Audio-visual Temporal Binding Window Research Articles

Audiovisual temporal binding window narrows with age in autistic individuals.

Atypical sensory perception has been recognized in autistic individuals since its earliest descriptions and is now considered a key characteristic of autism. Although the integration of sensory information (multisensory integration; MSI) has been demonstrated to be altered in autism, less is known about how this perceptual process differs with age. This study aimed to assess the integration of audiovisual information across autistic children and adolescents. MSI was measured using a non-social, simultaneity judgment task. Variation in temporal sensitivity was evaluated via Gaussian curve fitting procedures, allowing us to compare the width of temporal binding windows (TBWs), where wider TBWs indicate less sensitivity to temporal alignment. We compared TBWs in age and IQ matched groups of autistic (n= 32) and neurotypical (NT; n= 73) children and adolescents. The sensory profile of all participants was also measured. Across all ages assessed (i.e., 6 through 18 years), TBWs were negatively correlated with age in the autistic group. A significant correlation was not found in the NT group. When compared as a function of child (6-12 years) and adolescent (13-18 years) age groups, a significant interaction of group (autism vs NT) by age group was found, whereby TBWs became narrower with age in the autistic, but not neurotypical group. We also found a significant main effect of age and no significant main effect of group. Results suggest that TBW differences between autistic and neurotypical groups diminishes with increasing age, indicating an atypical developmental profile of MSI in autism which ameliorates across development.

Abnormal multisensory integration in relapsing\u2013remitting multiple sclerosis

Temporal Binding Window (TBW) represents a reliable index of efficient multisensory integration process, which allows individuals to infer which sensory inputs from different modalities pertain to the same event. TBW alterations have been reported in some neurological and neuropsychiatric disorders and seem to negatively affects cognition and behavior. So far, it is still unknown whether deficits of multisensory integration, as indexed by an abnormal TBW, are present even in Multiple Sclerosis. We addressed this issue by testing 25 participants affected by relapsing–remitting Multiple Sclerosis (RRMS) and 30 age-matched healthy controls. Participants completed a simultaneity judgment task (SJ2) to assess the audio-visual TBW; two unimodal SJ2 versions were used as control tasks. Individuals with RRMS showed an enlarged audio-visual TBW (width range = from − 166 ms to + 198 ms), as compared to healthy controls (width range = − 177/ + 66 ms), thus showing an increased tendency to integrate temporally asynchronous visual and auditory stimuli. Instead, simultaneity perception of unimodal (visual or auditory) events overall did not differ from that of controls. These results provide first evidence of a selective deficit of multisensory integration in individuals affected by RRMS, besides the well-known motor and cognitive impairments. The reduced multisensory temporal acuity is likely caused by a disruption of the neural interplay between different sensory systems caused by multiple sclerosis.

Narrowing of the Audiovisual Temporal Binding Window Due To Perceptual Training Is Specific to High Visual Intensity Stimuli.

The temporal binding window (TBW), which reflects the range of temporal offsets in which audiovisual stimuli are combined to form a singular percept, can be reduced through training. Our research aimed to investigate whether training-induced reductions in TBW size transfer across stimulus intensities. A total of 32 observers performed simultaneity judgements at two visual intensities with a fixed auditory intensity, before and after receiving audiovisual TBW training at just one of these two intensities. We show that training individuals with a high visual intensity reduces the size of the TBW for bright stimuli, but this improvement did not transfer to dim stimuli. The reduction in TBW can be explained by shifts in decision criteria. Those trained with the dim visual stimuli, however, showed no reduction in TBW. Our main finding is that perceptual improvements following training are specific for high-intensity stimuli, potentially highlighting limitations of proposed TBW training procedures.

Neural Correlates of Audiovisual Temporal Binding Window in Individuals With Schizotypal and Autistic Traits: Evidence From Resting-State Functional Connectivity.

