Processing Of Stimuli Research Articles

Musical Sophistication and Multilingualism: Effects on Arcuate Fasciculus Characteristics.

The processing of auditory stimuli which are structured in time is thought to involve the arcuate fasciculus, the white matter tract which connects the temporal cortex and the inferior frontal gyrus. Research has indicated effects of both musical and language experience on the structural characteristics of the arcuate fasciculus. Here, we investigated in a sample of n = 84 young adults whether continuous conceptualizations of musical and multilingual experience related to structural characteristics of the arcuate fasciculus, measured using diffusion tensor imaging. Probabilistic tractography was used to identify the dorsal and ventral parts of the white matter tract. Linear regressions indicated that different aspects of musical sophistication related to the arcuate fasciculus' volume (emotional engagement with music), volumetric asymmetry (musical training and music perceptual abilities), and fractional anisotropy (music perceptual abilities). Our conceptualization of multilingual experience, accounting for participants' proficiency in reading, writing, understanding, and speaking different languages, was not related to the structural characteristics of the arcuate fasciculus. We discuss our results in the context of other research on hemispheric specializations and a dual-stream model of auditory processing.

The Role of Gender in Cognitive Processing of Affective Linguistic Stimuli in Bilinguals

This study aims to compare the emotional reactions of bilingual men and women to affective valence by manipulating positive and negative linguistic stimuli. To achieve this aim, the semantic decision task was used. 56 Persian-English bilinguals, who were divided into two equal groups considering their gender (28 female and 28 male), were asked to decide whether the adjectives loaded with positive or negative valence (i.e., target words) were related in meaning to the preceding nouns (i.e., prime words). In order to find out whether there is any potential interaction between the valence of primes and targets, mixed factorial repeated measure ANOVA was run on reaction time and error rate data. The results of the present study on cognitive gender differences show that males and females, despite some few differences, generally follow a similar pattern in processing affective meaning of words in their second language.

Dopamine and Serotonin Transporter Genes Regulation in Highly Sensitive Individuals during Stressful Conditions: A Focus on Genetics and Epigenetics.

Background: Coping with stress is essential for mental well-being and can be critical for highly sensitive individuals, characterized by a deeper perception and processing of stimuli. So far, the molecular bases characterizing high-sensitivity traits have not been completely investigated and gene × environment interactions might play a key role in making some people more susceptible than others. Methods: In this study, 104 young adult university students, subjects that might face overwhelming experiences more than others, were evaluated for the genetics and epigenetics of dopamine (DAT1) and serotonin (SERT) transporter genes, in addition to the expression of miR-132, miR-491, miR-16, and miR-135. Results: We found an increase in DNA methylation at one specific CpG site at DAT1 5'UTR in highly sensitive students reporting high levels of perceived stress when compared to those less sensitive and/or less stressed. Moreover, considering DAT1 VNTR at 3'UTR, we observed that this effect was even more pronounced in university students having the 9/9 genotype when compared to those with the 9/10 genotype. These data are corroborated by the higher levels of miR-491, targeting DAT1, in highly sensitive subjects with high levels of perceived stress. SERT gene DNA methylation at one specific CpG site was reported to instead be higher in subjects reporting lower perceived stress when compared to more stressed subjects. Consistently, miR-135 expression, regulating SERT, was lower in subjects with higher perceived stress. Conclusions: We here suggest that the correlation of DAT1 and SERT genetic and epigenetic data with the analysis of stress and sensitivity might be useful to suggest possible biomarkers to monitor mental health wellness in vulnerable subjects.

Abnormal inter-hemispheric effective connectivity from left to right auditory regions during Mismatch Negativity (MMN) tasks in psychosis

