Perceptual Processing Research Articles

The effects of background noise and reverberation on speech perception in cochlear implant users

Indoor noise and reverberation interfere with speech understanding for listeners. Degradation in cochlear implant (CI) processing presents additional challenges for CI users to understand noisy and reverberant speech. Inthis study, we investigated the effect of adverse acoustics on speech perception on three tasks that changed in difficulty and increasing need for top-down processing: (1) word recall, (2) sentence recognition, and (3) conversation comprehension. Each task was tested in five conditions that varied in combinations of adverse acoustics from reverberation (i.e., anechoic, 0.4s RT, vs 1.2s RT) and noise (i.e., quiet versus Speech-shaped-noise at −3dB). We compared performances from normal-hearing (NH) listeners and bilateral CI users between 15 and 25 years old. Preliminary results show that while NH listeners may have some tolerance for speech perception under adverse acoustics, CI users experienced more graded performance deterioration with increasing reverberation and noise. Moreover, we observed task-dependent performance change across adverse acoustic conditions in both NH and CI listeners: While some context (i.e., sentences) may help speech perception, comprehension based on pragmatic language processing (i.e., conversations) is vulnerable under difficult listening situations. These results provide insights on how NH and CI listeners differ in their access to top-down processing in real-world speech perception.

How can anyone learn or teach? Experiences of autistic people with sound in schools and universities

An inadequate sound environment in schools and universities can lead to poorer learning, higher levels of stress and worse overall well-being, ultimately affecting people’s careers and opportunities. These short- and long-term impacts can be more accentuated in autistic students, teachers, and lecturers, as autistic and other neurodivergent people tend to have significant perceptual and sensory processing differences. This paper presents the data from our study on the experience of autistic people in daily life acoustic environments related to this topic. The study explored the experiences of 12 autistic adults through reflective thematic analysis of semi-structured interviews, providing much-needed first-hand perspectives on main challenges, impact, and common coping strategies. The results highlight the crucial importance that good acoustics has for the participants, some of whom are or have been teachers and lecturers. They also illustrate how the lack of better acoustic practices and understanding of their experiences, together with some trends like open-plan schools and offices, have had a disabling impact throughout their life since childhood.

The necessity of equivalent comparisons for interpreting masked priming effects: Implications for studies of unconscious perceptual processing.

The necessity of equivalent comparisons for interpreting masked priming effects: Implications for studies of unconscious perceptual processing.

How do perceptual benefits from musical experience compare with those from speech experience?

Acoustic consistency facilitates perceptual processing while acoustic variability challenges it. This is evident in perceptual interference tasks, in which listeners categorize a target word/pitch when produced by either a single talker/musical instrument or multiple talkers/instruments. Responses are faster and/or more accurate for single-talker (e.g., Stilp & Theodore, 2020 AP&P) and single-instrument conditions (e.g., Shorey et al., 2022 ASA). While patterns of results are parallel across domains, listening experience is not. Participants in speech tasks are experts at their native language, but in the music task the contribution of musical experience is unclear because Shorey et al. tested solely nonmusicians. This raises two questions: (1) does more musical training increasingly protect against timbral variability when making pitch judgments, and (2) how does musical expertise compare with speech expertise? To evaluate these questions, we tested native English speaking nonmusicians (<2 years of formal musical training), intermediate musicians (2–9 years), and experienced musicians (10 + years) in speech interference and music interference tasks. We predict that musical training offers resilience to variability, such that interference in the music task will decrease with increasing musical experience. We also predict correlated interference for advanced musicians (i.e., experts) across speech and music tasks. Results will be discussed.

The Relationship between P300 and Central Auditory Processing Test Result.

