Dr Aureliu Lavric
Senior Lecturer

Research

Research interests

My research interests are in the areas of cognitive control, attention, and psycholinguistics. Below I summarise the key directions of my research in these areas, as well research that sits at their intersection – on bilingualism. Methodologically, I rely on measures extracted from behavioural (performance), brain potentials and eye-movement data.

Cognitive control, attention

My primary interest is the control of task-set, which I investigate using the “task-switching” paradigm and a set of measures that include (in addition to performance) EEG-derived brain potentials and eye-tracking. My primary motivation for using EEG was to identify an on-line measure of preparation for a task switch, which could not be obtained behaviourally (because there is no overt behaviour during the preparation interval). In studies published in the European Journal of Neuroscience and Human Brain Mapping (and funded by ESRC) our group has documented such an electrophysiological “signature” of pro-active top-down control. We showed that its onset is not tightly coupled to the onset of the task cue, and that it “migrates” from the preparation interval into the post-stimulus interval when preparation is not effective. In more recent research published in Cognitive Psychology, we identified the same brain potential in a “switching” version of the “stop-signal” paradigm, in which participants had to switch among inhibiting a stopping the response when a signal occurred and executing another response in response to (or ignoring) the signal. The above research was conducted in collaboration with Heike Elchlepp, Stephen Monsell and Frederick Verbruggen.

More recently, my colleagues and I have examined whether shifting attention to a task-relevant perceptual attribute is a source of the “switch cost”. Traditionally, the switch cost has been explained in terms of interference from the irrelevant set of stimulus-response (S-R) mappings. In experiments published in the Journal of Experimental Psychology: General, and in more recent experiments, our group showed that even a prepared task switch, leads to a substantial delay in allocating attention to the relevant perceptual dimension of the stimulus (e.g. the colour of a letter string vs. its linguistic status). Using eye-tracking we have documented a similar delay for shifting the spatial attention to the task-relevant region of the stimulus. This delay is especially substantial when the experimental procedure encourages the “coupling” of spatial parameters of the task to other task-set parameters. In addition, we have documented a persisting tendency to allocate spatial attention to no-longer relevant location – a form of “attentional inertia”, which is difficult (though not impossible) to eliminate with preparation. This work was done in collaboration with Cai Longman, and Stephen Monsell and published in: Journal of Experimental Psychology: Learning, Memory and Cognition, Journal of Experimental Psychology: Human Perception and Performance, and The Quarterly Journal of Experimental Psychology. Currently we are extending this framework to study auditory attention – in particular, we are investigating the extent to which one can “tune in” in advance to listen to a voice in a dual/multi-speaker environment when the relevant voice changes frequently.

Another aspect of task-set control that has interested me is the nature of task-set representations in working memory and long-term memory. Are S-R mappings for the relevant task-set prepared via some form of verbal rehearsal? Is it harder to select a task-set among many candidate task-sets than among few candidates? In research conducted in collaboration with Félice Van’t Wout and Stephen Monsell (published in Journal of Experimental Psychology: Learning, Memory and Cognition) we have aimed to provide answers to these other related questions.

In addition to the research above I have also conducted ESRC-funded research on inhibitory control, in collaboration with Frederick Verbruggen (studies published in Journal of Experimental Psychology: Applied), and on the role of attentional phenomena in associative learning, in collaboration with Andy Wills and Ian McLaren (studies published in Journal of Cognitive Neuroscience, Neuroimage, and Journal of Experimental Psychology: Animal Learning and Cognition).

Psycholinguistics and bilingualism

I am interested in how the mind represents the morphemic constituents of words (e.g. player, played, replay, plays). In collaboration with Kathy Rastle and Davide Crepaldi I have investigated with EEG-derived brain potentials (ERPs) whether morphological decomposition of visual words occurs rapidly, before meaning is accessed, based purely on orthographic information – these studies have appeared in Journal of Cognitive Neuroscience, Psychophysiology, and Journal of Experimental Psychology: Human Perception and Performance). In prior work (funded by the British Academy and presented in Trends in Cognitive Sciences), I have also examined the production of morphologically complex words. More recently, I have also conducted research on top-down control of language selection in bilinguals. I have been interested in two aspects of such control. First, in task switching, the behavioural “litmus test” for top-down control is the effect of preparation – the reduction in the task switch cost with preparation. The effect of preparation on the language switch cost has been subject to less scrutiny, and my current work aims to address this lacuna. Second, I am also interested in whether bilinguals are able to set (select) independently the languages used for speaking and for comprehending – and I am currently conducting experiments that examine this issue.

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