Download or read book Age related Changes in Multisensory Integration Mechanisms written by Julia Diana Nannt and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigated the audiovisual integration between two age groups (aged 18-32 and 65-72 years). The impact of stimulus intensity and stimulus onset asynchrony (SOA) on the reaction time and the event-related potentials (ERPs) was assessed. Reaction time experiment: For both age groups, shorter reaction times were found for high intensity stimuli and bimodal stimuli with large SOA. Elderly adults exhibited slower reaction times to unimodal stimuli when compared to young adults. Both age groups had a similar amount of multisensory enhancement. Electroencephalography experiment: To determine the proportion of multisensory interaction, the ERP to the bimodal stimulus was compared to the sum of the two unimodal ERPs. Age-related changes were found for the positive integration component P150 where elderly adults exhibited longer latencies. The latency of the P150 was shorter for high intensity stimuli, and the proportion of multisensory interaction (amplitude) was highest for bimodal stimuli with negative SOA. engl.

Download or read book Aging Related Changes in Auditory Perception and Cognition Measurements Mechanisms and Interventions written by Qian Wang and published by Frontiers Media SA. This book was released on 2022-12-23 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Neural Bases of Multisensory Processes written by Micah M. Murray and published by CRC Press. This book was released on 2011-08-25 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has become accepted in the neuroscience community that perception and performance are quintessentially multisensory by nature. Using the full palette of modern brain imaging and neuroscience methods, The Neural Bases of Multisensory Processes details current understanding in the neural bases for these phenomena as studied across species, stages of development, and clinical statuses. Organized thematically into nine sub-sections, the book is a collection of contributions by leading scientists in the field. Chapters build generally from basic to applied, allowing readers to ascertain how fundamental science informs the clinical and applied sciences. Topics discussed include: Anatomy, essential for understanding the neural substrates of multisensory processing Neurophysiological bases and how multisensory stimuli can dramatically change the encoding processes for sensory information Combinatorial principles and modeling, focusing on efforts to gain a better mechanistic handle on multisensory operations and their network dynamics Development and plasticity Clinical manifestations and how perception and action are affected by altered sensory experience Attention and spatial representations The last sections of the book focus on naturalistic multisensory processes in three separate contexts: motion signals, multisensory contributions to the perception and generation of communication signals, and how the perception of flavor is generated. The text provides a solid introduction for newcomers and a strong overview of the current state of the field for experts.

Download or read book Age related Changes in Multisensory Self motion Perception written by Robert Charles Ramkhalawansingh and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To derive the precise estimates of self-motion necessary to perform mobility-related tasks like walking and driving, humans integrate information about their movement from across their sensory systems (e.g. visual, auditory, proprioceptive, vestibular). However, recent evidence suggests that the way in which multiple sensory inputs are integrated by the adult brain changes with age. The objective of this thesis was to consider, for the first time, whether age-related changes in multisensory integration are observed in the context of self-motion perception. Two research approaches were used. First, I used a simple, simulated driving task to provide visual cues to self-motion and to manipulate the availability of auditory and/or vestibular cues to self-motion (i.e., unisensory versus multisensory conditions). The results revealed that relative to younger adults, older adults generally demonstrate greater differences in performance between multisensory and unisensory conditions. However, the driving task could not disentangle the effects of age-related differences in real-world driving experience from age-related differences in sensory integrative mechanisms. Second, I used an established and highly controlled psychophysical heading perception task to evaluate whether, like younger adults, older adults integrate visual and vestibular cues to self-motion in a statistically optimal fashion. I considered conditions where each of the two cues was presented alone, in combination and congruent, or in combination but indicating conflicting heading angles. Results showed that while older adults did demonstrate optimal integration during congruent conditions, they were comparatively less tolerant to spatial conflicts between the visual and vestibular inputs. Overall, these results may have important implications for the way that older adults perform mobility-related tasks under various perceptual and environmental conditions.

