Processing Mechanisms Research Articles

Deep feature synthesis approach using selective graph attention for replay attack voice spoofing detection

<span lang="EN-US">As voice-based authentication becomes increasingly integrated into security frameworks, establishing effective defenses against voice spoofing, particularly replay attacks, is more crucial than ever. This paper presents a novel comprehensive framework for replay attack detection that leverages the integration of advanced spectral-temporal feature extraction and graph-based feature processing mechanisms. The proposed system presents the design of a waveform encoder and a novel temporal residual unit for spectral and temporal feature extraction in synchronous. Further, an approach of selective attention graph followed by multi-scale feature synthesis is employed to retain precise and spoof indicative feature vectors at the classification layer. The proposed method addresses the significant challenge of distinguishing genuine speech from replayed recordings. The validation of the proposed model is done on the ASVSpoof2019 dataset to demonstrate the efficacy of the proposed approach. The proposed system outperforms existing methods, achieving a lower equal error rate (EER) of 0.015 and a reduced tandem detection cost function (t-DCF) of 0.503. The comparative outcome exhibits the robustness of the method in identifying replay attacks.</span>

Impact of Power Quality on the Efficiency of the Mining Process

There are currently more than 30 underground mines operating in Poland. These are mines extracting hard coal, salt, and metal ores. Each of these plants has its own specifics for operation, but all operate under the same regulations. The basic principle is to ensure the safety of the crew and equipment. The progressive mechanization and automation of the mining process results in the installation of power electronic converters in the networks of mining plants, which significantly deteriorate the quality of the power in the plant supply networks. In addition, the constant reconfiguration of these networks related to the progress of the work can affect the safety conditions of the plant. This article describes problems occurring at one underground mining plant that are related to the structure of the power grid. Failures and interruptions in the production process were the result of poor power quality. They directly translated into increased production costs and significantly affected the safety level of the workforce, which could result in further consequences, not only in the financial sphere. The article also addresses the issue of existing legal regulations, the provisions of which may be insufficient in assessing the current state of power quality in mining plants.

Possible Mechanism for Perception of Auditory-Verbal Hallucinations in Schizophrenia and Approaches to Their Weakening

We put forward a hypothesis that the processing and perception of auditory-verbal hallucinations in schizophrenia — internally generated speech, occurs in the same neural circuits as speech from external sources. These topographically organized cortico—basal ganglia—thalamocortical neural circuits include auditory, language, and frontal neocortical areas. It follows from our proposed mechanism for sound processing, that the increased action on dopamine D2 receptors on striatal neurons, which is considered the cause of hallucinations, should lead to a determined reorganization of activity in these neural circuits. As a result of this reorganization, the inhibition of neurons in the thalamic nuclei, including the internal geniculate body, should decrease synergistically through the direct and indirect pathways in the basal ganglia, and the excitation of connected with them cortical neurons, in the activity of which speech is represented, should increase. From this mechanism it follows that in order to weaken the perception of auditory-verbal hallucinations, it is necessary to increase the inhibition of thalamic neurons. Taking into account the known data on the distribution of receptors of different types on neurons in the striatum, thalamus and neocortex, as well as the previously formulated unified modification rules for the effectiveness of synaptic transmission in different structures, we proposed that agonists of adenosine A1 and muscarinic M4 receptors located on striatonigral spiny cells, giving rise to a direct disinhibitory pathway through the basal ganglia as well as antagonists of delta-opioid and cannabinoid CB1 receptors, located on striatopallidal spiny cells, giving rise to an indirect inhibitory pathway through the basal ganglia may be useful to weaken the perception of hallucinations. In addition, activation of A1 receptors can directly weaken the activity of neurons in the thalamus and neocortex due to the induction of long-term depression in the efficiency of their excitation. Inactivation of cannabinoid CB1 receptors on the projection GABAergic cells of the reticular thalamic nucleus may enhance their inhibitory effect on neurons of different thalamic nuclei. Since the proposed substances only indirectly affect the dopaminergic system, their use should not cause such pronounced side effects as D2 receptor antagonists, antipsychotics that are widely used to suppress auditory-verbal hallucinations.

The two-stage processing of judgment of confidence: evidence from ERP.