Anomalous Mismatch Negativity (MMN) in psychosis could be a consequence of disturbed neural oscillatory activity at sensory/perceptual stages of stimulus processing. This study investigated effective connectivity within and between the auditory regions during auditory odd-ball deviance tasks. The analyses were performed on two magnetoencephalography (MEG) datasets: one on duration MMN in a cohort with various diagnoses within the psychosis spectrum and neurotypical controls, and one on duration and pitch MMN in first-episode psychosis patients and matched neurotypical controls. We applied spectral Granger causality to MEG source-reconstructed signals to compute effective connectivity within and between the left and right auditory regions. Both experiments showed that duration-deviance detection was associated with early increases of effective connectivity in the beta band followed by increases in the alpha and theta bands, with the connectivity strength linked to the laterality of the MMN amplitude. Compared to controls, people with psychosis had overall smaller effective connectivity, particularly from left to right auditory regions, in the pathway where bilateral information converges toward lateralized processing, often rightward. Blunted MMN in psychosis might reflect a deficit in inter-hemispheric communication between auditory regions, highlighting a “dysconnection” already at preattentive stages of stimulus processing as a model system of widespread pathophysiology.

Effects of color-flavor association on visual search process for reference pictures on beverage packaging: behavioral, electrophysiological, and causal mechanisms.

The visual search for product packaging involves intricate cognitive processes that are prominently impacted by learned associations derived from extensive long-term experiences. The present research employed EEG technology and manipulated the color display of reference pictures on beverage bottles to explore the underlying neurocognitive pathways. Specifically, we aimed to investigate the influence of color-flavor association strength on the visual processing of such stimuli as well as the in-depth neural mechanisms. The behavioral results revealed that stimuli with strong association strength triggered the fastest response and the highest accuracy, compared with the stimuli with weak association strength and the achromatic ones. The EEG findings further substantiated that the chromatic stimuli evoked a more pronounced N2 component than achromatic ones, and the stimuli with strong association strength elicited larger P3 and smaller N400 amplitudes than the ones with weak association strength. Additionally, the source localization using sLORETA showed significant activations in the inferior temporal gyrus. In conclusion, our research suggests that (1) color expectations would guide visual search process and trigger faster responses to congruent visual stimuli, (2) both the initial perceptual representation and subsequent semantic representation play pivotal roles in effective visual search for the targets, and (3) the color-flavor association strength potentially exerts an impact on visual processing by modulating memory accessibility.

The strength of anticipated distractors shapes EEG alpha and theta oscillations in a Working Memory task

Working Memory (WM) requires maintenance of task-relevant information and suppression of task-irrelevant/distracting information. Alpha and theta oscillations have been extensively investigated in relation to WM. However, studies that examine both theta and alpha bands in relation to distractors, encompassing not only power modulation but also connectivity modulation, remain scarce. Here, we depicted, at the EEG-source level, the increase in power and connectivity in theta and alpha bands induced by strong relative to weak distractors during a visual Sternberg-like WM task involving the encoding of verbal items. During retention, a strong or weak distractor was presented, predictable in time and nature. Analysis focused on the encoding and retention phases before distractor presentation. Theta and alpha power were computed in cortical regions of interest, and connectivity networks estimated via spectral Granger causality and synthetized using in/out degree indices. The following modulations were observed for strong vs. weak distractors. In theta band during encoding, the power in frontal regions increased, together with frontal-to-frontal and bottom-up occipital-to-temporal-to-frontal connectivity; even during retention, bottom-up theta connectivity increased. In alpha band during retention, but not during encoding, the power in temporal-occipital regions increased, together with top-down frontal-to-occipital and temporal-to-occipital connectivity. From our results, we postulate a proactive cooperation between theta and alpha mechanisms: the first would mediate enhancement of target representation both during encoding and retention, and the second would mediate increased inhibition of sensory areas during retention only, to suppress the processing of imminent distractor without interfering with the processing of ongoing target stimulus during encoding.

Effects of word presentation during treadmill walking on episodic memory and gait

Entrainment emerges when oscillatory movements synchronize with environmental stimuli processing. The purpose of this experiment was to assess how cognitive-motor entrainment during a dual-task would influence the quality of gait and affect episodic long-term memory. Twenty-one participants (22.56 y/o; 64 % F) walked at preferred paces while listening to 40-item word lists. In separate sessions, unique word lists were presented predictably on every fourth stride, unpredictably related to stepping, or predictably while standing. Memory tests administered 24-hr after encoding revealed that predictable word presentation led to better free-recall performance than unpredicted (p = .044); recognition memory was not impacted. Gait phase parameters during the predicted condition were more stable than the unpredicted condition or baseline assessments. Cognitive-motor entrainment may alleviate dual-task costs and enhance memory retention.