Download or read book Updates on multisensory perception from neurons to cognition written by Angelo Maravita and published by Frontiers E-books. This book was released on with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years there has been a dramatic progress in understanding how stimuli from different sensory modalities are integrated among each other. Multisensory integration results in a unitary representation of the world that strongly characterizes perception and cognition in humans. Knowledge about multi sensory integration has research techniques and approaches, including neurophysiology, experimental psychology, neuropsychology, neuroimaging, and computational modelling. This special issue aims at presenting an up-to-date integrative overview of the physiological, psychological, developmental, and functional processes associated with multisensory integration. The proposed collection of papers is organized thematically into sections, each featuring a state-of-the-art review of key themes in multisensory research, from more approaches in the animal, to the study of multisensory perception and cognition in humans. Specifically, this special issue will consider: The physiological mechanisms of multisensory processing in cortical and subcortical brain structures of model animal species, (rat, cat, and monkey); current biologically inspired computational modelling of multisensory integration; evidence about the multisensory contributions to perception in humans, as highlighted by psychophysical and neuropsychological evidence; the neural basis of multisensory processing in the human brain uncovered by recent neuroimaging techniques, including EEG, PET, fMRI; the consequences of the breakdown of normal sensory integration as shown by studies with techniques of brain stimulation in humans; developmental processes of multisensory perception in humans and the constrains for the emergence of multisensory processes in relation to sensory experience; the issue of crossmodal neuroplasticity concerning behavioral and neural changes following sensory deprivation. The challenge of this Research Topic is to provide an interdisciplinary context allowing to understand the basic principles of multisensory integration in humans and the key issues that this fascinating field of study rises for future research.

Download or read book Multisensory Development written by Andrew J. Bremner and published by Oxford University Press. This book was released on 2012-06-21 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: We perceive and understand our environment using many sensory systems-vision, touch, hearing, taste, smell, and proprioception. These multiple sensory modalities give us complementary sources of information about the environment. This book explores how we develop the ability to integrate our senses.

Download or read book A Matter of Bottom Up or Top Down Processes The Role of Attention in Multisensory Integration written by Jess Hartcher-O'Brien and published by Frontiers Media SA. This book was released on 2017-07-04 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: The integration of information from various sensory modalities influences behaviour. It can induce behavioural benefits such as faster reaction times and enhanced detection of noisy signals but may also produce illusions, all of which have been characterized by specific neuronal signatures. Yet, while these effects of multisensory integration are largely accepted, the role of attention in this process is still the object of intense debate. On the one hand, it has been suggested that attention may guide multisensory integration in a top-down fashion by selection of specific inputs to be integrated out of the plethora of information in our environment. On the other hand, there is evidence that integration could occur in a bottom-up manner, based on temporal and spatial correlations, and outside the focus of attention. An extreme example is the multisensory enhancement of neural responses in anesthetised animals. Attention itself is not a unitary construct, and may refer to a range of different selection mechanisms. Therefore, the interplay between attention and multisensory integration can take many forms which explain, in part, the diversity of findings and the disputes in the literature. The goal of this Research Topic is to help clarify the picture by trying to answer the following questions from various perspectives: Under which circumstances does multisensory integration take place without attention?, and, When does attention determine the fate of multisensory integration?

