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Akoto-Adjepong V, Appiah O, Mensah PK, Appiahene P. TTDCapsNet: Tri Texton-Dense Capsule Network for complex and medical image recognition. PLoS One 2024; 19:e0300133. [PMID: 38489277 PMCID: PMC10942055 DOI: 10.1371/journal.pone.0300133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 02/19/2024] [Indexed: 03/17/2024] Open
Abstract
Convolutional Neural Networks (CNNs) are frequently used algorithms because of their propensity to learn relevant and hierarchical features through their feature extraction technique. However, the availability of enormous volumes of data in various variations is crucial for their performance. Capsule networks (CapsNets) perform well on a small amount of data but perform poorly on complex images. To address this, we proposed a new Capsule Network architecture called Tri Texton-Dense CapsNet (TTDCapsNet) for better complex and medical image classification. The TTDCapsNet is made up of three hierarchic blocks of Texton-Dense CapsNet (TDCapsNet) models. A single TDCapsNet is a CapsNet architecture composed of a texton detection layer to extract essential features, which are passed onto an eight-layered block of dense convolution that further extracts features, and then the output feature map is given as input to a Primary Capsule (PC), and then to a Class Capsule (CC) layer for classification. The resulting feature map from the first PC serves as input into the second-level TDCapsNet, and that from the second PC serves as input into the third-level TDCapsNet. The routing algorithm receives feature maps from each PC for the various CCs. Routing the concatenation of the three PCs creates an additional CC layer. All these four feature maps combined, help to achieve better classification. On fashion-MNIST, CIFAR-10, Breast Cancer, and Brain Tumor datasets, the proposed model is evaluated and achieved validation accuracies of 94.90%, 89.09%, 95.01%, and 97.71% respectively. Findings from this work indicate that TTDCapsNet outperforms the baseline and performs comparatively well with the state-of-the-art CapsNet models using different performance metrics. This work clarifies the viability of using Capsule Network on complex tasks in the real world. Thus, the proposed model can be used as an intelligent system, to help oncologists in diagnosing cancerous diseases and administering treatment required.
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Affiliation(s)
- Vivian Akoto-Adjepong
- Department of Computer Science and Informatics, University of Energy and Natural Resources, Sunyani, Ghana
| | - Obed Appiah
- Department of Computer Science and Informatics, University of Energy and Natural Resources, Sunyani, Ghana
| | - Patrick Kwabena Mensah
- Department of Computer Science and Informatics, University of Energy and Natural Resources, Sunyani, Ghana
| | - Peter Appiahene
- Department of Computer Science and Informatics, University of Energy and Natural Resources, Sunyani, Ghana
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West GL, Patai ZE, Coutrot A, Hornberger M, Bohbot VD, Spiers HJ. Landmark-dependent Navigation Strategy Declines across the Human Life-Span: Evidence from Over 37,000 Participants. J Cogn Neurosci 2023; 35:452-467. [PMID: 36603038 DOI: 10.1162/jocn_a_01956] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Humans show a remarkable capacity to navigate various environments using different navigation strategies, and we know that strategy changes across the life span. However, this observation has been based on studies of small sample sizes. To this end, we used a mobile app-based video game (Sea Hero Quest) to test virtual navigation strategies and memory performance within a distinct radial arm maze level in over 37,000 participants. Players were presented with six pathways (three open and three closed) and were required to navigate to the three open pathways to collect a target. Next, all six pathways were made available and the player was required to visit the pathways that were previously unavailable. Both reference memory and working memory errors were calculated. Crucially, at the end of the level, the player was asked a multiple-choice question about how they found the targets (i.e., a counting-dependent strategy vs. a landmark-dependent strategy). As predicted from previous laboratory studies, we found the use of landmarks declined linearly with age. Those using landmark-based strategies also performed better on reference memory than those using a counting-based strategy. These results extend previous observations in the laboratory showing a decreased use of landmark-dependent strategies with age.
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Affiliation(s)
| | - Zita Eva Patai
- University College London, United Kingdom.,King's College London, United Kingdom
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3
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Spiers HJ, Coutrot A, Hornberger M. Explaining World-Wide Variation in Navigation Ability from Millions of People: Citizen Science Project Sea Hero Quest. Top Cogn Sci 2023; 15:120-138. [PMID: 34878689 DOI: 10.1111/tops.12590] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 02/01/2023]
Abstract
Navigation ability varies widely across humans. Prior studies have reported that being younger and a male has an advantage for navigation ability. However, these studies have generally involved small numbers of participants from a handful of western countries. Here, we review findings from our project Sea Hero Quest, which used a video game for mobile and tablet devices to test 3.9 million people on their navigation ability, sampling across every nation-state and from 18 to 99 years of age. Results revealed that the task has good ecological validity and across all countries sufficiently sampled (N = 63), age is linked to a near-linear decline in navigation ability from the early 20s. All countries showed a male advantage, but this varied considerably and could be partly predicted by gender inequality. We found that those who reported growing up in a city were on average worse at navigating than those who grew up outside cities and that navigation performance helped identify those at greater genetic risk of Alzheimer's disease. We discuss the advantages and challenges of using a mobile app to study cognition and the future avenues for understanding individual differences in navigation ability arising from this research.
