Initiating activity in behaviour - a functional property of the brain
Final Report Abstract
For the fly with a dozen appendages, five senses, auto-mobility, and spatial orientation it is a most demanding task to 'always do the right thing'. The fly generates a model of the world. It gathers 'knowledge' about temporal and spatial relations in the world and about relations between the world and its own behavior. This latter relation is highly problematic. An animal activates a behavior because of its outcome. The outcome lies in the future. It is not necessarily good. It is uncertain to some degree. It may have different significances in different contexts. Let us assume the fly is sitting somewhere at rest. Suddenly there is a shadow above the fly. Is this a predator? If so, does it aim at the fly? Would, for the fly, a jump start be the best escape? Would the flight system be ready in time? Or might the jump end for the fly as a disaster, e.g. on the back in the mud? Would immobility be a better way to hide? Which of all these considerations does actually occur in the fly during this brief episode of action selection? Brain research in flies is to a large extent brain/behavior research. The goal is to find out how the brain organizes action selection. One needs to study different cases of action selection, vary certain parameters, change the over-all situation of the fly and try to find out for all these conditions how they influence the potential outcome and how the fly makes use of outcome expectations optimizing the selection. Evidently, our six examples are just the very first beginning. Importantly, one would have to define functional terms that bridge the gap between behavior and neuronal circuitry, such as 'sensory stimulus' or 'memory'. Are outcome learning, outcome expectation, intention, recognition and selective attention adequate terms? The same applies to mood, emotion, disposition and motivation. Does a fly have outcome expectations? There is plenty of evidence that the fly monitors the outcome of its behavior. The term 'learning by punishment and reward' refers to outcome learning and to the gradual modulation of an outcome expectation. This is what is stored to serve in the next action selection process. Even the so-called inborn behavioral responses get modified by experience. There is a well known experiment first performed a century ago, showing that phototaxis in trapped flies depends upon the state of their flight system. They walk towards a light. Chances to reach free space are largest where the light is. Surprisingly, flies show this positive phototaxis only if their flight system is functional. Evidently, it is not the outcome of this behavior that is rewarding. Rather, the outcome may stimulate a second behavior, flight, that in turn may have a rewarding outcome. Should one call phototaxis under these conditions 'intentional'? Is it appropriate to say that the fly wants to escape the trap? Brain/behavior research is still in its infancy. I hope the results of the six sub-projects have provided first glimpses of what a brain can (and must) do to organize behavior. The highly artificial experimental conditions used in this study make it a bit easier to see what is going on in the brain. To find out how in more natural habitats the fly brain organizes the fly's behavior, requires entirely different approaches. Even in flies much of what happens in the brain (attention, learning, expectation, intention) is close to being classified as mental. It might be called meta-organization.
Publications
- (2013) Action selection – The brain as a behavioral organizer. In: R. Menzel and P. R. Benjamin (Eds.) Invertebrate Learning and Memory. pp 9 - 13; Elsevier
M. Heisenberg
(See online at https://doi.org/10.1016/B978-0-12-415823-8.00002-2) - (2013) Flies cope with uncontrollable stress by learned helplessness. Curr Biol 23, 799-803
Z. Yang, F. Bertolucci, R. Wolf, and M. Heisenberg
(See online at https://doi.org/10.1016/j.cub.2013.03.054) - (2014) The beauty of the network in the brain and the origin of the mind in the control of behavior. J Neurogenetics 28, 389-399
M. Heisenberg
(See online at https://doi.org/10.3109/01677063.2014.912279) - (2015) Central complex and mushroom bodies mediate novelty choice behavior in Drosophila. J Neurogenetics 29, 30-37
N. Solanki, R. Wolf and M. Heisenberg
(See online at https://doi.org/10.3109/01677063.2014.1002661) - (2015) Flies Remember the Time of Day. Curr Biol 25, 1619–1624
N. S. Chouhan, R. Wolf, C. Helfrich-Förster and M. Heisenberg
(See online at https://doi.org/10.1016/j.cub.2015.04.032) - (2015) Outcome learning, outcome expectations, and intentionality in Drosophila. LearnMem 22, 294–298
M. Heisenberg
(See online at https://doi.org/10.1101/lm.037481.114) - (2016) Inescapable Stress Changes Walking Behavior in Flies - Learned Helplessness Revisited. PLoS ONE 11(11): e0167066
S. Batsching, R. Wolf and M. Heisenberg
(See online at https://doi.org/10.1371/journal.pone.0167066) - (2016) Visual Attention in Flies - Dopamine in the Mushroom Bodies Mediates the After-Effect of Cueing. PLoS ONE 11(8): e0161412
S. König, R. Wolf and M. Heisenberg
(See online at https://doi.org/10.1371/journal.pone.0161412) - (2017) Starvation promotes odor/feeding time associations in flies. LearnMem 24, 318–321
N.S. Chouhan, R. Wolf and M. Heisenberg
(See online at https://doi.org/10.1101/lm.045039.117) - (2018) "Mind from Matter?" - über Verhalten und Gehirn. (Englische Fassung: "Mind from Matter?" - via Brain and Behavior) Neuroforum
M. Heisenberg
(See online at https://doi.org/10.1515/nf-2018-0002) - (2018) Der Zufall als kreatives Element in Gehirn und Verhalten. In: Zufall in der belebten Natur. U. Herkenrath (Hg.); Verlag Roman Kovar, Hennef; ISBN-13 978-3-86577-131-5
B. Brembs and M. Heisenberg
- (2018) Multi-stability with ambiguous visual stimuli in Drosophila orientation behavior. PLoSBiology
F. Töpfer, R. Wolf and M. Heisenberg
(See online at https://doi.org/10.1371/journal.pbio.2003113)
