Programme

I will consider how the structure of space constraints neural representations for perception, action and coherent imagery interact within a hippocampal system for memory. I will discuss why these representations must integrate information from self-motion and from the environment and how this may be achieved by grid cells and place cells. I will then try to explain how these representations might be understood within a broader framework for generalisation and prediction.

I will take you through some recent theoretical ideas and data that support the idea that the hippocampal system and its compuatations might be good at optimising the representation of the world for efficient learning.

Whilst experiencing a negative event can produce vivid, long-lasting memories, in some situations these memories can be debilitating and lead to distressing images that are involuntarily re-experienced, as seen in posttraumatic stress disorder (PTSD). In this talk I will discuss recent experiments supporting the view that negative emotional events can strengthen memory for the negative content of an experience via amygdala up-modulation but weaken associative binding via hippocampal down-modulation. I will also discuss how these opposing effects on memory can impact hippocampal pattern completion, resulting in fragmentary representations of negative content that contribute to intrusive memory re-experiencing in PTSD.

Abstract The brain is highly sensitive to auditory regularities. To appreciate the impact that the presence of predictability has on perception, we need to better understand how a predictable structure influences processing and attention. We recorded listeners’ pupil responses to sequences of tones that followed either a predictable or unpredictable pattern, as the pupil can be used to implicitly tap into these different cognitive processes. We found that the pupil showed a smaller sustained diameter to predictable sequences, indicating that predictability eased processing rather than boosted attention. The findings suggest that the pupil response can be used to study the automatic extraction of regularities, and that the effects are most consistent with predictability helping the listener to efficiently process upcoming sounds.

Abstract It is widely assumed that we must use predictions to determine what we perceive. However, theories concerning how predictions shape perception are wholly conflicting. Some perceptual domains propose that we cancel predicted events from perception to generate informative experiences - telling us what we did not already know. In contrast, others - typically couched within Bayesian frameworks - demonstrate that we are more, not less, likely to perceive what we expect. Such findings are thought to reflect processes that would generate veridical experiences in the face of sensory noise. Paradoxically, the proposed mechanisms that would render our experiences more veridical would make them less informative, and vice versa. I will present findings from our lab that demonstrate predictions in fact influence perceptual processing similarly regardless of domain. I will conclude by asking how we may, across domains, use predictions to generate experiences that are both veridical and informative.

Complex hierarchical structures occur in language, music and action planning. In these domains, it is difficult to establish the limits of hierarchical depth, especially when auxiliary memory resources are available. Recursive hierarchical embedding (RHE) is probably a key capacity to achieve this power. In this talk, I will summarize the results of our research program aiming at describing the cognitive architecture underlying the representation of RHE. Examining the results of a series of behavioural and fMRI experiments in the visual, musical and motor domains, I will draw a map of the cognitive resources that are general across domains, and those which seem domain-specific.

Magnetoencephalography (MEG) is a powerful non-invasive functional imaging method, which measures the magnetic fields from neural currents. Its combination of high temporal resolution, good spatial coverage and resolution make it an attractive tool for cognitive neuroscience. However, the current MEG systems available require participants to either sit or lie still in them, meaning that certain naturalistic paradigms are better off left to other imaging methods. In this talk I shall show you the next generation of MEG system – which is wearable and allows participants to move considerably further than previously possible. First, I shall describe some of the technical challenges the group at UCL and its collaborators have had to overcome to allow MEG to tolerate any movement at all. Secondly, I shall show you some of the first MEG experiments in the world to take advantage of this additional freedom, whether that’s freedom of movement, or freedom from the block design.

What makes live experiences special? Liveness is a central feature of music concerts, dance performances and theatre plays, but it is also relevant to political rallies, sporting events and online communication via zoom. In this talk, we will discuss some of the theoretical and practical challenges for a neuroscience of liveness. The key idea is that live experiences can be conceptualized and measured as a form of sustained entrainment between the minds, brains and bodies of at least two people in a defined here and now. We will discuss two studies that test this hypothesis, one in a live theatre context and the second one using fMRI. By their very nature, live experiences are unique, context-dependent and social, which makes them exceptionally difficult to study within a traditional, lab-based and reductionist framework of cognitive neuroscience. Studying live experiences can thus illustrate both the chances, as well as the challenges for real-world neuroscience.

Abstract tba

It is increasingly understood that recruitment of left inferior frontal cortex (LIFC), including Broca’s area is necessary to allow learning of a speech task. However, the neural mechanisms underpinning plasticity within this region and other language and cognitive control functions required in speech (and its recovery after aphasic stroke) are not well understood. In this talk I will outline recent studies ongoing in our lab where we use structural and functional magnetic resonance imaging, to simultaneously identify neural changes within speech systems in both healthy adults and people with aphasia, in response to transcranial direct current stimulation (tDCS) applied to LIFC, and aphasia treatment interventions.

I will discuss two distinct reading disorders caused by strokes affecting the dominant hemisphere. In one (pure alexia) patients only seem to have problems with identifying written words, other language functions are spared. In the other (central alexia) reading is affected alongside other language modalities (e.g. speaking and writing). Whole-word, app-delivered, practice-based therapy improves reading performance in both patient groups, but the effects play out very differently in their reading networks, as measured with MEG.

There have been rapid recent developments in our understanding of the neurobiology and neural mechanisms supporting speech perception. In this presentation I will summarise hierarchical and entrainment models of speech perception and explore how these models align with neuropsychological and neuroimaging evidence from individuals with acquired speech perception impairments. I will also explore how these models could be used to develop new treatments for those with language comprehension impairments after stroke.