Central auditory processing (CAP) refers to the perceptual processing of auditory inputs in the central nervous system and includes a series of auditory skills such as sound localization, auditory pattern recognition, and temporal sequencing which is a component of temporal processing. This skill can be assessed by frequency pattern test (FPT) and duration pattern test (DPT). Auditory attention is another skill that contributes to the CAP and can be analyzed by the P300. This study assesses the relationship between the P300 latency and the CAP test results of individuals with normal hearing. An experimental study was used in which the determined tests were applied to the participants. Thirty-four individuals with normal hearing between the ages of 20 and 40 years were included in the study. P300, FPT, and DPT were applied to the participants. The Spearman correlation test and Mann-Whitney U test were used for analysis. There were significant moderate and strong-level negative correlations between P300 latency and the scores obtained from frequency pattern and DPT (p < 0.01). We also analyzed whether P300 latency and frequency pattern and DPT scores differed according to gender and, as a result, did not find significant relationship (p > 0.05). We observed that frequency pattern and DPT scores decreased as P300 latency increased. We propose that these results could contribute to the diagnosis and follow-up process of CAP disorder by allowing P300 and CAP tests to be cross-checked.

Extending the Parallel Multiple-Analysis Processor

This article revisits the issue of perceived meter in rhythmically irregular post-tonal music by way of Danuta Mirka’s (2009) dynamic model of meter. Her model, which is a parallel multiple-analysis processor in the sense of Jackendoff (1991), accounts for rapidly fluctuating sensations of meter in the real-time listening process, while maintaining local regularity as a defining feature of metric processing. I offer two extensions to her model—one concerning the perceptual processing of non-isochronous meter and the other concerning meter in multiple perceptual streams—along with applications to music by Carter, Webern, Barber, Babbitt, Feldman, and Adès.

Multilayer privacy‐preserving model for security and privacy access control in edge computing

SummaryIn a recent scenario of a computing environment, the Internet of Things (IoT) provides a greater impact in several applications and services. For that Edge Computing techniques are effectively incorporated, in which the sensitive data are stored on servers. As a result, edge computing allows for data storage and operation at the network's edge to emerge as optimistic advancement. Regardless, the distinctive characteristics of edge computing including real‐time computing, content perception and parallel processing have introduced a number of innovative challenges in the domain of privacy preservation and data security. Edge computing provides an extension of the cloud for designing and deploying new security resolutions in the area of IoT. In this paper, a Trusted Platform Module with Ciphertext‐policy attribute‐based encryption technique is introduced to provide a solution to a multilayer privacy‐preserving model for efficient data storage. The developed model is adaptable and has a reliable data access control mechanism. Further, the results of the experiments demonstrate that the suggested technique operates better and give 83% results in terms of storage cost, load testing, effective runtime execution, higher security, credibility, and efficiency.

Molecular sensors in the taste system of Drosophila.

Most animals, including humans and insects, consume foods based on their senses. Feeding is mostly regulated by taste and smell. Recent insect studies shed insight into the cross-talk between taste and smell, sweetness and temperature, sweetness and texture, and other sensory modality pairings. Five canonical tastes include sweet, umami, bitter, salty, and sour. Furthermore, other receptors that mediate the detection of noncanonical sensory attributes encoded by taste stimuli, such as Ca2+, Zn2+, Cu2+, lipid, and carbonation, have been characterized. Deorphanizing receptors and interactions among different modalities are expanding the taste field. Our study explores the taste system of Drosophila melanogaster and perception processing in insects to broaden the neuroscience of taste. Attractive and aversive taste cues and their chemoreceptors are categorized as tables. In addition, we summarize the recent progress in animal behavior as affected by the integration of multisensory information in relation to different gustatory receptor neuronal activations, olfaction, texture, and temperature. We mainly focus on peripheral responses and insect decision-making. Drosophila is an excellent model animal to study the cellular and molecular mechanism of the taste system. Despite the divergence in the receptors to detect chemicals, taste research in the fruit fly can offer new insights into the many different taste sensors of animals and how to test the interaction among different sensory modalities.

A rough-set and AI based approach for hierarchical cognitive processing of perceptions

Modelling the psychological and cognitive processes is an important issue in theoretical and clinical aspects. Most of the modellings concern much on qualitative and philosophical descriptions. This research resorts to quantitative modelling of human cognitive processing based on rough sets, AI, and mathematical approaches. We formalise psychological targets and properties by objects and features. A feature domain is associated with these objects and features. Based on the subjects’ perception of the values in the feature domain, the cognitive processing is proceeded via deterministic procedures and non-deterministic procedures. The non-deterministic procedures involve the setting of rough set approximations. To evaluate the parameters involved in the setting, we design several experiments and algorithm, in particular probabilistic structures and entropy, to evaluate the effects of these parameters. These provide a great degree of flexibility in practical applications. These approaches could be easily implemented by or combined with machine learning and artificial intelligence techniques. Our approach could be applied directly in clinical assessment and mental health probing.

