The effect of cycling on cognitive function and well-being in older adults

It has been demonstrated that, on their own, both exercise and stimulation from the environment can improve cognitive function and well-being in older adults. The combined effect of exercising in the outdoor environment on psychological function is less well studied. The aim of the current study was to investigate the effect of an outdoor cycling intervention on cognitive function and mental health and well-being in older adults. A total of 100 older adults took part in the study (aged 50–83), 26 of which were non-cycling controls, 36 were conventional pedal cyclists and 38 were participants using an e-bike (a bike fitted with an electric motor to provide assistance with pedaling), as part of a larger project (www.cycleboom.org). Participants took part in the study for an eight-week period, with cycling participants required to cycle at least three times a week for thirty minutes in duration for each cycle ride. Cognitive function and well-being were measured before and after the intervention period. For executive function, namely inhibition (the Stroop task) and updating (Letter Updating Task), both cycling groups improved in accuracy after the intervention compared to non-cycling control participants. E-bike participants also improved in processing speed (reaction times in go trials of the Stop-It task) after the intervention compared to non-cycling control participants. Finally, e-bike participants improved in their mental health score after the intervention compared to non-cycling controls as measured by the SF-36. This suggests that there may be an impact of exercising in the environment on executive function and mental health. Importantly, we showed a similar (sometimes larger) effect for the e-bike group compared to the pedal cyclists. This suggests that it is not just the physical activity component of cycling that is having an influence. Both pedal cycles and e-bikes can enable increased physical activity and engagement with the outdoor environment with e-bikes potentially providing greater benefits

'You can go out 14 miles away with the knowledge that you’ve got the battery to help you back if you need it!': Narratives of ranging behaviour and wellbeing in diaries of e-bike trial participants.

This paper draws on data from a large UK study that aimed to understand cycling among the older population and how this affected independence, health and wellbeing. Part of the study involved an ‘e-bike trial’ where participants aged 50 and over, who were returning to cycling after a hiatus, were loaned an e-bike for an eight-week trial period. Pre-trial and post-trial cognitive tests of trial participants, reported previously Leyland et al. (2019), demonstrated how e-bikes, provide positive benefits to cognitive function and wellbeing. The paper builds on these findings, drawing specifically on the qualitative component, predominantly biographical interviews, written and visual material provided in rider diaries and a focus group discussion, to understand the reasons for this positive impact. The findings demonstrate how power assistance can provide riders with the opportunity to extend the distance and types of area they are willing to cycle from their homes (their ‘ranging behaviour’) and how this can promote health and wellbeing. Our evidence suggests that e-bikes have the potential to support cycling for leisure as well as everyday travel and that consideration should be given to the positive effects of e-cycling on mental wellbeing in addition to physical activity. This is particularly pertinent in the context of an ageing society, the push towards zero-emission cities and the need to ensure socially inclusive mobility, particularly in the context of the Covid-19 global pandemic

Visual dysfunction is a better predictor than retinal thickness for dementia in Parkinson's disease

BACKGROUND: Dementia is a common and devastating symptom of Parkinson's disease (PD). Visual function and retinal structure are both emerging as potentially predictive for dementia in Parkinson's but lack longitudinal evidence. METHODS: We prospectively examined higher order vision (skew tolerance and biological motion) and retinal thickness (spectral domain optical coherence tomography) in 100 people with PD and 29 controls, with longitudinal cognitive assessments at baseline, 18 months and 36 months. We examined whether visual and retinal baseline measures predicted longitudinal cognitive scores using linear mixed effects models and whether they predicted onset of dementia, death and frailty using time-to-outcome methods. RESULTS: Patients with PD with poorer baseline visual performance scored lower on a composite cognitive score (β=0.178, SE=0.05, p=0.0005) and showed greater decreases in cognition over time (β=0.024, SE=0.001, p=0.013). Poorer visual performance also predicted greater probability of dementia (χ² (1)=5.2, p=0.022) and poor outcomes (χ² (1) =10.0, p=0.002). Baseline retinal thickness of the ganglion cell-inner plexiform layer did not predict cognitive scores or change in cognition with time in PD (β=-0.013, SE=0.080, p=0.87; β=0.024, SE=0.001, p=0.12). CONCLUSIONS: In our deeply phenotyped longitudinal cohort, visual dysfunction predicted dementia and poor outcomes in PD. Conversely, retinal thickness had less power to predict dementia. This supports mechanistic models for Parkinson's dementia progression with onset in cortical structures and shows potential for visual tests to enable stratification for clinical trials

Visual dysfunction is a better predictor than retinal thickness for dementia in Parkinson's disease.

