scholarly journals Causal inference regulates audiovisual spatial recalibration via its influence on audiovisual perception

2021 ◽  
Vol 17 (11) ◽  
pp. e1008877
Author(s):  
Fangfang Hong ◽  
Stephanie Badde ◽  
Michael S. Landy
Keyword(s):  
Causal Inference ◽  
Fixed Ratio ◽  
Stimulus Presentation ◽  
Common Source ◽  
Visual Localization ◽  
Cue Reliability ◽  
Before And After ◽  
Audiovisual Perception ◽  
Audiovisual Stimuli ◽  
The Brain

To obtain a coherent perception of the world, our senses need to be in alignment. When we encounter misaligned cues from two sensory modalities, the brain must infer which cue is faulty and recalibrate the corresponding sense. We examined whether and how the brain uses cue reliability to identify the miscalibrated sense by measuring the audiovisual ventriloquism aftereffect for stimuli of varying visual reliability. To adjust for modality-specific biases, visual stimulus locations were chosen based on perceived alignment with auditory stimulus locations for each participant. During an audiovisual recalibration phase, participants were presented with bimodal stimuli with a fixed perceptual spatial discrepancy; they localized one modality, cued after stimulus presentation. Unimodal auditory and visual localization was measured before and after the audiovisual recalibration phase. We compared participants’ behavior to the predictions of three models of recalibration: (a) Reliability-based: each modality is recalibrated based on its relative reliability—less reliable cues are recalibrated more; (b) Fixed-ratio: the degree of recalibration for each modality is fixed; (c) Causal-inference: recalibration is directly determined by the discrepancy between a cue and its estimate, which in turn depends on the reliability of both cues, and inference about how likely the two cues derive from a common source. Vision was hardly recalibrated by audition. Auditory recalibration by vision changed idiosyncratically as visual reliability decreased: the extent of auditory recalibration either decreased monotonically, peaked at medium visual reliability, or increased monotonically. The latter two patterns cannot be explained by either the reliability-based or fixed-ratio models. Only the causal-inference model of recalibration captures the idiosyncratic influences of cue reliability on recalibration. We conclude that cue reliability, causal inference, and modality-specific biases guide cross-modal recalibration indirectly by determining the perception of audiovisual stimuli.

scholarly journals Causal-inference regulates audiovisual spatial recalibration via its influence on audiovisual perception

2021 ◽  
Author(s):  
Fangfang Hong ◽  
Stephanie Badde ◽  
Michael S. Landy
Keyword(s):  
Causal Inference ◽  
Fixed Ratio ◽  
Common Source ◽  
Inference Model ◽  
Cue Reliability ◽  
Before And After ◽  
Audiovisual Perception ◽  
Final Estimate ◽  
Audiovisual Stimuli ◽  
The Brain

AbstractTo obtain a coherent perception of the world, our senses need to be in alignment. When we encounter misaligned cues from two sensory modalities, the brain must infer which cue is faulty and recalibrate the corresponding sense. We examined whether and how the brain uses cue reliability to identify the miscalibrated sense by measuring the audiovisual ventriloquism aftereffect for stimuli of varying reliability. Visual spatial reliability was smaller, comparable to and greater than that of auditory stimuli. To adjust for modality-specific biases, visual stimulus locations were chosen based on perceived alignment with auditory stimulus locations for each participant. During audiovisual recalibration, participants were presented with bimodal stimuli with a fixed perceptual spatial discrepancy; they localized one modality, cued after stimulus presentation. Unimodal auditory and visual localization was measured before and after the recalibration phase. We compared participants’ behavior to the predictions of three models of recalibration: (a) Reliability-based: each modality is recalibrated based on its relative reliability—less reliable cues are recalibrated more; (b) Fixed-ratio: the degree of recalibration for each modality is fixed; (c) Causal-inference: recalibration is directly determined by the discrepancy between a cue and its final estimate, which in turn depends on the reliability of both cues, and inference about how likely the two cues derive from a common source. Vision was hardly recalibrated by audition. Auditory recalibration by vision changed idiosyncratically as visual reliability decreased: the extent of auditory recalibration either decreased monotonically, first increased and then decreased, or increased monotonically. The latter two patterns cannot be explained by either the reliability-based or fixed-ratio models. Only the causal-inference model of recalibration captures the idiosyncratic influences of cue reliability on recalibration. We conclude that cue reliability, causal inference, and modality-specific biases guide cross-modal recalibration indirectly by determining the perception of audiovisual stimuli.Author summaryAudiovisual recalibration of spatial perception occurs when we receive audiovisual stimuli with a systematic spatial discrepancy. The brain must determine to which extent both modalities should be recalibrated. In this study, we scrutinized the mechanisms the brain employs to do so. To this aim, we conducted a classical recalibration task in which participants were adapted to spatially discrepant audiovisual stimuli. The visual component of the bimodal stimulus was either less, equally, or more reliable than the auditory component. We measured the amount of recalibration by computing the difference between participants’ unimodal localization responses before and after the recalibration task. Across participants, the influence of visual reliability on auditory recalibration varied fundamentally. We compared three models of recalibration. Only a causal-inference model of recalibration captured the diverse influences of cue reliability on recalibration found in our study, and this model is able to replicate contradictory results found in previous studies. In this model, recalibration depends on the discrepancy between a cue and its final estimate. Cue reliability, perceptual biases, and the degree to which participants infer that the two cues come from a common source govern audiovisual perception and therefore audiovisual recalibration.

Different classes of audiovisual correspondences are processed at distinct levels of the cortical hierarchy

2012 ◽  
Vol 25 (0) ◽  
pp. 69
Author(s):  
Uta Noppeney ◽  
Ruth Adam ◽  
Sepideh Sadaghiani ◽  
Joost X. Maier ◽  
HweeLing Lee ◽  
...  
Keyword(s):  
Phonological Processing ◽  
Audiovisual Integration ◽  
Neural Systems ◽  
Common Source ◽  
Motion Direction ◽  
Sensory Inputs ◽  
Cortical Hierarchy ◽  
Audiovisual Stimuli ◽  
Linguistic Labels ◽  
The Brain

The brain should integrate sensory inputs only when they emanate from a common source and segregate those from different sources. Sensory correspondences are important cues informing the brain whether two sensory inputs are generated by a common event and should hence be integrated. Most prominently, sensory inputs should co-occur in time and space. More complex audiovisual stimuli may also be congruent in terms of semantics (e.g., objects and source sounds) or phonology (e.g., spoken and written words; linked via common linguistic labels). Surprisingly, metaphoric relations (e.g., pitch and height) have also been shown to influence audiovisual integration. The neural mechanisms that mediate these metaphoric congruency effects are only poorly understood. They may be mediated via (i) natural multisensory binding, (ii) common linguistic labels or (iii) semantics. In this talk, we will present a series of studies that investigate whether these different types of audiovisual correspondences are processed by distinct neural systems. Further, we investigate how those systems are employed by metaphoric audiovisual correspondences. Our results demonstrate that different classes of audiovisual correspondences influence multisensory integration at distinct levels of the cortical hierarchy. Spatiotemporal incongruency is detected already at the primary cortical level. Natural (e.g., motion direction) and phonological incongruency influences MSI in areas involved in motion or phonological processing. Critically, metaphoric interactions emerge in neural systems that are shared with natural and semantic incongruency. This activation pattern may reflect the ambivalent nature of metaphoric audiovisual interactions relying on both natural and semantic correspondences.

scholarly journals See what you hear – How the brain forms representations across the senses

Neuroforum ◽  
2018 ◽  
Vol 24 (4) ◽  
pp. A169-A181
Author(s):  
Uta Noppeney ◽  
Samuel A. Jones ◽  
Tim Rohe ◽  
Ambra Ferrari
Keyword(s):  
Causal Inference ◽  
Sensory Processing ◽  
Sensory Integration ◽  
Causal Structure ◽  
Multisensory Perception ◽  
Common Source ◽  
Behavioural Research ◽  
Parietal Cortices ◽  
The Brain ◽  
Different Sources

Abstarct Our senses are constantly bombarded with a myriad of signals. To make sense of this cacophony, the brain needs to integrate signals emanating from a common source, but segregate signals originating from the different sources. Thus, multisensory perception relies critically on inferring the world’s causal structure (i. e. one common vs. multiple independent sources). Behavioural research has shown that the brain arbitrates between sensory integration and segregation consistent with the principles of Bayesian Causal Inference. At the neural level, recent functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) studies have shown that the brain accomplishes Bayesian Causal Inference by dynamically encoding multiple perceptual estimates across the sensory processing hierarchies. Only at the top of the hierarchy in anterior parietal cortices did the brain form perceptual estimates that take into account the observer’s uncertainty about the world’s causal structure consistent with Bayesian Causal Inference.

Sensory evidence integration and action initiation occur in parallel during perceptual decisions

2020 ◽  
Author(s):  
Lluís Hernández-Navarro ◽  
Ainhoa Hermoso-Mendizabal ◽  
Daniel Duque ◽  
Alexandre Hyafil ◽  
Jaime de la Rocha
Keyword(s):  
Time Pressure ◽  
Reaction Times ◽  
Stimulus Presentation ◽  
Perceptual Decision Making ◽  
Evidence Accumulation ◽  
Action Preparation ◽  
Action Model ◽  
The Brain ◽  
Evidence Integration ◽  
Action Initiation

It is commonly assumed that, during perceptual decisions, the brain integrates stimulus evidence until reaching a decision, and then performs the response. There are conditions, however (e.g. time pressure), in which the initiation of the response must be prepared in anticipation of the stimulus presentation. It is therefore not clear when the timing and the choice of perceptual responses depend exclusively on evidence accumulation, or when preparatory motor signals may interfere with this process. Here, we find that, in a free reaction time auditory discrimination task in rats, the timing of fast responses does not depend on the stimulus, although the choices do, suggesting a decoupling of the mechanisms of action initiation and choice selection. This behavior is captured by a novel model, the Parallel Sensory Integration and Action Model (PSIAM), in which response execution is triggered whenever one of two processes, Action Initiation or Evidence Accumulation, reaches a bound, while choice category is always set by the latter. Based on this separation, the model accurately predicts the distribution of reaction times when the stimulus is omitted, advanced or delayed. Furthermore, we show that changes in Action Initiation mediates both post-error slowing and a gradual slowing of the responses within each session. Overall, these results extend the standard models of perceptual decision-making, and shed a new light on the interaction between action preparation and evidence accumulation.

PENGARUH PIJAT BAYI TERHADAP KUALITAS TIDUR BAYI UMUR 0 – 3 BULAN DI WILAYAH KERJA PUSKESMAS SOSIAL PALEMBANG TAHUN 2016

2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Juliana Widyastuti Wahyuningsih Juliana Widyastuti Wahyuningsih
Keyword(s):  
Experimental Design ◽  
Growth And Development ◽  
Sampling Technique ◽  
P Value ◽  
Development Phase ◽  
Quality Of Sleep ◽  
Infant Massage ◽  
Before And After ◽  
The Brain

ABSTRAK Tidur merupakan kebutuhan yang harus terpenuhi terutama pada fase perkembangan karena selama tidur akan terjadi perkembangan otak maupun tubuh, sehingga gangguan tidur merupakan masalah yang akan menimbulkan dampak buruk terhadap pertumbuhan dan perkembangan bayi. Kualitas tidur bayi yang baik dapat diciptakan dengan memberikan pemijatan bayi secara rutin. Penelitian ini bertujuan untuk membuktikan bahwa pemijatan dapat mempengaruhi kualitas tidur bayi umur 0-3 bulan. Penelitian ini menggunakan desain penelitian Quasy Eksperimental dengan metode One Group Pretest-Postest. Sampel 22 bayi yang dipilih dengan tehnik Total Sampling yang di observasi sebelum dan sesudah diberikan pemijatan. Variabel yang diukur dalam penelitian ini adalah kualitas tidur bayi 0-3 bulan. Hasil penelitian menunjukkan bahwa ada pengaruh pijat bayi terhadap kualitas tidur bayi umur 0-3 bulan (p value  0,008 < α = 0,05).Berdasarkan hasil penelitian ini disarankan agar keluarga dan masyarakat memberikan pemijatan secara rutin dan mandiri untuk meningkatkan kebutuhan tidur bayi yang berkualitas.   ABSTRACT Sleep is a human necessity that must be met, especially in the development phase because during sleep will occur the brain and body developments, so that sleep disturbance is a problem that would cause adverse effects on infants’ growth and development. The good quality of sleep can be created by providing the infants massage routinely. This study aimed to prove that the massage could affect the quality of sleep on the 0-3 months old baby. This study used Quasy-experimental design with One Group Pretest-Posttest. The sample 22 infants selected by total sampling technique observed on before and after the massage. The variables measured in this study are the quality of sleep. The results of study indicate that there is an effect of infant massage to the sleep quality on 0-3 months old babies (p value 0,008 < α = 0,05).Based on the results of this study it recommended for the families and communities to provide infant massage regularly and independently to increase the quality of sleep on the baby.  

Sources of the Scalp-Recorded Amplitude-Modulation Following Response

2002 ◽  
Vol 13 (04) ◽  
pp. 188-204 ◽  
Author(s):  
Shigeyuki Kuwada ◽  
Julia S. Anderson ◽  
Ranjan Batra ◽  
Douglas C. Fitzpatrick ◽  
Natacha Teissier ◽  
...  
Keyword(s):  
Animal Model ◽  
Amplitude Modulation ◽  
Single Unit ◽  
Modulation Frequency ◽  
Multiple Sources ◽  
High Modulation ◽  
Before And After ◽  
Single Unit Recordings ◽  
Composite Response ◽  
The Brain

The scalp-recorded amplitude-modulation following response (AMFR)” is gaining recognition as an objective audiometric tool, but little is known about the neural sources that underlie this potential. We hypothesized, based on our human studies and single-unit recordings in animals, that the scalp-recorded AMFR reflects the interaction of multiple sources. We tested this hypothesis using an animal model, the unanesthetized rabbit. We compared AMFRs recorded from the surface of the brain at different locations and before and after the administration of agents likely to enhance or suppress neural generators. We also recorded AMFRs locally at several stations along the auditory neuraxis. We conclude that the surface-recorded AMFR is indeed a composite response from multiple brain generators. Although the response at any modulation frequency can reflect the activity of more than one generator, the AMFRs to low and high modulation frequencies appear to reflect a strong contribution from cortical and subcortical sources, respectively.

scholarly journals Using Brain-Breaks® as a Technology Tool to Increase Attitude towards Physical Activity among Students in Singapore

2021 ◽  
Vol 11 (6) ◽  
pp. 784
Author(s):  
Govindasamy Balasekaran ◽  
Ahmad Arif Bin Ibrahim ◽  
Ng Yew Cheo ◽  
Phua Kia Wang ◽  
Garry Kuan ◽  
...  
Keyword(s):  
Physical Activity ◽  
Mixed Model ◽  
School Curriculum ◽  
Control Group ◽  
School Students ◽  
Mixed Model Analysis ◽  
Before And After ◽  
Brain Breaks ◽  
Student's Attitudes ◽  
The Brain

The purpose of this study was to investigate the effects of classroom-based Brain Breaks® Physical Activity Solution in Southeast Asia Singaporean primary school students and their attitude towards physical activity (PA) over a ten-week intervention. A total of 113 participants (8–11 years old) were randomly assigned to either an experimental (EG) or a control group (CG), with six classes to each group; the Brain Breaks® group (EG: six classes) and the Control group (CG: six classes). All EG members participated in a Brain Breaks® video intervention (three–five min) during academic classes and the CG continued their lessons as per normal. The student’s attitudes towards PA in both research conditions were evaluated using the self–reported Attitudes toward Physical Activity Scale (APAS), applied before and after intervention. The effects of the intervention on APAS scores were analysed using a mixed model analysis of variance with Time as within-subject and Group as between-subject factors. The analysis revealed evidence in support of the positive effect of classroom video interventions such as Brain Breaks® on student’s attitudes toward benefits, importance, learning, self-efficacy, fun, fitness, and trying to do their personal best in PA. The Brain Breaks® intervention provided a positive significant impact on students in Singapore. This study also revealed that interactive technology tools implemented into the school curriculum benefit students in terms of health and education.

scholarly journals Alpha EEG Frontal Asymmetries during Audiovisual Perception in Cochlear Implant Users

2015 ◽  
Vol 54 (06) ◽  
pp. 500-504 ◽  
Author(s):  
A. G. Maglione ◽  
A. Scorpecci ◽  
P. Malerba ◽  
P. Marsella ◽  
S. Giannantonio ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Alpha Rhythm ◽  
Normal Hearing ◽  
Experimental Conditions ◽  
Audiovisual Perception ◽  
Audiovisual Stimuli ◽  
The Difference ◽  
Eeg Alpha ◽  
The One ◽  
Hearing Children

SummaryObjectives: The aim of the present study is to investigate the variations of the electroencephalographic (EEG) alpha rhythm in order to measure the appreciation of bilateral and unilateral young cochlear implant users during the observation of a musical cartoon. The cartoon has been modified for the generation of three experimental conditions: one with the original audio, another one with a distorted sound and, finally, a mute version.Methods: The EEG data have been recorded during the observation of the cartoons in the three experimental conditions. The frontal alpha EEG imbalance has been calculated as a measure of motivation and pleasantness to be compared across experimental populations and conditions.Results: The EEG frontal imbalance of the alpha rhythm showed significant variations during the perception of the different cartoons. In particular, the pattern of activation of normal-hearing children is very similar to the one elicited by the bilateral implanted patients. On the other hand, results related to the unilateral subjects do not present significant variations of the imbalance index across the three cartoons.Conclusion: The presented results suggest that the unilateral patients could not appreciate the difference in the audio format as well as bilaterally implanted and normal hearing subjects. The frontal alpha EEG imbalance is a useful tool to detect the differences in the appreciation of audiovisual stimuli in cochlear implant patients.

Intraventricular injection of antibodies to β1-integrins generates pressure gradients in the brain favoring hydrocephalus development in rats

2009 ◽  
Vol 297 (5) ◽  
pp. R1312-R1321 ◽  
Author(s):  
Gurjit Nagra ◽  
Lena Koh ◽  
Isabelle Aubert ◽  
Minhui Kim ◽  
Miles Johnston
Keyword(s):  
Fluid Pressure ◽  
Active Role ◽  
Intraventricular Injection ◽  
Pressure Gradients ◽  
Tissue Pressure ◽  
Before And After ◽  
The Matrix ◽  
System 2 ◽  
Periventricular Area ◽  
The Brain

In some tissues, the injection of antibodies to the β1-integrins leads to a reduction in interstitial fluid pressure, indicating an active role for the extracellular matrix in tissue pressure regulation. If perturbations of the matrix occur in the periventricular area of the brain, a comparable lowering of interstitial pressures may induce transparenchymal pressure gradients favoring ventricular expansion. To examine this concept, we measured periventricular (parenchymal) and ventricular pressures with a servo-null micropipette system (2-μm tip) in adult Wistar rats before and after anti-integrin antibodies or IgG/IgM isotype controls were injected into a lateral ventricle. In a second group, the animals were kept for 2 wk after similar injections and after euthanization, the brains were removed and assessed for hydrocephalus. In experiments in which antibodies to β1-integrins ( n = 10) but not isotype control IgG/IgM ( n = 7) were injected, we observed a decline in periventricular pressures relative to the preinjection values. Under similar circumstances, ventricular pressures were elevated ( n = 10) and were significantly greater than those in the periventricular interstitium. We estimated ventricular to periventricular pressure gradients of up to 4.3 cmH2O. In the chronic preparations, we observed enlarged ventricles in many of the animals that received injections of anti-integrin antibodies (21 of 29 animals; 72%) but not in any animal receiving the isotype controls. We conclude that modulation/disruption of β1-integrin-matrix interactions in the brain generates pressure gradients favoring ventricular expansion, suggesting a novel mechanism for hydrocephalus development.

Study of electrical conductivity of biologically active points on the skin before and after mental activity

Vestnik ◽  
2021 ◽  
pp. 190-195
Author(s):  
М.С. Кулбаева ◽  
А.Н. Курал ◽  
Л.Б. Умбетьярова ◽  
Н.Т. Аблайханова ◽  
Г.К. Атанбаева ◽  
...  
Keyword(s):  
Physiological State ◽  
Mental Activity ◽  
The Body ◽  
Biologically Active ◽  
Mental Work ◽  
Heart Meridian ◽  
Before And After ◽  
Specific Organ ◽  
The Brain ◽  
Biologically Active Points

Человека давно интересует вопрос о том, как умственная нагрузка влияет на организм. Известно, что при длительной умственной работе преобразуется сила процессов возбуждения и торможения, изменяется соотношение между ними. С возникновением утомления в головном мозгу нарушаются взаимосвязи между корой больших полушарий и подкорковыми образованиями. При этом наблюдается снижение регулирующего влияния больших полушарий на все функции организма и уменьшение активизирующих воздействий подкорковых отделов мозга. Кроме того, длительное сидячие положение, состояние низкой двигательной активности ведут к значительному уменьшению центростремительных импульсов с рецепторов мышц, сухожилий, суставов. В исследовании приняли участие 17 относительно здоровые, имеющие стабильное физиологическое состояние девушек-студенток в возрасте от 21 до 25 лет. Для исследования были взяты 16 биологически активных точек на стандартных меридианах, связаных с определенным органом. Для оценки физиологического состояния органов до и после умственной нагрузки были исследованы показатели ЭП БАТ на коже. Выявлено снижение показателей каждого органа после умственной нагрузки по сравнению с показателями до ее выполнения со статистической достоверностью во всех исследуемых органах (р<0,05). Особенно низкие значения показателей ЭП БАТ после умственной нагрузки были выявлены в биоактивных точках меридиана печени F.3 Тай-Чун, меридиана толстой кишки GI.5 Ян-Си и GI.4 Хэ-Гу, меридиана сердца С.7 Шэнь-Мэнь, меридиана тонкой кишки IG.1 Шао-Цзе и IG.2 Цянь-Гу, меридиана почек R.1 Юн-Цюань и Р.2 Жань-Гу. Humans has long been interested in the question of how mental activity affects the body It is known that with prolonged mental work, the strength of the processes of excitation and inhibition is transformed, the ratio between them changes. With the onset of fatigue in the brain, the relationship between the cerebral cortex and subcortical formations is disrupted. At the same time, there is a decrease in the regulatory influence of the large hemispheres on all body functions and a decrease in the activating effects of the subcortical parts of the brain. In addition, prolonged sitting, a state of low motor activity leads to a significant decrease in centripetal impulses from the receptors of muscles, tendons, and joints. The study involved 17 relatively healthy, stable physiological condition of female students aged 21 to 25 years. For the study, 16 biologically active points were taken from standard meridians associated with a specific organ. To assess the physiological state of the organs before and after the load of mental labor, the indicators of EC BAP on the skin. A decrease in the indicators of each organ after mental labor was revealed in comparison with the indicators before mental labor with statistical reliability in all the studied organs (p˂0.05). Especially low values of the EC BAP values after a load of mental labor were found in the bioactive points of the liver meridian F. 3 Tai-Chun, the colon meridian GI.5 Yang-Si and GI. 4 He-Gu, the heart meridian C. 7 Shen-Men, the small intestine meridian IG.1 Shao-tse and IG.2 Qian-Gu, the meridian of the kidneys R. 1 Yun-Chuan and R. 2 Zhan-Gu.

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