Intra– and inter–hemispheric network dynamics supporting object recognition and speech production

We built normative brain atlases that animate millisecond-scale intra- and inter-hemispheric white matter-level connectivity dynamics supporting object recognition and speech production. We quantified electrocorticographic modulations during three naming tasks using event-related high-gamma activity from 1,114 nonepileptogenic intracranial electrodes (i.e., non-lesional areas unaffected by epileptiform discharges). Using this electrocorticography data, we visualized functional connectivity modulations defined as significant naming-related high-gamma modulations occurring simultaneously at two sites connected by direct white matter streamlines on diffusion-weighted imaging tractography. Immediately after stimulus onset, intra- and inter-hemispheric functional connectivity enhancements were confined mainly across modality-specific perceptual regions. During response preparation, left intra-hemispheric connectivity enhancements propagated in a posterior-to-anterior direction, involving the left precentral and prefrontal areas. After overt response onset, inter- and intra-hemispheric connectivity enhancements mainly encompassed precentral, postcentral, and superior-temporal (STG) gyri. We found task-specific connectivity enhancements during response preparation as follows. Picture naming enhanced activity along the left arcuate fasciculus between the inferior-temporal and precentral/posterior inferior-frontal (pIFG) gyri. Nonspeech environmental sound naming augmented functional connectivity via the left inferior longitudinal and fronto-occipital fasciculi between the medial-occipital and STG/pIFG. Auditory descriptive naming task enhanced usage of the left frontal U-fibers, involving the middle-frontal gyrus. Taken together, the commonly observed network enhancements include inter-hemispheric connectivity optimizing perceptual processing exerted in each hemisphere, left intra-hemispheric connectivity supporting semantic and lexical processing, and inter-hemispheric connectivity for symmetric oral movements during overt speech. Our atlases improve the currently available models of object recognition and speech production by adding neural dynamics via direct intra- and inter-hemispheric white matter tracts.

Extracting statistical information about shapes in the visual environment

It is well known that observers can use so-called summary statistics of visual ensembles to simplify perceptual processing. The assumption has been that instead of representing feature distributions in detail the visual system extracts the mean and variance of visual ensembles. But recent evidence from implicit testing using a method called feature distribution learning showed that far more detail of the distributions is retained than the summary statistic literature indicates. Observers also encode higher-order statistics such as the kurtosis of feature distributions of orientation and color. But this sort of learning has not been shown for more intricate aspects of visual information. Here we tested the learning of distractor ensembles for shape, using the feature distribution learning method. Using a linearized circular shape space, we found that learning of detailed distributions of shape does not occur for this shape space while observers were able to learn the mean and range of the distributions. Previous demonstrations of feature distribution learning involved simpler feature dimensions than the more complex shape space tested here, and our findings may therefore reveal important boundary conditions of feature distribution learning.

Digitally embodied lifespan neurocognitive development and Tactile Internet: Transdisciplinary challenges and opportunities.

Mechanisms underlying perceptual processing and inference undergo substantial changes across the lifespan. If utilized properly, technologies could support and buffer the relatively more limited neurocognitive functions in the still developing or aging brains. Over the past decade, a new type of digital communication infrastructure, known as the "Tactile Internet (TI)," is emerging in the fields of telecommunication, sensor and actuator technologies and machine learning. A key aim of the TI is to enable humans to experience and interact with remote and virtual environments through digitalized multimodal sensory signals that also include the haptic (tactile and kinesthetic) sense. Besides their applied focus, such technologies may offer new opportunities for the research tapping into mechanisms of digitally embodied perception and cognition as well as how they may differ across age cohorts. However, there are challenges in translating empirical findings and theories about neurocognitive mechanisms of perception and lifespan development into the day-to-day practices of engineering research and technological development. On the one hand, the capacity and efficiency of digital communication are affected by signal transmission noise according to Shannon's (1949) Information Theory. On the other hand, neurotransmitters, which have been postulated as means that regulate the signal-to-noise ratio of neural information processing (e.g., Servan-Schreiber et al., 1990), decline substantially during aging. Thus, here we highlight neuronal gain control of perceptual processing and perceptual inference to illustrate potential interfaces for developing age-adjusted technologies to enable plausible multisensory digital embodiments for perceptual and cognitive interactions in remote or virtual environments.

