Rebecca Hirst

Trinity College Dublin | TCD · Institute of Neuroscience

In the Sound-Induced Flash Illusion (SIFI) sound dramatically alters visual perception, as presenting a single flash with two beeps results in the perception of two flashes. In this comprehensive review, we synthesise 20 years of research using the SIFI, from over 100 studies. We discuss the neural and computational principles governing this illusi...

It is well established that physical activity leads to numerous health, cognitive, and psychological benefits. However, to date, very few studies have investigated the impact of physical activity on multisensory perception, that is, the brain’s capacity to integrate information across sensory modalities. Furthermore, it is unknown what level of lon...

There is evidence that cardiovascular function can influence sensory processing and cognition, which are known to change with age. However, whether the precision of unisensory and multisensory temporal perception is influenced by cardiovascular activity in older adults is uncertain. We examined whether seated resting heart rate (RHR) was associated...

Although object categorization is a fundamental cognitive ability, it is also a complex process going beyond the perception and organization of sensory stimulation. Here we review existing evidence about how the human brain acquires and organizes multisensory inputs into object representations that may lead to conceptual knowledge in memory. We fir...

Multisensory integration, the ability of the brain to integrate information from different sensory modalities, is critical for responding to environmental stimuli. While older adults show changes in multisensory integration with age, the impact of allostatic load (AL) (i.e., the effect of exposure to chronic stress, which can accelerate ageing) on...

The precision of temporal multisensory integration is associated with specific aspects of physical functioning in ageing, including gait speed and incidents of falling. However, it is unknown if such an association exists between multisensory integration and grip strength, an important index of frailty and brain health and predictor of disease and...

Sustained integration of sensory inputs over increased temporal delays is associated with reduced cognitive and physical functioning in older adults and adverse outcomes such as falls. Here, we explored the relationship between multisensory integration and a clinically relevant measure of balance/postural control; Sit-to-Stand Time, the efficiency...

Sustained multisensory integration over long inter-stimulus time delays is typically found in older adults, particularly those with a history of falls. However, the extent to which the temporal precision of audio-visual integration is associated with longitudinal fall or fall risk trajectories is unknown. A large sample of older adults (N = 2319) w...

Background: Multisensory integration is the ability to appropriately merge information from different senses for the purpose of perceiving and acting in the environment. During walking, information from multiple senses must be integrated appropriately to coordinate effective movements. We tested the association between a well characterised multise...

Background and Objectives Self-reported sensory data provide important insight into an individual’s perception of sensory ability. It remains unclear what factors predict longitudinal change in self-reported sensory ability across multiple modalities during healthy ageing. This study examined these associations in a cohort of older adults for visio...

Background The ability to precisely integrate sensory information is critical to everyday functions, including balance/postural control and navigation. Older adults typically integrate sensory information over longer time delays than younger adults, which can reduce the precision of their perceptual judgments. This is particularly evident in older...

Sustained multisensory integration over long inter-stimulus time delays is typically found in older adults, particularly those with a history of falls. However, the extent to which the temporal precision of audio-visual integration is associated with longitudinal fall or fall risk trajectories is unknown. A large sample of older adults ( N = 2,319)...

There is a growing body of evidence to suggest that multisensory processing changes with advancing age-usually in the form of an enlarged temporal binding window-with some studies linking these multisensory changes to negative clinical outcomes. Perceptual training regimes represent a promising means for enhancing the precision of multisensory inte...

The sound-induced flash illusion (SIFI) occurs when a rapidly presented visual stimulus is accompanied by two auditory stimuli, creating the illusory percept of two visual stimuli. While much research has focused on how the temporal proximity of the audiovisual stimuli impacts susceptibility to the illusion, comparatively less research has focused...

Age-related sensory decline impacts cognitive performance and exposes individuals to a greater risk of cognitive decline. Integration across the senses also changes with age, yet the link between multisensory perception and cognitive ageing is poorly understood. We explored the relationship between multisensory integration and cognitive function in...

Study Objectives This study examines the cross-sectional and two-year follow-up relationships between sleep and stress and total hippocampal volume and hippocampal subfield volumes among older adults. Methods 417 adults (aged 68.8±7.3; 54% women) from the Irish Longitudinal Study on Ageing completed an interview, a questionnaire and multiparametri...

Sensitivity to the temporal coherence of visual and tactile signals increases perceptual reliability and is evident during infancy. However, it is not clear how, or whether, bidirectional visuotactile interactions change across childhood. Furthermore, no study has explored whether viewing a body modulates how children perceive visuotactile sequence...

The stop-signal paradigm has become ubiquitous in investigations of inhibitory control. Tasks inspired by the paradigm, referred to as stop-signal tasks, require participants to make responses on go trials and to inhibit those responses when presented with a stop-signal on stop trials. Currently, the most popular version of the stop-signal task is...

