Living Machines

Obviously the whole purpose of this BLOG is to highlight interdisciplinary research around insect spatial behaviours. The idea that computer science and engineering can take inspiration from animals, as well as helping biologists understand living systems, is the mission statement for the Living Machines conference series. The proccedings of the latest event re published online there are many relevant papers. A short list of relevant submissions is below and full listings can be found here:

Artificial Compound Eye and Synthetic Neural System for Motion Recognition
Drago Bračun, Nicholas S. Szczecinski, Gašper Škulj, Alexander J. Hunt, Roger D. Quinn

Insect-Inspired Elementary Motion Detection Embracing Resistive Memory and Spiking Neural Networks
Thomas Dalgaty, Elisa Vianello, Denys Ly, Giacomo Indiveri, Barbara De Salvo, Etienne Nowak et al.
Pages 115-128

A Hexapod Walking Robot Mimicking Navigation Strategies of Desert Ants Cataglyphis
Julien Dupeyroux, Julien Serres, Stéphane Viollet

Simulation of the Arthropod Central Complex: Moving Towards Bioinspired Robotic Navigation Control
Shanel C. Pickard, Roger D. Quinn, Nicholas S. Szczecinski

Insect Behavioral Evidence of Spatial Memories During Environmental Reconfiguration
Diogo Santos-Pata, Alex Escuredo, Zenon Mathews, Paul F. M. J. Verschure

An Analysis of a Ring Attractor Model for Cue Integration
Xuelong Sun, Michael Mangan, Shigang Yue

Categories: Papers from 2018

Aspects of cognition in bees

In the race to discover ever more about the behavioural repertoires of insects, people cannot help but discover further aspects that can be considered intelligent. Here we have two further examples. Gallo and Chittka look at comb building behaviours and show how these are far from robotic and automated, rather bees need to plan ahead and behave flexibly towards a goal. Our other example from Lawson et al., shows that bees trained to identify a pattern made up of spots of odour, can transfer knowledge of that shape to the visual domain and will subsequently prefer visual patterns that conform to a similar shape. Such a transfer between sensory modalities might lead one to think about an abstract ability of bees to “think” about shapes. However, it might be that transfer happens through the shared motor patterns evoked by the patterns. Thus in both cases, we have further evidence for the sensori-motor basis for many of the smart things that we see in bees.

Gallo, V., & Chittka, L. (2018). Cognitive aspects of comb-building in the honeybee?. Frontiers in Psychology, 9, 900.

Lawson, D. A., Chittka, L., Whitney, H. M., & Rands, S. A. (2018). Bumblebees distinguish floral scent patterns, and can transfer these to corresponding visual patterns. Proc. R. Soc. B, 285(1880), 20180661.

Categories: Papers from 2018

The same tools can make different toolkits

Research into ant navigation has often highlighted how a simple ‘toolkit’ of strategies can lead to robust behaviour. Of course current research has to uncover how strategies are subtly tuned to different situations. This review discuss the current state of our understanding in this endeavour. From the abstract: “Here, we summarize recent behavioral work, focusing on how these cues are learned and stored as well as how different navigational cues are integrated, often between strategies and even across sensory modalities. Information can also be communicated between different navigational routines. In this way, a shared toolkit of fundamental navigational strategies can lead to substantial flexibility in behavioral outcomes. This allows individual ants to tune their behavioral repertoire to different tasks (e.g., foraging and homing), lifestyles (e.g., diurnal and nocturnal), or environments, depending on the availability and reliability of different guidance cues. We also review recent anatomical and physiological studies in ants and other insects that have started to reveal neural correlates for specific navigational strategies, and which may provide the beginnings of a truly mechanistic understanding of navigation behavior.”

Freas, C. A., & Schultheiss, P. (2018). How to navigate in different environments and situations: lessons from ants. Frontiers in Psychology, 9, 841.

Categories: Papers from 2018

What makes a visual scene navigable?

In considering the sensory ecology of an animal, we need to understand the information provided by the environment for a specific task. Within the insect navigation field, Jochen Zeil has been at the forefront of using image derived metrics to analyse the information in visual scenes. Here, the authors present a novel metric from work on navigation in humans, and investigate its utility for analysing the informational content of scenes for insect navigation.

