About
51
Publications
8,550
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
944
Citations
Introduction
Lecturer (Asst Prof) in Cognitive Neuroscience at the University of Dundee, Hons Lecturer in Psychology at the University of Stirling
Current institution
Additional affiliations
July 2019 - present
October 2013 - January 2014
February 2014 - April 2019
Publications
Publications (51)
Two largely independent research lines use rhythmic sensory stimulation to study visual processing. Despite the use of strikingly similar experimental paradigms, they differ crucially in their notion of the stimulus-driven periodic brain responses: one regards them mostly as synchronized (entrained) intrinsic brain rhythms; the other assumes they a...
Fluctuations in arousal, controlled by subcortical neuromodulatory systems, continuously shape cortical state, with profound consequences for information processing. Yet, how arousal signals influence cortical population activity in detail has so far only been characterized for a few selected brain regions. Traditional accounts conceptualize arousa...
Viewing brain function through the lense of other physiological processes has critically added to our understanding of human cognition. Further advances though may need a closer look at the interactions between these physiological processes themselves. Here we characterise the interplay of the highly periodic, and metabolically vital respiratory pr...
Research on brain-behaviour relationships often makes the implicit assumption that these derive from a co-variation of stochastic fluctuations in brain activity and performance across trials of an experiment. However, challenging this assumption, oscillatory brain activity, as well as indicators of performance, such as response speed, can show syst...
The cortical tracking of stimulus features is a crucial neural requisite of how we process continuous music. We here tested whether cortical tracking of the beat, typically related to rhythm processing, is modulated by pitch predictability and other top‐down factors. Participants listened to tonal (high pitch predictability) and atonal (low pitch p...
Viewing brain function through the lense of other physiological processes has critically added to our understanding of human cognition. Further advances though may need a closer look at the interactions between these physiological processes themselves. Here we characterise the interplay of the highly periodic, and metabolically vital respiratory pr...
Fluctuations in oscillatory brain activity have been shown to co-occur with variations in task performance. More recently, part of these fluctuations has been attributed to long-term (>1hr) monotonous trends in the power and frequency of alpha oscillations (8-13 Hz). Here we tested whether these time-on-task changes in EEG activity are limited to a...
Several studies have suggested that low-frequency brain oscillations could be key to understanding how the brain samples sensory information via rhythmic alternation of low and high excitability periods. However, this hypothesis has recently been called into question following the publication of some null findings. As part of the #EEGManyLabs initi...
Cortical tracking of stimulus features (such as the envelope) is a crucial tractable neural mechanism, allowing us to investigate how we process continuous music. We here tested whether cortical and behavioural tracking of beat, typically related to rhythm processing, are modulated by pitch predictability. In two experiments (n=20, n=52), participa...
Do humans perceive the world through discrete sampling of the sensory environment? Although it contrasts starkly with the intuition of a continuous perceptual flow, this idea dates back decades when brain rhythms were first suggested to work as periodic shutters. These would gate bouts of information into conscious perception and affect behavioural...
Fluctuations in arousal, controlled by subcortical neuromodulatory systems, continuously shape cortical state, with profound consequences for information processing. Yet, how arousal signals influence cortical population activity in detail has only been characterized for a few selected brain regions so far. Traditional accounts conceptualize arousa...
Attention is one of the most important higher cognitive processes underlying the normal functioning of the human brain. It refers to a set of neural mechanisms that govern the selection and gating of sensory events, thoughts, and actions. Although psychologists have described this concept more than 100 years ago, until recently, underlying computat...
Our visual system extracts the emotional meaning of human facial expressions rapidly and automatically. Novel paradigms using fast periodic stimulations have provided insights into the electrophysiological processes underlying emotional content extraction: the regular occurrence of specific identities and/or emotional expressions alone can drive di...
Successfully interpreting and navigating our natural visual environment requires us to track its dynamics constantly. Additionally, we focus our attention on behaviorally relevant stimuli to enhance their neural processing. Little is known, however, about how sustained attention affects the ongoing tracking of stimuli with rich natural temporal dyn...
