All group members are interested in memory as it is expressed in human behaviour. Many of us study the basic processes involved in the formation, retention, and retrieval of memory at various time scales and in different groups of individuals. Regarding short-term memory (or “working memory”), we investigate why working memory capacity is limited, and why it is reduced in healthy ageing. At longer time scales, we are interested in how information once encountered can transform into a stable, persistent long-term memory, how humans manage to retrieve such information from memory after days or even years, and which factors consistently boost remembering or cause forgetting.
Many group members translate this basic research into applied and clinical areas. These areas include studying memory changes in the elderly, the role memory plays for regulating our eating behaviour, how basic research might help to prevent intrusive memories and flashbacks in post-traumatic stress disorders, and the effect that physical exercise has on memory functioning.
To understand the whole-brain dynamics of memory formation, maintenance and retrieval, we apply functional neuroimaging using two different MRI setups. First, the University of Birmingham has its own neuroimaging centre on Campus (Birmingham University Imaging Centre), housing a research-dedicated 3T Philips Achieva MRI scanner. Second, through the 'Birmingham-Nottingham Strategic Collaboration Fund', we have access to a high-field 7T Philips Achieva MRI scanner located at the University of Nottingham’s Sir Peter Mansfield Magnetic Resonance Centre.
Both scanners allow us to employ simultaneous EEG-fMRI, directly relating the BOLD signal to co-occurring electrophysiological signals. In our analyses, we put a strong emphasis on investigating hippocampal-neocortical interactions via functional and effective connectivity analyses (e.g., PPI, DCM) as well as on capturing the representational content of our memories via multivariate pattern analyses (MVPA).
Memory relies on rapid interactions within distributed networks, which synchronize and desynchronize in a highly dynamic manner. Brain oscillations are a ubiquitous phenomenon in the brain and reflect these interactions with high temporal resolution. Oscillations are therefore a key approach that we use in order to unravel the mysteries behind memory.
We record brain oscillations using a range of electrophysiological methods, such as non-invasive EEG (32-128 channels), combined EEG-fMRI (Birmingham University Imaging Centre), and MEG, in collaboration with the University of Nottingham’s Sir Peter Mansfield Magnetic Resonance Centre. To understand these dynamics on the local level, i.e. in small cell assemblies, we also record local field potentials and single-unit firing invasively in epileptic patients undergoing pre-surgical evaluation (in collaboration with the local epilepsy unit at the QEHB in Birmingham, but also in Erlangen and Bonn in Germany). Finally, we also employ brain stimulation techniques like repetitive transcranial magnetic stimulation (rTMS) and transcranial alternating current stimulation (tACS) in order to induce brain oscillations, and test for a causal role of oscillations in memory.
We are interested broadly in the question of how memories are built and maintained in such a way that they are both long-lasting and accurate. We investigate these questions in quite simple rat memory settings. Therefore, there is a focus on memories that, while basic and unconscious in nature, have an important impact upon behaviour. These include pavlovian (both fear and rewarding) and instrumental memories, as well as object location learning.
We combine these memory paradigms with behavioural, pharmacological and cellular manipulations in order to target the processes of memory consolidation, retrieval, reconsolidation and extinction. Moreover, wecan target specific neural loci, both through intracerebral infusions and ex vivo analyses (immunohistochemistry, western blots, FACS).