Neural correlates of metacognition: Disentangling the brain circuits underlying prospective and retrospective second-order judgments through noninvasive brain stimulation.

Metacognition encompasses the capability to monitor and control one's cognitive processes, with metamemory and metadecision configuring among the most studied higher order functions. Although imaging experiments evaluated the role of disparate brain regions, neural substrates of metacognitive judgments remain undetermined. The aim of this systematic review is to summarize and discuss the available evidence concerning the neural bases of metacognition which has been collected by assessing the effects of noninvasive brain stimulation (NIBS) on human subjects' metacognitive capacities. Based on such literature analysis, our goal is, at first, to verify whether prospective and retrospective second-order judgments are localized within separate brain circuits and, subsequently, to provide compelling clues useful for identifying new targets for future NIBS studies. The search was conducted following the preferred reporting items for systematic reviews and meta-analyses guidelines among PubMed, PsycINFO, PsycARTICLES, PSYNDEX, MEDLINE, and ERIC databases. Overall, 25 studies met the eligibility criteria, yielding a total of 36 experiments employing transcranial magnetic stimulation and 16 ones making use of transcranial electrical stimulation techniques, including transcranial direct current stimulation and transcranial alternating current stimulation. Importantly, we found that both perspective and retrospective judgments about both memory and perceptual decision-making performances depend on the activation of the anterior and lateral portions of the prefrontal cortex, as well as on the activity of more caudal regions such as the premotor cortex and the precuneus. Combining this evidence with results from previous imaging and lesion studies, we advance ventromedial prefrontal cortex as a promising target for future NIBS studies.

Value Estimation versus Effort Mobilization: A General Dissociation between Ventromedial and Dorsomedial Prefrontal Cortex.

Deciding on a course of action requires both an accurate estimation of option values and the right amount of effort invested in deliberation to reach sufficient confidence in the final choice. In a previous study, we have provided evidence, across a series of judgment and choice tasks, for a dissociation between the ventromedial prefrontal cortex (vmPFC), which would represent option values, and the dorsomedial prefrontal cortex (dmPFC), which would represent the duration of deliberation. Here, we first replicate this dissociation and extend it to the case of an instrumental learning task, in which 24 human volunteers (13 women) choose between options associated with probabilistic gains and losses. According to fMRI data recorded during decision-making, vmPFC activity reflects the sum of option values generated by a reinforcement learning model and dmPFC activity the deliberation time. To further generalize the role of the dmPFC in mobilizing effort, we then analyze fMRI data recorded in the same participants while they prepare to perform motor and cognitive tasks (squeezing a handgrip or making numerical comparisons) to maximize gains or minimize losses. In both cases, dmPFC activity is associated with the output of an effort regulation model, and not with response time. Taken together, these results strengthen a general theory of behavioral control that implicates the vmPFC in the estimation of option values and the dmPFC in the energization of relevant motor and cognitive processes.

Neural correlates of confidence during decision formation in a perceptual judgment task.

When we make a decision, we also estimate the probability that our choice is correct or accurate. This probability estimate is termed our degree of decision confidence. Recent work has reported event-related potential (ERP) correlates of confidence both during decision formation (the centro-parietal positivity component; CPP) and after a decision has been made (the error positivity component; Pe). However, there are several measurement confounds that complicate the interpretation of these findings. More recent studies that overcome these issues have so far produced conflicting results. To better characterise the ERP correlates of confidence we presented participants with a comparative brightness judgment task while recording electroencephalography. Participants judged which of two flickering squares (varying in luminance over time) was brighter on average. Participants then gave confidence ratings ranging from "surely incorrect" to "surely correct". To elicit a range of confidence ratings we manipulated both the mean luminance difference between the brighter and darker squares (relative evidence) and the overall luminance of both squares (absolute evidence). We found larger CPP amplitudes in trials with higher confidence ratings. This association was not simply a by-product of differences in relative evidence (which covaries with confidence) across trials. We did not identify postdecisional ERP correlates of confidence, except when they were artificially produced by pre-response ERP baselines. These results provide further evidence for neural correlates of processes that inform confidence judgments during decision formation.

Cross-cultural differences in prefrontal cortex activity in moral judgment: A functional near-infrared spectroscopy (fNIRS) study based on the CNI model.

