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Background: The detailed extent of neuroinvasion or deleterious brain changes resulting from COVID-19 and their time courses remain to be determined in relation to “long-haul” COVID-19 symptoms. Our objective is to determine whether there are alterations in functional brain imaging measures among people with COVID-19 after hospital discharge or self-isolation. Methods: This paper describes a protocol for NeuroCOVID-19, a longitudinal observational study of adults aged 20–75 years at Sunnybrook Health Sciences Centre in Toronto, Ontario, that began in April 2020. We aim to recruit 240 adults, 60 per group: people who contracted COVID-19 and were admitted to hospital (group 1), people who contracted COVID-19 and self-isolated (group 2), people who experienced influenza-like symptoms at acute presentation but tested negative for COVID-19 and self-isolated (group 3, control) and healthy people (group 4, control). Participants are excluded based on premorbid neurologic or severe psychiatric illness, unstable cardiovascular disease, and magnetic resonance imaging (MRI) contraindications. Initial and 3-month follow-up assessments include multiparametric brain MRI and electroencephalography. Sensation and cognition are assessed alongside neuropsychiatric assessments and symptom self-reports. We will test the data from the initial and follow-up assessments for group differences based on 3 outcome measures: MRI cerebral blood flow, MRI resting state fractional amplitude of low-frequency fluctuation and electroencephalography spectral power. Interpretation: If neurophysiologic alterations are detected in the COVID-19 groups in our NeuroCOVID-19 study, this information could inform future research regarding interventions for long-haul COVID-19. The study results will be disseminated to scientists, clinicians and COVID-19 survivors, as well as the public and private sectors to provide context on how brain measures relate to lingering symptoms.

Neurological symptoms associated with coronavirus disease 2019 (COVID-19), such as fatigue and smell/taste changes, persist beyond infection. However, little is known of brain physiology in the post-COVID-19 timeframe.To determine whether adults who experienced flu-like symptoms due to COVID-19 would exhibit cerebral blood flow (CBF) alterations in the weeks/months beyond infection, relative to controls who experienced flu-like symptoms but tested negative for COVID-19.Prospective observational.A total of 39 adults who previously self-isolated at home due to COVID-19 (41.9 ± 12.6 years of age, 59% female, 116.5 ± 62.2 days since positive diagnosis) and 11 controls who experienced flu-like symptoms but had a negative COVID-19 diagnosis (41.5 ± 13.4 years of age, 55% female, 112.1 ± 59.5 since negative diagnosis).A 3.0 T; T1-weighted magnetization-prepared rapid gradient and echo-planar turbo gradient-spin echo arterial spin labeling sequences.Arterial spin labeling was used to estimate CBF. A self-reported questionnaire assessed symptoms, including ongoing fatigue. CBF was compared between COVID-19 and control groups and between those with (n = 11) and without self-reported ongoing fatigue (n = 28) within the COVID-19 group.Between-group and within-group comparisons of CBF were performed in a voxel-wise manner, controlling for age and sex, at a family-wise error rate of 0.05.Relative to controls, the COVID-19 group exhibited significantly decreased CBF in subcortical regions including the thalamus, orbitofrontal cortex, and basal ganglia (maximum cluster size = 6012 voxels and maximum t-statistic = 5.21). Within the COVID-19 group, significant CBF differences in occipital and parietal regions were observed between those with and without self-reported on-going fatigue.These cross-sectional data revealed regional CBF decreases in the COVID-19 group, suggesting the relevance of brain physiology in the post-COVID-19 timeframe. This research may help elucidate the heterogeneous symptoms of the post-COVID-19 condition.2.Stage 3.

