Publications by authors named "Giles Hamilton-Fletcher"

Persons with blindness and low vision experience increased fall and injury risk beyond atypical biomechanics and balance impairments. Falling risk doubles with blindness, and more than triples with depth perception losses. Despite this, physical therapy focuses on musculoskeletal injuries postevent rather than taking a proactive and preventative approach for persons with blindness and low vision.

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NOise Reduction with DIstribution Corrected (NORDIC) principal component analysis (PCA) has been shown to selectively suppress thermal noise and improve the temporal signal-to-noise ratio (tSNR) in human functional magnetic resonance imaging (fMRI). However, the feasibility to improve data quality for rodent fMRI using NORDIC PCA remains uncertain. NORDIC PCA may also be particularly beneficial for improving topological brain mapping, as conventional mapping requires precise spatiotemporal signals from large datasets (ideally ~1 hour acquisition) for individual representations.

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UNav is a computer-vision-based localization and navigation aid that provides step-by-step route instructions to reach selected destinations without any infrastructure in both indoor and outdoor environments. Despite the initial literature highlighting UNav's potential, clinical efficacy has not yet been rigorously evaluated. Herein, we assess UNav against standard in-person travel directions (SIPTD) for persons with blindness or low vision (PBLV) in an ecologically valid environment using a non-inferiority design.

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Article Synopsis
  • Distance estimation is important for assistive smartphone apps used by people who are blind or have low vision, but existing methods need assessment for accuracy and usability.
  • Five distance estimation approaches were tested, showing that while most techniques had low average errors in the image center, CoreML performed poorly at longer distances and in periphery measurements.
  • CoreML had advantages in usability, with lower processing and battery usage, making it a promising option for developing reliable visual assistive technologies.
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Recent object detection models show promising advances in their architecture and performance, expanding potential applications for the benefit of persons with blindness or low vision (pBLV). However, object detection models are usually trained on generic data rather than datasets that focus on the needs of pBLV. Hence, for applications that locate objects of interest to pBLV, object detection models need to be trained specifically for this purpose.

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Sensory substitution devices (SSDs) such as the 'vOICe' preserve visual information in sound by turning visual height, brightness, and laterality into auditory pitch, volume, and panning/time respectively. However, users have difficulty identifying or tracking multiple simultaneously presented tones - a skill necessary to discriminate the upper and lower edges of object shapes. We explore how these deficits can be addressed by using image-sonifications inspired by auditory scene analysis (ASA).

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The visual system retains profound plastic potential in adulthood. In the current review, we summarize the evidence of preserved plasticity in the adult visual system during visual perceptual learning as well as both monocular and binocular visual deprivation. In each condition, we discuss how such evidence reflects two major cellular mechanisms of plasticity: Hebbian and homeostatic processes.

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It is accepted knowledge that, for a given equivalent sound pressure level, sounds produced by planes are worse received from local communities than other sources related to transportation. Very little is known on the reasons for this special status, including any interactions that non-acoustical factors may have in listener assessments. Here we focus on one of such factors, the multisensory aspect of aircraft events.

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Cross-modal correspondences describe the widespread tendency for attributes in one sensory modality to be consistently matched to those in another modality. For example, high pitched sounds tend to be matched to spiky shapes, small sizes, and high elevations. However, the extent to which these correspondences depend on sensory experience (e.

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Article Synopsis
  • Interoception is the process of sensing internal bodily signals, with individual differences influencing emotional responses such as anxiety.
  • Most studies focus on heart-related signals, revealing a distinction between accuracy in detecting cardiac versus respiratory signals, yet a positive correlation in awareness of one's interoceptive abilities across both types.
  • The research indicates that respiratory accuracy is linked to higher anxiety levels, while greater awareness of heart signals may reduce anxiety, suggesting different sensory modalities influence emotional and cognitive experiences.
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There is a widespread tendency to associate certain properties of sound with those of colour (e.g., higher pitches with lighter colours).

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Visual sensory substitution devices (SSDs) can represent visual characteristics through distinct patterns of sound, allowing a visually impaired user access to visual information. Previous SSDs have avoided colour and when they do encode colour, have assigned sounds to colour in a largely unprincipled way. This study introduces a new tablet-based SSD termed the ‘Creole’ (so called because it combines tactile scanning with image sonification) and a new algorithm for converting colour to sound that is based on established cross-modal correspondences (intuitive mappings between different sensory dimensions).

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Visual sensory substitution devices (SSDs) allow visually-deprived individuals to navigate and recognise the 'visual world'; SSDs also provide opportunities for psychologists to study modality-independent theories of perception. At present most research has focused on encoding greyscale vision. However at the low spatial resolutions received by SSD users, colour information enhances object-ground segmentation, and provides more stable cues for scene and object recognition.

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