Unravelling the mechanisms for attention-like behaviour in the central brain of Drosophila melanogaster

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Selective attention is a cognitive process, allowing animals to interact adaptively with their surroundings, by focusing on a subset of relevant stimuli while ignoring unimportant sensory influences at the same time (Posner et al. 1980). It is therefore a crucial process for all species to create a working representation of their surrounding in the brain, and for placing their position within this representation. As such, selective attention is likely to be important for navigation, decision-making, and for learning and memory. Most animals appear to display a capacity for selective attention, although animal species differ considerably from humans in their behavioural repertoires and neuroanatomy. This raises the question of whether selective attention underlies fundamental mechanisms that are present in all brains, despite their differences in neuroanatomy? Also, does selective attention reflect conserved gain-control mechanisms in the brain that interact with other cognitive processes, such as navigation, decision making, or learning? In my experiments, I will focus on the smallest brain where selective-attention has been identified, in the fruit fly (Van Swinderen and Greenspan 2003), and try to understand how it works. Drosophila melanosgaster is a promising model for studying fundamental brain mechanisms. The central complex (CC), a region in the central brain of insects, has been increasingly implicated in the control of higher-order behaviours (Ofstad et al. 2011, Liu et al. 2006). These higher-order processes are being increasingly studied at the circuit level in the CC of fruit flies, in order to disentangle mechanisms underlying cognitive behaviour. In my proposal I aim to answer the following questions: Are attention-like processes (measured by gain-control of endogenous or exogenous oscillatory neuronal activity) present in the CC of fruit flies? What structures contribute to the generation of neuronal activity associated with selective attention, such as frequency-specific oscillations? How does feedback circuitry give rise to mechanisms of selective attention? How does this mechanism interact with or influence other cognitive functions, such as learning? To answer these questions, I will apply new paradigms that I have recently optimized to study neuronal mechanisms of attention in the fruit fly. These paradigms combine sophisticated methods common in human attention research, such as frequency tagging (Norcia et al. 2015), new approaches in fly brain electrophysiology and optogenetics, and a new virtual reality paradigm allowing attention to be studied in a historical context. The combination of these methods will lead to a better understanding of fundamental aspects of selective attention, and how it operates to shape complex behaviour.