BACKGROUND: Dementia is a common and devastating symptom of Parkinson's disease (PD). Visual function and retinal structure are both emerging as potentially predictive for dementia in Parkinson's but lack longitudinal evidence. METHODS: We prospectively examined higher order vision (skew tolerance and biological motion) and retinal thickness (spectral domain optical coherence tomography) in 100 people with PD and 29 controls, with longitudinal cognitive assessments at baseline, 18 months and 36 months. We examined whether visual and retinal baseline measures predicted longitudinal cognitive scores using linear mixed effects models and whether they predicted onset of dementia, death and frailty using time-to-outcome methods. RESULTS: Patients with PD with poorer baseline visual performance scored lower on a composite cognitive score (β=0.178, SE=0.05, p=0.0005) and showed greater decreases in cognition over time (β=0.024, SE=0.001, p=0.013). Poorer visual performance also predicted greater probability of dementia (χ² (1)=5.2, p=0.022) and poor outcomes (χ² (1) =10.0, p=0.002). Baseline retinal thickness of the ganglion cell-inner plexiform layer did not predict cognitive scores or change in cognition with time in PD (β=-0.013, SE=0.080, p=0.87; β=0.024, SE=0.001, p=0.12). CONCLUSIONS: In our deeply phenotyped longitudinal cohort, visual dysfunction predicted dementia and poor outcomes in PD. Conversely, retinal thickness had less power to predict dementia. This supports mechanistic models for Parkinson's dementia progression with onset in cortical structures and shows potential for visual tests to enable stratification for clinical trials

'Instead of "closing down" at our ages… we’re thinking of exciting and challenging things to do': older people’s microadventures outdoors on (e-)bikes

This paper explores how people aged 50 and over, who were returning to cycling as part of an eight-week health and wellbeing trial, created their own cycling microadventures. Applying a stage model of the process of adventure to qualitative data generated from personal diaries and focus groups, we examine how older people anticipated and prepared for their microadventures, the challenges and discoveries they experienced, the benefits they gained and how electrically assisted ‘e-bikes’ can provide further opportunities for adventure. We conclude that cycles are a mode uniquely placed to facilitate microadventures and that e-bikes, in particular, offer further potential to enable older people to (re-)connect with place and other people. But, while this type of activity can provide benefits in terms of health and wellbeing, we argue that more supportive physical and social infrastructure is required to provide opportunities for more people to undertake microadventures close to their homes

Aggregation-resistant alpha-synuclein tetramers are reduced in the blood of Parkinson's patients

Synucleinopathies such as Parkinson's disease (PD) are defined by the accumulation and aggregation of the α-synuclein protein in neurons, glia and other tissues. We have previously shown that destabilization of α-synuclein tetramers is associated with familial PD due to SNCA mutations and demonstrated brain-region specific alterations of α-synuclein multimers in sporadic PD patients following the classical Braak spreading theory. In this study, we assessed relative levels of disordered and higher-ordered multimeric forms of cytosolic α-synuclein in blood from familial PD with G51D mutations and sporadic PD patients. We used an adapted in vitro-cross-linking protocol for human EDTA-whole blood. The relative levels of higher-ordered α-synuclein tetramers were diminished in blood from familial PD and sporadic PD patients compared to controls. Interestingly, the relative amount of α-synuclein tetramers was already decreased in asymptomatic G51D carriers, supporting the hypothesis that α-synuclein multimer destabilization precedes the development of clinical PD. Our data, therefore suggest that measuring α-synuclein tetramers in blood may have potential as a facile biomarker assay for early detection and quantitative tracking of PD progression.</p