Temporal proximity is an important clue for multisensory integration. Previous evidence indicates that individuals with autism and schizophrenia are more likely to integrate multisensory inputs over a longer temporal binding window (TBW). However, whether such deficits in audiovisual temporal integration extend to subclinical populations with high schizotypal and autistic traits are unclear. Using audiovisual simultaneity judgment (SJ) tasks for nonspeech and speech stimuli, our results suggested that the width of the audiovisual TBW was not significantly correlated with self-reported schizotypal and autistic traits in a group of young adults. Functional magnetic resonance imaging (fMRI) resting-state activity was also acquired to explore the neural correlates underlying inter-individual variability of TBW width. Across the entire sample, stronger resting-state functional connectivity (rsFC) between the left superior temporal cortex and the left precuneus, and weaker rsFC between the left cerebellum and the right dorsal lateral prefrontal cortex were correlated with a narrower TBW for speech stimuli. Meanwhile, stronger rsFC between the left anterior superior temporal gyrus and the right inferior temporal gyrus was correlated with a wider audiovisual TBW for non-speech stimuli. The TBW-related rsFC was not affected by levels of subclinical traits. In conclusion, this study indicates that audiovisual temporal processing may not be affected by autistic and schizotypal traits and rsFC between brain regions responding to multisensory information and timing may account for the inter-individual difference in TBW width. LAY SUMMARY: Individuals with ASD and schizophrenia are more likely to perceive asynchronous auditory and visual events as occurring simultaneously even if they are well separated in time. We investigated whether similar difficulties in audiovisual temporal processing were present in subclinical populations with high autistic and schizotypal traits. We found that the ability to detect audiovisual asynchrony was not affected by different levels of autistic and schizotypal traits. We also found that connectivity of some brain regions engaging in multisensory and timing tasks might explain an individual's tendency to bind multisensory information within a wide or narrow time window. Autism Res 2021, 14: 668-680. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

Plasticity of temporal binding in children with autism spectrum disorder: A single case experimental design perceptual training study

BackgroundMany children with autism spectrum disorder (ASD) demonstrate atypical responses to multisensory stimuli. These disruptions, which are frequently seen in response to audiovisual speech, may produce cascading effects on the broader development of children with ASD. Perceptual training has been shown to enhance multisensory speech perception in typically developed adults. This study was the first to examine the effects of perceptual training on audiovisual speech perception in children with ASD. MethodA multiple baseline across participants design was utilized with four 7- to 13-year-old children with ASD. The dependent variable, which was probed outside the training task each day using a simultaneity judgment task in baseline, intervention, and maintenance conditions, was audiovisual temporal binding window (TBW), an index of multisensory temporal acuity. During perceptual training, participants completed the same simultaneity judgment task with feedback on their accuracy after each trial in easy-, medium-, and hard-difficulty blocks. ResultsA functional relation between the multisensory perceptual training program and TBW size was not observed. Of the three participants who were entered into training, one participant demonstrated a strong effect, characterized by a fairly immediate change in TBW trend. The two remaining participants demonstrated a less clear response (i.e., longer latency to effect, lack of functional independence). The first participant to enter the training condition demonstrated some maintenance of a narrower TBW post-training. ConclusionsResults indicate TBWs in children with ASD may be malleable, but additional research is needed and may entail further adaptation to the multisensory perceptual training paradigm.

Sensory loss enhances multisensory integration performance

Auditory and visual sensory loss has repeatedly been shown to alter abilities in remaining sensory modalities. It is, however, unclear whether sensory loss also impacts multisensory integration; an ability that is fundamental for the perception of the world around us. We determined effects of olfactory sensory deprivation on multisensory perception by assessing temporal as well as semantic aspects of audio-visual integration in 37 individuals with anosmia (complete olfactory sensory loss) and 37 healthy, matched controls. Participants performed a simultaneity judgement task to determine the temporal binding window, and a multisensory object identification task with individually degraded, dynamic visual, auditory, and audio-visual stimuli. Individuals with anosmia demonstrated an increased ability to detect multisensory temporal asynchronies, represented by a narrowing of the audio-visual temporal binding window. Furthermore, individuals with congenital, but not acquired, anosmia demonstrated indications of greater benefits from bimodal, as compared to unimodal, stimulus presentation when faced with degraded, semantic information. This suggests that the absence of the olfactory sense alters multisensory integration of remaining senses by sharpening the perception of cross-modal temporal violations, independent of sensory loss etiology. In addition, congenital sensory loss may further lead to increased gain from multisensory, compared to unisensory, information. Taken together, multisensory compensatory mechanisms at different levels of perceptual complexity are present in individuals with anosmia.