BACKGROUND: In the past, comparative cultural neurological studies of moral judgments have mainly focused on Eastern and Western groups. We initially examined Japanese and Chinese groups, both East Asian cultures. We utilized a recently proposed polynomial model known as the "consequences, norms, and generalized inaction" (CNI) model to investigate the variations in the overall prefrontal cortex activity between these two groups during moral judgment. METHODS: We employed functional near-infrared spectroscopy (fNIRS) to analyze the prefrontal cortex (PFC) activity within a CNI model of moral judgment among 23 healthy Japanese and 26 healthy Chinese adults. RESULTS AND CONCLUSIONS: Our study revealed significant differences in the PFC activation between Japanese and Chinese individuals in the CNI moral judgment task context. Specifically, during the CNI task, Chinese men exhibited higher right dorsolateral prefrontal cortex (R-DLPFC) activity than Chinese women. In contrast, Japanese women showed greater left dorsolateral prefrontal cortex (L-DLPFC) activity than Japanese men. In an international comparison, R-DLPFC activity was higher in Chinese men than in Japanese men. Conversely, the left ventrolateral prefrontal cortex activity was higher in Japanese men compared to Chinese men. Additionally, among women, the right ventromedial prefrontal cortex activity was higher in Japanese women than in Chinese women. In conclusion, our findings support the perspective of cultural psychology and identify cultural and sex differences in PFC activity between Japanese and Chinese individuals.

Multisensory perception depends on the reliability of the type of judgment.

The brain engages the processes of multisensory integration and recalibration to deal with discrepant multisensory signals. These processes consider the reliability of each sensory input, with the more reliable modality receiving the stronger weight. Sensory reliability is typically assessed via the variability of participants' judgments, yet these can be shaped by factors both external and internal to the nervous system. For example, motor noise and participant's dexterity with the specific response method contribute to judgment variability, and different response methods applied to the same stimuli can result in different estimates of sensory reliabilities. Here we ask how such variations in reliability induced by variations in the response method affect multisensory integration and sensory recalibration, as well as motor adaptation, in a visuomotor paradigm. Participants performed center-out hand movements and were asked to judge the position of the hand or rotated visual feedback at the movement end points. We manipulated the variability, and thus the reliability, of repeated judgments by asking participants to respond using either a visual or a proprioceptive matching procedure. We find that the relative weights of visual and proprioceptive signals, and thus the asymmetry of multisensory integration and recalibration, depend on the reliability modulated by the judgment method. Motor adaptation, in contrast, was insensitive to this manipulation. Hence, the outcome of multisensory binding is shaped by the noise introduced by sensorimotor processing, in line with perception and action being intertwined.NEW & NOTEWORTHY Our brain tends to combine multisensory signals based on their respective reliability. This reliability depends on sensory noise in the environment, noise in the nervous system, and, as we show here, variability induced by the specific judgment procedure.

Embracing beauty through leftward movements: An ERP study on metaphorical association between hand actions and aesthetic judgments.

In this study, we examined the metaphorical association between aesthetic judgments of faces and horizontal hand movements as well as their cognitive neural mechanisms using a joint categorical response task. In the "aesthetic-action" metaphorical representation situation, participants were asked to classify beautiful/ugly faces by moving the mouse to the left or the right. The results showed that the joint categorization condition "judge beautiful-move mouse left, judge ugly-move mouse right" had a shorter reaction time than the "judge beautiful-move mouse right, judge ugly-move mouse left" condition, which was accompanied by larger amplitudes of the early component N170, EPN, and the late component P300. Combining the behavioral and event-related potentials (ERPs) results, the present study demonstrated a metaphorical association between horizontal hand actions and aesthetic judgments. It suggested that horizontal hand actions can affect the speed of aesthetic judgments by influencing processing fluency, emotional arousal level, categorization motivation, and attentional resources. These findings provide new perspectives to better understand the cognitive process of aesthetic judgments and provide a basis for applying embodied cognition and metaphor theory to the field of aesthetic psychology.

Negative emotionality downregulation affects moral choice but not moral judgement of harm: a pharmacological study.