There has been growing attention on the effect of COVID-19 on white-matter microstructure, especially among those that self-isolated after being infected. There is also immense scientific interest and potential clinical utility to evaluate the sensitivity of single-shell diffusion MRI methods for detecting such effects. In this work, the sensitivities of three single-shell-compatible diffusion MRI modeling methods are compared for detecting the effect of COVID-19, including diffusion-tensor imaging, diffusion-tensor decomposition of orthogonal moments and correlated diffusion imaging. Imaging was performed on self-isolated patients at baseline and 3-month follow-up, along with age- and sex-matched controls. We demonstrate through simulations and experimental data that correlated diffusion imaging is associated with far greater sensitivity, being the only one of the three single-shell methods to demonstrate COVID-19-related brain effects. Results suggest less restricted diffusion in the frontal lobe in COVID-19 patients, but also more restricted diffusion in the cerebellar white matter, in agreement with several existing studies highlighting the vulnerability of the cerebellum to COVID-19 infection. These results, taken together with the simulation results, suggest that a significant proportion of COVID-19 related white-matter microstructural pathology manifests as a change in water diffusivity. Interestingly, different b-values also confer different sensitivities to the effects. No significant difference was observed in patients at the 3-month follow-up, likely due to the limited size of the follow-up cohort. To summarize, correlated diffusion imaging is shown to be a sensitive single-shell diffusion analysis approach that allows us to uncover opposing patterns of diffusion changes in the frontal and cerebellar regions of COVID-19 patients, suggesting the two regions react differently to viral infection.

The long-term consequences of coronavirus disease 2019 (COVID-19) on brain physiology and function are not yet well understood. From the recently described NeuroCOVID-19 study, we examined cerebral blood flow (CBF) in 50 participants recruited to one of two groups: 1) adults who previously self-isolated at home due to COVID-19 (n = 39; 116.5 ± 62.2 days since positive diagnosis), or 2) controls who experienced flu-like symptoms but had a negative COVID-19 diagnosis (n = 11). Participants underwent arterial spin labeling magnetic resonance imaging at 3 T to yield measures of CBF. Voxel-wise analyses of CBF were performed to assess for between-group differences, after controlling for age and sex. Relative to controls, the COVID-19 group exhibited decreased CBF in the thalamus, orbitofrontal cortex, and regions of the basal ganglia. Within the COVID-19 group, CBF differences in occipital and parietal regions were observed between those with (n = 11) and without (n = 28) self-reported on-going fatigue. These results suggest long-term changes in brain physiology in adults across the post-COVID-19 timeframe. Moreover, CBF may aid in understanding the heterogeneous symptoms of the post-COVID-19 condition. Future longitudinal studies are needed to further characterize the consequences of COVID-19 on the brain.

Spatial cognition is known to decline with aging. However, little is known about whether training can reduce or eliminate age-related deficits in spatial memory. We investigated whether a custom-designed video game involving spatial navigation, obstacle avoidance, and balance control would improve spatial memory in older adults. Specifically, 56 healthy adults aged 65 to 84 years received 10 sessions of multicomponent video game training, based on a virtual cityscape, over 5 weeks. Participants were allocated to one of three training conditions: the main intervention, the “CityQuest” group (n = 19), and two control groups, spatial navigation without obstacle avoidance (“Spatial Navigation-only” group, n = 21) and obstacle avoidance without spatial navigation (“Obstacles-only” group, n = 15). Performance on object recognition, egocentric and allocentric spatial memory (incorporating direction judgment tasks and landmark location tasks, respectively), navigation strategy preference, and executive functioning was assessed in pre- and post-intervention sessions. The results showed an overall benefit on performance in a number of spatial memory measures and executive function for participants who received spatial navigation training, particularly the CityQuest group, who also showed significant improvement on the landmark location task. However, there was no evidence of a shift from egocentric to allocentric strategy preference. We conclude that spatial memory in healthy older participants is amenable to improvement with training over a short term. Moreover, technology based on age-appropriate, multicomponent video games may play a key role in cognitive training in older adults.