Frontal midline theta power during the cue-target-interval reflects increased cognitive effort in rewarded task-switching

Cognitive performance largely depends on how much effort is invested during task-execution. This also means that we rarely perform as good as we could. Cognitive effort is adjusted to the expected outcome of performance, meaning that it is driven by motivation. The results from recent studies suggest that the expenditure of cognitive control is particularly prone to being affected by modulations of cognitive effort. Although recent EEG studies investigated the neural underpinnings of the interaction of effort and control, reports on how cognitive effort is reflected by oscillatory activity of the EEG are quite sparse. It is the goal of the present study to bridge this gap by performing an exploratory analysis of high-density EEG data from a switching-task using manipulations of monetary incentives. A beamformer approach is used to localize the sensor-level effects in source-space. The results indicate that the manipulation of cognitive effort was successful. The participants reported significantly higher motivation and cognitive effort in high versus low reward trials. Performance was also significantly increased. The analysis of the EEG data revealed that the increase of cognitive effort was reflected by an increased mid-frontal theta activity during the cue-target interval, suggesting an increased use of proactive control. This interpretation is supported by the result from a regression analysis performed on single-trial data, showing higher mid-frontal theta power prior to target-onset being associated with faster responses. Alpha-desynchronization throughout the trial was also more pronounced in high reward trials, signaling a bias of attention towards the processing of external stimuli. Source reconstruction suggests that these effects are located in areas related to cognitive control, and visual processing.

Brain–computer interface for simultaneous dual‐region spatial coding in hippocampal and somatosensory cortex of freely behaving rats

AbstractDecoding of spatial information from place cells is currently limited to individual brain regions, severely constraining the understanding of the brain's spatial navigation mechanisms. In this study, synchronized detection of dual‐brain region spatial encoding was conducted using brain–computer interface (BCI). Therefore, an implantable microelectrode array (MEA) was developed tailored for the simultaneous detection of neuronal activities in the CA1 of the hippocampus and the Barrel Cortex (BC) of the somatosensory cortex in rats as BCI. The MEA was improved by modifying the nanocomposite PtNP/PEDOT:PSS to improve their electrical properties (reducing impedance from 1.82 ± 0.17 MΩ to 3.4 ± 0.3 kΩ), facilitating neural recordings in freely behaving rats. The neural activities were obtained from the CA1 and the BC simultaneously and validated the existence of place cells in both brain regions. This study highlighted the potential of PtNP/PEDOT:PSS‐modified MEA as BCI in concurrently detecting neural activity associated with spatial encoding in two brain regions, offering novel perspectives on the processing of tactile stimuli and the formation of cognitive maps for navigation.

Homosexual and Heterosexual men present characteristic patterns of cortical synchronization in response to Visual Sexual Stimuli.

Since several cortical areas participate in the processing of sexual stimuli, this study characterized the electroencephalographic activity of prefrontal, temporal and parietal areas in men with different sexual orientation while observing erotic videos with homosexual (HOV) and heterosexual (HEV) content. The homosexual group presented lower absolute power of theta band in the right temporal cortex and higher right fronto-temporal correlation of beta band when observing the HOV. While the heterosexual group rated only the HEV as pleasant, also presented a higher left fronto-temporal correlation of beta band while watching the HEV, and a lower right fronto-parietal correlation of theta band during observation of the HOV. These results show a characteristic cortical functionality involved in the processing of sexually-relevant stimuli and its possible association with sexual orientation.

