Human factors in instructional augmented reality for intravehicular spaceflight activities and How gravity influences the setup of interfaces operated by direct object selection

In human spaceflight, advanced user interfaces are becoming an interesting mean to facilitate human-machine interaction, enhancing and guaranteeing the sequences of intravehicular space operations. The efforts made to ease such operations have shown strong interests in novel human-computer interaction like Augmented Reality (AR). The work presented in this thesis is directed towards a user-driven design for AR-assisted space operations, iteratively solving issues arisen from the problem space, which also includes the consideration of the effect of altered gravity on handling such interfaces.Auch in der bemannten Raumfahrt steigt das Interesse an neuartigen Benutzerschnittstellen, um nicht nur die Mensch-Maschine-Interaktion effektiver zu gestalten, sondern auch um einen korrekten Arbeitsablauf sicherzustellen. In der Vergangenheit wurden wiederholt Anstrengungen unternommen, Innenbordarbeiten mit Hilfe von Augmented Reality (AR) zu erleichtern. Diese Arbeit konzentriert sich auf einen nutzerorientierten AR-Ansatz, welcher zum Ziel hat, die Probleme schrittweise in einem iterativen Designprozess zu lösen. Dies erfordert auch die Berücksichtigung veränderter Schwerkraftbedingungen

Towards Improving Learning with Consumer-Grade, Closed-Loop, Electroencephalographic Neurofeedback

Learning is an enigmatic process composed of a multitude of cognitive systems that are functionally and neuroanatomically distinct. Nevertheless, two undeniable pillars which underpin learning are attention and memory; to learn, one must attend, and maintain a representation of, an event. Psychological and neuroscientific technologies that permit researchers to “mind-read” have revealed much about the dynamics of these distinct processes that contribute to learning. This investigation first outlines the cognitive pillars which support learning and the technologies that permit such an understanding. It then employs a novel task—the amSMART paradigm—with the goal of building a real-time, closed-loop, electroencephalographic (EEG) neurofeedback paradigm using consumergrade brain-computer interface (BCI) hardware. Data are presented which indicate the current status of consumer-grade BCI for EEG cognition classification and enhancement, and directions are suggested for the developing world of consumer neurofeedback

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

Directing Attention in an Augmented Reality Environment: An Attentional Tunneling Evaluation

Augmented Reality applications use explicit cuing to support visual search. Explicit cues can help improve visual search performance but they can also cause perceptual issues such as attentional tunneling. An experiment was conducted to evaluate the relationship between directing attention and attentional tunneling, in a dual task structure. One task was tracking a target in motion and the other was detection of non-target elements. Three conditions were tested: baseline without cuing the target, cuing the target with the average scene color, and using a red cue. A different color for the cue was used to vary the attentional tunneling level. The results show that directing attention induced attentional tunneling only the in red condition and that effect is attributable to the color used for the cue

Effect of Dual Tasking On Walking Over Even and Uneven Surfaces in Functionally Independent Community Older Adults

While several studies have reported a decrement in performance by older adults while walking and concurrently performing a dual task on even surfaces, to date the effects of dual tasking while walking on uneven surfaces commonly found in the community has received less attention. Thus, we sought to test the hypothesis that an incremental decrement in gait parameters will be observed, when walking on an uneven versus an even surface and furthermore, that this decrement would be dependent upon the concurrent performance of a secondary cognitive and/or motor task in functionally independent-living-community older adults. Dynamic Gait Index assessed the subject’s ability to modify gait in response to changing task demands and Mini Mental State Examination was used to screen cognitive functionof the participants. Twenty-eight participants walked at a comfortable speed over the GAITRiteTM walkway placed over an even and uneven surface. Twenty-four strips of wood measuring 0.10 square meters and 0.05 meter high attached randomly under the smooth surface of an artificial grass mat measuring 6 meter long and 1.2 meter in width simulated a natural uneven surface. Each participant randomly performed a total of three (3) trials each under the following four task conditions as they walked over an even or uneven surface: 1) no secondary task (single task), 2) concurrent cognitive task, 3) concurrent motor task, 4) concurrent cognitive-motor task. The presentation of the task conditions were counterbalanced across subjects. Gait speed, cadence, stride time, and double support time were analyzed using a 2 x 4 repeated measures ANOVA. Also, to quantify subjects\u27 ability for executing two tasks concurrently, we calculated the dual task costs. In addition, the cognitive, motor and cognitive/motor tasks performances on even and uneven surfaces were assessed using Mann-Whitney U. The results of these analyses revealed significant main effects for concurrent dual-tasking as well as surface for speed [F(1.86,50)= 21.93; p ≤ 0.05; F(1,27)= 24.3, p ≤ 0.05] , cadence [F(1.85,50)=33.824; p ≤ 0.05. F(1,27)= 22.2, p ≤ 0.05], stride time [F(1.94,52.34)= 33.41, p ≤ 0.05; F(1,27)= 23.49, p ≤ 0.05], and double support time [F(1.99,53.62)= 7.4; p ≤ 0.05; F(1,27)= 7.4, p = .011]. It was observed that the elderly slow down, take a lesser number of steps per minute, increase their stride time and spend more time in double support when walking on uneven surfaces and when performing a concurrent dual-task. However, interaction effects failed to achieve significance. This study provides some preliminary evidence that independent, community living older adults use a default strategy that rely on making adjustments in gait that result in greater motor control. In other words the older adults err on the side of safety and focus their anticipatory resources towards controlling balance. It is important for clinicians to be aware of these strategies and incorporate them in the management of the elderly patient