Previous neuroscientific research has expounded on the fundamental role played by emotion during moral decision-making. Negative emotionality has been observed to exert a general inhibitory effect towards harmful behaviors against others. Nevertheless, the downregulation of negative affects at different levels of moral processing (e.g. impersonal versus personal moral dilemmas) alongside its possible interactions with other factors (e.g. perspective taking) hasn't been directly assessed; both of which can assist in predicting future moral decision-making. In the present research, we empirically test (Study 1, N = 41) whether downregulating negative emotionality through pharmacological interventions using lorazepam (a GABA receptor agonist), modulate the permissibility of harm to others -i.e. if participants find it more morally permissible to harm others when harm is unavoidable (inevitable harm moral dilemmas), than when it may be avoided (evitable harm moral dilemmas). Furthermore, using another sample (Study 2, N = 31), we assess whether lorazepam's effect is modulated by different perspective-taking conditions during a moral dilemma task -e.g. "is it morally permissible for you to […]?" (1st person perspective), relative to "is it morally permissible for [x individual] to […]?" (3rd person perspective)-, where the outcome of the different scenarios is controlled. The results of both studies converge, revealing an emotion-dependent, rather than an outcome-dependent, pharmacological modulation. Lorazepam only influenced interpersonal moral judgments when not modulated by the evitable/inevitable condition. Furthermore, there was a significant interaction between perspective-taking and drug administration, as lorazepam exerted a larger effect in modulating moral choices rather than moral judgements.

Two social minds in one brain? error-related negativity provides evidence for parallel processing pathways during social evaluation.

Several authors assume that evaluative conditioning (EC) relies on high-level propositional thinking. In contrast, the dual-process perspective proposes two processing pathways, one associative and the other propositional, contributing to EC. Dual-process theorists argue that attitudinal ambiguity resulting from these two pathways' conflicting evaluations demonstrate the involvement of both automatic and controlled processes in EC. Previously, we suggested that amplitude variations of error-related negativity and error-positivity, two well-researched event-related potentials of performance monitoring, allow for the detection of attitudinal ambiguity at the neural level. The present study utilises self-reported evaluation, categorisation performance, and neural correlates of performance monitoring to explore associative-propositional ambiguity during social attitude formation. Our results show that compared to associative-propositional harmony, attitudinal ambiguity correlates with more neutral subjective evaluations, longer response times, increased error commission, and diminished error-related negativity amplitudes. While our findings align with dual-process models, we aim to offer a propositional interpretation. We discuss dual-process theories in the context of evolutionary psychology, suggesting that associative processes may only represent a small piece of the EC puzzle.

Does cross-modal correspondence modulate modality-specific perceptual processing? Study using timing judgment tasks.

Cross-modal correspondences refer to associations between stimulus features across sensory modalities. Previous studies have shown that cross-modal correspondences modulate reaction times for detecting and identifying stimuli in one modality when uninformative stimuli from another modality are present. However, it is unclear whether such modulation reflects changes in modality-specific perceptual processing. We used two psychophysical timing judgment tasks to examine the effects of audiovisual correspondences on visual perceptual processing. In Experiment 1, we conducted a temporal order judgment (TOJ) task that asked participants to judge which of two visual stimuli presented with various stimulus onset asynchronies (SOAs) appeared first. In Experiment 2, we conducted a simultaneous judgment (SJ) task that asked participants to report whether the two visual stimuli were simultaneous or successive. We also presented an unrelated auditory stimulus, simultaneously or preceding the first visual stimulus, and manipulated the congruency between audiovisual stimuli. Experiment 1 indicated that the points of subjective simultaneity (PSSs) between the two visual stimuli estimated in the TOJ task shifted according to the audiovisual correspondence between the auditory pitch and visual features of vertical location and size. However, these audiovisual correspondences did not affect PSS estimated using the SJ task in Experiment 2. The different results of the two tasks can be explained through the response bias triggered by audiovisual correspondence that only the TOJ task included. We concluded that audiovisual correspondence would not modulate visual perceptual timing and that changes in modality-specific perceptual processing might not trigger the congruency effects reported in previous studies.

The development of modal intuitions: A test of two accounts.

Young children, unlike adults, deny that improbable events can happen. We test two accounts explaining this developmental shift. The development = reflection account posits that this shift is driven by an emerging ability to reflect on modal intuitions. In contrast, the development = intuition account posits that this shift is driven by changes in modal intuitions themselves, due to age-related changes in what people know and how they sample their knowledge and memories. These accounts make competing predictions about how long children and adults should take to make possibility judgments. In Experiment 1, we asked 123 children (39 5-year-olds, 42 7-year-olds, 42 9-year-olds; 49.60% White) and 40 adults (50% White) to judge the possibility of 78 ordinary, improbable, and impossible events and recorded their response times. In Experiment 2, we tested an additional 52 adults (42.32% White) who were under speeded conditions and thus less able to reflect before responding. Our results favor the development = intuition account. At all ages, people judged improbable events more slowly than ordinary or impossible events, and slow responding did not consistently predict affirmation over denial. Further, adults' possibility judgments did not change under speeded conditions. We also fit a drift-diffusion model to our data, which suggested that adults and children may sample different kinds of knowledge when generating intuitions. Our findings suggest that possibility judgments are often driven by modal intuitions with little reflection, and that a developmental shift in what children know and how knowledge is retrieved can explain why these intuitions change over time. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The brain dynamics of visuospatial perspective-taking captured by intracranial EEG.