Neuronal Remodelling as a Predictor of Autism Spectrum Disorder Diagnosis

People with Autism Spectrum Disorder (ASD) are a neurodevelopmental symptom group characterized by significant deficits in information connectivity, mainly caused by specific genetic mutations affecting the fluency of the gamma-aminobutyric acid (GABAergic) system. This disruption, to a greater or lesser degree, hinders the interactive process of incoming stimuli with previously stored information, preventing working memory from fulfilling its role of facilitating access to information in permanent memory and later recovery. In addition to the genetic components, environmental processes occurring, above all, in early childhood, related to specific organic and severe psycho-emotional diseases can produce the same effects in the brain system as the genetic karyotypic component through the concept of neuronal remodelling. In this sense, this research aims to empirically show the influence of neuronal remodelling on the GABAergic pathway leading to the traits of autism spectrum behaviour. A total of 175 participants from the three levels of ASD intensity have participated in this study. Data have been analysed through Linear Logistic Regression, which shows that both components, the genetic process and the environmental process, significantly influence the neural connective pathway that relates information, unlike other operationalized covariates, such as gender or age of the participants. Likewise, as shown by the Chi-Square Test, the interactions between genetic and environmental variables showed no differences in their interaction regarding the connectivity level that would explain the different levels of disorder. However, when there is a combination of genetic mutations in the diagnostic karyotype, there are significant differences between the genetic group and the environmental process over the neural network.

The role of attentional control in moderating attentional bias towards game-related stimuli in individuals with a high tendency for internet gaming addiction.

The aim of this study was to elucidate individual difference factors that modulate the attentional processing of game stimuli to explain the heterogeneity of extant findings. The current study examined whether individual differences in components of attentional control (AC-shifting and AC-focusing) moderated the link between internet gaming addiction symptom and attentional engagement to and disengagement biases from game-relevant cues. A total of 75 male undergraduate students who have played League of Legend (LOL) for more than 2 years completed well-established self-report questionnaires of internet gaming disorder symptoms and attentional control. The attentional bias toward game stimuli was measured for attentional engagement and disengagement using the attentional response to the distal vs. proximal emotional information (ARDPEI) task. The results revealed that attentional control was a significant moderator of the relationship between internet game addiction symptoms and attentional disengagement bias. Further analyses revealed a positive relationship between internet game addiction symptoms and attentional disengagement bias only among those with low levels of AC-shifting ability. Contrary to our expectations, AC-shifting also moderated the relationship between internet gaming disorder and attentional engagement bias. The positive relationship between internet game addiction symptoms and attentional engagement bias only appeared among those with low levels of AC-shifting ability. Individual differences in AC-focusing did not moderate the relationship between internet gaming disorder and any attentional bias. This study confirmed that the greater the symptoms of game addiction, the stronger the attentional bias, especially in individuals with low AC-shifting ability. Therefore, it is necessary to examine sub-factors of AC in understanding the nature of attentional bias mechanisms in the development of internet game addiction and consider it as a psychological intervention to improve attentional bias.

Physical effort modulates perceptual awareness judgment independent of level of processing

Recent studies have emphasized the association between action and perceptual awareness, suggesting that action-related information can contribute to perceptual awareness. Given that the Level of Processing (LoP) hypothesis proposes that the emergence of awareness depends on the level of stimulus processing, the current study examines whether action impacts perceptual awareness across different processing levels. In Experiment 1, participants identified target stimuli’s color (low-level task) or category (high-level task) via mouse clicks, followed by visual awareness ratings. Experiment 2 replicated the tasks using hand-grip dynamometers. Results from Experiment 1 support the LoP theory, showing a more gradual emergence of awareness for low-level features and a more dichotomous emergence for high-level features. In Experiment 2, higher reported visual awareness ratings were observed at greater physical effort, regardless of task type. These results suggest that action-related information influences reported awareness of stimuli in the same way at low- and high-level stimulus processing.

Emotion perception through the nose: how olfactory emotional cues modulate the perception of neutral facial expressions in affective disorders

Humans can decode emotional states from the body odors of the conspecifics and this type of emotional communication is particularly relevant in conditions in which social interactions are impaired, as in depression and social anxiety. The present study aimed to explore how body odors collected in happiness and fearful conditions modulate the subjective ratings, the psychophysiological response and the neural processing of neutral faces in individuals with depressive symptoms, social anxiety symptoms, and healthy controls (N = 22 per group). To this aim, electrocardiogram (ECG) and HD-EEG were recorded continuously. Heart Rate Variability (HRV) was extracted from the ECG as a measure of vagal tone, event-related potentials (ERPs) and event-related spectral perturbations (ERPSs) were extracted from the EEG. The results revealed that the HRV increased during the fear and happiness body odors conditions compared to clean air, but no group differences emerged. For ERPs data, repeated measure ANOVA did not show any significant effects. However, the ERPSs analyses revealed a late increase in delta power and a reduced beta power both at an early and a late stage of stimulus processing in response to the neutral faces presented with the emotional body odors, regardless of the presence of depressive or social anxiety symptoms. The current research offers new insights, demonstrating that emotional chemosignals serve as potent environmental cues. This represents a substantial advancement in comprehending the impact of emotional chemosignals in both individuals with and without affective disorders.