Probing the Promises of Noninvasive Transcranial Electrical Stimulation for Boosting Mental Performance in Sports.

While the importance of physical abilities is noncontested to perform in elite sport, more focus has recently been turned toward cognitive processes involved in sport performance. Practicing any sport requires a high demand of cognitive functioning including, but not limited to, decision-making, processing speed, working memory, perceptual processing, motor functioning, and attention. Noninvasive transcranial electrical stimulation (tES) has recently attracted considerable scientific interest due to its ability to modulate brain functioning. Neuromodulation apparently improves cognitive functions engaged in sports performance. This opinion manuscript aimed to reveal that tES is likely an adjunct ergogenic resource for improving cognitive processes, counteracting mental fatigue, and managing anxiety in elite athletes. Nevertheless, the first evidence is insufficient to guarantee its real effectiveness and benefits. All tES techniques could be add-ons to make performance-related cognitive functions more efficient and obtain better results. Modulating inhibitory control through tES over the frontal cortex might largely contribute to the improvement of mental performance. Nevertheless, studies in elite athletes are required to assess the long-term effects of tES application as an ergogenic aid in conjunction with other training methods (e.g., neurofeedback, mental imagery) where cognitive abilities are trainable.

A unified neural account of contextual and individual differences in altruism.

Altruism is critical for cooperation and productivity in human societies but is known to vary strongly across contexts and individuals. The origin of these differences is largely unknown, but may in principle reflect variations in different neurocognitive processes that temporally unfold during altruistic decision making (ranging from initial perceptual processing via value computations to final integrative choice mechanisms). Here, we elucidate the neural origins of individual and contextual differences in altruism by examining altruistic choices in different inequality contexts with computational modeling and electroencephalography (EEG). Our results show that across all contexts and individuals, wealth distribution choices recruit a similar late decision process evident in model-predicted evidence accumulation signals over parietal regions. Contextual and individual differences in behavior related instead to initial processing of stimulus-locked inequality-related value information in centroparietal and centrofrontal sensors, as well as to gamma-band synchronization of these value-related signals with parietal response-locked evidence-accumulation signals. Our findings suggest separable biological bases for individual and contextual differences in altruism that relate to differences in the initial processing of choice-relevant information.

Vowel-initial glottalization as a prominence cue in speech perception and online processing

Three experiments examined the relevance of vowel-initial glottalization in the perception of vowel contrasts in American English, in light of the claimed prominence-marking function of glottalization in word-initial vowels. Experiment 1 showed that the presence of a preceding glottal stop leads listeners to re-calibrate their perception of a vowel contrast in line with the prominence-driven modulation of vowel formants. Experiment 2 manipulated cues to glottalization along a continuum and found that subtler cues generate the same effect, with bigger perceptual shifts as glottalization cues increase in strength. Experiment 3 examined the timecourse of this effect in a visual world eyetracking task, finding a rapid influence of glottalization which is simultaneous with the influence of formant cues in online processing. Results are discussed in terms of the importance of phonetically detailed prominence marking in speech perception, and implications for models of processing which consider segmental and prosodic information jointly.

Colour perception deficits after posterior stroke: Not so rare after all?