Our visual system extracts the emotional meaning of human facial expressions rapidly and automatically. Novel paradigms using fast periodic stimulations have provided insights into the electrophysiological processes underlying emotional content extraction: brain responses not only follow the presentation rate of individual stimuli, but also the reg...
Successfully interpreting and navigating our natural visual environment requires us to track its dynamics constantly. Additionally, we focus our attention on behaviorally relevant stimuli to enhance their neural processing. Little is known, however, about how sustained attention affects the ongoing tracking of stimuli with rich natural temporal dyn...
Interpreting and navigating our natural visual environment requires us to constantly track its dynamics, while focusing attention on behaviorally relevant stimuli to enhance their neural processing. Little is known about how sustained attention affects the ongoing tracking of natural stimuli with rich temporal dynamics. Here, we used MRI-informed s...
Interpreting and navigating our natural visual environment requires us to constantly track its dynamics, while focusing attention on behaviorally relevant stimuli to enhance their neural processing. Little is known about how sustained attention affects the ongoing tracking of natural stimuli with rich temporal dynamics. Here, we used MRI-informed s...
Oscillatory neural activity is a fundamental characteristic of the mammalian brain spanning multiple levels of spatial and temporal scale. Current theories of neural oscillations and analysis techniques employed to investigate their functional significance are based on an often implicit assumption: In the absence of experimental manipulation, the s...
Oscillatory neural activity is a fundamental characteristic of the mammalian brain spanning multiple levels of spatial and temporal scale. Current theories of neural oscillations and analysis techniques employed to investigate their functional significance are based on an often implicit assumption: In the absence of experimental manipulation, the s...
Appendix S1. Supplementary material.
Fig. S1 plots the relationships between jackknife single‐trial estimates of EEG power and both spatial bias (PSE: 1A) and discrimination sensitivity measures (curve width: 1B) from the data points corresponding to the peak t‐values of the respective cluster‐analysis effects (PSE peak data point: 14 Hz, −1.78 s at electrode AF4; Curve width peak dat...
Two largely independent research lines use rhythmic sensory stimulation to study visual processing. Despite the use of strikingly similar experimental paradigms, they differ crucially in their notion of the stimulus-driven periodic brain responses: One regards them mostly as synchronised (entrained) intrinsic brain rhythms; the other assumes they a...
Recent studies have probed the role of the parieto‐occipital alpha rhythm (8 – 12 Hz) in human visual perception through attempts to drive its neural generators. To that end, paradigms have used high‐intensity strictly‐periodic visual stimulation that created strong predictions about future stimulus occurrences and repeatedly demonstrated perceptua...
In order to make optimal use of its neural capacity the visual system has the important capability to filter the continuous stream of massive real-world sensory inputs with their rich temporal and spatial dynamics and to selectively focus on processing only relevant information. In neuroimaging, brain activity evoked by continuous visual inputs (i....
Many recent studies have probed the role of the parieto-occipital alpha rhythm (8 – 12 Hz) in human visual perception through attempts to drive its neural generators. To that end, paradigms have used high-intensity strictly-periodic visual stimulation that created strong predictions about future stimulus occurrences and repeatedly demonstrated perc...
Human perception of perithreshold stimuli critically depends on oscillatory EEG-activity prior to stimulus-onset. However, it remains unclear exactly which aspects of perception are shaped by this pre-stimulus activity and what role stochastic (trial-by-trial) variability plays in driving these relationships. We employed a novel Jackknife approach...
The neural processing of a visual stimulus can be facilitated by attending to its position or by a co-occurring auditory tone. Using frequency-tagging we investigated whether facilitation by spatial attention and audio-visual synchrony rely on similar neural processes. Participants attended to one of two flickering Gabor patches (14.17 and 17 Hz) l...
The neural processing of a visual stimulus can be facilitated by attending to its position or by a co-occurring auditory tone. Using frequency-tagging we investigated whether facilitation by spatial attention and audio-visual synchrony rely on similar neural processes. Participants attended to one of two flickering Gabor patches (14.17 and 17 Hz) l...