Visuospatial perspective-taking (VPT) is the ability to imagine a scene from a position different from the one used in self-perspective judgments (SPJ). We typically use VPT to understand how others see the environment. VPT requires overcoming the self-perspective, and impairments in this process are implicated in various brain disorders, such as schizophrenia and autism. However, the underlying brain areas of VPT are not well distinguished from SPJ-related ones and from domain-general responses to both perspectives. In addition, hierarchical processing theory suggests that domain-specific processes emerge over time from domain-general ones. It mainly focuses on the sensory system, but outside of it, support for this hypothesis is lacking. Therefore, we aimed to spatiotemporally distinguish brain responses domain-specific to VPT from the specific ones to self-perspective, and domain-general responses to both perspectives. In particular, we intended to test whether VPT- and SPJ specific responses begin later than the general ones. We recorded intracranial EEG data from 30 patients with epilepsy who performed a task requiring laterality judgments during VPT and SPJ, and analyzed the spatiotemporal features of responses in the broad gamma band (50-150 Hz). We found VPT-specific processing in a more extensive brain network than SPJ-specific processing. Their dynamics were similar, but both differed from the general responses, which began earlier and lasted longer. Our results anatomically distinguish VPT-specific from SPJ-specific processing. Furthermore, we temporally differentiate between domain-specific and domain-general processes both inside and outside the sensory system, which serves as a novel example of hierarchical processing.

Test of Practical Judgment (TOP-J): Construct, Criterion, and Incremental Validity in a Community Sample of Older Adults.

OBJECTIVE: The Test of Practical Judgment (TOP-J) is a stand-alone judgment measure that is considered to tap into aspects of executive functioning (EF) and inform clinical predictions of daily functioning in older adults. Past validation research is variable and has some limitations. The present study sought to examine the reliability and construct, criterion, and incremental validities of scores on TOP-J 9-item version (TOP-J/9). METHOD: Participants were 95 community-dwelling older adults aged 60 to 85. Participants completed TOP-J/9, measures of EF and global cognition, and three different modalities of instrumental activities of daily living (IADLs) (self-report, performance-based tasks conducted in the laboratory, and performance-based tasks completed at home over 3 weeks). RESULTS: TOP-J/9 scores showed adequate internal consistency (α = 0.73) after correcting for the low number of items. TOP-J/9 was correlated with global cognition and EF, although EF did not survive correction for lower-order processes. Finally, although TOP-J/9 scores were associated with home-based IADL tasks (but not with self-report and laboratory-based IADLs), providing some evidence of criterion validity, they did not incrementally contribute to home-based IADL performance beyond other cognitive measures. However, when two items pertaining to social/ethical judgment were removed, this modified version of TOP-J did relate to EF beyond lower-order processes and contributed uniquely to prediction of home-based IADLs beyond other measures. CONCLUSION: Results suggest that TOP-J/9 taps into global cognitive status (but not necessarily EF) and predicts "real-world" functioning (but not above and beyond other cognitive measures). TOP-J psychometrics may be improved by removing two social/ethical items.

Adaptive adjustment after conflict with group opinion: evidence from neural electrophysiology.

Individuals inherently seek social consensus when making decisions or judgments. Previous studies have consistently indicated that dissenting group opinions are perceived as social conflict that demands attitude adjustment. However, the neurocognitive processes of attitude adjustment are unclear. In this electrophysiological study, participants were recruited to perform a face attractiveness judgment task. After forming their own judgment of a face, participants were informed of a purported group judgment (either consistent or inconsistent with their judgment), and then, critically, the same face was presented again. The neural responses to the second presented faces were measured. The second presented faces evoked a larger late positive potential after conflict with group opinions than those that did not conflict, suggesting that more motivated attention was allocated to stimulus. Moreover, faces elicited greater midfrontal theta (4-7 Hz) power after conflict with group opinions than after consistency with group opinions, suggesting that cognitive control was initiated to support attitude adjustment. Furthermore, the mixed-effects model revealed that single-trial theta power predicted behavioral change in the Conflict condition, but not in the No-Conflict condition. These findings provide novel insights into the neurocognitive processes underlying attitude adjustment, which is crucial to behavioral change during conformity.