Visual and cognitive processing in hemispatial neglect

A number of theoretical issues can be investigated by examining patterns of eye movements in hemispatial neglect. For example, how the brain codes spatial information, how oculomotor behaviour relates to perception and awareness and what affects the allocation of spatial attention. These interesting questions will be outlined and discussed in a literature review presented in Chapter 1. Experiment 1 involved collection of behavioural and eye movement data obtained from a chronic neglect patient (SS), stroke controls and older adult controls during completion of the three cancellation tasks from the Behavioural Inattention Test (Wilson, Cockburn, &amp; Halligan, 1987). This revealed underlying deficits that were contributing to neglect. Not only was SS’s visual sampling of the neglected information limited, she also exhibited deficient and delayed processing of contralesional information when it was sampled. Experiments 2 and 3, through newly developed cancellation tasks, examined whether different frames of reference for the coding of spatial information operate in neglect. The findings indicated that an allocentric (object-based) reference frame was not exhibited by patients with neglect when searching for specific targets letters, or clocks displaying specific times. Importantly, an egocentric reference frame based upon the position of gaze was able to account for the neglect behaviour exhibited. This suggests that many findings interpreted as evidence for allocentric neglect may be explained by the left side of the object falling to the left of the point of fixation, and therefore results from egocentric neglect. Experiment 4 determined that the reference frame operating in neglect could be affected by task demands. As a processing deficit for contralesional information was shown in all the previous experiments reported in this thesis, Experiment 4 also aimed to investigate the stages of visual and cognitive processing that may be disrupted in neglect for contralesional information. The final chapter summarises the main findings and discussion of the main theoretical questions that have been outlined is presented. Conclusions are drawn with regards to these issues, which have previously been considered elusive functions of the brain (Buxbaum, 2006)

The influence of word shading and word length on eye movements during reading. Quarterly Journal of Experimental Psychology

An interesting issue in reading is how parafoveal information affects saccadic targeting and fixation durations. We investigated the influence of shading selected regions of text on eye movements during reading of long and short words within sentences. A target word, either four- or eight-letters long, was presented in one of four shading conditions: the whole target word shaded; the first half shaded; second half shaded; no shading. There was no evidence of a visually mediated parafoveal-on-foveal effect. Saccadic targeting was modulated by the shading on the first half of the word, such that fixations landed closer to the beginning of the word than in the other three shading conditions. Furthermore, partial word shading, resulting in visual non-uniformity of the target word, produced longer gaze durations than the other conditions. Finally, readers spent more time re-reading target words when they were partially shaded than in the other two conditions. We suggest that our effects are due to targeting of the optimal viewing location and revisits to check words that appear visually unusual. Together, the results indicate robust effects of low-level visual characteristics of the word on oculomotor decisions of where and when to move the eyes during reading

Patterns of Eye Movements during Cancellation Tasks in Stroke Patients Exhibiting Hemispatial Neglect

To investigate whether hemispatial neglect arises due to an information sampling deficit or impaired processing of information on the left we measured eye movements of stroke patients whilst they completed a sub-set of the Behavioural Inattention Test (BIT; Wilson et al., 1987, Behavioural Inattention Test. Suffolk, UK: Thames Valley Test Company) over three sessions. Participants who initially demonstrated left neglect in star and letter cancellation tasks exhibited a marked sampling deficit, with fewer visits made and less total time spent on the far left region of the stimulus. In the later testing sessions, a different pattern of eye movements emerged, with compensatory eye movements being made. The amount of time spent on the left increased and gaze durations were longer in the far left region compared with the other regions. This suggests that, although participants over time could sample information from the neglected region, the acquisition and processing of that information was impaired. Furthermore, behavioural measures (from the letter cancellation task) showed that, despite fixations on the left of the stimulus in the later testing sessions, neglect was still present, indicating a processing deficit. Overall, these results demonstrate neglect can arise due to both information sampling and information processing deficits

Patterns of Eye Movements during Cancellation Tasks in Stroke Patients Exhibiting Hemispatial Neglect

To investigate whether hemispatial neglect arises due to an information sampling deficit or impaired processing of information on the left we measured eye movements of stroke patients whilst they completed a sub-set of the Behavioural Inattention Test (BIT; Wilson et al., 1987, Behavioural Inattention Test. Suffolk, UK: Thames Valley Test Company) over three sessions. Participants who initially demonstrated left neglect in star and letter cancellation tasks exhibited a marked sampling deficit, with fewer visits made and less total time spent on the far left region of the stimulus. In the later testing sessions, a different pattern of eye movements emerged, with compensatory eye movements being made. The amount of time spent on the left increased and gaze durations were longer in the far left region compared with the other regions. This suggests that, although participants over time could sample information from the neglected region, the acquisition and processing of that information was impaired. Furthermore, behavioural measures (from the letter cancellation task) showed that, despite fixations on the left of the stimulus in the later testing sessions, neglect was still present, indicating a processing deficit. Overall, these results demonstrate neglect can arise due to both information sampling and information processing deficits