In the past 20 years, there has been growing research interest in the association between video games and cognition. Although many studies have found that video game players are better than non-players in multiple cognitive domains, other studies failed to replicate these results. Until now, the vast majority of studies defined video game players based on the number of hours an individual spent playing video games, with relatively few studies focusing on video game expertise using performance criteria. In the current study, we sought to examine whether individuals who play video games at a professional level in the esports industry differ from amateur video game players in their cognitive and learning abilities. We assessed 14 video game players who play in a competitive league (Professional) and 16 casual video game players (Amateur) on set of standard neuropsychological tests evaluating processing speed, attention, memory, executive functions, and manual dexterity. We also examined participants’ ability to improve performance on a dynamic visual attention task that required tracking multiple objects in three-dimensions (3D-MOT) over five sessions. Professional players showed the largest performance advantage relative to Amateur players in a test of visual spatial memory (Spatial Span), with more modest benefits in a test of selective and sustained attention (d2 Test of Attention), and test of auditory working memory (Digit Span). Professional players also showed better speed thresholds in the 3D-MOT task overall, but the rate of improvement with training did not differ in the two groups. Future longitudinal studies of elite video game experts are required to determine whether the observed performance benefits of professional gamers may be due to their greater engagement in video game play, or due to pre-existing differences that promote achievement of high performance in action video games.

Previous studies have suggested that discrete cross-sensory events could be incorrectly combined in the brain of older adults with a history of falls, possibly undermining motor and balance control. Based on previous findings that multisensory integration is modifiable with practice, even in an ageing population, we designed a serious game, named CityQuest, to train typical, everyday multisensory processes including sensori-motor control, spatial navigation, obstacle avoidance and balance control. Played over several sessions, this game was shown to improve these functions in older adults with and without a history of falls, depending on the specific condition of the game on which they were trained. Here, using voxel-based morphometry analysis of anatomical magnetic resonance imaging (MRI) data, we investigated structural changes in the brain of a smaller group of older adults from those who successfully completed this five-week intervention. A grey-matter (GM) volume increase in the precentral gyrus, and GM volume reduction in the inferior temporal and orbitofrontal gyri, was found for all participants. Changes in GM volume within regions of the cerebellum were differentially associated with fall-prone and healthy older adults. Furthermore, a greater GM volume increase in the precentral gyrus was observed in participants who performed the full CityQuest intervention relative to those required to avoid obstacles only. Our results support previous evidence that multisensory training can affect structural changes in the older brain and have implications for programmes designed for the successful rehabilitation of perceptual and cognitive functions.

The presence of a moving sound has been shown to facilitate the detection of an independently moving visual target embedded among an array of identical moving objects simulating forward self-motion (Calabro et al., Proc. R. Soc. B, 2011). Given that the perception of object motion within self-motion declines with aging, we investigated whether older adults can also benefit from the presence of a congruent dynamic sound when detecting object motion within self-motion. Visual stimuli consisted of nine identical spheres randomly distributed inside a virtual rectangular prism. For 1 s, all the spheres expanded outward simulating forward observer translation at a constant speed. One of the spheres (the target) had independent motion either approaching or moving away from the observer at three different speeds. In the visual condition, stimuli contained no sound. In the audiovisual condition, the visual stimulus was accompanied by a broadband noise sound co-localized with the target, whose loudness increased or decreased congruent with the target’s direction. Participants reported which of the spheres had independent motion. Younger participants showed higher target detection accuracy in the audiovisual compared to the visual condition at the slowest speed level. Older participants showed overall poorer target detection accuracy than the younger participants, but the presence of the sound had no effect on older participants’ target detection accuracy at either speed level. These results indicate that aging may impair cross-modal integration in some contexts. Potential reasons for the absence of auditory facilitation in older adults are discussed.