Neural processing of dynamic continuous visual input, and cognitive influences thereon, are frequently studied in paradigms employing strictly rhythmic stimulation. However, the temporal structure of natural stimuli is hardly ever fully rhythmic but possesses certain spectral bandwidths (e.g. lip movements in speech, gestures). Examining periodic b...
We tested a novel combination of two neuro-stimulation techniques, transcranial alternating current stimulation (tACS) and frequency tagging, that promises powerful paradigms to study the causal role of rhythmic brain activity in perception and cognition. Participants viewed a stimulus flickering at 7 or 11 Hz that elicited periodic brain activity,...
Shifting attention from one color to another color or from color to another feature dimension such as shape or orientation is imperative when searching for a certain object in a cluttered scene. Most attention models that emphasize feature-based selection implicitly assume that all shifts in feature-selective attention underlie identical temporal d...
Visual attention can be focused concurrently on two stimuli at noncontiguous locations while intermediate stimuli remain ignored. Nevertheless, behavioral performance in multifocal attention tasks falters when attended stimuli fall within one visual hemifield as opposed to when they are distributed across left and right hemifields. This “different-...
Our brain relies on neural mechanisms of selective attention and converging sensory processing to efficiently cope with rich and unceasing multisensory inputs. One prominent assumption holds that audio-visual synchrony can act as a strong attractor for spatial attention. Here, we tested for a similar effect of audio-visual synchrony on feature-sele...
Current research frequently refers to visual stimulus-driven neural rhythms as phase-locked “entrainment” of intrinsic oscillators in the alpha frequency range (8-13 Hz) of the human EEG/MEG. This assumed identity suggests that visual perception or attention can easily be hi-jacked by stimuli flickering with frequencies around 10 Hz when considerin...
Unlabelled:
Shifting attention from one color to another color or from color to another feature dimension such as orientation is imperative when searching for a certain object in a cluttered scene. Most attention models that emphasize feature-based selection implicitly assume that within- and cross-dimensional shifts take equally long. In contrast...
Human brain activity is rich in rhythms of various characteristic frequencies. The last few decades have seen an increase in their use as an explanatory means, with a vast literature describing manifold correlations between dynamics of brain rhythms and behavioral performance in perceptual and
Many everyday situations require focusing on visual or auditory information while ignoring the other modality. Previous findings suggest an attentional mechanism that operates between sensory modalities and governs such states. To date, evidence is equivocal as to whether this 'intermodal' attention relies on a distribution of resources either comm...
Attention has been conceptualized as a filter mechanism that suffices the fundamental capacity limitation of sensory processing by selecting the input of most behavioral relevance. Recent research has demonstrated that information can be selected by attention based on the sensory modality it is presented in. However, it is not yet known whether thi...
Attention filters behaviorally relevant stimuli from the constant stream of sensory information comprising our environment. Research into underlying neural mechanisms in humans suggests that visual attention biases mutual suppression between stimuli resulting from competition for limited processing resources. As a consequence, processing of an atte...
In older adults, difficulties processing complex auditory scenes, such as speech comprehension in noisy environments, might be due to a specific impairment of temporal processing at early, automatic processing stages involving auditory sensory memory (ASM). Even though age effects on auditory temporal processing have been well-documented, there is...
Intermodal attention (IA) is assumed to allocate limited neural processing resources to input from one specific sensory modality. We investigated effects of sustained IA on the amplitude of a 40-Hz auditory (ASSR) and a 4.3-Hz visual steady-state response (VSSR). To this end, we concurrently presented amplitude-modulated multi-speech babble and a s...
Multiple concurrently presented stimuli are thought to compete for neuronal processing resources. Such competitive stimulus interactions can be investigated by "frequency tagging" each stimulus with an individual temporal frequency. In this case, all stimuli will drive distinct steady-state visual evoked potentials (SSVEPs), hence allowing for an a...