Independent replications reveal anterior and posterior cingulate cortex activation underlying state anxiety-attenuated face encoding

Anxiety involves the anticipation of aversive outcomes and can impair neurocognitive processes, such as the ability to recall faces encoded during the anxious state. It is important to precisely delineate and determine the replicability of these effects using causal state anxiety inductions in the general population. This study therefore aimed to replicate prior research on the distinct impacts of threat-of-shock-induced anxiety on the encoding and recognition stage of emotional face processing, in a large asymptomatic sample (n = 92). We successfully replicated previous results demonstrating impaired recognition of faces encoded under threat-of-shock. This was supported by a mega-analysis across three independent studies using the same paradigm (n = 211). Underlying this, a whole-brain fMRI analysis revealed enhanced activation in the posterior cingulate cortex (PCC), alongside previously seen activity in the anterior cingulate cortex (ACC) when combined in a mega-analysis with the fMRI findings we aimed to replicate. We further found replications of hippocampus activation when the retrieval and encoding states were congruent. Our results support the notion that state anxiety disrupts face recognition, potentially due to attentional demands of anxious arousal competing with affective stimuli processing during encoding and suggest that regions of the cingulate cortex play pivotal roles in this.

Listen to your heart: Trade-off between cardiac interoceptive processing and visual exteroceptive processing

Internal bodily signals, such as heartbeats, can influence conscious perception of external sensory information. Spontaneous shifts of attention between interoception and exteroception have been proposed as the underlying mechanism, but direct evidence is lacking. Here, we used steady-state visual evoked potential (SSVEP) frequency tagging to independently measure the neural processing of visual stimuli that were concurrently presented but varied in heartbeat coupling in healthy participants. Although heartbeat coupling was irrelevant to participants’ task of detecting brief color changes, we found decreased SSVEPs for systole-coupled stimuli and increased SSVEPs for diastole-coupled stimuli, compared to non-coupled stimuli. These results suggest that attentional and representational resources allocated to visual stimuli vary according to fluctuations in cardiac-related signals across the cardiac cycle, reflecting spontaneous and immediate competition between cardiac-related signals and visual events. Furthermore, frequent coupling of visual stimuli with stronger cardiac-related signals not only led to a larger heartbeat evoked potential (HEP) but also resulted in a smaller color change evoked N2 component, with the increase in HEP amplitude associated with a decrease in N2 amplitude. These findings indicate an overall or longer-term increase in brain resources allocated to the internal domain at the expense of reduced resources available for the external domain. Our study highlights the dynamic reallocation of limited processing resources across the internal-external axis and supports the trade-off between interoception and exteroception.

Behavioral and neural correlates of diverse conditioned fear responses in male and female rats.

Pavlovian fear conditioning is a widely used tool that models associative learning in rodents. For decades the field has used predominantly male rodents and focused on a sole conditioned fear response: freezing. However, recent work from our lab and others has identified darting as a female-biased conditioned response, characterized by an escape-like movement across a fear conditioning chamber. It is also accompanied by a behavioral phenotype: Darters reliably show decreased freezing compared to Non-darters and males and reach higher velocities in response to the foot shock ("shock response"). However, the relationship between shock response and conditioned darting is not known. This study investigated if this link is due to differences in general processing of aversive stimuli between Darters, Non-darters and males. Across a variety of modalities, including corticosterone measures, the acoustic startle test, and sensitivity to thermal pain, Darters were found not to be more reactive or sensitive to aversive stimuli, and, in some cases, they appear less reactive to Non-darters and males. Analyses of cFos activity in regions involved in pain and fear processing following fear conditioning identified discrete patterns of expression among Darters, Non-darters, and males exposed to low and high intensity foot shocks. The results from these studies further our understanding of the differences between Darters, Non-darters and males and highlight the importance of studying individual differences in fear conditioning as indicators of fear state.