The judgment of confidence (JOC) refers to the confidence in the accuracy of the target item individuals have just retrieved and is a typical retrospective metacognitive monitoring process. In the classical paradigm of JOC, JOC occurs after the recognition or recall task. While initially viewed as a single-stage monitoring process, recent research on JOC suggests its internal mechanisms may be more complex, potentially encompassing both retrieval and monitoring processes. This study aims to delve into these mechanisms concerning neural temporal processes. In this study, event-related potential (ERP) was used to compare N400 and slow-wave ERPs of high and low JOCs at different time windows using a classic JOC paradigm. Behavioral results showed an inverted-U shaped relationship between response time (RT) and JOCs, peaking at magnitude 3 before declining. There were significantly longer RT for low JOCs compared with high JOCs, along with lower recognition scores. The ERP results showed that low JOCs induced larger N400 in the right frontal lobe and right central area, while high JOCs induced larger slow-wave components (500 ~ 700ms) in the right frontal lobe. Based on these findings, the present study suggests that JOC involves two processing stages. N400 reflects the process of cue acquisition, while the slow-wave component reflects the process of cue application. Furthermore, a two-stage model was proposed and validated, enriching the study of metacognition monitoring mechanisms, offering insights into the processing mechanisms of retrospective metacognitive monitoring.

A review of level-1 visual perspective-taking: potential relationship with the uncanny valley effect

Calculating others' visual perspective automatically is a pivotal ability in human social communications. In the dot-perspective task, the ability is shown as a consistency effect: adults respond more slowly to judge the number of discs that they can see when a computer-generated avatar sees fewer discs. The implicit mentalizing account attributes the effect to relatively automatic tracking of others' visual perspective. However, the submentalizing account attributes the effect to domain-general attentional orienting. Accordingly, the current study focuses on elucidating the ongoing implicit mentalizing vs. submentalizing debate. The review tried to shed light on the debate regarding level-1 visual perspective taking and its potential relationship between the uncanny valley effect. Future research may focus on new manipulations of uncanny valley effect to further uncover the relationship between uncanny valley effect and level-1 visual perspective taking. This may provide new insight into the debate and the processing mechanisms of level-1 visual perspective-taking and uncanny valley effect, which may be beneficial for AI development.

Role of dry media in influencing performance during processing by centrifugal superfinishing

ABSTRACT To achieve better surface quality and higher efficient finishing of AISI 52,100 steel cylindrical roller surfaces, a novel dry medium was prepared, which is composed of millimeter-sized adsorptive medium matrix and polishing paste containing micron-sized abrasives. The study utilized centrifugal superfinishing to examine the effects of dry media with various abrasive types, sizes, and polishing paste ratios. The influence of these dry media on the processing performance was comprehensively evaluated, covering parameters including material removal rate, roughness decrease rate constant (K r ), roughness limit (Ra lim ) value, surface morphology, and profile. In addition, the processing mechanism was revealed. This study provides valuable insights into the development and performance regulation of new media for nano-level superfinishing of complex surfaces.

Comparing retro-cue benefit mechanisms in visual working memory: completely valid vs. highly valid retro-cues

Visual working memory (VWM) plays a crucial role in temporarily maintaining and manipulating visual information. Retro-cue benefit (RCB) refers to the enhancement of memory performance when attention is directed toward a subset of items in VWM after their initial encoding. Our recent electroencephalogram (EEG) studies indicate that cue validity affects the mechanisms underlying RCB formation. However, previous research has not thoroughly examined whether these mechanisms differ between completely valid and highly valid cue conditions. This study investigates the consistency of RCB mechanisms under conditions of complete (100%) and high (80%) retro-cue validity. We manipulated retro-cue validity and examined cognitive processing mechanisms under different validity conditions using EEG. Specifically, we focused on the N2pc component, which reflects attentional resource allocation, and the contralateral delay activity (CDA) component, which reflects the quantity of information retained in VWM. The results, encompassing both behavioral and event-related potential (ERP) findings, show that participants in both the 100% and 80% cue validity conditions exhibit robust RCB. Notably, the degree of RCB remains consistent across these conditions, indicating that participants utilize retro-cues to enhance VWM performance to the same extent. In the 80% cue validity condition, a significant retro-cue cost (RCC) was observed, indicating that participants selectively discarded uncued items from VWM. In invalid trials, response accuracy drops to chance levels, supporting the removal hypothesis. ERP results reveal that attentional resource allocation (N2pc) and the quantity of retained information (CDA) remain uniform across cue validity conditions. The mechanism responsible for RCB formation appears to involve an all-or-nothing process of discarding uncued information rather than a flexible resource allocation strategy. This study provides insights into attention allocation and information-processing mechanisms in VWM, suggesting that conclusions drawn from tasks with completely valid retro-cues can be integrated with findings from highly valid cue tasks. These findings also illuminate the flexibility of internal attentional resource allocation during RCB formation and contribute to our understanding of attention processes in VWM.

