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Bálint Syndrome (including Simultagnosia)
Published in Alexander R. Toftness, Incredible Consequences of Brain Injury, 2023
Imagine that you can't see more than one thing at a time. That is, you can't pay attention to more than one object within your vision at the same time. Looking at an aisle in a store to search for the item you wish to buy becomes a lengthy task: rather than scanning the shelves, you have to look at each item in sequence in order to find the one that you want. Reading, too, becomes tricky. Instead of seeing all of the words on the page, which shows you where to start and stop, you find just one word or letter at a time and have difficulty locating the others. What has caused your ability to distribute visual attention to go awry?
The Fundamentals of Signal Processing for Evoked Potential BCIs:
Published in Chang S. Nam, Anton Nijholt, Fabien Lotte, Brain–Computer Interfaces Handbook, 2018
Garett D. Johnson, Dean J. Krusienski
This scenario is based on an SSVEP interface with arbitrary number n possible classes (Sutter 1992). The n targets are spatially distinct symbols, that is, icons, that each flash at distinct constant frequency on a computer monitor or LED display. As the user shifts visual attention to one of the targets, the EEG over the visual cortex exhibits stronger oscillatory components at the target frequency and its harmonics. For this case, the canonical correlation analysis (CCA) algorithm generates an EEG spatial filter for each target that maximizes the correlation between a set of sinusoidal templates at each target frequency and its harmonic frequencies (Bin et al. 2009). The spatial filter associated with one of the target frequencies that produces the highest correlation for a given data window designates the current target of the user’s visual attention. The idea is that the sinusoidal templates corresponding to the target frequency should better match the EEG than the templates at the other frequencies. See Figure 20.2 for a graphical depiction of CCA. This approach has an advantage over standard spectral analysis, for example, techniques based on the Fourier transform, in that it simultaneously combines spatial and spectral information in the classification decision and tends to provide more reliable performance. This approach does not require calibration or training before online operation and allows for continuous, asynchronous operation.
A review of school-based studies on the effect of acute physical activity on cognitive function in children and young people
Published in Romain Meeusen, Sabine Schaefer, Phillip Tomporowski, Richard Bailey, Physical Activity and Educational Achievement, 2017
Andy Daly-Smith, Jim McKenna, Greta Defeyter, Andrew Manley
Another example of a title that has many facets is attention. This is a well-researched area due to its importance in everyday life and prediction of school achievement (Steinmayr, Ziegler, & Träuble, 2010). Although attention is cross-modal, the majority of researchers have examined the effects of physical activity on visual attention. Posner (1980) proposes visual attention acts as a spotlight, while others have suggested a more flexible approach using the analogy of a zoom lens (Eriksen & St James, 1986). A third, and less well-supported, approach uses the analogy of multiple spotlights, where attention can be split between two or more regions of space not adjacent to each other (Awh & Pashler, 2000). Essential to learning, visual attention enables an individual to process information while resisting distractors within a single task or across multiple tasks.
Pilot study to explore poor visual searching capabilities in children with ADHD: a tablet-based computerized test battery study
Published in Nordic Journal of Psychiatry, 2023
Joanna Aflalo, Simona Caldani, Eric Acquaviva, Ana Moscoso, Richard Delorme, Maria Pia Bucci
Futures studies with larger sample size would improve the robustness of our findings. The identification of a biomarker requested a long process of validation, including an estimation of its specificity but also its sensitivity. Similarly, we aimed to explore visual attention impairment in first degree relatives of children with ADHD. The heritability of ADHD is high (0.74) and underlines the burden of genes in the determinism of this disorder [22]. Visual attention impairment may participate in the delineation of this complex disorder and shed new insight into its physiopathology. Previous findings from Gau and Huang [23] also suggested that sustained attention deficit may be shared by the unaffected siblings of youth with ADHD. These authors reported that unaffected siblings when compared to controls displayed significantly higher total omissions and lower probability of hits during the rapid visual information processing task of the Cambridge Neuropsychological Test Automated Battery (CANTAB).
Clinical provision of compensatory visual training after neurological injury: example of a multisite outpatient program
Published in Disability and Rehabilitation, 2021
Megan J. Metzler, Meghan Maiani, Brittany Jamieson, Sean P. Dukelow
Attention Process Training (APT-3, Lash & Associates Publishing, Youngsville, NC) is available as a computer program-based platform developed for individuals with traumatic brain injury. Most activities in the program focus on auditory stimuli, but the program also contains a number of visual tasks. Various tasks are intended to exercise sustained attention, selective attention (choosing relevant stimuli in the presence of distractors), alternating attention (switching between two tasks), and executive function tasks that blend visual attention with a cognitive load (e.g., recalling words in a previously displayed sentence and ordering by length). The occupational therapist can create customized programs for a specific client by selecting tasks and indicating the level of difficulty and often the amount or type of other distractors present. The program tracks success for each task as the client does the program, which the therapist can review later. Attention Process Training can also be downloaded on a thumb drive for use at home and updated in the clinic as needed. Therapists typically update the program to keep task success around 80%.
Object search in neovascular age‐related macular degeneration: the crowding effect
Published in Clinical and Experimental Optometry, 2020
Miguel Thibaut, Muriel Boucart, Thi Ha Chau Tran
Visual search is a frequent task in daily life. Indeed, everyone searches for something all the time in modern society, where a substantial amount of time is spent searching for computer icons or phone applications or shopping online, or simply searching for objects to prepare meals. Human visual search involves multiple visual and cognitive functions, ranging from spatial vision, visual attention, oculomotor control, temporal integration of information across eye movements as search progresses, memory and decision making.2011 Using real‐world visual search tasks, visual search has been shown to be impaired in those with low vision.2015 In self‐reported quality of life questionnaires, AMD patients report difficulties in searching and finding things on a crowded shelf, suggesting that the spatial proximity of elements may have an impact on object search.1998