Download or read book Age dependent Mechanisms of Multisensory Integration and Crossmodal Learning written by Sophie Rohlf and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Self motion Perception and Multisensory Integration in Older Adults written by Grace A. Gabriel and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aging is associated with changes in how our brains combine sensory information when perceiving self-motion. Despite age-related changes in sensory integration, little is known about whether multisensory self-motion perception changes in older adults (OAs). Understanding such changes is important since OAs are particularly vulnerable to errors during self-motion, which can increase their risk of injury (e.g., when walking, driving). Vestibular cues are very important for self-motion perception, yet how vestibular perception changes with older age and age-related sensory declines is understudied. Therefore, in Chapter 2, I explored whether vestibular perceptual thresholds differ between healthy OAs (i.e., no sensory/cognitive decline) and younger adults (YAs), for two different motion types (heave and pitch). Thresholds were measured using two different perceptual tasks: 1) detection task, and 2) discrimination task. Postural stability was also assessed. OAs demonstrated higher (worse) detection thresholds than YAs for both motions. Larger postural sway in OAs was also associated with higher vestibular thresholds.Age-related hearing loss (ARHL) is highly prevalent in OAs and is associated with increased falls risk. Therefore, using the same paradigm as Chapter 2, in Chapter 3 I evaluated whether higher vestibular perceptual thresholds are observed in individuals with ARHL than those with normal hearing. Here, OAs with ARHL showed higher pitch discrimination thresholds than those with normal hearing. Hearing loss in the low-frequency ranges also predicted worse pitch detection. Given that older age (Chapter 2) and ARHL (Chapter 3) were shown to predict poorer self-motion perception, in Chapter 4 I evaluated whether self-motion perception could be improved with training. Specifically, I trained OAs and YAs on a visual-vestibular heading-discrimination task. While OAs showed poorer overall precision than YAs, both groups showed improved precision post-training for the sensory condition with the lowest pre-training precision (visual-only). A sub-group of OAs who initially could not perform the visual heading task demonstrated greatly improved performance post-training. Collectively, I show that while healthy aging and common age-related sensory declines may be associated with poorer self-motion perception, training can potentially be used to improve these abilities. Together, these results may have implications for informing fall/collision prevention strategies.

Download or read book Age related Differences in Audiovisual Multisensory Integration written by Denton Jack DeLoss and published by . This book was released on 2015 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent research has demonstrated that multisensory integration, once thought to be isolated to later stages of processing in polysensory areas, may play a significant part in nearly all sensory processing. A large volume of research has also found a wide array of perceptual and cognitive changes with age. Given these sensory declines, we would also expect similar declines in multisensory integration. The present studies examined age-related changes in multisensory integration using the sound-induced flash illusion. The illusion is studied by presenting a number of visual flashes paired with a discrepant number of auditory beeps. The first experiment examined multisensory integration in younger and older individuals using the sound-induced flash illusion. Older individuals were found to have stronger multisensory integration as compared to younger individuals. The second experiment examined whether this increased integration could be due to decreased inhibitory control in older individuals, or a decrease in their ability to ignore the auditory beeps. This was examined by including an unrelated task in the visual and auditory modalities. The results of the study found that the addition of the task did influence the strength of the illusion in both older and younger individuals. However, this did not differ by age, indicating that attentional differences are not the cause of increased integration in older individuals. The third experiment examined whether the strength of the visual and auditory stimuli influences the strength of integration and whether this differs for older and younger individuals. The strength of the stimuli was found to influence the strength of the illusion, with decreased stimulus strength increasing the strength of the illusion. No age-related differences were found for the sound-induced flash illusion. However, older individuals showed a greater change in integration with decreased stimulus strength for the reverse illusion in which participants report the number of beeps presented instead of the number of flashes. Lastly, the fourth experiment examined whether spatial disparity influences the illusion and whether this changes with age. Spatial disparity between the auditory and visual flashes was not found to influence the illusion to a high degree and no age-related differences were found.

Download or read book Advances of Multisensory Integration in the Brain written by Yong Gu and published by Springer. This book was released on 2024-02-29 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest research on multisensory brain function. Namely, the mechanisms by which the brain processes and integrates information from multiple sensory modalities. Its contents cover a broad range of topics, including optimal integration, cross-modal interactions, calibration, and causal inference – with an emphasis on their neuronal underpinnings. By bringing together efforts from different laboratories around the world we aim to collaboratively shed light on these fundamental brain processes, that underlie perception, cognition, and behavior in a complex multisensory world, and to spur innovation of brain-inspired technologies

Download or read book Enhancing Performance for Action and Perception written by Andrea Michelle Green and published by Elsevier. This book was released on 2011 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume of Progess in Brain Research follows on from the 32nd International Symposium of the Groupe de recherche sur le système nerveux central (GRSNC), May 2010, and aims to provide an overview of the various neural mechanisms that contribute to learning new motor and sensory skills, and to adapting to changed circumstances including the use of devices and implants to substitute for lost sensory or motor abilities (brain machine interfaces). The focus is on recent developments covering five major themes: Mechanisms to improve motor performance Neuro-rehabilitation of motor function Mechanisms to enhance sensory perception Cross modal interationc for enhancing sensorimotor performance Assistive technologies to enhance sensorimotor performance Leading authors review the state-of-the-art in their field of investigation, and provide their views and perspectives for future research Chapters are extensively referenced to provide readers with a comprehensive list of resources on the topics covered All chapters include comprehensive background information and are written in a clear form that is also accessible to the non-specialist.

