"Eyes Closed" and "Eyes Open" Expectations Guide Fixations in Real-World Search

Investigations of search within realistic scenes have identified both bottom-up and top-down influences on performance. Here, I describe two types of top-down expectations that might guide observers looking for objects. Initially, likely locations can be predicted based only on the target identity but without any visual information from the scene (?Eyes closed?). When a visual preview becomes available, a more refined prediction can be made based on scene layout (?Eyes open?). In two experiments participants guessed the location of a target with or without a brief preview of the scene. Responses were consistent between observers and were used to predict the eye movements of new observers in a third experiment. The results confirm that participants use both types of top-down cues during search, and provide a simple method for estimating these expectations in predictive models

Diagnostic Palpation in Osteopathic Medicine: A Putative Neurocognitive Model of Expertise

This thesis examines the extent to which the development of expertise in diagnostic palpation in osteopathic medicine is associated with changes in cognitive processing. Chapter 2 and Chapter 3 review, respectively, the literature on the role of analytical and non-analytical processing in osteopathic and medical clinical decision making; and the relevant research on the use of vision and haptics and the development of expertise within the context of an osteopathic clinical examination. The two studies reported in Chapter 4 examined the mental representation of knowledge and the role of analogical reasoning in osteopathic clinical decision making. The results reported there demonstrate that the development of expertise in osteopathic medicine is associated with the processes of knowledge encapsulation and script formation. The four studies reported in Chapters 5 and 6 investigate the way in which expert osteopaths use their visual and haptic systems in the diagnosis of somatic dysfunction. The results suggest that ongoing clinical practice enables osteopaths to combine visual and haptic sensory signals in a more efficient manner. Such visuo-haptic sensory integration is likely to be facilitated by top-down processing associated with visual, tactile, and kinaesthetic mental imagery. Taken together, the results of the six studies reported in this thesis indicate that the development of expertise in diagnostic palpation in osteopathic medicine is associated with changes in cognitive processing. Whereas the experts’ diagnostic judgments are heavily influenced by top-down, non-analytical processing; students rely, primarily, on bottom-up sensory processing from vision and haptics. Ongoing training and clinical practice are likely to lead to changes in the clinician’s neurocognitive architecture. This thesis proposes an original model of expertise in diagnostic palpation which has implications for osteopathic education. Students and clinicians should be encouraged to appraise the reliability of different sensory cues in the context of clinical examination, combine sensory data from different channels, and consider using both analytical and nonanalytical reasoning in their decision making. Importantly, they should develop their skills of criticality and their ability to reflect on, and analyse their practice experiences in and on action

Face perception: an approach to the study of autism

The autistic child's ability to identify others' faces and their expressions was investigated in comparison with the ability of non-autistic children. A study of the children's ability to identify peers' from isolated facial areas revealed that the autistic children were abnormally good at this task. Reasons for these findings were investigated in a series of experiments which revealed that the autistic children were also abnormally good at recognising inverted faces and inverted text. The conclusion was drawn that the autistic children's performance was due to their possessing a perceptual integration deficit which prevents them seeing stimuli like faces and words as meaningful wholes. This was investigated further by tests of their ability to discern facial expression and the results of these studies supported the above conclusion. Tests of the children's ability to lip read revealed that the autistic children also had problems with between modality perceptual integration. Studies of their ability to produce facial expressions showed them to be poor at both spontaneous and elicited expressions. Further, whilst they were as good as controls at copying facial expression, they were less able to make use of visual feedback to improve their attempts. This was seen as further evidence for a perceptual integration deficit. Finally, a computerised study of autistic children's eye movements whilst viewing live facial expressions and other stimuli supported much of the previous findings, adding the finding that they had abnormally brief visual fixation times and that they engaged in very few feature-to-feature gaze shifts. The results were discussed and found to favour a theory in which the autistic child's problems with social and communicative competence are linked to his problems with perceptual integration. The possession versus the use of abilities was discussed, as was possible sites of neurological damage, and the possibility that autistic children lack some vital usually 'innate' abilities and propensities