Previous studies have reported an age-related decline in spatial abilities. However, little is known about whether the presence of other, task-irrelevant stimuli during learning further affects spatial cognition in older adults. Here we embedded virtual environments with moving crowds of virtual human pedestrians (Experiment 1) or objects (Experiment 2) whilst participants learned a route and landmarks embedded along that route. In subsequent test trials we presented clips from the learned route and measured spatial memory using three different tasks: a route direction task (i.e. whether the video clip shown was a repetition or retracing of the learned route); an intersection direction task; and a task involving identity of the next landmark encountered. In both experiments, spatial memory was tested in two separate sessions: first following learning of an empty maze environment and second using a different maze which was populated. Older adults performed worse than younger adults in all tasks. Moreover, the presence of crowds during learning resulted in a cost in performance to the spatial tasks relative to the 'no crowds' condition in older adults but not in younger adults. In contrast, crowd distractors did not affect performance on the landmark sequence task. There was no age-related cost on performance with object distractors. These results suggest that crowds of human pedestrians selectively capture older adults' attention during learning. These findings offer further insights into how spatial memory is affected by the ageing process, particularly in scenarios which are representative of real-world situations.

Recent evidence suggests that familiarity with an environment may protect against spatial memory decline for familiar objects in older adults. We investigated whether a familiar context also reduces age-related decline in spatial memory for novel objects. Twenty-four younger and 23 older participants viewed a virtual rendering of a local environment along two different routes, each through a well-known (West) or lesser-known (East) area within the environment. Older and younger participants reported being more familiar with one (i.e. West) area than the other. In each trial, participants were presented with one route and were instructed to learn ten novel objects and their locations along the route. Following learning, participants immediately completed five test blocks: an object recognition task, an egocentric spatial processing (direction judgement) task, an allocentric spatial processing (proximity judgement) task and two pen-and-paper tests to measure cognitive mapping abilities. First we found an age effect with worse performance by older than younger adults in all spatial tasks, particularly in allocentric spatial processing. However, our results suggested better memory for objects and directions, but not proximity judgements, when the task was associated with more familiar than unfamiliar contexts, in both age groups. There was no benefit of context when a separate young adult group (N = 24) was tested, who reported being equally familiar with both areas. These results suggest an important facilitatory role of context familiarity on object recognition, and in particular egocentric spatial memory, and have implications for enhancing spatial memory in older adults.

The current study examined the role of temporal resolution of attention in the decline in multiple object tracking abilities with healthy aging. The temporal resolution of attention is known to limit attentional tracking of one and multiple targets (Holcombe & Chen, 2013). Here, we examined whether aging is associated with a lower temporal resolution of attention when tracking one target, the efficiency of splitting attention across multiple targets, or both. Stimuli comprised three concentric rings containing five or 10 equally spaced dots. While maintaining central fixation, younger and older participants tracked a target dot on one, two, or three rings while the rings rotated around fixation in random directions for 5 s. Rotational speed was varied to estimate speed or temporal frequency thresholds in six conditions. Results showed that younger and older participants had similar temporal frequency thresholds for tracking one target, but the addition of one and two more targets reduced thresholds more in the older group compared to the younger group. Gender also affected performance, with men having higher temporal frequency thresholds than women, independently of the number of targets. These findings indicate that the temporal resolution of attention for a single target depends on gender but is not affected by aging, whereas aging specifically affects the efficiency of dividing attention across multiple targets.

To accurately represent the environment, our brains must integrate sensory signals from a common source while segregating those from independent sources. A reasonable strategy for performing this task is to restrict integration to cues that coincide in space and time. However, because multisensory signals are subject to differential transmission and processing delays, the brain must retain a degree of tolerance for temporal discrepancies. Recent research suggests that the width of this ‘temporal binding window’ can be reduced through perceptual learning, however, little is known about the mechanisms underlying these experience-dependent effects. Here, in separate experiments, we measure the temporal and spatial binding windows of human participants before and after training on an audiovisual temporal discrimination task. We show that training leads to two distinct effects on multisensory integration in the form of (i) a specific narrowing of the temporal binding window that does not transfer to spatial binding and (ii) a general reduction in the magnitude of crossmodal interactions across all spatiotemporal disparities. These effects arise naturally from a Bayesian model of causal inference in which learning improves the precision of audiovisual timing estimation, whilst concomitantly decreasing the prior expectation that stimuli emanate from a common source.

