Perceptual plasticity in the peripheral visual field of older adults

Perceptual learning is an important mechanism in the human visual system, and can lead to long-lasting improvements across a broad range of perceptual tasks. In this study we demonstrated how perceptual learning can be applied to improve word recognition in the peripheral visual field of a sample of older individuals. We have shown that improvements in thresholds can be equalised across age, simply by increasing the number of training sessions available to older observers. Based on this initial finding we further sought to establish a protocol to induce improvements in reading ability for a sample of individuals with age-related macular disease (AMD). As a prelude to this work, we investigated the effects of crowding and fixation instability on similar tasks. Having suffered damage to their central vision, our target population (individuals with AMD) must use peripheral vision for daily viewing tasks. Peripheral vision is known to be highly susceptible to crowding, the influence of which has previously been shown to strengthen with age. We investigated the relationship between age and crowding on a letter recognition task, and found that (for this task) crowding was age in-variant, implying that this key inhibitor to peripheral visual perception should not have an inordinate influence on learning in our AMD sample. Our work on fixation stability also led to promising results. We demonstrated that our proxy for fixation instability (a dynamic target or dynamic fixation point) did not adversely affect letter recognition thresholds. Fixation instability is a common issue in AMD, but our data suggests that this may not adversely affect learning on our word recognition task. The final part of this work has been the implementation of a small study in which we trained a sample of individuals with AMD on our word recognition task. Significant improvements in thresholds were observed, though these did not quite reach the level of an age-matched normally sighted sample. Nonetheless, the trajectory of the learning curve suggests that further improvements would be possible with extended training sessions. Crucially, we also observed significant transfer of learning – from the trained word recognition task to an untrained sentence reading task (the MNRead Acuity chart). This is a key aspect of the study, as we are primarily interested in developing training protocols that lead to real-world improvements in visual ability. Improvements on MNRead scores are promising, and suggest that our approach may prove to be a useful starting point in the development of a robust therapeutic protocol

Keyframe detection in visual lifelogs

The SenseCam is a wearable camera that passively captures images. Therefore, it requires no conscious effort by a user in taking a photo. A Visual Diary from such a source could prove to be a valuable tool in assisting the elderly, individuals with neurodegenerative diseases, or other traumas. One issue with Visual Lifelogs is the large volume of image data generated. In previous work we spit a day's worth of images into more manageable segments, i.e. into distinct events or activities. However, each event coud stil consist of 80-100 images. thus, in this paper we propose a novel approach to selecting the key images within an event using a combination of MPEG-7 and Scale Invariant Feature Transform (SIFT) features

Perceptual plasticity in the peripheral visual field of older adults

Perceptual learning is an important mechanism in the human visual system, and can lead to long-lasting improvements across a broad range of perceptual tasks. In this study we demonstrated how perceptual learning can be applied to improve word recognition in the peripheral visual field of a sample of older individuals. We have shown that improvements in thresholds can be equalised across age, simply by increasing the number of training sessions available to older observers. Based on this initial finding we further sought to establish a protocol to induce improvements in reading ability for a sample of individuals with age-related macular disease (AMD). As a prelude to this work, we investigated the effects of crowding and fixation instability on similar tasks. Having suffered damage to their central vision, our target population (individuals with AMD) must use peripheral vision for daily viewing tasks. Peripheral vision is known to be highly susceptible to crowding, the influence of which has previously been shown to strengthen with age. We investigated the relationship between age and crowding on a letter recognition task, and found that (for this task) crowding was age in-variant, implying that this key inhibitor to peripheral visual perception should not have an inordinate influence on learning in our AMD sample. Our work on fixation stability also led to promising results. We demonstrated that our proxy for fixation instability (a dynamic target or dynamic fixation point) did not adversely affect letter recognition thresholds. Fixation instability is a common issue in AMD, but our data suggests that this may not adversely affect learning on our word recognition task. The final part of this work has been the implementation of a small study in which we trained a sample of individuals with AMD on our word recognition task. Significant improvements in thresholds were observed, though these did not quite reach the level of an age-matched normally sighted sample. Nonetheless, the trajectory of the learning curve suggests that further improvements would be possible with extended training sessions. Crucially, we also observed significant transfer of learning – from the trained word recognition task to an untrained sentence reading task (the MNRead Acuity chart). This is a key aspect of the study, as we are primarily interested in developing training protocols that lead to real-world improvements in visual ability. Improvements on MNRead scores are promising, and suggest that our approach may prove to be a useful starting point in the development of a robust therapeutic protocol