Social Saliency: Visual Psychophysics and Single-Neuron Recordings in Humans

My thesis studies how people pay attention to other people and the environment. How does the brain figure out what is important and what are the neural mechanisms underlying attention? What is special about salient social cues compared to salient non-social cues? In Chapter I, I review social cues that attract attention, with an emphasis on the neurobiology of these social cues. I also review neurological and psychiatric links: the relationship between saliency, the amygdala and autism. The first empirical chapter then begins by noting that people constantly move in the environment. In Chapter II, I study the spatial cues that attract attention during locomotion using a cued speeded discrimination task. I found that when the motion was expansive, attention was attracted towards the singular point of the optic flow (the focus of expansion, FOE) in a sustained fashion. The more ecologically valid the motion features became (e.g., temporal expansion of each object, spatial depth structure implied by distribution of the size of the objects), the stronger the attentional effects. However, compared to inanimate objects and cues, people preferentially attend to animals and faces, a process in which the amygdala is thought to play an important role. To directly compare social cues and non-social cues in the same experiment and investigate the neural structures processing social cues, in Chapter III, I employ a change detection task and test four rare patients with bilateral amygdala lesions. All four amygdala patients showed a normal pattern of reliably faster and more accurate detection of animate stimuli, suggesting that advantageous processing of social cues can be preserved even without the amygdala, a key structure of the “social brain”. People not only attend to faces, but also pay attention to others’ facial emotions and analyze faces in great detail. Humans have a dedicated system for processing faces and the amygdala has long been associated with a key role in recognizing facial emotions. In Chapter IV, I study the neural mechanisms of emotion perception and find that single neurons in the human amygdala are selective for subjective judgment of others’ emotions. Lastly, people typically pay special attention to faces and people, but people with autism spectrum disorders (ASD) might not. To further study social attention and explore possible deficits of social attention in autism, in Chapter V, I employ a visual search task and show that people with ASD have reduced attention, especially social attention, to target-congruent objects in the search array. This deficit cannot be explained by low-level visual properties of the stimuli and is independent of the amygdala, but it is dependent on task demands. Overall, through visual psychophysics with concurrent eye-tracking, my thesis found and analyzed socially salient cues and compared social vs. non-social cues and healthy vs. clinical populations. Neural mechanisms underlying social saliency were elucidated through electrophysiology and lesion studies. I finally propose further research questions based on the findings in my thesis and introduce my follow-up studies and preliminary results beyond the scope of this thesis in the very last section, Future Directions

Application of neuroergonomics in the industrial design of mining equipment.

Neuroergonomics is an interdisciplinary field merging neuroscience and ergonomics to optimize performance. In order to design an optimal user interface, we must understand the cognitive processing involved. Traditional methodology incorporates self-assessment from the user. This dissertation examines the use of neurophysiological techniques in quantifying the cognitive processing involved in allocating cognitive resources. Attentional resources, cognitive processing, memory and visual scanning are examined to test the ecological validity of theoretical laboratory settings and how they translate to real life settings. By incorporating a non-invasive measurement technique, such as the quantitative electroencephalogram (QEEG), we are able to examine connectivity patterns in the brain during operation and discern whether or not a user has obtained expert status. Understanding the activation patterns during each phase of design will allow us to gauge whether our design has balanced the cognitive requirements of the user.Doctor of Philosophy (PhD) in Natural Resources Engineerin

Congruency of eye movement metrics across motor simulation states: implications for motor (re)learning.

This thesis contains a series of studies that report, for the first time, the congruence between physical, imagined and observed movement though a range of eye movement markers as a test of Jeannerod’s Simulation Theory (Jeannerod, 1994, 2001). First, the eye gaze metrics of healthy young individuals across all the action-related processes in a single paradigm is reported. The finding from this study suggested a temporal and spatial similarity between action execution (AE) and action observation (AO), and a spatial similarity between AE and motor imagery (MI). These findings suggest that AO could be used to simulate actions that involve a critical temporal element. Second, the influence of early ageing on gaze metrics was examined. The findings from this study indicated that whilst the profile of metrics for AE showed age-related decline, it was less evident in AO and MI although there was evidence of some age-related decline across all the three processes. Third, the influence of visual perspective on eye movements during movement simulation is reported. The data analysis in this study was novel and allowed, for the first time, eye gaze to be used to quantify MI and highlighted the importance of social gaze in AO and its absence in MI. Taken together, the finding that some eye metrics are preserved in more covert behaviours provides support for the efficacy of (re)learning optimal eye gaze strategies through AO- and MI-supported movement-based interventions for older adults with movement dysfunction. Therefore, in the final study, the development of a fully-integrated AE-AO-MI toolkit is reported. A new, App-based approach to the integration of movement simulation in rehabilitation is described in detail. Twenty years after he first proposed his Simulation Theory of MI the novel findings from this programme of work provide substantial support for the concept. This thesis highlights the advantage of using advanced eye gaze technology as an important marker to inform the on-going debate on the extent of the neural substrate sharedness as the central tenet to Simulation Theory. The findings of the studies will make an important impact on the use of simulation procedures for motor relearning

Behavioral, physiological and neural evidence of the role of political ideology in social cognition