Our understanding of human perception has developed significantly over the last 50 years, informed by research in neurophysiology, behavioural studies, psychophysics and neuroimaging. When the Department of Psychology at Trinity College Dublin was founded 50 years ago, teaching and research in perception was based on each sense in isolation, with a strong focus on vision. Recent research has revealed that perception in one sensory modality can be significantly modified by inputs from the other senses. Moreover, such cross-sensory interactions seem to occur much earlier in information processing than was historically assumed. Here we highlight some of the main studies that best demonstrate how research in multisensory perception has enhanced our understanding of how the human brain processes information from the external world. In particular, we focus on higher-level perceptual tasks such as object, face, and body perception, and the perception of socially meaningful information, such as emotion and attrac...

The present study examined the effect of aging on the detection and discrimination of contours embedded in a dense field of distractors. The minimum stimulus duration required to correctly discriminate (Experiment 1) and detect (Experiment 2) three types of "C" shaped contours was measured. Overall, older subjects required longer stimulus durations than younger subjects in all conditions. Comparing performance for contours comprising elements oriented tangentially to the contour path (aligned) and those oriented orthogonally to the contour (radial) revealed that the effect of local orientation on contour discrimination is slightly greater in older than younger subjects. Control experiments showed that these age differences were not due to differences in retinal illuminance, or the detectability or discriminability of the elements comprising the contours. These findings suggest that ability to extract global contours embedded in clutter declines in older age.

There is growing evidence of the involvement of executive control in the maintenance of balance in old age. We examined whether healthy older adults who completed five sessions of nonmotor cognitive dual-task training would show significant improvements on measures of dual-task standing balance and mobility, compared with an untrained control group.Twenty healthy older adults were assigned to either training or control groups. In the pre- and post-training sessions, all participants performed tests of cognition, balance, and mobility (single-support balance, dynamic posturography, sit-to-stand, 40-foot walk) under single- and dual-task conditions. The training group completed five sessions of cognitive dual-task training spaced at least 2 days apart. The two tasks involved making two-choice decisions to visually presented stimuli. Participants completed multiple blocks of single-task (task A or B, blockwise) and mixed (A, B, or A + B) trials in each training session.The training group showed significant improvements in body sway during single-support balance and center of gravity alignment during double-support dynamic balance. The control group showed no appreciable improvements.This study is the first to demonstrate training-related benefits to gross motor performance stemming from cognitive dual-task training. The results support the view that motor control in aging is influenced by executive control and have implications for theories of cognitive training and transfer.

Perception of global patterns requires the integration of local orientation information across space. The present study examined whether this integration ability declines in older age. We measured contrast thresholds for discriminating the global orientation of a “C” shaped contour against a blank background in younger and older subjects. Performance of younger subjects improved when the elements composing the “C” were aligned along the contour path, as opposed to being orthogonal to it or of mixed orientations. However, older subjects’ performance was not affected by the orientation of the local elements. This indicates an age-related decline in contour integration.

Previous studies have reported an age-related decline in spatial abilities. However, little is known about whether the presence of other, task-irrelevant stimuli during learning further affects spatial cognition in older adults. Here we embedded virtual environments with moving crowds of virtual human pedestrians (Experiment 1) or objects (Experiment 2) whilst participants learned a route and landmarks embedded along that route. In subsequent test trials we presented clips from the learned route and measured spatial memory using three different tasks: a route direction task (i.e. whether the video clip shown was a repetition or retracing of the learned route); an intersection direction task; and a task involving identity of the next landmark encountered. In both experiments, spatial memory was tested in two separate sessions: first following learning of an empty maze environment and second using a different maze which was populated. Older adults performed worse than younger adults in all tasks. Moreover, the presence of crowds during learning resulted in a cost in performance to the spatial tasks relative to the 'no crowds' condition in older adults but not in younger adults. In contrast, crowd distractors did not affect performance on the landmark sequence task. There was no age-related cost on performance with object distractors. These results suggest that crowds of human pedestrians selectively capture older adults' attention during learning. These findings offer further insights into how spatial memory is affected by the ageing process, particularly in scenarios which are representative of real-world situations.