The impact of crossmodal predictions on the neural processing of aesthetic stimuli.

Neuroaesthetic research has focused on neural predictive processes involved in the encounter with art stimuli or the related evaluative judgements, and it has been mainly conducted unimodally. Here, with electroencephalography, magnetoencephalography and an affective priming protocol, we investigated whether and how the neural responses to non-representational aesthetic stimuli are top-down modulated by affective representational (i.e. semantically meaningful) predictions between audition and vision. Also, the neural chronometry of affect processing of these aesthetic stimuli was investigated. We hypothesized that the early affective components of crossmodal aesthetic responses are dependent on the affective and representational predictions formed in another sensory modality resulting in differentiated brain responses, and that audition and vision indicate different processing latencies for affect. The target stimuli were aesthetic visual patterns and musical chords, and they were preceded by a prime from the opposing sensory modality. We found that early auditory-cortex responses to chords were more affected by valence than the corresponding visual-cortex ones. Furthermore, the assessments of visual targets were more facilitated by affective congruency of crossmodal primes than the acoustic targets. These results indicate, first, that the brain uses early affective information for predictively guiding aesthetic responses; second, that an affective transfer of information takes place crossmodally, mainly from audition to vision, impacting the aesthetic assessment. This article is part of the theme issue 'Art, aesthetics and predictive processing: theoretical and empirical perspectives'.

Probability, measurement mismatches, and sacrificial moral decision-making.

Despite the importance of uncertainty in decision-making, few published studies have examined how individuals make moral judgments under uncertainty. Across four experiments (N = 445), we examined whether a relatively small shift in probability affected participants' judgments of both moral acceptability and choice. Overall, reading dilemmas where the characters were either certain or likely to die, the probability of the sacrificed individual and the group at risk dying both had independent effects on participants' responses. That is, participants were more accepting of sacrificing the individual if they were not certain to die, but less accepting if the group was only likely to die when the individual was not sacrificed. Furthermore, a number of participants made acceptability ratings that did not match the action they endorsed, either finding the sacrificial decision more acceptable but refusing to make it, or choosing the sacrificial decision while viewing it as less acceptable. Many participants also stated that this was because they recognised a crucial difference between what they viewed as morally acceptable in a dilemma and what they were actually willing to do. Such mismatches may reflect the sensitivity and complexity of the moral principles that individuals employ during their moral decision-making.

Sparsity in an artificial neural network predicts beauty: Towards a model of processing-based aesthetics.

Generations of scientists have pursued the goal of defining beauty. While early scientists initially focused on objective criteria of beauty ('feature-based aesthetics'), philosophers and artists alike have since proposed that beauty arises from the interaction between the object and the individual who perceives it. The aesthetic theory of fluency formalizes this idea of interaction by proposing that beauty is determined by the efficiency of information processing in the perceiver's brain ('processing-based aesthetics'), and that efficient processing induces a positive aesthetic experience. The theory is supported by numerous psychological results, however, to date there is no quantitative predictive model to test it on a large scale. In this work, we propose to leverage the capacity of deep convolutional neural networks (DCNN) to model the processing of information in the brain by studying the link between beauty and neuronal sparsity, a measure of information processing efficiency. Whether analyzing pictures of faces, figurative or abstract art paintings, neuronal sparsity explains up to 28% of variance in beauty scores, and up to 47% when combined with a feature-based metric. However, we also found that sparsity is either positively or negatively correlated with beauty across the multiple layers of the DCNN. Our quantitative model stresses the importance of considering how information is processed, in addition to the content of that information, when predicting beauty, but also suggests an unexpectedly complex relationship between fluency and beauty.

Systematic testing of three Language Models reveals low language accuracy, absence of response stability, and a yes-response bias.