Download or read book Age dependent Mechanismus of Multisensory Integration and Crossmodal Learning written by Sophie Rohlf and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book From Green to Great Dane written by Radhika Gosavi and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A large portion of our experience combines information from multiple sensory modalities. The ability to process an abundance of information, and to identify the relevant pieces is highly dependent on mechanisms of multisensory integration (MSI) (Stein & Meredith, 1993). This dissertation focused on audiovisual (AV) MSI, in which sensory information is combined from the auditory and visual modalities to create one, coherent, multisensory percept. While simple stimuli such as flashes and beeps have formed the basis of many past experiments, more recently, studies have started advocating for the use of more naturalistic stimuli, which mimic the complexities present in the environment (Stevenson & Wallace, 2013). Studies have shown that MSI improves performance on a range of tasks from basic perceptual tasks to cognitive tasks involving learning (Newell, Mamassian, & Alais, 2010; Shams & Seitz, 2008). Although past studies have linked MSI and mnemonic processes, studies of MSI and working memory remain sparse. In a series of studies, this dissertation aimed to answer the following outstanding questions: Do multisensory stimuli provide a benefit for working memory processing? Are the auditory and visual modalities linked differently based on stimulus properties? What are the effects of crossmodal congruency on MSI and working memory? To address these questions, we tested the impact of simple and complex multisensory stimuli on working memory in adults using a change detection paradigm. We found enhancements in visual and auditory working memory when presented with multisensory stimuli. However, the attentional demands of the task, complexity of stimuli presented, crossmodal congruency, type of working memory (visual or auditory) tested, and memory load presented mediate the nature of this enhancement. The findings in this thesis make a contribution to the growing scientific literature in the domains of multisensory integration and memory, and also have implications for educational practices.

Download or read book Multisensory Integration as a Measure of Plasticity and Cognitive Ageing written by Philip Julian Sanders and published by . This book was released on 2019 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Background: Age-related declines in health result in challenges to individuals and society. Previous research has suggested a relationship between age-related sensory and cognitive decline. A possible factor mediating this relationship is declining brain plasticity with age. If this hypothesis is correct, then measuring sensory plasticity could have clinical value for diagnosing cognitive decline. Enhancing activity-dependent plasticity through multimodal stimulation may be a means of combatting sensory decline as interactions between signals from different senses produce different brain activity to unimodal signals, and multimodal stimulation can also have beneficial effects on perception, especially in the elderly. Aims: 1) Review methods of studying multisensory temporal perception and sensory-induced plasticity. 2) Investigate whether multimodal stimulation enhances plasticity effects measured with evoked potentials, relative to unimodal stimulation in the elderly. 3) Investigate links between age-related declines in plasticity, sensory processing, and cognition, non-invasively. Methods: Reviews: A scoping review on multisensory temporal processing and a descriptive review on plasticity induced using high frequency sensory stimulation (sensory tetanization) were undertaken. Pilot and Experiment 1: Sensory evoked potentials derived from the electroencephalogram were compared before and after unimodal and multimodal sensory tetanization in an elderly group and group of young adults. Experiment 2: A correlational analysis compared scores on a cognition battery with effects of visual tetanization on visual evoked potentials and training-induced improvements on an auditory-visual simultaneity judgement task in an elderly sample. Results: Descriptive review: Evidence for functional consequences of sensory tetanization is scarce, but studies with clinical populations indicate that sensory-induced plasticity paradigms may be developed into clinical tools. Individual differences in the effects of sensory tetanization provide an interesting direction for future research. Differences in results reported between research groups have emerged as the field has progressed and are yet to be resolved. Scoping review: 106 articles were reviewed covering behaviour, neuroimaging, computational models and special populations. Recent research provides support for early integration of crossmodal information. Pilot: Multimodal stimulation produced different patterns of results to unimodal stimulation in young and elderly groups. Auditory tetanization was more likely to produce potentiation of the auditory N1 component than multimodal tetanization. Visual tetanization was more likely to produce potentiation of the visual N1b in the young group, whereas multimodal tetanization was more likely to do so in the elderly group. Potentiation effects were heterogeneous between individuals and there was evidence of cross-modal contamination. Experiment 1: Visual tetanization induced a decrease in the N1 to P2 peak-to-peak measure in the elderly group and an increase in the young group. This age-difference was negated when the elderly group received multimodal tetanization, suggesting that multimodal stimulation has the potential to rescue age-related declines in visually-induced potentiation. The young group showed less potentiation after multimodal than visual tetanization. Experiment 2: The visual N1b component was potentiated post-tetanization. Training improved simultaneity judgements. Cognition correlated with improved simultaneity judgements. Tetanization effects did not correlate with the other measures. Conclusions: A benefit in the induction of plasticity with multimodal relative to unimodal tetanization was suggested for the elderly. A possible inhibitory effect of multimodal tetanization on potentiation was suggested for the young. Multimodal tetanization may have influenced potentiation effects on evoked potentials through cross-modal interactions. Results did not suggest that plasticity decline was a common factor underlying sensory and cognitive decline, instead some sensory decline may be countered through sensory training and this may have implications for improving cognition.