While ageing can lead to significant declines in perceptual and cognitive function, the effects of age on multisensory integration, the process in which the brain combines information across the senses, are less clear. Recent reports suggest that older adults are susceptible to the sound-induced flash illusion (Shams et al., 2000) across a much wider range of temporal asynchronies than younger adults (Setti et al., 2011). To assess whether this cost for multisensory integration is a general phenomenon of combining asynchronous audiovisual input, we compared the time courses of two variants of the sound-induced flash illusion in young and older adults: the fission illusion, where one flash accompanied by two beeps appears as two flashes, and the fusion illusion, where two flashes accompanied by one beep appears as one flash. Twenty-five younger (18-30 years) and older (65+ years) adults were required to report whether they perceived one or two flashes, whilst ignoring irrelevant auditory beeps, in bimodal trials where auditory and visual stimuli were separated by one of six stimulus onset asynchronies (SOAs). There was a marked difference in the pattern of results for the two variants of the illusion. In conditions known to produce the fission illusion, older adults were significantly more susceptible to the illusion at longer SOAs compared to younger participants. In contrast, the performance of the younger and older groups was almost identical in conditions known to produce the fusion illusion. This surprising difference between sound-induced fission and fusion in older adults suggests dissociable age-related effects in multisensory integration, consistent with the idea that these illusions are mediated by distinct neural mechanisms.

Variations in the timing and speed of movements in human interactions carry important social information. For example, seeing one player push another player at a football game, we can deduce whether the player being pushed resisted or anticipated the oncoming push based on subtle differences in the timing and velocity of movements of both players. With the development of computer animations of human characters, it is important to understand the sensitivity and limits of human perception in such interactions to accurately portray human interactions.

The perception of naturalistic events relies on the ability to integrate information from multiple sensory systems, an ability that may change with healthy aging. When two objects move toward and then past one another, their trajectories are perceptually ambiguous: the objects may seem to stream past one another or bounce off one another. Previous research showed that auditory or visual events that occur at the time of discs' coincidence could bias the percept toward bouncing or streaming. We exploited this malleable percept to assay age-related changes in the integration of multiple inter- and intra-modal cues. The discs' relative luminances were manipulated to produce stimuli strongly favoring either bouncing or streaming, or to produce ambiguous motion (equal luminances). A sharp sound coincident with the discs' overlap increased both groups' perception of bouncing, but did so significantly less for older subjects. An occluder's impact on motion perception varied with its duration: a long duration occluder promoted streaming in both groups; a brief occluder promoted bouncing in younger subjects, but not older ones. Control experiments demonstrated that the observed differences between younger and older subjects resulted from neither age-related changes in retinal illuminance nor age-related changes in hearing, pointing to weakened inter- and intra-modal integration with aging. These changes could contribute to previously demonstrated age-related perceptual and memory deficits.

The ability to extract contours in cluttered visual scenes, which is a crucial step in visual processing, declines with healthy aging, but the reasons for this decline are not well understood. In three experiments, we examined how the effect of aging on contour discrimination varies as a function of contour and distracter inter-element spacing, collinearity, and stimulus duration. Spiral-shaped contours composed of Gabors were embedded within a field of distracter Gabors of uniform density. In a four alternative forced-choice task, younger and older subjects were required to report the global orientation of the contour. In Experiment 1, the absolute contour element spacing varied from two to eight times the Gabor wavelength and contour element collinearity was disrupted with five levels of orientation jitter. Contour discrimination accuracy was lower in older subjects, but the effect of aging did not vary with contour spacing or orientation jitter. Experiment 2 found that decreasing stimulus durations from 0.8 to 0.04 s had a greater effect on older subjects' performance, but only for less salient contours. Experiment 3 examined the effect of the background on contour discrimination by varying the spacing and orientation of the distracter elements for contours with small and large absolute spacing. As in Experiment, the effect of aging did not vary with absolute contour spacing. Decreasing the distracter spacing, however, had a greater detrimental effect on accuracy in older subjects compared to younger subjects. Finally, both groups showed equally high accuracy when all distracters were iso-oriented. In sum, these findings suggest that aging does not affect the sensitivity of contour integration to proximity or collinearity. However, contour integration in older adults is slower and is especially vulnerable when distracters are denser than contour elements.

