On the dimensionality of behavior.

There is a growing effort in the "physics of behavior" that aims at complete quantitative characterization of animal movements under more complex, naturalistic conditions. One reaction to the resulting explosion of high-dimensional data is the search for low-dimensional structure. Here I try to define more clearly what we mean by the dimensionality of behavior, where observable behavior may consist of either continuous trajectories or sequences of discrete states. This discussion also serves to isolate situations in which the dimensionality of behavior is effectively infinite.

Jürgen Boeckh (1934-2023) and Vera Boeckh, née von Zwehl (1928-2022): pioneers of sensory physiology and neuroethology.

Jürgen Boeckh, a respected pioneer of insect olfaction died shortly after his beloved wife Vera Boeckh, née von Zwehl, who pioneered insect vision. Both met in 1958, at the Zoological Institute in Munich. There, Jürgen worked in the group of his PhD advisor Dietrich Schneider, while Vera finished her PhD with Werner Jacobs before she joined the group of Hansjochem Autrum. There, Vera characterized the spectral sensitivity of bee photoreceptors, laying the physiological foundation of Karl von Frisch´s behavioral experiments with bee color vision. Meanwhile, Jürgen focused on the physiological characterization of insect antennal olfactory sensilla. In 1962 Vera and Jürgen married in Munich. Sadly, but characteristic of German woman at these times, Vera´s career ended after her marriage, while Jürgen moved with his mentor Schneider to the Max Planck Institute of Behavioral Physiology in Seewiesen near Munich, which became a famous cradle of insect neuroethology. Vera accompanied and supported her husband Jürgen´s career during his scientific Wanderschaft which ended in 1969, when Jürgen received a full professorship at the University of Regensburg. There, Jürgen became an accomplished German professor, focusing on insect olfaction from peripheral sensory transduction to information processing in the brain´s antennal lobe. After Jürgens retirement in 2000 they moved to Hopfen, Enzensberg near Füssen, where they enjoyed happy years together, before especially Vera´s health deteriorated. Both died shortly after one another during the Corona pandemic. We lost a remarkable couple of insect scientists that will be remembered as pioneers of sensory physiology and neuroethology.

Ocular Necessities: A Neuroethological Perspective on Vertebrate Visual Development.

BACKGROUND: By examining species-specific innate behaviours, neuroethologists have characterized unique neural strategies and specializations from throughout the animal kingdom. Simultaneously, the field of evolutionary developmental biology (informally, "evo-devo") seeks to make inferences about animals' evolutionary histories through careful comparison of developmental processes between species, because evolution is the evolution of development. Yet despite the shared focus on cross-species comparisons, there is surprisingly little crosstalk between these two fields. Insights can be gleaned at the intersection of neuroethology and evo-devo. Every animal develops within an environment, wherein ecological pressures advantage some behaviours and disadvantage others. These pressures are reflected in the neurodevelopmental strategies employed by different animals across taxa. SUMMARY: Vision is a system of particular interest for studying the adaptation of animals to their environments. The visual system enables a wide variety of animals across the vertebrate lineage to interact with their environments, presenting a fantastic opportunity to examine how ecological pressures have shaped animals' behaviours and developmental strategies. Applying a neuroethological lens to the study of visual development, we advance a novel theory that accounts for the evolution of spontaneous retinal waves, an important phenomenon in the development of the visual system, across the vertebrate lineage. KEY MESSAGES: We synthesize literature on spontaneous retinal waves from across the vertebrate lineage. We find that ethological considerations explain some cross-species differences in the dynamics of retinal waves. In zebrafish, retinal waves may be more important for the development of the retina itself, rather than the retinofugal projections. We additionally suggest empirical tests to determine whether Xenopus laevis experiences retinal waves.

Managing Colorectal Cancer from Ethology to Interdisciplinary Treatment: The Gains and Challenges of Modern Medicine.