Cerebral achromatopsia is an acquired colour perception impairment caused by brain injury, and is generally considered to be rare. Both hemispheres are thought to contribute to colour perception, but most published cases have had bilateral or right hemisphere lesions. In contrast to congenital colour blindness that affects the discrimination between specific hues, cerebral achromatopsia is often described as affecting perception across all colours. Most studies of cerebral achromatopsia have been single cases or case series of patients with colour perception deficits. Here, we explore colour perception deficits in an unbiased sample of patients with stroke affecting the posterior cerebral artery (N=63) from the Back of the Brain project. Patients were selected based on lesion location only, and not on the presence of a given symptom. All patients were tested with the Farnsworth D-15 Dichotomous Colour Blindness Test and performance compared to matched controls (N=45) using single case statistics. In patients with abnormal performance, the patterns of colour difficulties were qualitatively analysed. 22% of the patients showed significant problems with colour discrimination (44% of patients with bilateral lesions, 28% with left hemisphere lesions and 5% with right hemisphere lesions). Lesion analyses identified two regions in ventral occipital temporal areas in the left hemisphere as particularly strongly related to impaired performance in colour perception, but also indicated that bilateral lesions are more strongly associated with impaired performance that unilateral lesions. While some patients only had mild deficits, colour perception impairments were in many cases severe. Many patients had selective deficits only affecting the perception of some hues. The results suggest that colour perception difficulties following PCA stroke are common, and that they vary in severity and expression. In addition, the results point towards bilateral processing of colour perception with a left hemispheric domination, contradicting previous reports.

The high frequency oscillation in orbitofrontal cortex is susceptible to phenethylamine psychedelic 25C–NBOMe in male rats

Serotoninergic psychedelics induced extensive alterations in perception and cognition, which has been attributable to its disruptive effect on oscillatory rhythms of prefrontal cortex. However, there is a lack of information how serotoninergic psychedelics affect the intra-prefrontal network, which intrinsically interact to accomplish perceptual processing. Uncovering the altered neural network caused by psychedelics helps to understand the mechanisms of their psychoactive effects and contribute to develop biological markers of psychedelic effects. In present study, we investigated the effects of substituted phenethylamine psychedelic 25C–NBOMe on neural oscillations in the intra-prefrontal and hippocampal-prefrontal network. The effective dose of 25C–NBOMe (0.1 mg/kg) disrupting sensorimotor gating in male Sprague–Dawley rats was used to observe its effects on neural oscillations in the prelimbic cortex, anterior cingulate cortex, orbitofrontal cortex (OFC) and hippocampus CA1. The power of high frequency oscillation (HFO, 120–150 Hz) was potentiated by 25C–NBOMe selectively in the OFC, with peaking at 20–30 min after treatment. 25C–NBOMe strengthened HFO coherence within the intra-prefrontal, rather than hippocampal-prefrontal network. Potentiated HFO in the OFC had a strong positive correlation with the strengthened inter-prefrontal HFO coherence by 25C–NBOMe. The 25C–NBOMe-induced alterations of rhythmic patterns were prevented by pre-treatment with selective serotonin 2A receptor antagonist MDL100,907. These results demonstrate that OFC rhythmic activity in HFO is relatively susceptible to substituted phenethylamine and potentially drives drug-induced rhythmic coherence within intra-prefrontal regions. Our findings provide additional insight into the neuropathophysiology of the psychoactive effects of psychedelics and indicate that the altered HFO might be applied as a potential biological marker of psychedelic effect.