Abstract: Recent work on virtual reality navigation in humans has suggested that navigational success is inversely correlated with the fractal dimension (FD) of artificial scenes. Here we investigate the generality of this claim by analysing the relationship between the fractal dimension of natural insect navigation environments and a quantitative measure of the navigational information content of natural scenes. We show that the fractal dimension of natural scenes is in general inversely proportional to the information they provide to navigating agents on heading direction as measured by the rotational image difference function (rotIDF). The rotIDF determines the precision and accuracy with which the orientation of a reference image can be recovered or maintained and the range over which a gradient descent in image differences will find the minimum of the rotIDF, that is the reference orientation. However, scenes with similar fractal dimension can differ significantly in the depth of the rotIDF, because FD does not discriminate between the orientations of edges, while the rotIDF is mainly affected by edge orientation parallel to the axis of rotation. We present a new equation for the rotIDF relating navigational information to quantifiable image properties such as contrast to show (1) that for any given scene the maximum value of the rotIDF (its depth) is proportional to pixel variance and (2) that FD is inversely proportional to pixel variance. This contrast dependence, together with scene differences in orientation statistics, explains why there is no strict relationship between FD and navigational information. Our experimental data and their numerical analysis corroborate these results.

Zahedi, M. S., & Zeil, J. (2018). Fractal dimension and the navigational information provided by natural scenes. PloS one, 13(5), e0196227.

Categories: Papers from 2018

They do it with magnets.

The animal kingdom has a breadth of sensory modalities that can be used by different navigational behaviours. One of the most evocative is the potential use of the earth’s magnetic field and many animals have been shown to be able to use magnetic cues to set directions or even know their latitude. Strong evidence however, has been absent from studies of ant navigation. No longer. We now have a fantastically elegant example of how magnetic cues are used by ants as part of their navigation. As we have seen here recently, some ants perform a particular pirouette behaviour as part of their learning walks. That is, as the learning walk proceeds the ant will occasionally pause and then turn to accurately fixate the nest entrance. Here, Fleischmann et al show that these pirouettes are under the control of magnetic cues; by rotating their direction with use of a magnetic coil.

This is a simple but profound finding, and it is worth applauding the cleverness of observing the pirouettes as an indicator of which cues might be being used by ants. By their nature, pirouettes are dissociable from the rest of the learning walk and it is this that gives a chance to observe the influence of a particular sensory cue. Lovely stuff.

Pauline Nikola Fleischmann, Robin Grob, Valentin Leander Müller, Rüdiger Wehner, Wolfgang Rössler (2018) The Geomagnetic Field Is a Compass Cue in Cataglyphis Ant Navigation. Current Biology.

Categories: Papers from 2018

Ants need space to learn

We know that over the early foraging life of an ant, the ability to navigate using path integration is then complemented by a building visual knowledge of the world, which is initially facilitated by learning walks. Initially, these learning walks are useful in learning about the next position. Using an ingenious system of water moats, Fleischmann et al. constrained the area over which ants could move near their nest, thus disrupting natural learning walks. It was found that a large area was required, if learning walks were to be effective in providing visual knowledge that could compete with path integration in cue conflict experiments. Further analysis of the learning walks could be useful in determining whether it is the learning walk per se, that is disrupted by the restrictive moat. An alternative is that an enclosed nest surround means that ants cannot store views from far enough away from the nest. Having stored views from opposite sides of the nest that are different enough to be distinguished may be a fundamentally important to the implementation of visual homing.

Fleischmann, P., Rössler, W. and Wehner, R. (2018) Early foraging life: spatial and temporal aspects of landmark learning in the ant Cataglyphis noda. Journal of Comparative Physiology A

Categories: Papers from 2018

Studying ants with simple mazes

There has been a lot of knowledge gained from experiments using T or Y mazes with bees (e.g. for pattern choice experiments) and ants (e.g. for pheromone trail experiments). Maze experiments allow for neat logical experimental designs and can address big questions in a low-tech way. This paper is both a how-to guide for T-maze experiments and a review of their strengths and weaknesses. It could be a fantastic resource for student projects.

Czaczkes, T. J. (2018). Using T-and Y-mazes in myrmecology and elsewhere: a practical guide. Insectes Sociaux, 1-12.

Categories: Papers from 2018