Colorectal cancer (CRC) is a common malignant tumor of the gastrointestinal tract, which has become a serious threat to human health worldwide. This article exhaustively reviews colorectal cancer's incidence and relevance, carcinogenesis molecular pathways, up-to-date treatment opportunities, prophylaxis, and screening program achievements, with attention paid to its regional variations and changes over time. This paper provides a concise overview of known CRC risk factors, including familial, hereditary, and environmental lifestyle-related risk factors. The authors take a closer look into CRC's molecular genetic pathways and the role of specific enzymes involved in carcinogenesis. Moreover, the role of the general practitioner and multidisciplinary approach in CRC treatment is summarized and highlighted based on recent recommendations and experience. This article gives a clear understanding and review of the gains and challenges of modern medicine towards CRC. The authors believe that understanding the current patterns of CRC and its revolution is imperative to the prospects of reducing its burden through cancer prevention and cancer-adjusted treatment.

Foraging for foundations in decision neuroscience: insights from ethology.

Modern decision neuroscience offers a powerful and broad account of human behaviour using computational techniques that link psychological and neuroscientific approaches to the ways that individuals can generate near-optimal choices in complex controlled environments. However, until recently, relatively little attention has been paid to the extent to which the structure of experimental environments relates to natural scenarios, and the survival problems that individuals have evolved to solve. This situation not only risks leaving decision-theoretic accounts ungrounded but also makes various aspects of the solutions, such as hard-wired or Pavlovian policies, difficult to interpret in the natural world. Here, we suggest importing concepts, paradigms and approaches from the fields of ethology and behavioural ecology, which concentrate on the contextual and functional correlates of decisions made about foraging and escape and address these lacunae.

The Presidential Symposium at the International Congress of Neuroethology 2022 in Lisbon, Portugal.

In this special issue of articles from leading neuroethologists-all of whom gave outstanding presentations within the Presidential Symposium of the 2022 International Congress of Neuroethology held in Lisbon, Portugal-we learn about the role of cryptochrome molecules in the magnetic sense of animals, how honeybees construct their honeycombs, why fish eyes are built the way they are in species from different depths, how archerfish intercept their newly downed prey with a swift muscular curving of the body (known as a C-start) and how birds process optic flow information to control flight. Each contribution showcases how nervous systems have evolved to control behaviour, the raison d'être of neuroethology.

After 150 years of watching: is there a need for synthetic ethology?

The Darwinian idea of mental continuity is about 150 years old. Although nobody has strongly denied this evolutionary link, both conceptually and practically, relative slow advance has been made by ethology and comparative psychology to quantify mental evolution. Debates on the mechanistic interpretation of cognition often struggle with the same old issues (e.g., associationism vs cognitivism), and in general, experimental methods have made also relative slow progress since the introduction of the puzzle box. In this paper, we illustrate the prevailing issues using examples on 'mental state attribution' and 'perspective taking" and argue that the situation could be improved by the introduction of novel methodological inventions and insights. We suggest that focusing on problem-solving skills and constructing artificial agents that aim to correspond and interact with biological ones, may help to understand the functioning of the mind. We urge the establishment of a novel approach, synthetic ethology, in which researchers take on a practical stance and construct artificial embodied minds relying of specific computational architectures the performance of which can be compared directly to biological agents.

Beyond the Instinct Debate: Daniel Lehrman's Contributions to Animal Behavior Studies.

This paper examines the contributions of Daniel S. Lehrman (1919-1972) to animal behavior studies. Though widely cited as a critic of the early ethological program presented by Konrad Lorenz and Niko Tinbergen, other significant aspects of Lehrman's career and research have not received historical attention. In this paper, I offer a fuller account of Lehrman's work by situating his debate with ethologists within the larger context of Lehrman's early scholarly development under G. K. Noble and T. C. Schneirla, by examining his scientific research on the ring-dove as well as his epistemological views about the best way to understand animal behaviour, and by presenting his leadership in institution and network-building of interdisciplinary approaches to animal behavior. This essay highlights Lehrman's impact on the evolution of ethology, endocrinology, and developmental biology.

Epistemological discipline in animal behavior studies: Konrad Lorenz and Daniel Lehrman on intuition and empathy.

