Previous research has suggested that viewing of another’s averted eye gaze causes automatic orienting of attention and eye movements in observers due to the importance of eye gaze for effective social interaction. Other types of visual cues with no social or biological relevance, such as arrows, are claimed not to produce such a direct effect on orienting behaviour. The finding that processing of eye gaze is reduced in individuals with Autistic Spectrum Disorders as well as following damage to the orbitofrontal cortex of the brain, suggests that gaze processing is indeed critical for effective social behaviour and therefore eye gaze may constitute a “special” directional cue. This thesis tested these ideas by examining the influence of socio-biological (eye gaze and finger pointing) and non-social cues (arrows and words) on eye movement responses in both healthy control participants and those with damage to the frontal lobes of the brain. It further investigated the relationship between orienting to gaze and arrow cues and autistic traits in a healthy population. Important differences between the effects of socio-biological and non-social cues were found on saccadic eye movements. Although in the pro-saccade tasks, arrow cues caused a similar facilitation of responses in the cued direction as eye gaze and pointing cues, in the anti-saccade tasks (in which participants have to respond away from the location of a peripheral onset), arrows had a greatly reduced effect on oculomotor programming relative to the biologically relevant cues. Importantly, although the socio-biological cues continued to influence saccadic responses, the facilitation was in the opposite direction to the cues. This finding suggests that the cues were being processed within the same "anti-response" task set (i.e. "go opposite") as the target stimulus. Word cues had almost no effects on saccadic orienting in either pro- or anti-saccade tasks. Schematicised eye gaze cues had a smaller magnitude effect than photographic gaze cues suggesting that ecological validity ("biological-ness") is an important factor in influencing oculomotor responses to social cues. No relationship was found between autistic traits and orienting to gaze or arrow cues in a large sample of males. However, findings from the neurological patients point to a possible double-dissociation between the neural mechanisms subserving processing of socio-biological and non-social cues, with the former reliant on the orbitofrontal cortex, and the latter on lateral frontal cortex. Taken together, these results suggest that biologically relevant cues have privileged access to the oculomotor system. The findings are interpreted in terms of a neurocognitive model of saccadic orienting to socio-biological and non-social cues, and an extension to an existing model of saccade generation is proposed. Finally, limitations of the research, its wider impact and directions for future work are discussed.

Title: Brain Activity Changes During Walking Affected by Cuieng in Parkinson's Disease Patients Viewed by sLORETA Imaging. Objectives: The aim of this diploma thesis is to acertain changes in electrical activity of the brain, evaluated by sLORETA program, between gait affected by visual and auditory cueing and normal comfortable gait in patients with Parkinson's disease. Methods: This experiment was conducted on 11 patients with Parkinson's Disease aged between 60-78 years. The electrical activity of the brain was registred by scalp EEG during the whole experiment. The experiment consisted of 4 parts. In the beginning we measured resting EEG with closed and then opened eyes (5 + 5 minutes), after that we measured EEG during normal comfortable gait on 3 meters long track (3 minutes). Subsequently we measured EEG during walking affected by cueing, again on the 3 meters long track (3 + 3 minutes). The order of visual and auditory cueing was randomized. Visual cueing was mediated by white lines (tapes) stuck to the floor within 50 centimetres of each other. Auditory cueing was mediated by a metronome. The basic rhythm of the metronome was set on the 70 BPM. Next, the data from the experiment were transferred into the sLORETA program, which enabled statistical proccessing and also imaging of the active...

The ability to drive a car is an important skill for individuals with a spinal cord injury to maintain a high quality of life, particularly their freedom and independence. However, driving with a physical disability often requires the installation of an adaptive driving system to control steering, gas, and braking. The two main types of adaptive driving controls are mechanical and electrical, also known as drive by wire (DBW). DBW controls work by converting electric signals to mechanical actuators. Driving simulators are useful tools for adaptive driving systems because they allow users to test different control devices, to practice driving without the dangers of being on the road, and can be used as a safe way to evaluate disabled drivers. This study focused on the development of a dynamic driving simulator using DBW controls because many studies focus on mechanical controls and not DBW controls and often use static simulators. The simulator was developed using the Computer Assisted Rehabilitation Environment (CAREN) virtual reality system. The CAREN system (Motek Medical, Amsterdam, Netherlands) includes a six degree of freedom (DOF) motion base, an optical motion capture system, a sound system, and a 180-degree projection screen. The two DBW controls, a lever device to control the gas and brake and a small wheel device to control steering, sent an electric signal to a Phidget microcontroller board, which interfaced with the CAREN system. Several different driving scenarios were created and imported into CAREN's D-Flow software. A program was developed in D-Flow to control the scene and motion of the platform appropriately based on the DBW controls via the Phidget. The CAREN system dynamically controlled the motion platform based on the user's input. For example, if the user applied the brake suddenly, the user felt a deceleration from the motion platform moving backwards. Human testing was performed and through the use of a survey, feedback about the system was obtained. Changes were made to the simulator using the feedback obtained and further testing showed that those changes improved the simulator. The driving simulator showed the capability to provide dynamic feedback and, therefore, may be more realistic and beneficial than current static adaptive driving simulators. The dynamic adaptive driving simulator developed may improve driving training and performance of persons with spinal cord injuries. Future work will include more human testing. The dynamic feedback provided through the system's moving platform and virtual camera movement will be optimized in order to perform similarly to a real car. Testing will also be completed with and without the dynamics from the moving platform to see how this type of feedback affects the user's driving ability in the virtual environment.

