The Origin of Behavioral Bursts in Decision-Making Circuitry

Abstract

From ants to humans, the timing of many animal behaviors comes in bursts of activity separated by long periods of inactivity. Recently, mathematical modeling has shown that simple algorithms of priority-driven behavioral choice can result in bursty behavior. To experimentally test this link between decision-making circuitry and bursty dynamics, we have turned to Drosophila melanogaster. We have found that the statistics of intervals between activity periods in endogenous activity-rest switches of wild-type Drosophila are very well described by the Weibull distribution, a common distribution of bursty dynamics in complex systems. The bursty dynamics of wild-type Drosophila walking activity are shown to be determined by this inter-event distribution alone and not by memory effects, thus resembling human dynamics. Further, using mutant flies that disrupt dopaminergic signaling or the mushroom body, circuitry implicated in decision-making, we show that the degree of behavioral burstiness can be modified. These results are thus consistent with the proposed link between decision-making circuitry and bursty dynamics, and highlight the importance of using simple experimental systems to test general theoretical models of behavior. The findings further suggest that analysis of bursts could prove useful for the study and evaluation of decision-making circuitry.

Anomalous diffusion and multifractality enhance mating encounters in the ocean

“…However, there is still a limited understanding of the causes of movement (2). In particular, it is unclear how much of an organism motion is internally governed without contributing external influences (48)(49)(50)(51). Our results are consistent with the interesting possibility that, in the absence of chemical cues (in a featureless and uniform environment), copepods exhibit innate intermittent search patterns, which evolve with both the sex and the degree of experience of the tested individuals.…”

Foraging success of biological Lévy flights recorded in situ

“…Although there is no clear evidence of an innate Lévy process driving movements of vertebrates, experimental studies have shown that in featureless environments Drosophila activity patterns are well approximated by a Lévy flight (8,27). Furthermore, Drosophila with silenced parts of the brain's mushroom body, or modified dopaminergic signaling-circuitry linked to decision-making-show disrupted activity patterning and behavioral burstiness, where burstiness is described as heavy-tailed distributions of move or pause times (28). Such evidence for neurophysiological pattern generation linked to decision-making behavior, taken together with our results showing Lévy movements of albatrosses can yield high energy gains in resource-sparse habitats, raises the question of whether an innate stochastic search process based on Lévy flight foraging has naturally evolved in organisms.…”

Scaling laws of ambush predator ‘waiting’ behaviour are tuned to a common ecology

“…To explore spatial and temporal patterning in behaviour, some recent investigations have used a statistical modelling approach centred on identifying simple features or rules operating in complex biological systems [6,7], which draws on concepts and techniques used in statistical physics to describe stochastic dynamical physical systems [6,8,9]. Results show that behavioural sequences in diverse organisms spanning insects to humans can show spatial and temporal scaling [6,7,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26], patterns that may embody such general rules. Thus, identifying behavioural scaling laws across diverse species may help to understand how apparently complex behaviours evolved [1,7].…”