Mental Blocks: The behavioural effects and neural encoding of obstacles when reaching and grasping

The ability to adeptly interact with a cluttered and dynamic world requires that the brain simultaneously encode multiple objects. Theoretical frameworks of selective visuomotor attention provide evidence for parallel encoding (Baldauf & Deubel, 2010; Cisek & Kalaska, 2010; Duncan, 2006) where concurrent object processing results in neural competition. Since the end goal of object representation is usually action, these frameworks argue that the competitive activity is best characterized as the development of visuomotor biases. While some behavioural and neural evidence has been accumulated in favour of this explanation, one of the most striking, yet deceptively common, demonstrations of this capacity is often overlooked; the movement of the arm away from an obstacle while reaching for a target object is definitive proof that both objects are encoded and affect behaviour. In the current thesis, I discuss three experiments exploring obstacle avoidance. While some previous studies have shown how visuomotor biases develop prior to movement onset, the dynamics of the bias during movement remains largely unexplored. In the first experiment I use the availability and predictability of vision during movement as a means of exploring whether obstacle representations might change during a reach (Chapter 2, Chapman & Goodale, 2010b). While the visuomotor system seems optimized to use vision, I found no difference between reaching with and without vision, providing no evidence that obstacle representations were altered. To more directly test this question, in the second experiment participants made reaches to a target that sometimes changed position during the reach (Chapter 3, Chapman & Goodale, 2010a). The automatic online corrections to the new target location were sometimes interfered with by an obstacle. Using this more direct approach we found definitive evidence that obstacle representations were accessed or updated during movement. In the third experiment, I directly tested the neural encoding of obstacles using functional magnetic resonance imaging (Chapter 4, Chapman, Gallivan, Culham, & Goodale, 2010). When participants planned a grasp movement that was interfered with by an obstacle versus when the grasp was not interfered with, one area in the left posterior intraparietal sulcus was activated. This activity was concurrent with a suppression of early visual areas that were responsive to the position of the obstacle. This study confirmed that the PPC was involved with the encoding of obstacles, and demonstrated that one effect of interference was the suppression of the visual cortical signal associated with the obstacle. These findings extend our understanding of competitive visuomotor biases. Critically, in a world filled with potential action targets, the selection of one target necessarily means all other objects in the workspace are potential obstacles. My results indicate that the visuomotor biasing signal to inhibit obstacle activity is putatively provided by the PPC, which in turn causes the visual cortical representation of the obstacle to be suppressed. The behavioural result of biasing the visual input is the propagation of this suppression to the motor output - ultimately resulting in a reach which intelligently deviates away from potential obstacles

Retrospective Prime Reliance: A Flexible Retrospective Mechanism for Semantic Priming in Visual Word Recognition