It has long been held that processing at the single word level during reading is automatic. However, research has recently begun to emerge that challenges this view. The literature surrounding the processing of emotion while recognizing printed words is limited, but some findings in the processing of emotion in faces suggest that negative stimuli (especially threat stimuli) promote quick and accurate processing. The purpose of the present experiments is to investigate whether negative emotionally-laden words are afforded priority processing in visual word recognition compared to positive emotionally-laden words. Two experiments are reported that manipulated the lexicality and valence of the target and distractor stimuli (Experiments 1 & 2), the validity of a spatial pre-cue (Experiments 1 & 2), and the presence of a distractor item (Experiment 2). Participants were asked to determine whether the target stimulus spelled a word or not. Response times on valid trials were faster compared to invalid trials, response times to negative emotionally-laden words were slower compared to positive emotionally-laden words, and the presence of a distractor item encouraged better focus on the target stimuli in the absence of any evidence that the valence of the distractor itself was processed. These results are consistent with the hypothesis that visual word recognition is not automatic given that processing benefited from the accurate direction of spatial attention. Furthermore, negative emotionally-laden words benefited equally compared to positive emotionally-laden words and therefore provide no evidence of automatic processing.

The analysis of performance gains arising from cueing in cooperative search systems with autonomous vehicles has been studied using Continuous Time Markov Chains; where the search time distributions are assumed to follow the exponential distributions. This work proposes the use of Petri Nets to model and analyze these systems. The Petri Net model considers two types of autonomous vehicles: a search-only vehicle and n search-engage vehicles. Specific performance metrics are defined to measure system’s performance. Through simulation, it is shown that the search time with stationary targets and cues that provide exact target location follows a triangular distribution. A methodology for approximating general distributions and incorporating them into the Petri Net model for performance analysis is presented.

It has long been held that processing at the single word level during reading is automatic. However, research has recently begun to emerge that challenges this view. The literature surrounding the processing of emotion while recognizing printed words is limited, but some findings in the processing of emotion in faces suggest that negative stimuli (especially threat stimuli) promote quick and accurate processing. The purpose of the present experiments is to investigate whether negative emotionally-laden words are afforded priority processing in visual word recognition compared to positive emotionally-laden words. Two experiments are reported that manipulated the lexicality and valence of the target and distractor stimuli (Experiments 1 & 2), the validity of a spatial pre-cue (Experiments 1 & 2), and the presence of a distractor item (Experiment 2). Participants were asked to determine whether the target stimulus spelled a word or not. Response times on valid trials were faster compared to invalid trials, response times to negative emotionally-laden words were slower compared to positive emotionally-laden words, and the presence of a distractor item encouraged better focus on the target stimuli in the absence of any evidence that the valence of the distractor itself was processed. These results are consistent with the hypothesis that visual word recognition is not automatic given that processing benefited from the accurate direction of spatial attention. Furthermore, negative emotionally-laden words benefited equally compared to positive emotionally-laden words and therefore provide no evidence of automatic processing.

[Truncated abstract] This study was carried out to investigate the teaching and learning processes occurring in the topic of reaction mechanisms in three tertiary level organic chemistry courses and focussed on investigating perceptions about the importance of teaching and learning about reaction mechanisms and about the difficult aspects of the topic .... In the organic chemistry courses under investigation, students achieved many of the explicitly stated aims that their lecturers identified. The students rarely achieved implicit outcomes anticipated by the lecturer. Lecturers demonstrate a tendency to use particular structural representations when discussing certain types of reaction process. The study identified that students commonly use these same types when working through particular reaction processes. In addition, it was found that the use of a particular structure could cue students into thinking about only one type of reaction process taking place in a given reaction. The use of language that is consistent with a consideration of only single reaction particles was also commonly observed in lectures. While this can be adequate in some circumstances, other aspects of reaction processes are better considered in terms of multiple reaction particles ... The project proposes an integrated model, which takes into account the many levels (macroscopic, single particle molecular, multiple particle molecular and intramolecular) involved when describing reaction processes. It is felt that a consideration of the levels discussed in this model is useful when teaching and learning about reaction mechanisms.