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Affiliation(s)
- Hugo J Spiers
- Department of Experimental Psychology, Division of Psychology and Language Sciences, Institute of Behavioural Neuroscience, University College London
| | - Antoine Coutrot
- Laboratoire des Sciences du Numérique de Nantes, CNRS.,Laboratoire d'InfoRmatique en Image et Systèmes d'information, CNRS
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Lowry E, Coughlan G, Morrissey S, Jeffs S, Hornberger M. Spatial orientation - a stable marker for vascular cognitive impairment? CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2022; 4:100155. [PMID: 36632487 PMCID: PMC9826950 DOI: 10.1016/j.cccb.2022.100155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/06/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
Vascular cognitive impairment (VCI) is the second most prevalent form of dementia, but little is known about the early cognitive and neuroimaging markers. Spatial navigation deficits are an emerging marker for Alzheimer's disease (AD), yet less is known about spatial orientation deficits sensitive to VCI. This case report follows up on the first VCI patient identified to have an egocentric orientation deficit. The study aimed to examine the patient's spatial deficits three years on and gain insights from the addition of the patient's MRI brain scan. A battery of spatial navigation tasks were administered following neuropsychological assessment. Results continue to show spatial orientation deficits. Critically, these changes appear stable and are sensitive to novel spatial tests. Whereas conventional screening tools demonstrate patient recovery. MRI DTI analysis indicates a non-significant trend towards loss of structural integrity to the posterior tracts of the longitudinal superior fasciculus (SLF), while the medial temporal lobe, typically implicated in spatial navigation, is unaffected. This finding potentially reflects reduced network connectivity in posterior to anterior white matter tracts co-existing with spatial orientation deficits. Findings have clinical utility and show spatial orientation as a potential sensitive cognitive marker for VCI.
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Affiliation(s)
- Ellen Lowry
- Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, United Kingdom,Corresponding author at: Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ.
| | - Gillian Coughlan
- Harvard Medical School, Massachusetts General Hospital, United States
| | - Sol Morrissey
- Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Stephen Jeffs
- Department of Psychology, University of Exeter, United Kingdom
| | - Michael Hornberger
- Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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Lowry E, Puthusseryppady V, Johnen AK, Renoult L, Hornberger M. Cognitive and neuroimaging markers for preclinical vascular cognitive impairment. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2021; 2:100029. [PMID: 36324708 PMCID: PMC9616378 DOI: 10.1016/j.cccb.2021.100029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 09/30/2021] [Accepted: 10/03/2021] [Indexed: 12/22/2022]
Abstract
Detection of incipient cognitive impairment and dementia pathophysiology is critical to identify preclinical populations and target potentially disease modifying interventions towards them. There are currently concerted efforts for such detection for Alzheimer's disease (AD). By contrast, the examination of cognitive markers and their relationship to biomarkers for Vascular Cognitive Impairment (VCI) is far less established, despite VCI being highly prevalent and often concomitantly presenting with AD. Critically, vascular risk factors are currently associated with the most viable treatment options via pharmacological and non-pharmacological intervention, hence early identification of vascular factors have important implications for modifying dementia disease trajectories. The aim of this review is to examine the current evidence of cognitive marker correlates to VCI pathology. We begin by examining midlife risk factors that predict VCI. Next, discuss preclinical cognitive hallmarks of VCI informed by insights from neuropsychological assessment, network connectivity and ERP/EEG experimental findings. Finally, we discuss limitations of current cognitive assessments and the need for future cognitive test development to inform diagnostic assessment. As well as, intervention outcome measures for preclinical VCI. In turn, these tests will inform earlier detection of vascular changes and allow implementation of disease intervention approaches.