Humans are universally good in providing stable and accurate judgments about what forms part of their language and what not. Large Language Models (LMs) are claimed to possess human-like language abilities; hence, they are expected to emulate this behavior by providing both stable and accurate answers, when asked whether a string of words complies with or deviates from their next-word predictions. This work tests whether stability and accuracy are showcased by GPT-3/text-davinci-002, GPT-3/text-davinci-003, and ChatGPT, using a series of judgment tasks that tap on 8 linguistic phenomena: plural attraction, anaphora, center embedding, comparatives, intrusive resumption, negative polarity items, order of adjectives, and order of adverbs. For every phenomenon, 10 sentences (5 grammatical and 5 ungrammatical) are tested, each randomly repeated 10 times, totaling 800 elicited judgments per LM (total n = 2,400). Our results reveal variable above-chance accuracy in the grammatical condition, below-chance accuracy in the ungrammatical condition, a significant instability of answers across phenomena, and a yes-response bias for all the tested LMs. Furthermore, we found no evidence that repetition aids the Models to converge on a processing strategy that culminates in stable answers, either accurate or inaccurate. We demonstrate that the LMs' performance in identifying (un)grammatical word patterns is in stark contrast to what is observed in humans (n = 80, tested on the same tasks) and argue that adopting LMs as theories of human language is not motivated at their current stage of development.

Opening the Black Box: Agreement and Reliability of a Situational Judgment Test Across Multiple Institutions.

OBJECTIVE: The primary objective of this study was to examine the levels of agreement and reliability of a situational judgment test (SJT) using a diverse pool of pharmacy practice faculty as subject matter experts. Secondary aims included analyses to build support for test validity and fairness. METHODS: An SJT containing 18 scenarios and 118 responses assessing empathy, integrity, and teamwork was developed and delivered to pharmacy practice faculty at 5 schools of pharmacy across the United States. Reliability was assessed by examining internal consistency, inter-rater reliability, and split-half reliability. Only responses which attained an inter-rater agreement>0.7 were included in the final version of the SJT. All responses were scored using a near-miss system, allowing higher scores for answers more closely aligned with the key, which was determined by the faculty who completed the SJT. Test fairness was reported using descriptive statistics. RESULTS: Thirty-nine faculty across the 5 participating institutions completed the SJT. The final version of the SJT included 105 responses, achieving an inter-rater agreement of>0.7 (inter-rater reliability of 0.98). Split-half reliability was 0.72. The average score was 85.7%, and no differences in performance were observed based on demographic characteristics. CONCLUSION: An SJT designed to assess empathy, integrity, and teamwork achieved reasonable levels of reliability among pharmacy practice faculty across the United States, and the results provided initial support for test validity and fairness. These results support a pilot to assess this SJT among students representing multiple institutions.

The best fitting of three contemporary observer models reveals how participants' strategy influences the window of subjective synchrony.

When experimenters vary the timing between two intersensory events, and participants judge their simultaneity, an inverse-U-shaped psychometric function is obtained. Typically, this simultaneity function is first fitted with a model for each participant separately, before best-fitting parameters are utilized (e.g., compared across conditions) in the second stage of a two-step inferential procedure. Often, simultaneity-function width is interpreted as representing sensitivity to asynchrony, and/or ascribed theoretical equivalence to a window of multisensory temporal binding. Here, we instead fit a single (principled) multilevel model to data from the entire group and across several conditions at once. By asking 20 participants to sometimes be more conservative in their judgments, we demonstrate how the width of the simultaneity function is prone to strategic change and thus questionable as a measure of either sensitivity to asynchrony or multisensory binding. By repeating our analysis with three different models (two implying a decision based directly on subjective asynchrony, and a third deriving this decision from the correlation between filtered responses to sensory inputs) we find that the first model, which hypothesizes, in particular, Gaussian latency noise and difficulty maintaining the stability of decision criteria across trials, is most plausible for these data. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The characteristics of audiovisual temporal integration in streaming-bouncing bistable motion perception: considering both implicit and explicit processing perspectives.

This study explored the behavioral and neural activity characteristics of audiovisual temporal integration in motion perception from both implicit and explicit perspectives. The streaming-bouncing bistable paradigm (SB task) was employed to investigate implicit temporal integration, while the corresponding simultaneity judgment task (SJ task) was used to examine explicit temporal integration. The behavioral results revealed a negative correlation between implicit and explicit temporal processing. In the ERP results of both tasks, three neural phases (PD100, ND180, and PD290) in the fronto-central region were identified as reflecting integration effects and the auditory-evoked multisensory N1 component may serve as a primary component responsible for cross-modal temporal processing. However, there were significant differences between the VA ERPs in the SB and SJ tasks and the influence of speed on implicit and explicit integration effects also varied. The aforementioned results, building upon the validation of previous temporal renormalization theory, suggest that implicit and explicit temporal integration operate under distinct processing modes within a shared neural network. This underscores the brain's flexibility and adaptability in cross-modal temporal processing.