What is the biggest question facing your field today?
One of the most enduring questions in the field of cognitive neuroscience is the matter of how memories are formed. In short, how do we remember the past? This deceptively simple question belies the underlying complexity of human memory and speaks to the fact that we still do not fully understand the cognitive, neural, and molecular mechanisms of memory. How is it possible to seamlessly travel back in subjective time to relive the past in exquisite detail? Why are some memories so enduring yet others fade away? Why are our memories so vulnerable to error, distortion, and decay? Despite significant advances in this field, the underlying mechanisms of human memory remain a topic of vigorous debate and robust empirical research, and represent a question that lies at the heart of understanding what makes us unique as individuals.
Since time immemorial, humans have grappled with the question of what memory is and why it is important. The capacity to encode, store, and retrieve information is central to our everyday adaptive functioning, and yet, paradoxically, it remains one of the most elusive aspects of human cognition. Our memories for the past shape who we are as individuals, imbuing our life history with meaning and conferring a sense of continuity and identity across subjective time. Recent research underscores the importance of memory not only for remembering defining events from the past, but for envisaging what might unfold in the future. By harnessing our previous experiences and drawing upon our conceptual knowledge store, we can envisage and predict possible outcomes in the future without engaging in costly mistakes. Perhaps most importantly, however, is the devastating effects of losing one’s memory, whether through brain injury, or as a result of pathological disease processes such as Alzheimer’s disease. Understanding the core mechanisms of memory consolidation may provide the key to earlier and more accurate diagnoses of dementia, potentially paving the way towards a cure.
Where will the answer likely come from?
Ultimately, the key to unlocking the mystery of memory likely lies in the concerted efforts of multidisciplinary consortia, combining cutting-edge brain imaging, lesion mapping, and computational modelling. With the advent of high-resolution brain imaging methods, it is now possible to delineate the neural substrates of memory consolidation in vivo at varying degrees of complexity – ranging from the coordinated activity of large-scale neural networks, to activation of substructures deep within the brain, as well as the role of white matter microstructure in facilitating communication between different brain regions. Pairing these sophisticated brain imaging techniques with lesion studies, allows us to observe how damage to structural and functional brain networks impacts memory performance in various clinical disorders, refining our understanding of which regions and pathways are crucial for memory integrity.
This is precisely the line of enquiry that the MIND (Memory and Imagination in Neurological Disorders) team is pursuing at the Brain and Mind Centre, University of Sydney. We study how damage to large-scale brain networks in neurodegenerative disorders impacts the capacity to remember the past and to imagine the future. Using this convergent approach, we have revealed new insights into the cognitive and neural mechanisms which must be functional to support complex expressions of memory (see Irish et al. 2011; 2012; 2014). Our ultimate aim is to delineate the fundamental mechanisms of human memory, enabling us to intervene swiftly and effectively when memory begins to fail.