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

Efficient compression of motion compensated residuals

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2018 Faculty Excellence Showcase, AFIT Graduate School of Engineering & Management

Excerpt: As an academic institution, we strive to meet and exceed the expectations for graduate programs and laud our values and contributions to the academic community. At the same time, we must recognize, appreciate, and promote the unique non-academic values and accomplishments that our faculty team brings to the national defense, which is a priority of the Federal Government. In this respect, through our diverse and multi-faceted contributions, our faculty, as a whole, excel, not only along the metrics of civilian academic expectations, but also along the metrics of military requirements, and national priorities

The effects of emotionally salient unimodal and multimodal stimuli on low-level visual perception

Sensory information can both impair and enhance low-level visual feature processing, and this can be significantly modulated depending on the whether this information matches the visual sensory modality. Emotionally significant visual and auditory stimuli can have opposing effects on attention. While task-irrelevant emotionally salient visual stimuli can often impair task attention, task-irrelevant emotionally salient auditory stimuli have been shown to enhance aspects of attention. To date, no study has directly compared how emotionally salient information presented to different sensory modalities can affect low-level vision. Using Gabor patches of differing contrasts to measure the threshold of visual perception, we hypothesized that emotionally salient visual stimuli would impair low-level vision, while emotionally salient auditory stimuli would enhance low-level vision. We found that sensory modulation may be dependant on matched sensory domain presentation, as visual emotional stimuli impaired low-level vision, but emotional auditory stimuli did not affect low-level vision

Least angle and ℓ1\ell_1 penalized regression: A review

Least Angle Regression is a promising technique for variable selection applications, offering a nice alternative to stepwise regression. It provides an explanation for the similar behavior of LASSO ($\ell_1$-penalized regression) and forward stagewise regression, and provides a fast implementation of both. The idea has caught on rapidly, and sparked a great deal of research interest. In this paper, we give an overview of Least Angle Regression and the current state of related research.Comment: Published in at http://dx.doi.org/10.1214/08-SS035 the Statistics Surveys (http://www.i-journals.org/ss/) by the Institute of Mathematical Statistics (http://www.imstat.org

Visual Impairment and Blindness

Blindness and vision impairment affect at least 2.2 billion people worldwide with most individuals having a preventable vision impairment. The majority of people with vision impairment are older than 50 years, however, vision loss can affect people of all ages. Reduced eyesight can have major and long-lasting effects on all aspects of life, including daily personal activities, interacting with the community, school and work opportunities, and the ability to access public services. This book provides an overview of the effects of blindness and visual impairment in the context of the most common causes of blindness in older adults as well as children, including retinal disorders, cataracts, glaucoma, and macular or corneal degeneration

Academic Year 2019-2020 Faculty Excellence Showcase, AFIT Graduate School of Engineering & Management

An excerpt from the Dean\u27s Message: There is no place like the Air Force Institute of Technology (AFIT). There is no academic group like AFIT’s Graduate School of Engineering and Management. Although we run an educational institution similar to many other institutions of higher learning, we are different and unique because of our defense-focused graduate-research-based academic programs. Our programs are designed to be relevant and responsive to national defense needs. Our programs are aligned with the prevailing priorities of the US Air Force and the US Department of Defense. Our faculty team has the requisite critical mass of service-tested faculty members. The unique composition of pure civilian faculty, military faculty, and service-retired civilian faculty makes AFIT truly unique, unlike any other academic institution anywhere

Artificial intelligence within the interplay between natural and artificial computation:Advances in data science, trends and applications

