Memory Tower

2010, Dr. Timothy J. Senior David J. Zielinski Yang Su

The Memory Tower is a full-immersion virtual reality environment exploring the neural mechanisms behind the stabilization and reorganization of memory traces during sleep (termed memory consolidation). The nature of memory formation is reflected through the use of historical, architectural motifs, serving as visual metaphors for both the content and structure of memory traces. By creating a rich cityscape that encompasses more familiar notions of memory from our everyday encounters with the world around us, the work aims to extend beyond a reductionist, scientific description of memory content and to acknowledge notions of collective human experience and history.

The capacity to record our waking experiences in memory – the what, where and when of our lives – allows us to act in accordance with that experienced in the past and be prepared for what may be encountered in the future. Information that has been encoded in the brain during waking experience, however, is initially unstable. It is only through a process of memory consolidation that new labile memories can be transformed into a more stable, long-lasting form. In the standard model of memory consolidation, waking experience is initially encoded in a variety of neural networks distributed within the neocortex (the outer layers of the cerebral hemispheres), each reflecting different perceptual, motor and cognitive features of that experience. Activity in these networks is coordinated through a brain structure called the hippocampus, whose activity binds these different features into a single ‘memory trace’ reflecting the spatial and temporal features of waking experience. During memory consolidation (a state promoted during sleep), memory traces within the hippocampal-neocortical circuitry undergo repeated reactivation, strengthening the connectivity between those neocortical networks representing features of experience. This results in a stabilisation of the memory trace within the neocortex alone, freeing the hippocampus once again for supporting the encoding of new experiences in memory.

Set principally in the neocortex, the structures of the Memory Tower reflect this process of memory consolidation during slow wave (SW) sleep and rapid eye movement (REM) sleep. The characteristic ‘slow wave’ of SW sleep – represented with simple wave-like structures – forms an urban enclosure encasing the memory content of the work, represented through architectural forms. Locked with the rhythmic cycles of the slow wave are narrow curved spines projecting up into the space above, representing brief bursts of memory reactivation in the hippocampus that occur during SW sleep. From these spines, thin threads project to the centre of the memory space, connecting to clusters of architectural fragments. These fragments – together forming a tower – represent the features of the new memory trace that is undergoing consolidation. Whilst undergoing consolidation, this new memory structure will itself become integrated into memory networks that share similar content. As such, the central tower is surrounded by a constellation of urban structures, each sharing with the tower common design principles and motifs derived from Classical architecture. With each from a different epoch of the past, these older memory structures will have undergone consolidation to varying degrees of completeness; whilst some have all structural elements bound together, others remain partially fragmented. REM sleep, a state that is also thought to contribute to memory consolidation by aiding the strengthening of new memory networks and facilitating the comparison of related memory content, is also represented within the work.

The narrative structure of the Memory Tower is shaped by three core sets of encounters with texts and images projected onto the walls of the DiVE. Although there is a sequence to the narrative, the visitor is free to explore the environment at leisure, using a virtual map located within the virtual environment to help reorient / relocate a specific location. These encounters introduce key neuroscience perspectives on memory consolidation, the correlative nature of architectural forms and neural processes in the work, and the position of architecture in collective and cultural memory and human experience. As the work is explored, the change in emphasis from scientific to cultural and experiential perspectives places the individual account of memory in the context of sleep at centre stage. From inquiring into an urban landscape through scientific knowledge, the visitor now inquires into his/her own encounters with memory and sleep through urban landscape. At the heart of the Memory Tower, therefore, is not only a scientific narrative about sleep’s role in memory consolidation as made visible through the cultural lens of architecture, but a deeper investigation into our own unique experiences with sleep and memory.