The social and economic crisis of the last decade seems to have given new impetus to a thirty years old idea claiming that we are living in post-ideological and post-political world (Fukuyama 1992). This idea is supported by the rising of a wide range of populistic movements claiming their detachment from any political ideology (see for example, Movimento 5 Stelle in Italy, Podemos in Spain, Le Front National in France). Although different, these movements share their opposition to the actual political system and their contempt toward its representatives (i.e., politicians). Starting from this point, we asked ourselves whether this ideological crisis depends on the fact that political ideologies have no longer who can represent them and thus on how political ideology is actually conveyed and perceived by people. Thus, with the present work we aimed at extending the current knowledge on how political ideology affects social cognition, specifically by looking at the impact that presenting political information in different way has on how people perceive, categorize, evaluate and interact with other social entities. In doing so, we either employed different tools and techniques taken both from experimental psychology and neuroscience and we tested politically polarized and non-aligned people to provide a detailed description of these processes. In the second chapter we present three studies that tested whether the way political ideology is conveyed can impact the emergence of the intergroup bias in left and right-wing people. Specifically, we measured how participants evaluated on an emotional and cognitive level their political ingroup and outgroup presented in different forms (i.e., images of politicians, ideological words and items referring to general people belonging to their political ingroup and outgroup). In keeping with this, the study presented in the third chapter explores whether different political ideologies presented in different forms could affect moral decision-making. Specifically, by means of an eye-tracker we measured physiologically whether images of politicians and ideological words representing left and right-wing ideologies and used as primes could affect how politically non-aligned people allocate their attention toward specific information (i.e., personal vs social) and how this, in turn, could drive their tendency to deceive other people during an interactive game. The study in the fourth chapter provides very preliminary evidence of how biases associated to political ideology and another source of social information, such as ethnicity, affect how these information are processed in the brain and, in turn, their impact on people’s ability to discriminate their own facial identity from that of other social entities

Cognitive processing in complex situations : the dynamics of information flow

The thesis describes and develops a new theoretical approach to the study of human cognitive processing performance in complex situation so this approach utilises and integrates existing theoretical and empirical data from a number of traditionally separate areas of Information processing psychology, such as cognition, perception, memory, imagery, skill and vigilance. Contemporary cognitive psychology considers perception, memory and imagery as functionally inter-related and inter-dependent processes characterised by active, constructive, conscious information processing. In the present thesis the implications of this view are extended, in that this processing is considered to occupy the cognitive processing capacity of the subject in qualitatively the same way as does normal decision-making, problem-solving, or conscious Internalised thought processing of any kind. The theoretical approach of the thesis stresses and accepts the functional inter-relationship and inter-dependence of the various higher mental processes, and is primarily concerned with the sustained dynamic performance properties of the total system. The nature of the research emphasis and direction of the thesis originates from the author's direct concern with applied problems resulting from the increasing cognitive load imposed upon human operators in present complex man-machine systems, such as jet aircraft, for example. Performance failure of the human operator in these systems often has very serious consequences. There is a critical lack of knowledge regarding the fundamental nature and limitations of human information processing in such situations. The basic motivation behind the work reported in the thesis was that, in order to study meaningfully the relevant aspects of the applied situation, further pure research, both theoretical and empirical, had to be undertaken to clarify particular issues. A new conceptual approach to vigilance-type situations is suggested by the theory developed in the thesis, A task was devised in which the signals to be detected were clearly visible, but embedded at random in complex visual patterns (photographs). These patterns were presented on a television screen at regular intervals, over 600 times to subjects during a single testing session. At each of these presentations subjects had to respond with respect to the identification of the picture shown; and to the presence or absence of a signal within it. From the theory it was predicted that where the complex pattern remained the same throughout the testing session, signal detection performance would show a typical vigilance decrement. However, when the set of possible pictures in which the signal may or may not be embedded is vastly increased, and the subject' has to respond at each event in the manner described, it was predicted that signal detection performance would be significantly improved in relation to the single picture condition. These predictions were empirically confirmed at a highly significant level. (On the basis of visual signal-to-noise ratios only, a signal detection analysis of the experimental situation would predict a result opposite to that actually obtained in the experiment). A computer simulation program based on fundamental theoretical ideas outlined in the thesis was developed. The program was used to simulate the vigilance experiment reported in the dissertation. The purpose and implications of the use of this technique as an applied research tool are discussed. The final chapter discusses the results achieved, and outlines the proposed application of the theoretical ideas, and empirical results of the research to the cognitive load problems of human operators in real man-machine systems, in particular aircrew flying advanced jet aircraft