Exploiting context information to aid landmark detection in SenseCam images

In this paper, we describe an approach designed to exploit context information in order to aid the detection of landmark images from a large collection of photographs. The photographs were generated using Microsoft’s SenseCam, a device designed to passively record a visual diary and cover a typical day of the user wearing the camera. The proliferation of digital photos along with the associated problems of managing and organising these collections provide the background motivation for this work. We believe more ubiquitious cameras, such as SenseCam, will become the norm in the future and the management of the volume of data generated by such devices is a key issue. The goal of the work reported here is to use context information to assist in the detection of landmark images or sequences of images from the thousands of photos taken daily by SenseCam. We will achieve this by analysing the images using low-level MPEG-7 features along with metadata provided by SenseCam, followed by simple clustering to identify the landmark images

Dementia care mapping in long-term care settings: a systematic review of the evidence

YesThis systematic review identifies and reports the extent and nature of evidence to support the use of Dementia Care Mapping as an intervention in care settings. The review was limited to studies that used Dementia Care Mapping as an intervention and included outcomes involving either care workers and/or people living with dementia. Searches were conducted in PubMed, Web of Knowledge, CINAHL, PsychINFO, EBSCO and Scopus and manually from identified articles reference lists. Studies published up to January 2017 were included. Initial screening of identified papers was based on abstracts read by one author; full-text papers were further evaluated by a second author. The quality of the identified papers was assessed independently by two authors using the Cochrane Risk of Bias Tool. A narrative synthesis of quantitative findings was conducted. We identified 6 papers fulfilling predefined criteria. Studies consist of recent, large scale, good quality trials that had some positive impacts upon care workers’ stress and burnout and benefit people with dementia in terms of agitated behaviours, neuropsychiatric symptoms, falls and quality of life. Available research provides preliminary evidence that Dementia Care Mapping may benefit care workers and people living with dementia in care settings. Future research should build on the successful studies to date and use other outcomes to better understand the benefits of this intervention

The effect of normal aging and age-related macular degeneration on perceptual learning

We investigated whether perceptual learning could be used to improve peripheral word identification speed. The relationship between the magnitude of learning and age was established in normal participants to determine whether perceptual learning effects are age invariant. We then investigated whether training could lead to improvements in patients with age-related macular degeneration (AMD). Twenty-eight participants with normal vision and five participants with AMD trained on a word identification task. They were required to identify three-letter words, presented 10° from fixation. To standardize crowding across each of the letters that made up the word, words were flanked laterally by randomly chosen letters. Word identification performance was measured psychophysically using a staircase procedure. Significant improvements in peripheral word identification speed were demonstrated following training (71% ± 18%). Initial task performance was correlated with age, with older participants having poorer performance. However, older adults learned more rapidly such that, following training, they reached the same level of performance as their younger counterparts. As a function of number of trials completed, patients with AMD learned at an equivalent rate as age-matched participants with normal vision. Improvements in word identification speed were maintained at least 6 months after training. We have demonstrated that temporal aspects of word recognition can be improved in peripheral vision with training across a range of ages and these learned improvements are relatively enduring. However, training targeted at other bottlenecks to peripheral reading ability, such as visual crowding, may need to be incorporated to optimize this approach