The ability to inhibit ongoing responses that suddenly become inappropriate is essential for safe and effective interaction with an ever-changing and often unpredictable world. This ability is quantified by the stop-signal reaction time (SSRT), the completion time of an inhibitory process triggered by a signal to stop responding. Because SSRT canno...

Recent studies suggest that the lived environment can affect cognition across the lifespan. We examined, in a large cohort of older adults (n = 3447), whether susceptibility to a multisensory illusion, the Sound-Induced Flash Illusion (SIFI), was influenced by the reported urbanity of current and childhood (at age 14 years) residence. If urban envi...

Multisensory perception might provide an important marker of brain function in ageing. However, the cortical structures supporting multisensory perception in ageing are poorly understood. In this study, we compared regional grey matter volume in a group of middle-aged (n = 101; 49 – 64 years) and older (n = 116; 71 – 87 years) adults from The Irish...

Sensory impairment is common in ageing, as are approaches to treat it. However, the impact of age-related sensory impairment upon multisensory perception remains unex-plored, despite the multisensory nature of our environment. Here, we used data from The Irish Longitudinal Study of Ageing (TILDA) to investigate whether common, age-related eye disea...

The thalamus is a central hub of the autonomic network and thalamic volume has been associated with high‐risk phenotypes for sudden cardiac death. Heart rate response to physiological stressors (e.g., standing) and the associated recovery patterns provide reliable indicators of both autonomic function and cardiovascular risk. Here we examine if tha...

In the Sound-Induced Flash Illusion (SIFI) sound dramatically alters visual perception, as presenting a single flash with two beeps results in the perception of two flashes. In this timely review, we synthesise 20 years of research using the SIFI, from over 100 studies. We discuss the neural and computational principles governing this illusion and...

Perception of our world is proposed to arise from combining multiple sensory inputs according to their relative reliability. We tested multisensory processes in a large sample of 2920 older adults to assess whether sensory ability mediates age-related changes in perception. Participants completed a test of audio-visual integration, the Sound Induce...

Interference-control is the ability to exclude distractions and focus on a specific task or stimulus. However, it is currently unclear whether the same interference-control mechanisms underlie the ability to ignore unimodal and cross-modal distractions. In 2 experiments we assessed whether unimodal and cross-modal interference follow similar trajec...

Background: In everyday life we must frequently ignore distractions arising from multiple senses. However, most of our understanding about this cognitive process (known as interference control) is derived from unimodal paradigms, in which relevant and irrelevant information are presented in the same sense. Thus, it remains unclear whether the mecha...

Across development, vision increasingly influences audio-visual perception. This is evidenced in illusions such as the McGurk effect, in which a seen mouth movement changes the perceived sound. The current paper assessed the effects of manipulating the clarity of the heard and seen signal upon the McGurk effect in children aged 3-6 (n = 29), 7-9 (n...

The Colavita effect occurs when participants respond only to the visual element of an audio-visual stimulus. This visual dominance effect is proposed to arise from asymmetric facilitation and inhibition between modalities. It has also been proposed that, unlike adults, children appear predisposed to auditory information. We provide the first quanti...

The McGurk effect is a visually induced illusion in which a seen mouth movement changes the sound perceived. The influence of vision over audition is proposed to increase across development such that vision plays an increasingly important role in in perception (Nava & Pavani, 2013). In this study we assessed the impact of auditory and visual noise...

The Colavita effect occurs when participants respond only to the visual element of an audio-visual stimulus. This visual dominance effect is proposed to arise from asymmetric facilitation and inhibition between modalities. It has also been proposed that, unlike adults, children appear predisposed to auditory information. We provide the first quanti...

Date : 1st of November 2017, 11:00AM until 12:00PM Location : Australian Hearing Hub, 3.610, Macquarie University. In everyday life we are bombarded with information from all sensory modalities. The ability to select relevant information from multisensory environments, and ignore irrelevant information, is an essential executive ability at every st...

It has been reported that when adults are presented with an auditory stimulus at the same time as a visual stimulus, they respond as though only the visual stimulus was presented (“Colavita Effect”). This has been proposed to be due to visual dominance over audition or due to asymmetric facilitation and inhibition between the two modalities. These...

Commonly displayed functional asymmetries such as hand dominance and hemispheric speech lateralisation are well researched in adults. However there is debate about when such functions become lateralised in the typically developing brain. This study examined whether patterns of speech laterality and hand dominance were related and whether they varie...

Commonly displayed functional asymmetries such as hand dominance and hemispheric speech lateralisation are well researched in adults. However there is debate about when such functions become lateralised in the typically developing brain. This study examined whether patterns of speech laterality and hand dominance were related and whether they varie...