We used a random-dot two-frame apparent motion paradigm to investigate whether age-related declines in motion perception are caused by deficits in integrating spatial information, temporal information, or both. Two random-dot patterns were presented sequentially on a black screen, separated by a blank inter-stimulus interval ranging from 0.01 s to 0.240 s. From the first to the second pattern, all the dots were shifted to the left or right by an equal displacement ranging from 0.03 deg to 1.64 deg. The spatiotemporal range yielding good direction discrimination performance was greatly reduced with age. For ISIs longer than 0.04 s, older subjects performed less accurately than younger subjects across a wide range of spatial displacements. Older subjects also showed poorer performance for large spatial displacements across a wide range of ISIs. Age-related differences in performance were also found with small displacements; however, these were largely accounted for by age-related declines in visual acuity. Overall, the results show that the maximum temporal interval and maximum spatial displacement over which two frames can be integrated are reduced in older age.

Multisensory integration appears to be enhanced in older age (e.g., Laurienti et al., 2006; Maguinness et al., 2011). Given that motion perception declines with ageing, we examined whether multisensory integration may enhance motion perception in older adults. Calabro et al. (2011) recently showed that the detection of object motion in the context of self-motion is facilitated by the presentation of a co-localized and directionally congruent auditory stimulus. We compared performance of younger (mean age: 26 years) and older (mean age: 68 years) participants on this task. On each trial, nine identical spheres were randomly distributed within 10 degrees of fixation and 8 spheres expanded outward for 1 s, simulating forward translation at a constant speed. One sphere (the target) had independent motion either expanding or receding at one of three different speeds. A response screen prompted the participants to report which of four highlighted spheres was the target. The task was presented with no sound and with a co-localized sound that simulated motion congruent with the target’s direction. Older participants showed overall poorer target detection than younger participants. Consistent with Calabro et al. (2011), the auditory stimulus improved target detection in younger participants, however, it had less of an effect on older participants’ performance. A control experiment confirmed that both groups were able to localize the auditory stimulus, however localization was poorer in the older group. Future studies equating unisensory performance in younger and older participants are needed to determine whether multisensory integration in motion is affected in older age.

Given the inherently noisy nature of sensory signals, the brain must maintain a degree of tolerance for temporal discrepancies when combining multisensory information. While the limits of this temporal window of integration are well established, little is known about how they are affected by sensory experience. Powers et al. (2009) reported that training on an audiovisual simultaneity task narrows the temporal window of integration. However, because subjects were trained on the same task that was used to measure their integration windows, it is unclear whether this effect reflects a genuine change in multisensory integration or a simple improvement in task performance. Here, we examine whether perceptual training affects multisensory integration using independent training and test measures. In pre- and post-training sessions, participants were required to report the position of an auditory noise burst while ignoring a visual stimulus, across a range of stimulus onset asynchronies. The ventriloquist effect induced by the visual stimulus was greatest for simultaneous stimuli and declined with increasing inter-stimulus asynchrony. Training consisted of three 45-minute sessions where participants practiced a 2-IFC audiovisual simultaneity task. Training resulted in narrowing of the time window of integration comparable to that observed by Powers et al., as well as a reduction in the amplitude of the peak ventriloquist effect. Unisensory localisation thresholds were unaffected by training, ruling out changes in auditory and visual sensitivity as the cause of improvements. These findings demonstrate that perceptual training can affect multisensory integration and have implications for the future development of multisensory training protocols.