Download or read book Multisensory Integration and Recalibration in the Human Brain written by Máté Aller and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: To cope with the challenges posed by our dynamically changing environment we rely on a number of senses as sources of information. The information provided by different senses must be seamlessly merged into an accurate and reliable percept at any moment throughout our lives regardless of the noisyness of our environment and the constantly changing nature of our sensory systems. Our understanding of these processes has expanded exponentially in recent decades; however there is an abundance of questions yet to be answered. The present thesis addresses some of the outstanding questions regarding multisensory integration and recalibration. In Chapter 1, we give an introduction to the background of multisensory integration. In Chapter 2 we review the neural mechanisms of auditory spatial perception. In Chapter 3 we lay methodological foundations for the empirical chapters. In Chapter 4, we investigate whether multisensory integration emerges prior to perceptual awareness. In Chapter 5, we scrutinize the neural dynamics of computations related to Bayesian Causal Inference. In Chapter 6 we examine the spatio-temporal characteristics of the neural processes of multisensory adaptation. Finally, in Chapter 7 we summarise the results of the empirical chapters, discuss their contribution to the literature and outline directions of future research.

Download or read book Spatial memory a unique window into healthy and pathological ageing written by Thomas Wolbers and published by Frontiers E-books. This book was released on 2015-01-09 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: The global population aged over 60 is set to rise dramatically in the coming decades. In many countries, the older population now faces the prospect of spending a quarter of their lives aged over 65, and a significant proportion will have to cope with cognitive decline associated with normal ageing or with dementia disorders. Given that these fundamental demographic changes will pose a significant challenge to health care systems, a detailed understanding of age-related cognitive and neurobiological changes is essential in helping elderly populations maintain cognitive performance. In addition, developing sensitive biomarkers to identify those at risk of developing dementia is crucial for early and effective interventions. To make inferences about the ageing process from the animal model back to the human, rigorous behavioral paradigms must be used to ensure that the same function is being examined across species. Given that similar navigational paradigms can easily be applied to humans and animals, recent years have seen an expansion of studies attempting to bridge the gap between age-related changes in animal and human spatial cognition. These studies begin to suggest that disruptions in spatial computations are among the earliest indicators of impending cognitive decline. In addition, although many animal studies have identified pathological mechanisms with paradigms involving spatial navigation, these mechanisms support many nonspatial cognitive functions as well. As a consequence, a successful characterization of how spatial processing changes in the ageing brain could reveal fundamental effects of cognitive ageing that could inform about general mechanisms underlying decline in perception, mnemonic processing and multisensory integration.