Association of Neural Connectome With Early Experiences of Abuse in Adults

More than 10% of children experience sexual, physical, or emotional abuse, and abuse experienced during sensitive neurodevelopmental periods is associated with a greater risk of psychiatric disorders. To investigate the extent to which a history of abuse is associated with alterations in the intrinsic functional connectome of the adult brain independent from the restriction of associated psychiatric conditions. This cohort study assessed data from 768 adult participants from the greater Sydney, Australia, area who were included in the study without diagnostic restrictions and categorized based on a history of childhood sexual, physical, and/or emotional abuse. Data were collected from January 1, 2009, to December 31, 2015; data analysis was performed from October 1, 2020, to March 31, 2022. Outcomes were structured psychiatric interview responses, self-report of the frequency and extent of various types of negative experiences in childhood and adolescence, and intrinsic functional connectivity derived from 5 functional magnetic resonance imaging tasks and estimated among 436 brain regions, comprising intranetwork and internetwork connectivity of 8 large-scale brain networks. Among the 647 individuals with usable data (330 female [51.0%]; mean [SD] age, 33.3 [12.0] years; age range, 18.2-69.2 years), history of abuse was associated with greater likelihood of a current psychiatric illness (odds ratio, 4.55; 95% CI, 3.07-6.72; P < .001) and with greater depressive, anxiety, and stress symptoms (mean difference, 20.4; 95% CI, 16.1-24.7; P < .001). An altered connectome signature of higher connectivity within somatomotor, dorsal, and ventral attention networks and between these networks and executive control and default mode networks was observed in individuals with a history of abuse experienced during childhood (n = 127) vs those without a history of abuse (n = 442; mean difference, 0.07; 95% CI, 0.05-0.08; familywise, Bonferroni-corrected P = .01; Cohen d = 0.82) and compared with those who experienced abuse in adolescence (n = 78; mean difference, 0.06; 95% CI, 0.04-0.08]; familywise, Bonferroni-corrected P < .001; Cohen d = 0.68). Connectome alterations were not observed for those who experienced abuse in adolescence. Connectivity of this signature was transdiagnostic and independent of the nature and frequency of abuse, sex, or current symptomatic state. Findings highlight the associations of exposure to abuse before and during adolescence with the whole-brain functional connectome. The experience of child abuse was found to be associated with physiologic changes in intrinsic connectivity, independent of psychopathology, in a way that may affect functioning of systems responsible for perceptual processing and attention.

Temporal attention affects contrast response function by response gain.

Orienting attention to a specific point in time has been shown to improve the contrast sensitivity at the attended time point and impair it earlier or later. This phenomenon could be explained by temporal attention increasing the effective contrast of the target presented at the attended time point which leads to changes in contrast psychometric function by contrast gain. Another explanation is that temporal attention multiplicatively amplifies the amplitude of behavioral or neural response to contrast, resulting in alterations in contrast psychometric function by response gain. To explore the underlying mechanism, we adopted a temporal cueing orientation discrimination task using audio pre-cues composed of different frequency components to induce different attentional allocations in the time domain and targets of various contrast intensities to measure contrast psychometric functions. Obtained psychometric functions for contrast sensitivity were fitted for different conditions with discrepant attentional states in time. We found that temporal attention manipulated by cue affected contrast psychometric function by response gain, indicating that multiplying the contrast response of the visual target occurring at the selected point in time by a fixed factor is a crucial way for temporal attention to modulate perceptual processing.

The Tensor Brain: A Unified Theory of Perception, Memory, and Semantic Decoding.

We present a unified computational theory of an agent's perception and memory. In our model, both perception and memory are realized by different operational modes of the oscillating interactions between a symbolic index layer and a subsymbolic representation layer. The two layers form a bilayer tensor network (BTN). The index layer encodes indices for concepts, predicates, and episodic instances. The representation layer broadcasts information and reflects the cognitive brain state; it is our model of what authors have called the "mental canvas" or the "global workspace." As a bridge between perceptual input and the index layer, the representation layer enables the grounding of indices by their subsymbolic embeddings, which are implemented as connection weights linking both layers. The propagation of activation to earlier perceptual processing layers in the brain can lead to embodiments of indices. Perception and memories first create subsymbolic representations, which are subsequently decoded semantically to produce sequences of activated indices that form symbolic triple statements. The brain is a sampling engine: only activated indices are communicated to the remaining parts of the brain. Triple statements are dynamically embedded in the representation layer and embodied in earlier processing layers: the brain speaks to itself. Although memory appears to be about the past, its main purpose is to support the agent in the present and the future. Recent episodic memory provides the agent with a sense of the here and now. Remote episodic memory retrieves relevant past experiences to provide information about possible future scenarios. This aids the agent in decision making. "Future" episodic memory, based on expected future events, guides planning and action. Semantic memory retrieves specific information, which is not delivered by current perception, and defines priors for future observations. We argue that it is important for the agent to encode individual entities, not just classes and attributes. Perception is learning: episodic memories are constantly being formed, and we demonstrate that a form of self-supervised learning can acquire new concepts and refine existing ones. We test our model on a standard benchmark data set, which we expanded to contain richer representations for attributes, classes, and individuals. Our key hypothesis is that obtaining a better understanding of perception and memory is a crucial prerequisite to comprehending human-level intelligence.