Nucleosome flipping drives kinetic proofreading and processivity by SWR1.

The yeast SWR1 complex catalyses the exchange of histone H2A-H2B dimers in nucleosomes, with Htz1-H2B dimers1-3. Here we used single-molecule analysis to demonstrate two-step double exchange of the two H2A-H2B dimers in a canonical yeast nucleosome with Htz1-H2B dimers, and showed that double exchange can be processive without release of the nucleosome from the SWR1 complex. Further analysis showed that bound nucleosomes flip between two states, with each presenting a different face, and hence histone dimer, to SWR1. The bound dwell time is longer when an H2A-H2B dimer is presented for exchange than when presented with an Htz1-H2B dimer. A hexasome intermediate in the reaction is bound to the SWR1 complex in a single orientation with the 'empty' site presented for dimer insertion. Cryo-electron microscopy analysis revealed different populations of complexes showing nucleosomes caught 'flipping' between different conformations without release, each placing a different dimer into position for exchange, with the Swc2 subunit having a key role in this process. Together, the data reveal a processive mechanism for double dimer exchange that explains how SWR1 can 'proofread' the dimer identities within nucleosomes.

Proton‐Modulated Resistive Switching in a Synapse‐Like Tyrosine‐Rich Peptide‐Based Memristor

AbstractArtificial intelligence has become an essential part of the daily lives and has revolutionized various sectors, including healthcare, finance, transportation, and entertainment. With a substantial increase in processed data, neuromorphic devices that replicate the operation of the human brain have been emphasized owing to their superior efficiency. Typical neuromorphic devices focus on constructing synapse‐like structures. However, biological synapses have more complex mechanisms for efficient data processing. One of the most prominent mechanisms is proton activation, which forms an ion concentration gradient prior to the transmission of neurotransmitters and plays a key role in efficient computation. In this study, proton‐mediated signaling at biological synapses is successfully replicated by fabricating a proton‐modulated memristor device using a tyrosine‐rich peptide film. The ionic input of the memristor is controlled by applying a voltage to proton‐permeable PdHx contacts in a hydrogen atmosphere, thus successfully adjusting the resistive switching behavior. Remarkable improvements in resistive switching and computing performance are observed through proton injection, analogous to “proton‐mediated signaling” at the actual synapse. It is believed that this study proposes a new paradigm for designing biorealistic devices and provides inspiration for precisely controllable ion‐based neuromorphic devices.

The aging of emotional words processing in implicit and explicit emotion task: an ERP study.

This study examined how cognitive aging affects emotional word processing using event-related potential technique. Young and older adults completed both implicit lexical decision and explicit emotion categorization tasks involving positive, negative, and neutral words. Behaviorally, older adults displayed a negative emotion effect in the implicit task, which was absent in young adults. While both age groups exhibited both positive and negative emotion effects in the explicit task, older adults demonstrated a greater positivity bias compared to young adults. Event-related potential technique data revealed that young adults exhibited an early negative emotion effect on the P2 and a late emotion effect on the late positivity potentials in the implicit task. In contrast, older adults exhibited an early negativity bias effect on the P2, as well as both negative and positive emotion effects on the N400, and positive emotion effects on the late positivity potentials. In the explicit task, young adults showed both early and late negative emotion effects on the P2 and late positivity potentials, while older adults showed both negative and positive emotion effects on the late positivity potentials. The results suggest distinct processing mechanisms for emotion words in young and older adults, involving both bottom-up and top-down mechanisms, which support the socioemotional selectivity theory.