The Effect of Aging on Crowded Letter Recognition in the Peripheral Visual Field

Purpose.: Crowding describes the increased difficulty in identifying a target object when it is surrounded by nearby objects (flankers). A recent study investigated the effect of age on visual crowding and found equivocal results: Although crowded visual acuity was worse in older participants, crowding expressed as a ratio did not change with age. However, the spatial extent of crowding is a better index of crowding effects and remains unknown. In the present study, we used established psychophysical methods to characterize the effect of age on visual crowding (magnitude and extent) in a letter recognition task. Methods.: Letter recognition thresholds were determined for three different flanker separations in 54 adults (aged 18–76 years) with normal vision. Additionally, the spatial extent of crowding was established by measuring spacing thresholds: the flanker-to-target separation required to produce a given reduction in performance. Uncrowded visual acuity, crowded visual acuity, and spacing thresholds were expressed as a function of age, avoiding arbitrary categorization of young and old participants. Results.: Our results showed that uncrowded and crowded visual acuities do not change significantly as a function of age. Furthermore, spacing thresholds did not change with age and approximated Bouma's law (half eccentricity). Conclusions.: These data show that crowding in adults is unaffected by senescence and provide additional evidence for distinct neural mechanisms mediating surround suppression and visual crowding, since the former shows a significant age effect. Finally, our data suggest that the well-documented age-related decline in peripheral reading ability is not due to age-related changes in visual crowding

The Effect of Aging on Crowded Letter Recognition in the Peripheral Visual Field

PURPOSE. Crowding describes the increased difficulty in identifying a target object when it is surrounded by nearby objects (flankers). A recent study investigated the effect of age on visual crowding and found equivocal results: Although crowded visual acuity was worse in older participants, crowding expressed as a ratio did not change with age. However, the spatial extent of crowding is a better index of crowding effects and remains unknown. In the present study, we used established psychophysical methods to characterize the effect of age on visual crowding (magnitude and extent) in a letter recognition task. METHODS. Letter recognition thresholds were determined for three different flanker separations in 54 adults (aged 18-76 years) with normal vision. Additionally, the spatial extent of crowding was established by measuring spacing thresholds: the flanker-to-target separation required to produce a given reduction in performance. Uncrowded visual acuity, crowded visual acuity, and spacing thresholds were expressed as a function of age, avoiding arbitrary categorization of young and old participants. RESULTS. Our results showed that uncrowded and crowded visual acuities do not change significantly as a function of age. Furthermore, spacing thresholds did not change with age and approximated Bouma's law (half eccentricity). CONCLUSIONS. These data show that crowding in adults is unaffected by senescence and provide additional evidence for distinct neural mechanisms mediating surround suppression and visual crowding, since the former shows a significant age effect. Finally, our data suggest that the well-documented age-related decline in peripheral reading ability is not due to agerelated changes in visual crowding

Pilot cluster randomised trial of an evidence-based intervention to reduce avoidable hospital admissions in nursing home residents (Better Health in Residents of Care Homes with Nursing - BHiRCH-NH Study)

YesObjectives To pilot a complex intervention to support healthcare and improve early detection and treatment for common health conditions experienced by nursing home (NH) residents. Design Pilot cluster randomised controlled trial. Setting 14 NHs (7 intervention, 7 control) in London and West Yorkshire. Participants NH residents, their family carers and staff. Intervention Complex intervention to support healthcare and improve early detection and treatment of urinary tract and respiratory infections, chronic heart failure and dehydration, comprising: (1) ‘Stop and Watch (S&W)’ early warning tool for changes in physical health, (2) condition-specific care pathway and (3) Situation, Background, Assessment and Recommendation tool to enhance communication with primary care. Implementation was supported by Practice Development Champions, a Practice Development Support Group and regular telephone coaching with external facilitators. Outcome measures Data on NH (quality ratings, size, ownership), residents, family carers and staff demographics during the month prior to intervention and subsequently, numbers of admissions, accident and emergency visits, and unscheduled general practitioner visits monthly for 6 months during intervention. We collected data on how the intervention was used, healthcare resource use and quality of life data for economic evaluation. We assessed recruitment and retention, and whether a full trial was warranted. Results We recruited 14 NHs, 148 staff, 95 family carers and 245 residents. We retained the majority of participants recruited (95%). 15% of residents had an unplanned hospital admission for one of the four study conditions. We were able to collect sufficient questionnaire data (all over 96% complete). No NH implemented intervention tools as planned. Only 16 S&W forms and 8 care pathways were completed. There was no evidence of harm. Conclusions Recruitment, retention and data collection processes were effective but the intervention not implemented. A full trial is not warranted