Artificial intelligence and all its supporting tools, e.g. machine and deep learning in computational intelligence-based systems, are rebuilding our society (economy, education, life-style, etc.) and promising a new era for the social welfare state. In this paper we summarize recent advances in data science and artificial intelligence within the interplay between natural and artificial computation. A review of recent works published in the latter field and the state the art are summarized in a comprehensive and self-contained way to provide a baseline framework for the international community in artificial intelligence. Moreover, this paper aims to provide a complete analysis and some relevant discussions of the current trends and insights within several theoretical and application fields covered in the essay, from theoretical models in artificial intelligence and machine learning to the most prospective applications in robotics, neuroscience, brain computer interfaces, medicine and society, in general.BMS - Pfizer(U01 AG024904). Spanish Ministry of Science, projects: TIN2017-85827-P, RTI2018-098913-B-I00, PSI2015-65848-R, PGC2018-098813-B-C31, PGC2018-098813-B-C32, RTI2018-101114-B-I, TIN2017-90135-R, RTI2018-098743-B-I00 and RTI2018-094645-B-I00; the FPU program (FPU15/06512, FPU17/04154) and Juan de la Cierva (FJCI-2017–33022). Autonomous Government of Andalusia (Spain) projects: UMA18-FEDERJA-084. Consellería de Cultura, Educación e Ordenación Universitaria of Galicia: ED431C2017/12, accreditation 2016–2019, ED431G/08, ED431C2018/29, Comunidad de Madrid, Y2018/EMT-5062 and grant ED431F2018/02. PPMI – a public – private partnership – is funded by The Michael J. Fox Foundation for Parkinson’s Research and funding partners, including Abbott, Biogen Idec, F. Hoffman-La Roche Ltd., GE Healthcare, Genentech and Pfizer Inc

Electrocortical underpinnings of error monitoring in health and pathology

It becomes clear from the literature described above (Chapter 1), that the error monitoring mechanisms play a fundamental role in signalling the need for cognitive control. Many studies already provided a consistent evidence on the existence of peculiar ways in which the brain signals this need through electrophysiological changes. However, the following set of empirical studies aims to gain further insight into these complex processes by measuring brain activity changes in situations that alter the way one experience errors. The second Chapter (Chapter 2) consists of a brief commentary that was made in response to an article on the brain activity to action errors. In this commentary we propose new possibilities to explore our topic of interest, by taking advantage of EEG and modern virtual reality facilities. The thesis includes three EEG-VR studies: one on the error-mechanism in healthy participants (Chapter 3) and two studies on error monitoring system in pathological populations (Chapter 4, 5), as main parts of the core of the thesis. As a collateral project, in the Appendix, there is an EEG study on action observation in elite players (Chapter 7). In the first study (Chapter 3), we investigated a very simple but fundamental question. As we saw in the introduction, error-related signatures are evoked when an error occurs. But it is not clear how much of this is due to the occurrence of a violation of the intended goal or simply to the observation of a rare – thus less predictable – event. To this aim, we used a paradigm developed in the former years in our laboratory (Pavone et al., 2016; Spinelli et al., 2017), characterized by a setup in immersive Virtual Reality (VR) and simultaneous EEG recording. Building on the previous findings, we designed an EEG-VR study in which we manipulated the probability of observing errors in actions. In another study (Chapter 4) we investigated how erroneous actions are experienced by people with brain damage and diagnosis of Apraxia. Apraxic patients are people with hemispheric lesions and defective awareness on a variety of aspects that cover perceptuo-motor, cognitive or emotional domains. This study was developed after the results obtained by Canzano and colleagues (2014) in a behavioral study in which apraxic patients were asked to imitate the actions executed by the experimenter and judge their correctness; results revealed that bucco-facial apraxic patients manifest a specific deficit in detecting their own gestural errors when they are explicitly asked to judge them. With the present study we wanted to investigate apraxic brain’ response to action errors, while they embody an avatar in first person perspective (EEG-VR setup). The third study (Chapter 5) investigates the integrity of the error-monitoring system in Parkinson’s Disease and the impact of the dopaminergic treatment in the brain response to errors. To this aim we used the proposed VR action-observation paradigm, in which Parkinson patients observed successful and unsuccessful reach-to-grasp actions in first person perspective while EEG activity was recorded; the same patients were tested while being under dopaminergic treatment and during a dopaminergic withdrawal state. In another chapter we provide a critical overview of the findings of this work (General Discussion, Chapter 6). In the last chapter, the Appendix (Chapter 7), there is a collateral project of another research line of the Laboratory, in which I have being involved. In this study we are investigating the cortical underpinning of elite players during observation of goal-directed actions, in their domain of expertise. We recorded the EEG activity of elite wheelchair basketball players while observing free-throws performed by paraplegic athletes. We expected their brain correlates to be different from novice players and to be able to easily discriminate whether a basketball shot would be successful or unsuccessful (project still ongoing)