Recent evidences (Balota et al., 2008; Thomas et al., 2012) suggest that the cognitive system can retrospectively (i.e., after target presentation) increase its reliance on prime information when target-word recognition is made more difficult by experimental manipulations such as visual degradation. In fact, response time (RT) distributional analyses have shown that for clearly visible target-words the priming effect has the same size in all the portions of the RT distribution. In contrast, for degraded target-words, priming effects increase across the RT distribution, coherently with the idea of an increased reliance on prime information for degraded targets, which would be particularly beneficial for the most difficult responses (i.e., the slowest ones). The first study (with English-speaking participants), investigated the idea of retrospective prime reliance in the context of an important empirical conundrum within the word recognition literature, produced by the joint effects of stimulus visual quality (SQ), semantic priming and word frequency. The manipulation of these variables, in fact, has traditionally produced constraining results for models of priming (e.g., McNamara, 2005), as well as for visual word recognition models (e.g., Reynolds & Besner, 2004). In Experiment 1, all the three variables have been manipulated within a single speeded pronunciation task, where words and nonwords were randomly appearing as targets. The results indicated that the joint effect of SQ and word frequency on RTs were dependent upon prime relatedness. More specifically, additive effects of SQ and frequency were observed after related primes, while an overadditive interaction was observed after unrelated primes. Distributional analyses showed that this three-way interaction was mediated by slowest RTs and it was hypothesized that the pattern of effects reflects reliance on prime information. To test this hypothesis, in Experiment 2 related primes were eliminated from the list, to produce a context in which there was no reason to rely on prime information. Interactive effects of SQ and frequency found following unrelated primes in Experiment 1 reverted, in Experiment 2, to additive effects for the same unrelated prime conditions. Note that, in English, additive effects of SQ and frequency are found in standard speeded pronunciation tasks (i.e., with no primes), provided that words and nonwords are randomly intermixed in the target set (as was the case in Experiment 2). In a second study, the same experiments as in the first one were tested within a different priming paradigm, namely in zero-lag repetition priming (e.g., Ferguson et al., 2009) and within a different language (Italian). Although distributional analyses provided preliminary evidences that retrospective prime reliance is operative even in this context (Experiment 3), cross-linguistic differences were nonetheless observed. More specifically, in English SQ and frequency produce additive effects in a speeded pronunciation task, provided that nonword targets are intermixed with real words (O’Malley & Besner, 2008) and provided that primes (if present) are all unrelated (Experiment 2). This finding does not seem to be replicated in Italian, where the two variables still produced, in Experiment 4, an overadditive interaction despite the presence of nonwords in the target-set and despite the fact that only unrelated primes were presented (exactly as in Experiment 2). It was hypothesized the discrepancy might stem from the fact that, while in English the system needs to place a functional threshold at an earlier processing level in order to overcome the detrimental effect of visual degradation before lexical representations get activated (thus avoiding lexicalization errors), in a transparent language this might not be the case. It was thus argued that in Italian it is sufficient to increase the reliance on sublexical output, without qualitatively altering the activation-dynamics of the system. The third study explored the possibility that retrospective prime reliance entails episodic retrieval. In a first experiment, English-speaking participants first performed a lexical decision task where SQ and semantic priming were manipulated. After completing the lexical decision and a brief distracter-task, they also performed a recognition memory task on primes presented during the lexical decision. Results showed a trend towards better recognition of those primes that preceded degraded targets, as opposed to clearly visible ones. The result is coherent with the hypothesis that, for those primes that preceded degraded targets, episodic retrieval takes place even in lexical decision, thereby facilitating the recognition of these items in a subsequent memory task. In a second experiment (Italian participants), the effect of SQ in the memory task was not replicated, probably due to specific features of the materials used in the experiment. On the other hand, a strong lexicality effect was found in the memory performance: primes that preceded real words were recognized much better compared to those that preceded nonwords in the previous experimental phase. These results suggest that the interplay between primes and targets, and the cognitive operations required to process them in lexical decision may reflect into the memory traces left by these stimuli. In conclusion, retrospective prime reliance proved to be a useful theoretical tool to understand the joint effect of semantic priming, SQ, and frequency, thereby proposing a new perspective on this issue. Moreover, preliminary evidences suggest that a retrospective component might be involved even in a zero-lag repetition priming paradigm and that the mechanism beside retrospective reliance might entail the episodic retrieval of the prime’s representation. Most importantly, the results highlight the flexibility and the sensitivity of the reading system to the context (i.e., experimental task, characteristics of the stimuli)

Advances in Human-Robot Interaction

Rapid advances in the field of robotics have made it possible to use robots not just in industrial automation but also in entertainment, rehabilitation, and home service. Since robots will likely affect many aspects of human existence, fundamental questions of human-robot interaction must be formulated and, if at all possible, resolved. Some of these questions are addressed in this collection of papers by leading HRI researchers

Cognitive-motor interference in people with multiple sclerosis: a kinematic approach to clarify the effect of cognitive load on walking performance