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Affiliation(s)
- Ellen Lowry
- School of Psychology, University of East Anglia, Norwich NR4 7TJ, United Kingdom
- Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | | | - Ann-Kathrin Johnen
- School of Psychology, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Louis Renoult
- School of Psychology, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Michael Hornberger
- Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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Shannon OM, Lee V, Bundy R, Gillings R, Jennings A, Stephan B, Hornberger M, Balanos G, Paddick SM, Hanson S, Hardeman W, Holmes R, Garner N, Aldred S, Siervo M, Mathers JC, Minihane AM. Feasibility and acceptability of a multi-domain intervention to increase Mediterranean diet adherence and physical activity in older UK adults at risk of dementia: protocol for the MedEx-UK randomised controlled trial. BMJ Open 2021; 11:e042823. [PMID: 33550254 PMCID: PMC7925921 DOI: 10.1136/bmjopen-2020-042823] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 12/20/2020] [Accepted: 01/21/2021] [Indexed: 11/04/2022] Open
Abstract
INTRODUCTION Dementia prevalence continues to increase, and effective interventions are needed to prevent, delay or slow its progression. Higher adherence to the Mediterranean diet (MedDiet) and increased physical activity (PA) have been proposed as strategies to facilitate healthy brain ageing and reduce dementia risk. However, to date, there have been no dementia prevention trials in the UK focussed on combined dietary and PA interventions. This study aims to: (1) assess feasibility and acceptability of a theory-underpinned digital and group-based intervention for dementia risk reduction in an 'at risk' UK cohort; (2) evaluate behaviour change responses to the intervention; and, (3) provide information on cognitive, neurological, vascular and physiological outcomes to inform the design of a follow-on, full-scale efficacy trial. METHODS One hundred and eight participants aged 55 to 74 years with a QRISK2 score of ≥10% will be recruited to take part in this 24-week multi-site study. Participants will be randomised into three parallel arms: (1) Control; (2) MedDiet; and, (3) MedDiet+PA. The study will evaluate a personalised website, group session and food delivery intervention to increase MedDiet adherence and PA in older adults at risk of dementia. Diet and PA will be monitored prior to, during and following the intervention. Feasibility, acceptability and hypothesised mediators will be assessed in addition to measures of cognitive function, brain structure/perfusion (MRI), vascular function and metabolic markers (blood, urine and faecal) prior to, and following, the intervention. DISCUSSION This trial will provide insights into the feasibility, acceptability and mechanism of effect of a multi-domain intervention focussed on the MedDiet alone and PA for dementia risk reduction in an 'at risk' UK cohort. ETHICS AND DISSEMINATION The study has received NHS REC and HRA approval (18/NI/0191). Findings will be disseminated via conference presentations, public lectures, and peer-reviewed publications. TRIAL REGISTRATION DETAILS ClinicalTrials.gov NCT03673722.
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Affiliation(s)
- Oliver M Shannon
- Human Nutrition Research Centre, Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Vivian Lee
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Rafe Bundy
- Department of Nutrition and Preventive Medicine, Norwich Medical School, University of East Anglia, Norwich, UK
| | - Rachel Gillings
- Department of Nutrition and Preventive Medicine, Norwich Medical School, University of East Anglia, Norwich, UK
| | - Amy Jennings
- Department of Nutrition and Preventive Medicine, Norwich Medical School, University of East Anglia, Norwich, UK
| | - Blossom Stephan
- Institute of Mental Health, Division of Psychiatry and Applied Psychology, School of Medicine, University of Nottingham, Nottingham, Nottinghamshire, UK
| | | | - George Balanos
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Stella Maria Paddick
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, Tyne and Wear, UK
- Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, Newcastle, UK
| | - Sarah Hanson
- School of Health Sciences, Norwich Medical School, University of East Anglia, Norwich, UK
| | - Wendy Hardeman
- Behavioural and Implementation Science Group, School of Health Sciences, University of East Anglia, Norwich, UK
| | - Rebecca Holmes
- Department of Nutrition and Preventive Medicine, Norwich Medical School, University of East Anglia, Norwich, UK
| | - Nikki Garner
- Department of Nutrition and Preventive Medicine, Norwich Medical School, University of East Anglia, Norwich, UK
- Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK
| | - Sarah Aldred
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
- Centre for Human Brain Health, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Mario Siervo
- School of Life Sciences, University of Nottingham, Nottingham, Nottinghamshire, UK
| | - John C Mathers
- Human Nutrition Research Centre, Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Anne Marie Minihane
- Department of Nutrition and Preventive Medicine, Norwich Medical School, University of East Anglia, Norwich, UK
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Tuena C, Mancuso V, Stramba-Badiale C, Pedroli E, Stramba-Badiale M, Riva G, Repetto C. Egocentric and Allocentric Spatial Memory in Mild Cognitive Impairment with Real-World and Virtual Navigation Tasks: A Systematic Review. J Alzheimers Dis 2021; 79:95-116. [PMID: 33216034 PMCID: PMC7902987 DOI: 10.3233/jad-201017] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Spatial navigation is the ability to estimate one's position on the basis of environmental and self-motion cues. Spatial memory is the cognitive substrate underlying navigation and relies on two different reference frames: egocentric and allocentric. These spatial frames are prone to decline with aging and impairment is even more pronounced in Alzheimer's disease (AD) or in mild cognitive impairment (MCI). OBJECTIVE To conduct a systematic review of experimental studies investigating which MCI population and tasks are used to evaluate spatial memory and how allocentric and egocentric deficits are impaired in MCI after navigation. METHODS PRISMA and PICO guidelines were applied to carry out the systematic search. Down and Black checklist was used to assess methodological quality. RESULTS Our results showed that amnestic MCI and AD pathology are the most investigated typologies; both egocentric and allocentric memory are impaired in MCI individuals, and MCI due to AD biomarkers has specific encoding and retrieval impairments; secondly, spatial navigation is principally investigated with the hidden goal task (virtual and real-world version), and among studies involving virtual reality, the privileged setting consists of non-immersive technology; thirdly, despite subtle differences, real-world and virtual versions showed good overlap for the assessment of MCI spatial memory. CONCLUSION Considering that MCI is a subclinical entity with potential risk for conversion to dementia, investigating spatial memory deficits with navigation tasks might be crucial to make accurate diagnosis and rehabilitation.