Research on bearing ring processing mechanism by barrel finishing based on granular media flow behavior

The bearing ring is the critical component of bearings, which play an important role in any rotary mechanism. A better finishing surface quality of bearing rings would improve their performance. Nevertheless, one of the challenges is to realize overall uniformity finishing under the condition that non-destructive clamping. Accordingly, this paper proposed a bearing ring processing method based on barrel finishing, which can realize overall uniformity finishing by the floating clamp of bearing ring. The granular media flow behavior is methodically set up by discrete element method (DEM) simulation, which is a vital issue in the mass finishing industry. Then the finishing experiments are conducted to investigate the surface roughness and morphology. The effect of vessel rotation speed, granular media filling level, and configuration of support bars on granular media flowability was firstly investigated. And then the effect of granular media flowability on bearing ring processing mechanism was further studied. The results show that the better flowability of granular media, the greater media kinetic energy reaching the surface of bearing ring, which means the erosion behavior is intensive. The higher collision behavior between media and bearing ring occurs when the cataracting pattern is dominant. The results indicate that the optimal finishing performance would be obtained at the rotation speed of 40 rpm, filling level of 80 %, and the configuration of support bars of 350 mm. After finishing experiment, the surface roughness and morphology of all surfaces were improved.

Speech Mismatch Negativity (MMN) in Schizophrenia with Auditory Verbal Hallucinations.

Auditory verbal hallucinations (AVH) are experienced by many individuals with schizophrenia (SZ), a neurodevelopmental disease that encumbers the quality of life and psychosocial outcome of those afflicted by it. While many hypotheses attempt to better define the etiology of AVHs in SZ, their neural profile and its moderation by current neuroleptics remains limited. The Mismatch Negativity (MMN) is an event related potential (ERP) measured from electroencephalographic (EEG) activity during the presentation of a deviance detection auditory paradigm. The neural regions and activity underlying the generation of the MMN include the primary auditory cortex and the prefrontal cortex which are regions also found to be activated during the experience of AVHs. Decreased MMN amplitudes have been robustly noted in SZ patients during the presentation of MMN tasks using auditory tones. However, the MMN generation to speech stimuli has not been extensively examined in SZ nor in relation to AVHs. The primary objective of this study was to examine the MMN to five speech-based deviants in SZ patients and healthy controls. Second, we assessed MMN features with AVH characteristics in 19 SZ patients and 21 HC. While AVH features did not correlate with measures of MMN, we found decreased MMN amplitudes to speech-based frequency and vowel change deviants in SZ patients compared to HC potentially reflecting deficiencies in basic speech processing mechanisms.

Neural mechanisms of dynamic syntactic and semantic processing in Chinese garden-path sentence comprehension: An ERP study

In this study, the neural mechanisms of dynamic syntactic and semantic processing in Chinese garden-path sentence comprehension were investigated using electrophysiological and behavioral measures. Two groups of garden-path sentences were designed, with the ambiguity of multiple word categories in Group 1 and classifier-noun agreements in Group 2. Besides the ambiguous condition, there were also control and semantic violation conditions. Participants made plausibility judgment of each sentence. The ERPs elicited by the last three critical word regions in each sentence were examined continuously to uncover the time course of the revision process clearly. Relative to the control sentence, the ambiguous sentences of both groups elicited the smallest N400 before and on the disambiguating region, but the largest P600 at the disambiguation position, indicating that the sentences were misparsed and/or misinterpreted initially, and revised efficiently when the input cannot be integrated into the syntactic structure constructed. No significant N400 difference was observed between the ambiguous and the control condition on the disambiguating regions, indicating that semantic processing proceeded even no appropriate syntactic structures were built for the incomplete sentences. Therefore, without morphosyntactic constraints in Chinese, semantic processing is generally prior to the syntactic one, which will be revised only when semantic integration fails.

Firing dynamics and coupling synchronization of memristive EMR-based Chaivlo neuron utilizing equivalent energy approach.