Beyond primary visual cortex: The leading role of lateral occipital complex in early conscious visual processing

The study of the neural substrates that serve conscious vision is one of the unsolved questions of cognitive neuroscience. So far, consciousness literature has endeavoured to disentangle which brain areas and in what order are involved in giving rise to visual awareness, but the problem of consciousness still remains unsolved. Availing of two different but complementary sources of data (i.e., Fast Optical Imaging and EEG), we sought to unravel the neural dynamics responsible for the emergence of a conscious visual experience. Our results revealed that conscious vision is characterized by a significant increase of activation in extra-striate visual areas, specifically in the Lateral Occipital Complex (LOC), and that, more interestingly, such activity occurred in the temporal window of the ERP component commonly thought to represent the electrophysiological signature of visual awareness, i.e., the Visual Awareness Negativity (VAN). Furthermore, Granger causality analysis, performed to further investigate the flow of activity occurring in the investigated areas, unveiled that neural processes relating to conscious perception mainly originated in LOC and subsequently spread towards visual and motor areas. In general, the results of the present study seem to advocate for an early contribution of LOC in conscious vision, thus suggesting that it could represent a reliable neural correlate of visual awareness. Conversely, striate visual areas, showing awareness-related activity only in later stages of stimulus processing, could be part of the cascade of neural events following awareness emergence.

Reduced spatial frequency differentiation and sex-related specificities in fearful face detection in autism: Insights from EEG and the predictive brain model.

Face processing relies on predictive processes driven by low spatial frequencies (LSF) that convey coarse information prior to fine information conveyed by high spatial frequencies. However, autistic individuals might have atypical predictive processes, contributing to facial processing difficulties. This may be more normalized in autistic females, who often exhibit better socio-communicational abilities than males. We hypothesized that autistic females would display a more typical coarse-to-fine processing for socio-emotional stimuli compared to autistic males. To test this hypothesis, we asked adult participants (44 autistic, 51 non-autistic) to detect fearful faces among neutral faces, filtered in two orders: from coarse-to-fine (CtF) and from fine-to-coarse (FtC). Results show lower d' values and longer reaction times for fearful detection in autism compared to non-autistic (NA) individuals, regardless of the filtering order. Both groups presented shorter P100 latency after CtF compared to FtC, and larger amplitude for N170 after FtC compared to CtF. However, autistic participants presented a reduced difference in source activity between CtF and FtC in the fusiform. There was also a more spatially spread activation pattern in autistic females compared to NA females. Finally, females had faster P100 and N170 latencies, as well as larger occipital activation for FtC sequences than males, irrespective of the group. Overall, the results do not suggest impaired predictive processes from LSF in autism despite behavioral differences in fear detection. However, they do indicate reduced brain modulation by spatial frequency in autism. In addition, the findings highlight sex differences that warrant consideration in understanding autistic females.

A review of the impact of sensory processing sensitivity on mental health in university students.

The concept of sensory processing sensitivity (SPS) was first introduced by Aron and Aron (1996) as an innate trait characterized by heightened processing of sensory, emotional, and physical stimuli. Since the concept's introduction in 1996, high SPS has been shown to be associated with poor physical and mental health. It is possible that this is especially true in university students, who are frequently faced with numerous stressors, such as intense workloads and test anxiety. This article is a systematic literature review conducted through EBSCOHost using the following databases: Academic Search Complete, APA PsycArticles, APA PsycInfo, Education Research Complete, ERIC, MEDLINE Complete, and SocINDEX. Search terms included terms regarding high sensory processing sensitivity, university or professional students, and mental health. A total of 6 studies were included. University students with high SPS experienced heightened reactions to sensory, emotional, and physical stimuli. The studies demonstrate correlations of high SPS with outcomes such as depressive tendencies and difficulty adjusting to college. These findings highlight that SPS is associated with poor mental health outcomes. The results underscore the importance of developing support methods for students with high SPS. Future studies should further explore SPS in university students to develop targeted support methods and programs.