The simultaneous performance of cognitive tasks during locomotion (or cognitive-motor dual-task) is known to cause performance deficits in either one of, or both tasks. Furthermore, these performance decrements are exacerbated by the presence of motor impairments and cognitive dysfunctions characteristic of numerous neurological diseases, such as multiple sclerosis (MS). In this regard the assessment of walking while performing a cognitive task may represent a relevant outcome measure, because it allows measuring, in a laboratory setting, individual’s ability to cope with walking challenging situations similar to everyday living. The first aim of this thesis is to provide an experimental setup, based on the use of optoelectronic stereophotogrammetry, for obtaining quantitative evaluation of walking biomechanics and motor strategies during dual-task performance in both healthy adults and people with MS (pwMS). Then, this experimental methodology is tested as suitable method not only for detecting, measuring and characterizing disability, but also for testing intervention effectiveness in clinical practice. Specifically, the study is focused on the assessment of spatiotemporal parameters and lower limb kinematics during single- (normal pace walking) and dual-task (walking while performing a discrimination and decision-making). This thesis is composed of four experiments. The first two aimed to measure the effect of cognitive-motor interference on walking biomechanics in terms of spatiotemporal parameters and lower limb joint kinematics. In this regard, a sample of pwMS stratified by disability level (low disability, EDSS 1.0-2.5, n=37; mild to moderate disability, EDSS 3.0-6.0, n=44) and a sample of age- and gender-matched healthy adults (n=41) underwent a 3D kinematic evaluation of single- and dual-task performance using a motion capture system. Differences between conditions and groups were investigated using a two-way repeated ANOVA. The results reported that gait speed and stride length were sensitive motor variables in detecting differences from single- to dual-task condition in both pwMS and unaffected individuals, whereas spatiotemporal parameters closely related to balance control (e.g. step width, double support phase duration) were sensitive to changes only in pwMS with moderate disability. Moreover, those patients showed significant changes in the kinematics of distal joint (shank-foot) and proximal joint (hip), including a reduction in ankle plantarflexion and hip extension peak at the terminal stance phase. These observed changes in more impaired patients are compensatory mechanism to stabilize body posture and allow safe locomotion during complicate dual-task activities. Finally, the other two experiments were designed to provide a clinical application of this methodology, as a tool for quantitatively assessing biomechanics changes after an innovative therapeutic intervention. In this regard, a sample of pwMS (n=34) with mild to moderate disability participated in a bicentric clinical trial. As per protocol, pwMS completed an intervention consisting of either active or sham multiple sessions of transcranial direct current stimulation (tDCS) combined with physical activity, aimed to improve walking performance. Following repeated application of active tDCS, the results obtained from the quantitative gait analysis showed greater improvements in gait velocity, step length and walking endurance. This improvement measured in walking had corresponding effects on walking dual-task performance. In fact, the dual-task cost of gait parameters was significantly reduced after the active tDCS intervention. In conclusion, the quantitative assessment of walking impairments during the execution of functional task in pwMS can support a deep learning of both movement features and motor strategies, which should have implications for the design and validation of clinical intervention aimed at improving functional walking

Designing, delivering, and evaluating novel interventions to support dietary change for weight management

Background: Recent empirical research and theoretical models acknowledge that impulsive processes, can often undermine peoples’ attempts to lose weight despite currently available and effective support (Chapter 2). Aim: To develop, deliver, and evaluate an impulse management intervention to support weight loss in adults. Methods: A systematic review was conducted to identify available impulse management techniques for influencing eating behaviour (Chapter 3). Intervention Mapping was used to develop the intervention (Chapter 4) which drew on various sources including the findings from the systematic review, stakeholder consultations, existing guidance, and qualitative interviews. A two-arm randomised controlled feasibility trial (Chapter 5), with nested mixed-methods process evaluation and two cycles of intervention delivery and data collection (Chapter 6), was conducted. This assessed the feasibility and acceptability of, and informed refinements to, both the intervention and trial procedures in preparation for a full-scale effectiveness evaluation. Weight was measured as the proposed primary outcome for a full-scale trial at baseline, one-month, and three-months of follow-up, app usage data were collected at both follow-up time points, and semi-structured interviews were conducted at one-month with a subsample of intervention group participants only. Results: The systematic review critically appraised and synthesised evidence on 17 identified techniques which were categorised as Impulse-focused or Reflective techniques. Promising changes in eating behaviour and craving were found for the techniques of visuospatial loading, physical activity, and implementation intentions. Intervention Mapping resulted in development of a novel smartphone app-based intervention (ImpulsePal) aimed to reduce unhealthy snacking, overeating, and alcoholic and sugary drink consumption using impulse management techniques identified in the systematic review. Eighty-eight adults with a Body Mass Index of ≥25kg/m2 and wishing to lose weight, were recruited and randomised in a 2:1 ratio to use ImpulsePal (n=58) or to a waiting list control (n=30) group. Data were available for 74 participants (84%) at one-month and 67 (76%) at three months. Exploratory analyses suggest that the ImpulsePal group (n=43) lost 1.03kg (95% CI 0.33 to 1.74) more than controls (n=26) at one-month, and 1.01kg (95% CI -0.45 to 2.47) more at three months. Participants reported high satisfaction with the intervention and trial procedures. The process evaluation suggests that ImpulsePal and the impulse management techniques are feasible to deliver and acceptable to users. Interviews with twenty-two participants suggest that they valued having access to in-the-moment support, felt more aware of their own eating behaviour and influences on it, and felt an increased ability to resist temptations. Conclusions: This work has developed a novel, theory- and evidence-informed, person-centred app which showed potential to improve impulse management, promote healthier eating, and support weight loss. ImpulsePal is acceptable to overweight and obese adults who want to lose weight and is now ready for evaluation in a full-scale trial. The thesis discusses theoretical, methodological, and practical implications for the future development, evaluation, and implementation of digital behaviour change interventions.UEM