Firing dynamics and its energy property of neuron are crucial for exploring the mechanism of intricate information processing within the nervous system. However, the energy analysis of discrete neuron is significantly lacking in comparison to the vast literature and mature theory available on continuous neuron, thereby necessitating a focused effort in this underexplored realm. In this paper, we introduce a Chaivlo neuron map by employing a flux-controlled memristor to simulate electromagnetic radiation (EMR), and a detailed analysis of its firing dynamics is conducted based on an equivalent Hamiltonian energy approach. Our observations reveal that a range of energy-based firing behaviors, such as spike firing, coexistence firing, mixed-mode firing, and chaotic bursting firing, can be induced by EMR and injected current. To delve deeper into the synchronous firing dynamics, we establish a Chaivlo network by electrically coupling two memristive EMR-based Chaivlo neurons. Subsequently, we experimentally evaluate the synchronization behavior of this network by quantifying both the synchronization factor and the average difference of equivalent Hamiltonian energy. Our findings conclusively demonstrate that both EMR and coupling strength positively contribute to the network's synchronization ability.

Visual Processing by Hierarchical and Dynamic Multiplexing.

The complexity of natural environments requires highly flexible mechanisms for adaptive processing of single and multiple stimuli. Neuronal oscillations could be an ideal candidate for implementing such flexibility in neural systems. Here, we present a framework for structuring attention-guided processing of complex visual scenes in humans, based on multiplexing and phase coding schemes. Importantly, we suggest that the dynamic fluctuations of excitability vary rapidly in terms of magnitude, frequency and wave-form over time, i.e., they are not necessarily sinusoidal or sustained oscillations. Different elements of single objects would be processed within a single cycle (burst) of alpha activity (7-14 Hz), allowing for the formation of coherent object representations while separating multiple objects across multiple cycles. Each element of an object would be processed separately in time-expressed as different gamma band bursts (>30 Hz)-along the alpha phase. Since the processing capacity per alpha cycle is limited, an inverse relationship between object resolution and size of attentional spotlight ensures independence of the proposed mechanism from absolute object complexity. Frequency and wave-shape of those fluctuations would depend on the nature of the object that is processed and on cognitive demands. Multiple objects would further be organized along the phase of slower fluctuations (e.g., theta), potentially driven by saccades. Complex scene processing, involving covert attention and eye movements, would therefore be associated with multiple frequency changes in the alpha and lower frequency range. This framework embraces the idea of a hierarchical organization of visual processing, independent of environmental temporal dynamics.

Strategies for constructing harmonious colour combinations by art students with autism spectrum disorders

Introduction. The survey discussed in the article represents the first experience of an empirical study of the peculiarities characterising the ways of construction and perception of colour harmony by students with autism spectrum disorders – professional art education learners. The relevance of the study is conditioned by new trends in education related to the need to create an inclusive and favourable environment for people with autism. This environment is necessary for their successful integration and professional training in art specialities that are considered a promising area for professional realisation of people with autism. Methods. The survey was carried out using the experimental method involving 21 participants with autism spectrum disorders (mean age = 20.4 years; SD = 2.4; 9 males, 12 females). The participants’ answers in the experimental group were compared with those of an age-, gender-, and education-matched control group (N=21). The participants’ task was to match two given shades with a third one in the palette, for the colour combination to be as harmonious as possible. The experimental palette allowed to change the hue, lightness and chroma of shades. Results. The participants with autism spectrum disorders were twice as likely to choose yellow (23.8% compared to 12.4% in the control group) and purple shades (16.2% compared to 9.5%); hardly used orange (1.9%) and blue (4.8%) and preferred lighter shades (the mean L value was 67.8 compared to the control group’s 63.0). The chroma of the selected shades correlated with their hue and lightness. The stimulus selection strategy depended on the distance (∆E*00) between the given (upper and lower) shades in the CIELAB colour space and was based on a specific “geometry” (a particular ratio of values characterising the angles and side lengths formed by the given and selected shades, as well as a preference for a particular triangle area and its type). Discussion. The experiment showed that the students with autism spectrum disorders differed markedly from neurotypical students in a number of indicators when constructing a colour harmony. The experimental group participants’ responses showed a “preference for sameness” characteristic of autism. The significant inter-group differences were applied more to the lightness and chroma of the chosen shades than to their hue. The shades preferred by the participants with autism spectrum disorders better matched the conditions of the habitual “chromatic diet” and the colour’s statistics in nature. The observed specificity may also reflect the reduced ability to generalise and average out colours in terms of holistic perception, specific to autism. Conclusion. The survey results make an important contribution to the improvement of the professional training methodology for art students, and for the development of scientifically based educational approaches to teaching people with autism spectrum disorders, primarily in the context of the formation of colour-related competencies; in addition, they may provide new impulses for investigating the fundamental mechanisms of cognitive processing of colour-related information.