The audiovisual temporal binding window in unilateral amblyopia: monocular and binocular effects

The audiovisual temporal binding window in unilateral amblyopia: monocular and binocular effects

On the Temporal Precision of Thought: Individual Differences in the Multisensory Temporal Binding Window Predict Performance on Verbal and Nonverbal Problem Solving Tasks

Although psychology is greatly preoccupied by the tight link between the way that individuals perceive the world and their intelligent, creative behavior, there is little experimental work on the relationship between individual differences in perception and cognitive ability in healthy populations. Here, individual differences in problem solving ability were examined in relation to multisensory perception as measured by tolerance for temporal asynchrony between auditory and visual inputs, i.e., the multisensory temporal binding window. The results demonstrated that enhanced performance in both verbal and nonverbal problem solving tasks (the Remote Associates Test and Raven’s Advanced Progressive Matrices Task) is predicted by a narrower audio-visual temporal binding window, which reflects greater sensitivity to subtle discrepancies in sensory inputs. This suggests that the precision of individuals’ temporal window of multisensory integration might mirror their capacities for complex reasoning and thus the precision of their thoughts.

Altered multisensory temporal binding window in low-grade inflammation

Obesity has been associated with decreased performance on cognitive tests, including abstract reasoning, visuospatial organization, and attention. However, recent evidence suggests that alterations of unisensory and multisensory processing are also present. The aim of this study was to compare the temporal features of multisensory integration in twenty obese people to those of twenty healthy controls, by measuring the audio-visual temporal binding window, defined as the range of stimulus onset asynchrony in which multiple sensory inputs have a high probability of altering responses. Results revealed an extended temporal binding window in obese participants as compared to healthy controls, suggesting an alteration of multisensory binding. An explanatory hypothesis would regard the effect of the chronic low-grade inflammatory state, clinically observed in obesity, on neural activity. We speculate that pro-inflammatory cytokines, which are overexpressed in obesity, alter the temporal structure of the ongoing brain activity. This, in turn, impacts on the neural mechanisms enabling multisensory integration. We believe that our finding sheds new light on the link between the brain and the immune system, and it has potential implications for future experimental design and therapeutic implementation in obesity treatment.

Zapping the gap: Reducing the multisensory temporal binding window by means of transcranial direct current stimulation (tDCS).

Synchrony among the senses lies at the heart of our possession of a unified conscious perception of the world. However, due to discrepancies in physical and neural information processing from different senses, the brain accommodates a limited range of temporal asynchronies between sensory inputs, i.e. the multisensory temporal binding window (TBW). Using non-invasive brain stimulation, we sought to modulate the audio-visual TBW and to identify cortical areas implicated in the conscious perception of multisensory synchrony. Participants performed a simultaneity judgment task while experiencing anodal (Experiment 1) or cathodal (Experiment 2) transcranial direct current stimulation (tDCS) over parietal and frontal regions. The results demonstrate that stimulating the right posterior parietal cortex significantly reduces the audio-visual TBW by approximately 30%, thereby causally linking this region to the plasticity of the TBW. This highlights a potential interventional technique for populations with a wider TBW, such as in autism and dyslexia.

The audiovisual temporal binding window narrows in early childhood.

Binding is key in multisensory perception. This study investigated the audio-visual (A-V) temporal binding window in 4-, 5-, and 6-year-old children (total N = 120). Children watched a person uttering a syllable whose auditory and visual components were either temporally synchronized or desynchronized by 366, 500, or 666 ms. They were asked whether the voice and face went together (Experiment 1) or whether the desynchronized videos differed from the synchronized one (Experiment 2). Four-year-olds detected the 666-ms asynchrony, 5-year-olds detected the 666- and 500-ms asynchrony, and 6-year-olds detected all asynchronies. These results show that the A-V temporal binding window narrows slowly during early childhood and that it is still wider at 6 years of age than in older children and adults.