Pas de résumé en français / The goal of our studies was to test the effect of segmentation, cueing, and 2D/3D presentations to foster complex animation rocessing. The material was an upright mechanical piano system. We used an eye tracking system which provides information about learners’ attention direction during the animation processing. We analyzed the effect of the format presentations and the eye movements during learning. Based on animation and multimedia research background, four experiments were conducted. In the first experiment the effect of the presentation of simplified external representations on learning from complex animation was investigated. Experiment two and three aimed at studying the cognitive processes involved in learning to complex mechanism system with new cueing techniques with spatial-temporal colored tokens. In the fourth experiment, 2D and 3D presentation of the same animated content were compared. Results of these experiments showed that (1) the use of a dual format presentation is better for developing a dynamic mental model from the animation than a single format, (2) the signaling strategies using cued tokens of dual format can guide efficiently learner’s building of mental model and can enhance learner’s comprehension of complex system, (3) a sequential format presentation followed by an animation format presentation helps the learner to understand the key stages of a dynamic process and to create a high quality mental model, (4) 3D animation presentation is better than 2D animation presentation to direct attention on relevant component of the animation. For depth processing, comprehension with 3D animation presentation is better than 2D animation format. Eye tracking measures provided insights into how people understood and learned complex systems. The analysis of eye tracking also contributed to the understanding of the subject’s perceptual processing during learning. Overall, results provide a significant contribution in the field of learning with complex animation. Recommendations in the ergonomics area for the design of animations are proposed.

In this thesis, we will explore direct and indirect measures of learning in a visual search task commonly called contextual cueing. In the first part, we present a review of the scientific literature on contextual cueing, in order to give the readers of this thesis a better general idea of existing evidence and open questions within this relatively new research field. The aims of our own experimental studies presented in the succeeding chapters are the following ones: (1) to replicate and extend the findings described in the various papers by Marvin Chun and various colleagues on contextual cueing of visual attention; (2) to explore the nature of memory representations underlying the observed learning effects, especially whether learning is actually implicit and whether memory representations are distinctive, episodic and instance-based or rather distributed, continuous and graded; (3) to extend the study of contextual cueing to more realistic visual stimuli, in order to test its robustness across various situations and validate its adaptive value in ecologically sound conditions;<p>and (4) to investigate whether such knowledge about the association between visual contexts and “meaningful” locations can be (automatically) transferred to other tasks, namely a change detection task.<p><p>In a first series of four experiments, we tried to replicate the documented contextual cueing effect using a wide range of various direct measures of learning (tasks that are supposed to be related to explicit knowledge) and we systematically varied the distinctiveness of context configurations to study its effect on both direct and indirect measures of learning. <p><p>We also ran a series of neural network simulations (briefly described in the general discussion of this thesis), based on a very simple association-learning mechanism, that not only account for the observed contextual cueing effect, but also yield rather specific predictions about future experimental data: contextual cueing effects should also be observed when repetitions of context configurations are not perfect, i.e. the networks were able to react to slightly distorted versions of repeating contexts in a similar way than they did to completely identical contexts. Human participants, we conjectured, should therefore (if the simple connectionist model captures some relevant aspects of the contextual cueing effect) become faster at detecting targets surrounded by context configurations that are only partially identical from trial to trial compared to those trials where the context configurations were randomly generated. These predictions were tested in a second series of experiments using pseudo-repeated context configurations, where some distractor items were either displaced from trial to trial or their orientation changed, while conserving their global layout. <p><p>In a third series of experiments, we used more realistic images of natural landscapes as background contexts to establish the robustness of the contextual cueing effect as well as its ecological relevance claimed by Chun and colleagues. We furthermore added a second task to these experiments to study whether the acquired knowledge about the background-target location associations would (automatically) transfer to another visual search task, namely a change detection task. If participants have learned that certain locations of the repeated images are “important”, since they contain the target item to look for, then changes occurring at those specific locations should lead to less “change blindness” than changes occurring at other irrelevant locations. We used two different types of instructions to introduce this second task after the visual search task, where we either stressed the link between the two tasks, i.e. telling them that remembering the “important” locations for each image could be used to find the changes faster, or we simply told them to perform the second task without any reference to the first one. <p><p>We will close this thesis with a general discussion, combining findings based on our review of the existing research literature and findings based on our own experimental explorations of the contextual cueing effect. By this we will discuss the implications of our empirical studies for the scientific investigation of contextual cueing and implicit learning, in terms of theoretical, empirical and methodological issues. / Doctorat en sciences psychologiques / info:eu-repo/semantics/nonPublished

Obesity is a contributing factor to many diseases. Unhealthy food choices are a behavior that can lead to obesity. Teaching children to make healthy food choices at an early age could lead to healthy food choices throughout a lifetime, which would mitigate potential for obesity. A number of different treatments have evaluated healthy food choices in children; however, many did not evaluate or show maintenance effects. The purpose of this study was to utilize correspondence training to acquire healthy food choices in preschoolers and to evaluate of natural communities of reinforcement as a maintenance procedure. Results showed that correspondence training is likely to increase healthy food choices in most preschoolers; however, maintenance of healthy snack choices is variable.