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Affiliation(s)
- Cosimo Tuena
- Applied Technology for Neuro-Psychology Lab, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Valentina Mancuso
- Applied Technology for Neuro-Psychology Lab, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Chiara Stramba-Badiale
- Applied Technology for Neuro-Psychology Lab, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Elisa Pedroli
- Applied Technology for Neuro-Psychology Lab, IRCCS Istituto Auxologico Italiano, Milan, Italy.,Faculty of Psychology, Universitá eCampus, Novedrate, Italy
| | - Marco Stramba-Badiale
- Department of Geriatrics and Cardiovascular Medicine, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Giuseppe Riva
- Applied Technology for Neuro-Psychology Lab, IRCCS Istituto Auxologico Italiano, Milan, Italy.,Humane Technology Lab, Università Cattolica del Sacro Cuore, Milan, Italy
| | - Claudia Repetto
- Department of Psychology, Università Cattolica del Sacro Cuore, Milan, Italy
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Functional connectivity between the entorhinal and posterior cingulate cortices underpins navigation discrepancies in at-risk Alzheimer's disease. Neurobiol Aging 2020; 90:110-118. [DOI: 10.1016/j.neurobiolaging.2020.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 02/10/2020] [Accepted: 02/10/2020] [Indexed: 01/29/2023]
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Lowry E, Puthusseryppady V, Coughlan G, Jeffs S, Hornberger M. Path Integration Changes as a Cognitive Marker for Vascular Cognitive Impairment?-A Pilot Study. Front Hum Neurosci 2020; 14:131. [PMID: 32372934 PMCID: PMC7186341 DOI: 10.3389/fnhum.2020.00131] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/20/2020] [Indexed: 12/11/2022] Open
Abstract
Path integration spatial navigation processes are emerging as promising cognitive markers for prodromal and clinical Alzheimer’s disease (AD). However, such path integration changes have been less explored in Vascular Cognitive Impairment (VCI), despite neurovascular change being a major contributing factor to dementia and potentially AD. In particular, the sensitivity and specificity of path integration impairments in VCI compared to AD is unclear. In the current pilot study, we explore path integration performance in early-stage AD and VCI patient groups and hypothesize that: (i) medial parietal mediated egocentric processes will be more affected in VCI; and (ii) medial temporal mediated allocentric processes will be more affected in AD. This cross-sectional study included early-stage VCI patients (n = 9), AD patients (n = 10) and healthy age-matched controls (n = 20). All participants underwent extensive neuropsychological testing, as well as spatial navigation testing. The spatial navigation tests included the virtual reality “Supermarket” task assessing egocentric (body-based) and allocentric (map-based) navigation as well as the “Clock Orientation” test assessing egocentric and path integration processes. Results showed that egocentric integration processes are only impaired in VCI, potentially distinguishing it from AD. However, in contrast to our prediction, allocentric integration was not more impaired in AD compared to VCI. These preliminary findings suggest limited specificity of allocentric integration deficits between VCI and AD. By contrast, egocentric path integration deficits emerge as more specific to VCI, potentially allowing for more specific diagnostic and treatment outcome measures for vascular impairment in dementia.
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Affiliation(s)
- Ellen Lowry
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom.,School of Psychology, University of East Anglia, Norwich, United Kingdom
| | | | - Gillian Coughlan
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Stephen Jeffs
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Michael Hornberger
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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