Face emojis vs. Non-face emojis: Exploring neural mechanisms in text processing

With the rapid development of digital communication, emojis have played an increasingly important role in computer-mediated communication (CMC). Although Non-face emojis account for approximately 90 % of emoji usage, related research remains relatively scarce. Furthermore, there is limited exploration of the differences in the mechanisms of text processing between Face and Non-face emojis. The aim of this study is to investigate the neural mechanisms underlying the differences in text processing between Face emojis and Non-face emojis. We employed a semantic violation paradigm to analyze the cognitive processes of 28 participants as they processed texts in which emojis replaced words. The experimental materials consisted of 8 target stimuli, each corresponding to 15 text sentences. The results indicate that Non-face emojis elicited a strong N400 effect in incongruent texts, suggesting that Non-face emojis may have higher semantic complexity and can function as substitutes for words. In contrast, Face emojis primarily elicited an LNC component, indicating that they are more likely to be perceived as symbols of emotional expression rather than carriers of explicit semantic information. These results reveal the distinct roles of Face and Non-face emojis in text comprehension, providing new insights into emoji semantics and their impact on language processing.

Granger Causal Inference Based on Dual Laplacian Distribution and Its Application to MI-BCI Classification.

Granger causality-based effective brain connectivity provides a powerful tool to probe the neural mechanism for information processing and the potential features for brain computer interfaces. However, in real applications, traditional Granger causality is prone to the influence of outliers, such as inevitable ocular artifacts, resulting in unreasonable brain linkages and the failure to decipher inherent cognition states. In this work, motivated by constructing the sparse causality brain networks under the strong physiological outlier noise conditions, we proposed a dual Laplacian Granger causality analysis (DLap-GCA) by imposing Laplacian distributions on both model parameters and residuals. In essence, the first Laplacian assumption on residuals will resist the influence of outliers in electroencephalogram (EEG) on causality inference, and the second Laplacian assumption on model parameters will sparsely characterize the intrinsic interactions among multiple brain regions. Through simulation study, we quantitatively verified its effectiveness in suppressing the influence of complex outliers, the stable capacity for model estimation, and sparse network inference. The application to motor-imagery (MI) EEG further reveals that our method can effectively capture the inherent hemispheric lateralization of MI tasks with sparse patterns even under strong noise conditions. The MI classification based on the network features derived from the proposed approach shows higher accuracy than other existing traditional approaches, which is attributed to the discriminative network structures being captured in a timely manner by DLap-GCA even under the single-trial online condition. Basically, these results consistently show its robustness to the influence of complex outliers and the capability of characterizing representative brain networks for cognition information processing, which has the potential to offer reliable network structures for both cognitive studies and future brain-computer interface (BCI) realization.

Investigating the Influence of Driving on Brain Connectivity Networks and Emotion Processing Mechanism Based on EEG Signals

Investigating the Influence of Driving on Brain Connectivity Networks and Emotion Processing Mechanism Based on EEG Signals

When project outcomes matter: Organizational integration in managing long-term target benefits

We build on the research on managing long-term benefits by focusing on the management of outcomes during project execution through the theoretical lens of organizational integration research. Our research question is as follows: How can organizations arrange integration among organizational levels, functions, and projects to ensure the effective development of project outcomes and long-term target benefits? To address this question, we conducted a single case study with the Finnish Defence Forces (FDF) and four defense system projects as embedded cases. Our study provides new knowledge on project benefits management in three distinct areas: the integration mechanisms connecting projects, executives, and functions throughout project execution; effective information processing mechanisms for managing the development of outcomes; and the rhythmic initiation of new projects based on improved knowledge from ongoing projects. Based on our findings, we develop a model that covers project-to-organization, organization-to-project, and project-to-project interactions.