre-recorded video, a distinction that may contribute to studies of memory encoding. This study examined differences in fixation behavior for when participants falsely believed they were engaging in a real-time interaction over the internet (“Real-time stimulus”) compared to when they knew they were watching a pre-recorded video (“Pre-recorded stimulus”). Results indicated that participants fixated significantly longer towards the eyes for the pre-recorded stimulus than for the real-time stimulus, suggesting that previous studies which utilize pre-recorded videos may lack ecological validity. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection