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Fulltext Measuring the performance of visual to auditory information conversion

Tan SS, Maul TH, Mennie NR

PLoS One, 2013;8(5):e63042.
PMID: 23696791 DOI: 10.1371/journal.pone.0063042

Visual to auditory conversion systems have been in existence for several decades. Besides being among the front runners in providing visual capabilities to blind users, the auditory cues generated from image sonification systems are still easier to learn and adapt to compared to other similar techniques. Other advantages include low cost, easy customizability, and universality. However, every system developed so far has its own set of strengths and weaknesses. In order to improve these systems further, we propose an automated and quantitative method to measure the performance of such systems. With these quantitative measurements, it is possible to gauge the relative strengths and weaknesses of different systems and rank the systems accordingly.

Matched MeSH terms: Visual Perception/physiology*
Fulltext Eating with our eyes: From visual hunger to digital satiation

Spence C, Okajima K, Cheok AD, Petit O, Michel C

Brain Cogn, 2016 12;110:53-63.
PMID: 26432045 DOI: 10.1016/j.bandc.2015.08.006

One of the brain's key roles is to facilitate foraging and feeding. It is presumably no coincidence, then, that the mouth is situated close to the brain in most animal species. However, the environments in which our brains evolved were far less plentiful in terms of the availability of food resources (i.e., nutriments) than is the case for those of us living in the Western world today. The growing obesity crisis is but one of the signs that humankind is not doing such a great job in terms of optimizing the contemporary food landscape. While the blame here is often put at the doors of the global food companies - offering addictive foods, designed to hit 'the bliss point' in terms of the pleasurable ingredients (sugar, salt, fat, etc.), and the ease of access to calorie-rich foods - we wonder whether there aren't other implicit cues in our environments that might be triggering hunger more often than is perhaps good for us. Here, we take a closer look at the potential role of vision; Specifically, we question the impact that our increasing exposure to images of desirable foods (what is often labelled 'food porn', or 'gastroporn') via digital interfaces might be having, and ask whether it might not inadvertently be exacerbating our desire for food (what we call 'visual hunger'). We review the growing body of cognitive neuroscience research demonstrating the profound effect that viewing such images can have on neural activity, physiological and psychological responses, and visual attention, especially in the 'hungry' brain.

Matched MeSH terms: Visual Perception/physiology*
Fulltext Changing hands: persistent alterations to body image following brief exposure to multisensory distortions

Perera AT, Newport R, McKenzie KJ

Exp Brain Res, 2017 06;235(6):1809-1821.
PMID: 28293693 DOI: 10.1007/s00221-017-4935-2

The dynamic flexibility of body representation has been highlighted through numerous lines of research that range from clinical studies reporting disorders of body ownership, to experimentally induced somatic illusions that have provided evidence for the embodiment of manipulated representations and even fake limbs. While most studies have reported that enlargement of body parts alters somatic perception, and that these can be more readily embodied, shrunken body parts have not been found to consistently alter somatic experiences, perhaps due to reduced feelings of ownership over smaller body parts. Over two experiments, we aimed to investigate the mechanisms responsible for altered somatic representations following exposure to both enlarged and shrunken body parts. Participants were given the impression that their hand and index finger were either longer or shorter than veridical length and asked to judge veridical finger length using online and offline size estimation tasks, as well as to report the degree of ownership towards the distorted finger and hand representations. Ownership was claimed over all distorted representations of the hand and finger and no differences were seen across ownership ratings, while the online and offline measurements of perceived size demonstrated differing response patterns. These findings suggest that ownership towards manipulated body representations is more bidirectional than previously thought and also suggest differences in perceived body representation with respect to the method of measurement suggesting that online and offline tasks may tap into different aspects of body representation.

Matched MeSH terms: Visual Perception/physiology*
Study of target and non-target interplay in spatial attention task

Sweeti, Joshi D, Panigrahi BK, Anand S, Santhosh J

J Med Eng Technol, 2018 Feb;42(2):113-120.
PMID: 29448856 DOI: 10.1080/03091902.2018.1433244

Selective visual attention is the ability to selectively pay attention to the targets while inhibiting the distractors. This paper aims to study the targets and non-targets interplay in spatial attention task while subject attends to the target object present in one visual hemifield and ignores the distractor present in another visual hemifield. This paper performs the averaged evoked response potential (ERP) analysis and time-frequency analysis. ERP analysis agrees to the left hemisphere superiority over late potentials for the targets present in right visual hemifield. Time-frequency analysis performed suggests two parameters i.e. event-related spectral perturbation (ERSP) and inter-trial coherence (ITC). These parameters show the same properties for the target present in either of the visual hemifields but show the difference while comparing the activity corresponding to the targets and non-targets. In this way, this study helps to visualise the difference between targets present in the left and right visual hemifields and, also the targets and non-targets present in the left and right visual hemifields. These results could be utilised to monitor subjects' performance in brain-computer interface (BCI) and neurorehabilitation.

Matched MeSH terms: Visual Perception/physiology
Effects of action observation on corticospinal excitability: Muscle specificity, direction, and timing of the mirror response

Naish KR, Houston-Price C, Bremner AJ, Holmes NP

Neuropsychologia, 2014 11;64:331-48.
PMID: 25281883 DOI: 10.1016/j.neuropsychologia.2014.09.034

Many human behaviours and pathologies have been attributed to the putative mirror neuron system, a neural system that is active during both the observation and execution of actions. While there are now a very large number of papers on the mirror neuron system, variations in the methods and analyses employed by researchers mean that the basic characteristics of the mirror response are not clear. This review focuses on three important aspects of the mirror response, as measured by modulations in corticospinal excitability: (1) muscle specificity; (2) direction; and (3) timing of modulation. We focus mainly on electromyographic (EMG) data gathered following single-pulse transcranial magnetic stimulation (TMS), because this method provides precise information regarding these three aspects of the response. Data from paired-pulse TMS paradigms and peripheral nerve stimulation (PNS) are also considered when we discuss the possible mechanisms underlying the mirror response. In this systematic review of the literature, we examine the findings of 85 TMS and PNS studies of the human mirror response, and consider the limitations and advantages of the different methodological approaches these have adopted in relation to discrepancies between their findings. We conclude by proposing a testable model of how action observation modulates corticospinal excitability in humans. Specifically, we propose that action observation elicits an early, non-specific facilitation of corticospinal excitability (at around 90ms from action onset), followed by a later modulation of activity specific to the muscles involved in the observed action (from around 200ms). Testing this model will greatly advance our understanding of the mirror mechanism and provide a more stable grounding on which to base inferences about its role in human behaviour.

Matched MeSH terms: Visual Perception/physiology*
Visual-perceptual-kinesthetic inputs on influencing writing performances in children with handwriting difficulties

Tse LF, Thanapalan KC, Chan CC

Res Dev Disabil, 2014 Feb;35(2):340-7.
PMID: 24333804 DOI: 10.1016/j.ridd.2013.11.013

This study investigated the role of visual-perceptual input in writing Chinese characters among senior school-aged children who had handwriting difficulties (CHD). The participants were 27 CHD (9-11 years old) and 61 normally developed control. There were three writing conditions: copying, and dictations with or without visual feedback. The motor-free subtests of the Developmental Test of Visual Perception (DTVP-2) were conducted. The CHD group showed significantly slower mean speeds of character production and less legibility of produced characters than the control group in all writing conditions (ps<0.001). There were significant deteriorations in legibility from copying to dictation without visual feedback. Nevertheless, the Group by Condition interaction effect was not statistically significant. Only position in space of DTVP-2 was significantly correlated with the legibility among CHD (r=-0.62, p=0.001). Poor legibility seems to be related to the less-intact spatial representation of the characters in working memory, which can be rectified by viewing the characters during writing. Visual feedback regarding one's own actions in writing can also improve legibility of characters among these children.

Matched MeSH terms: Visual Perception/physiology*
Fulltext Can people guess what happened to others from their reactions?

Pillai D, Sheppard E, Mitchell P

PLoS One, 2012;7(11):e49859.
PMID: 23226227 DOI: 10.1371/journal.pone.0049859

Are we able to infer what happened to a person from a brief sample of his/her behaviour? It has been proposed that mentalising skills can be used to retrodict as well as predict behaviour, that is, to determine what mental states of a target have already occurred. The current study aimed to develop a paradigm to explore these processes, which takes into account the intricacies of real-life situations in which reasoning about mental states, as embodied in behaviour, may be utilised. A novel task was devised which involved observing subtle and naturalistic reactions of others in order to determine the event that had previously taken place. Thirty-five participants viewed videos of real individuals reacting to the researcher behaving in one of four possible ways, and were asked to judge which of the four 'scenarios' they thought the individual was responding to. Their eye movements were recorded to establish the visual strategies used. Participants were able to deduce successfully from a small sample of behaviour which scenario had previously occurred. Surprisingly, looking at the eye region was associated with poorer identification of the scenarios, and eye movement strategy varied depending on the event experienced by the person in the video. This suggests people flexibly deploy their attention using a retrodictive mindreading process to infer events.

Matched MeSH terms: Visual Perception/physiology*
Fulltext A preliminary study of mirror-induced self-directed behaviour on wildlife at the Royal Belum Rainforest Malaysia

Hamdan A, Ab Latip MQ, Abu Hassim H, Mohd Noor MH, Tengku Azizan TRP, Mohamed Mustapha N, et al.

Sci Rep, 2020 08 24;10(1):14105.
PMID: 32839483 DOI: 10.1038/s41598-020-71047-1

Mirror-induced behaviour has been described as a cognitive ability of an animal to self-direct their image in front of the mirror. Most animals when exposed to a mirror responded with a social interactive behaviour such as aggressiveness, exploratory and repetitive behaviour. The objective of this study is to determine the mirror-induced self-directed behaviour on wildlife at the Royal Belum Rainforest, Malaysia. Wildlife species at the Royal Belum Rainforest were identified using a camera traps from pre-determined natural saltlick locations. Acrylic mirrors with steel frame were placed facing the two saltlicks (Sira Batu and Sira Tanah) and the camera traps with motion-detecting infrared sensor were placed at strategically hidden spot. The behavioural data of the animal response to the mirror were analysed using an ethogram procedure. Results showed that barking deer was the species showing the highest interaction in front of the mirror. Elephants displayed self-directed response through inspecting behaviour via usage of their trunk and legs while interacting to the mirror. Interestingly, the Malayan tapir showed startled behaviour during their interaction with the mirror. However, the absence of interactive behaviour of the Malayan tiger signalled a likelihood of a decreased social response behaviour. These results suggested that the ability to self-directed in front of the mirror is most likely related to the new approach to study the neural mechanism and its level of stimulus response in wildlife. In conclusion, research on mirror-induced self-directed behaviour in wildlife will have profound implications in understanding the cognitive ability of wildlife as an effort to enhance the management strategies and conservation.

Matched MeSH terms: Visual Perception/physiology
Fulltext Association between reduced visual-motor integration performance and socioeconomic factors among preschool children in Malaysia: A cross-sectional study

Hairol MI, Nordin N, P'ng J, Sharanjeet-Kaur S, Narayanasamy S, Mohd-Ali M, et al.

PLoS One, 2021;16(3):e0246846.
PMID: 33657109 DOI: 10.1371/journal.pone.0246846

Visual-motor integration (VMI) is related to children's academic performance and school readiness. VMI scores measured using the Beery-Bucktenicka Developmental Test of Visual-Motor Integration (Beery-VMI) can differ due to differences in cultural and socioeconomic backgrounds. This study compared the VMI scores of Malaysian preschoolers with the corresponding US norms and determined the association between their VMI scores and socioeconomic factors. A cross-sectional study was conducted among 435 preschoolers (mean age: 5.95±0.47 years; age range: 5.08-6.83 years) from randomly selected public and private preschools. VMI scores were measured using Beery-VMI in the preschools' classrooms. Information on the socioeconomic characteristics of the preschoolers was obtained using a parent-report questionnaire. One sample t-test was used to compare their VMI scores with the corresponding US norms. Multivariate logistic regression models were used to explore the influence of socioeconomic factors on the preschoolers' VMI scores. Overall, Malaysian preschoolers' VMI performance was similar to the US standardized norms (p>0.05). Children from low-income families were twice likely to obtain lower than average VMI scores than those from higher-income families (OR = 2.47, 95%CI 1.05, 5.86). Children enrolled at public preschools were more likely to obtain a lower than average VMI score than those who enrolled at private preschools (OR = 2.60, 95%CI 1.12, 6.06). Children who started preschool at the age of six were more likely to obtain lower than average VMI scores than those who started at an earlier age (OR = 4.66, 95%CI 1.97, 11.04). Low maternal education level was also associated with lower than average VMI score (OR = 2.60, 95%CI 1.12, 6.06). Malaysian preschoolers' Beery-VMI performance compared well to their US counterparts. Some socioeconomic factors were associated with reduced VMI scores. Those from disadvantaged socioeconomic backgrounds are more likely to have reduced VMI performance, potentially adversely affecting their school readiness, cognitive performance, and future academic achievements.

Matched MeSH terms: Visual Perception/physiology*
A fuzzy integral method based on the ensemble of neural networks to analyze fMRI data for cognitive state classification across multiple subjects

Cacha LA, Parida S, Dehuri S, Cho SB, Poznanski RR

J Integr Neurosci, 2016 Dec;15(4):593-606.
PMID: 28093025 DOI: 10.1142/S0219635216500345

The huge number of voxels in fMRI over time poses a major challenge to for effective analysis. Fast, accurate, and reliable classifiers are required for estimating the decoding accuracy of brain activities. Although machine-learning classifiers seem promising, individual classifiers have their own limitations. To address this limitation, the present paper proposes a method based on the ensemble of neural networks to analyze fMRI data for cognitive state classification for application across multiple subjects. Similarly, the fuzzy integral (FI) approach has been employed as an efficient tool for combining different classifiers. The FI approach led to the development of a classifiers ensemble technique that performs better than any of the single classifier by reducing the misclassification, the bias, and the variance. The proposed method successfully classified the different cognitive states for multiple subjects with high accuracy of classification. Comparison of the performance improvement, while applying ensemble neural networks method, vs. that of the individual neural network strongly points toward the usefulness of the proposed method.

Matched MeSH terms: Visual Perception/physiology
Fulltext Divergent Solutions to Visual Problem Solving across Mammalian Species

Mustafar F, Harvey MA, Khani A, Arató J, Rainer G

eNeuro, 2018 07 11;5(4).
PMID: 30073190 DOI: 10.1523/ENEURO.0167-18.2018

Our understanding of the neurobiological underpinnings of learning and behavior relies on the use of invasive techniques, which necessitate the use of animal models. However, when different species learn the same task, to what degree are they actually producing the same behavior and engaging homologous neural circuitry? This question has received virtually no recent attention, even as the most powerful new methodologies for measuring and perturbing the nervous system have become increasingly dependent on the use of murine species. Here, we test humans, rats, monkeys, and an evolutionarily intermediate species, tree shrews, on a three alternative, forced choice, visual contrast discrimination task. As anticipated, learning rate, peak performance, and transfer across contrasts was lower in the rat compared to the other species. More interestingly, rats exhibited two major behavioral peculiarities: while monkeys and tree shrews based their choices largely on visual information, rats tended to base their choices on past reward history. Furthermore, as the task became more difficult, rats largely disengaged from the visual stimulus, reverting to innate spatial predispositions in order to collect rewards near chance probability. Our findings highlight the limitation of muridae as models for translational research, at least in the area of visually based decision making.

Matched MeSH terms: Visual Perception/physiology*
The influences of age, gender and geometric pattern of visual image on the verticality perception: A subjective visual vertical (SVV) study among Malaysian adults

Zakaria MN, Salim R, Tahir A, Zainun Z, Mohd Sakeri NS

Clin Otolaryngol, 2019 03;44(2):166-171.
PMID: 30411501 DOI: 10.1111/coa.13255

OBJECTIVES: Subjective visual vertical (SVV) is a simple, quick and reliable test for measuring utricular function. The literature on the effects of fundamental demographic variables such as age and gender on SVV is inconclusive and should be supported by research with larger samples. The aim of the present study was to determine the influences of age, gender and geometric pattern of visual image on SVV among healthy adults.
STUDY DESIGN: This study employed a repeated measures design.
SETTINGS: Otorhinolaryngology Clinic, Hospital Universiti Sains Malaysia, Malaysia.
PARTICIPANTS: Eligible Malaysian adults (N = 187, aged 21-75 years) were recruited and categorised into young (N = 60), middle-aged (N = 66) and older (N = 61) groups. Most of them were Malay, and 51.3% were men.
MAIN OUTCOME MEASURES: Subjective visual vertical angles (in degrees) were determined from each participant in a static upright condition using a computerised SVV device. They were asked to indicate their verticality perception for three types of visual images (solid line, dotted line and arrow pattern).
RESULTS: Three-way mixed ANOVA revealed insignificant influences of age and gender on SVV results (P > 0.05). In contrast, mean SVV angles were significantly higher for the arrow pattern than for other visual images (P = 0.004).
CONCLUSION: While the insignificant influences of age and gender on static SVV are further ascertained with larger samples, the perception of verticality is less accurate when aligning a more geometrically complex visual image (ie, arrow pattern). Further SVV research on vestibular-disordered patients is beneficial, particularly to verify the normative data obtained with this complex visual image.

Matched MeSH terms: Visual Perception/physiology*
Illusions With Hands, but Not With Balloons - Comparing Ownership and Referral of Touch for a Corporal and Noncorporal Object After Visuotactile Stimulation

Kalckert A, Bico I, Fong JX

Perception, 2019 May;48(5):447-455.
PMID: 30939992 DOI: 10.1177/0301006619839286

The rubber hand illusion is a perceptual illusion of perceiving an object like a model hand as part of the own body. The question whether the illusion can be induced with noncorporal objects that do not look like a human body part is not perfectly resolved yet. In this study, we directly assessed the subjective experience of two different components within the illusion (i.e., ownership and referral of touch) when a model hand and a balloon are stimulated. We observed significantly stronger illusion ratings for the hand as compared with the balloon, and only the hand ratings showed a clear affirmation of the illusion. We further conclude that (a) a significant difference between synchronous and asynchronous conditions may not be sufficient to argue for the successful induction of the illusion and (b) the subcomponents show a different pattern in the different conditions, which may lead to alternative interpretations. These observations call for a more fine-grained interpretation of questionnaire data in rubber hand illusion studies.

Matched MeSH terms: Visual Perception/physiology*
The influence of type of visual image and gender on the perception of horizontality: a subjective visual horizontal (SVH) study

Zakaria MN, Tahir A, Zainun Z, Salim R, Mohd Sakeri NS, Abdul Wahat NH

Acta Otolaryngol, 2021 Jan;141(1):62-65.
PMID: 32957810 DOI: 10.1080/00016489.2020.1817552

BACKGROUND: The graviceptive otolith function can be measured using subjective visual horizontal (SVH) testing. Nevertheless, more research efforts are required to understand the essential variables affecting SVH.
OBJECTIVE: The aim of the present study was to determine the effects of type of visual image and gender on subjective visual horizontal (SVH) perception among healthy adults.
MATERIALS AND METHODS: In this comparative study, 50 healthy young adults were enrolled. While in an upright body position, they were required to report their perception of horizontality for two types of visual images (solid line and arrow pattern) using a computerized SVH device.
RESULTS: The arrow pattern produced significantly bigger SVH angles than the solid line (p < .001). In contrast, no significant influence of gender was found on SVH results (p = .743), Based on the statistical outcomes, the preliminary normative data for SVH were established.
CONCLUSIONS AND SIGNIFICANCE: The arrow pattern (a more complex visual image) produced bigger SVH deviations than the simple solid line image. In contrast, the horizontality perception does not appear to be affected by gender. The preliminary normative SVH data gathered from the present study can be beneficial for clinical and future research applications.

Matched MeSH terms: Visual Perception/physiology*
Effects of modality and repetition in a continuous recognition memory task: Repetition has no effect on auditory recognition memory

Amir Kassim A, Rehman R, Price JM

Acta Psychol (Amst), 2018 Apr;185:72-80.
PMID: 29407247 DOI: 10.1016/j.actpsy.2018.01.012

Previous research has shown that auditory recognition memory is poorer compared to visual and cross-modal (visual and auditory) recognition memory. The effect of repetition on memory has been robust in showing improved performance. It is not clear, however, how auditory recognition memory compares to visual and cross-modal recognition memory following repetition. Participants performed a recognition memory task, making old/new discriminations to new stimuli, stimuli repeated for the first time after 4-7 intervening items (R1), or repeated for the second time after 36-39 intervening items (R2). Depending on the condition, participants were either exposed to visual stimuli (2D line drawings), auditory stimuli (spoken words), or cross-modal stimuli (pairs of images and associated spoken words). Results showed that unlike participants in the visual and cross-modal conditions, participants in the auditory recognition did not show improvements in performance on R2 trials compared to R1 trials. These findings have implications for pedagogical techniques in education, as well as for interventions and exercises aimed at boosting memory performance.

Matched MeSH terms: Visual Perception/physiology*
Fulltext In search of a reliable electrophysiological marker of oculomotor inhibition of return

Satel J, Hilchey MD, Wang Z, Reiss CS, Klein RM

Psychophysiology, 2014 Oct;51(10):1037-45.
PMID: 24976355 DOI: 10.1111/psyp.12245

Inhibition of return (IOR) operationalizes a behavioral phenomenon characterized by slower responding to cued, relative to uncued, targets. Two independent forms of IOR have been theorized: input-based IOR occurs when the oculomotor system is quiescent, while output-based IOR occurs when the oculomotor system is engaged. EEG studies forbidding eye movements have demonstrated that reductions of target-elicited P1 components are correlated with IOR magnitude, but when eye movements occur, P1 effects bear no relationship to behavior. We expand on this work by adapting the cueing paradigm and recording event-related potentials: IOR is caused by oculomotor responses to central arrows or peripheral onsets and measured by key presses to peripheral targets. Behavioral IOR is observed in both conditions, but P1 reductions are absent in the central arrow condition. By contrast, arrow and peripheral cues enhance Nd, especially over contralateral electrode sites.

Matched MeSH terms: Visual Perception/physiology*
Fulltext Differential coding of perception in the world's languages

Majid A, Roberts SG, Cilissen L, Emmorey K, Nicodemus B, O'Grady L, et al.

Proc Natl Acad Sci U S A, 2018 Nov 06;115(45):11369-11376.
PMID: 30397135 DOI: 10.1073/pnas.1720419115

Is there a universal hierarchy of the senses, such that some senses (e.g., vision) are more accessible to consciousness and linguistic description than others (e.g., smell)? The long-standing presumption in Western thought has been that vision and audition are more objective than the other senses, serving as the basis of knowledge and understanding, whereas touch, taste, and smell are crude and of little value. This predicts that humans ought to be better at communicating about sight and hearing than the other senses, and decades of work based on English and related languages certainly suggests this is true. However, how well does this reflect the diversity of languages and communities worldwide? To test whether there is a universal hierarchy of the senses, stimuli from the five basic senses were used to elicit descriptions in 20 diverse languages, including 3 unrelated sign languages. We found that languages differ fundamentally in which sensory domains they linguistically code systematically, and how they do so. The tendency for better coding in some domains can be explained in part by cultural preoccupations. Although languages seem free to elaborate specific sensory domains, some general tendencies emerge: for example, with some exceptions, smell is poorly coded. The surprise is that, despite the gradual phylogenetic accumulation of the senses, and the imbalances in the neural tissue dedicated to them, no single hierarchy of the senses imposes itself upon language.

Matched MeSH terms: Visual Perception/physiology*
Removal of BCG artefact from concurrent fMRI-EEG recordings based on EMD and PCA

Javed E, Faye I, Malik AS, Abdullah JM

J Neurosci Methods, 2017 11 01;291:150-165.
PMID: 28842191 DOI: 10.1016/j.jneumeth.2017.08.020

BACKGROUND: Simultaneous electroencephalography (EEG) and functional magnetic resonance image (fMRI) acquisitions provide better insight into brain dynamics. Some artefacts due to simultaneous acquisition pose a threat to the quality of the data. One such problematic artefact is the ballistocardiogram (BCG) artefact.
METHODS: We developed a hybrid algorithm that combines features of empirical mode decomposition (EMD) with principal component analysis (PCA) to reduce the BCG artefact. The algorithm does not require extra electrocardiogram (ECG) or electrooculogram (EOG) recordings to extract the BCG artefact.
RESULTS: The method was tested with both simulated and real EEG data of 11 participants. From the simulated data, the similarity index between the extracted BCG and the simulated BCG showed the effectiveness of the proposed method in BCG removal. On the other hand, real data were recorded with two conditions, i.e. resting state (eyes closed dataset) and task influenced (event-related potentials (ERPs) dataset). Using qualitative (visual inspection) and quantitative (similarity index, improved normalized power spectrum (INPS) ratio, power spectrum, sample entropy (SE)) evaluation parameters, the assessment results showed that the proposed method can efficiently reduce the BCG artefact while preserving the neuronal signals.
COMPARISON WITH EXISTING METHODS: Compared with conventional methods, namely, average artefact subtraction (AAS), optimal basis set (OBS) and combined independent component analysis and principal component analysis (ICA-PCA), the statistical analyses of the results showed that the proposed method has better performance, and the differences were significant for all quantitative parameters except for the power and sample entropy.
CONCLUSIONS: The proposed method does not require any reference signal, prior information or assumption to extract the BCG artefact. It will be very useful in circumstances where the reference signal is not available.

Matched MeSH terms: Visual Perception/physiology
Fulltext The other-race effect and holistic processing across racial groups

Wong HK, Estudillo AJ, Stephen ID, Keeble DRT

Sci Rep, 2021 04 19;11(1):8507.
PMID: 33875735 DOI: 10.1038/s41598-021-87933-1

It is widely accepted that holistic processing is important for face perception. However, it remains unclear whether the other-race effect (ORE) (i.e. superior recognition for own-race faces) arises from reduced holistic processing of other-race faces. To address this issue, we adopted a cross-cultural design where Malaysian Chinese, African, European Caucasian and Australian Caucasian participants performed four different tasks: (1) yes-no face recognition, (2) composite, (3) whole-part and (4) global-local tasks. Each face task was completed with unfamiliar own- and other-race faces. Results showed a pronounced ORE in the face recognition task. Both composite-face and whole-part effects were found; however, these holistic effects did not appear to be stronger for other-race faces than for own-race faces. In the global-local task, Malaysian Chinese and African participants demonstrated a stronger global processing bias compared to both European- and Australian-Caucasian participants. Importantly, we found little or no cross-task correlation between any of the holistic processing measures and face recognition ability. Overall, our findings cast doubt on the prevailing account that the ORE in face recognition is due to reduced holistic processing in other-race faces. Further studies should adopt an interactionist approach taking into account cultural, motivational, and socio-cognitive factors.

Matched MeSH terms: Visual Perception/physiology*

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