Can empathy be a tool for obtaining scientific knowledge or is it incompatible with the detached objectivity that is often seen as the ideal in scientific inquiry? This paper examines the views of Austrian ethologist Konrad Lorenz and American comparative psychologist Daniel Lehrman on the role of intuition and empathy in the study of animal behavior. It situates those views within the larger project of establishing ethology as an objective science. Lehrman challenged Lorenz and Niko Tinbergen, the main founders of this field, to clarify their epistemological positions regarding how to deal with the subjectivity of the animals they studied as well as the scientist's own subjectivity. I argue that there was a tension between their desire to eliminate the subjectivities of ethological researchers (and of their subjects) and the public perception that Lorenz had a remarkable ability to enter into the lives of the animals he studied. I explain why Lorenz rejected empathy as valid in scientific inquiry, showing that his epistemological position was grounded in his ideal of science and his proposed ontology for ethology. Yet, Lehrman insisted that full detachment was neither possible nor desirable.

[Effect of Ganmai Dazao Decoction on ethology of rats with PTSD and its mechanism].

This study aimed to explore the effect of Ganmai Dazao Decoction on the ethology of rats with posttraumatic stress disorder(PTSD) and study the related mechanism through the changes in magnetic resonance imaging and protein expression. Sixty rats were randomly divided into 6 groups, namely the normal group, the model group, the low(1 g·kg~(-1)), medium(2 g·kg~(-1)), and high-dose Ganmai Dazao Decoction groups(4 g·kg~(-1)), and the positive control group(intragastric administration with 10.8 mg·kg~(-1) of fluoxetine), with 10 rats in each group. Two weeks after inducing PTSD by single-prolonged stress(SPS) in rats, the positive control group was given fluoxetine hydrochloride capsule by gavage, the low, medium, and high-dose groups were given Ganmai Dazao Decoction by gavage, and both the normal group and the model group were given the same volume of normal saline by gavage, each for 7 days. The open field experiment, elevated cross elevated maze, forced swimming experiment, and new object recognition test were carried out for the behavioral test. Three rats in each group were selected to detect the expression of neuropeptide receptor Y1(NPY1R) protein in the hippocampus by Western blot. Then, the other three rats in each group were selected to use the 9.4T magnetic resonance imaging experiment to observe the overall structural changes in the brain region and the anisotropy fraction of the hippocampus. The results of the open field experiment showed that the total distance and central distance of rats in the model group were significantly lower than those in the normal group, and the total distance and central distance of rats in the middle and high-dose Ganmai Dazao Decoction groups were higher than those in the model group. The results of the elevated cross maze test showed that medium and high-dose Ganmai Dazao Decoction remarkably increased the number of open arm entries and the residence time of open arm of rats with PTSD. The results of the forced swimming experiment showed that the immobility time in the water of the model group rats was significantly higher than that of the normal group, and Ganmai Dazao Decoction hugely reduced the immobility time in the water of rats with PTSD. The results of the new object recognition test showed that Ganmai Dazao Decoction significantly increased the exploration time of new objects and familiar objects in rats with PTSD. The results of Western blot showed that Ganmai Dazao Decoction significantly reduced the expression of NYP1R protein in the hippocampus of rats with PTSD. The 9.4T magnetic resonance examination found that there was no significant difference in the structural image among the groups. In the functional image, the fractional anisotropy(FA value) of the hippocampus in the model group was significantly lower than that in the normal group. The FA value of the hippocampus in the middle and high-dose Ganmai Dazao Decoction groups was higher than that in the model group. Ganmai Dazao Decoction reduces the injury of hippocampal neurons by inhibiting the expression of NYP1R in the hippocampus of rats with PTSD, thereby improving the nerve function injury of rats with PTSD and playing a neuroprotective role.

The cognitive map debate in insects: A historical perspective on what is at stake.

Though well established in mammals, the cognitive map hypothesis has engendered a decades-long, ongoing debate in insect navigation studies involving many of the field's most prominent researchers. In this paper, I situate the debate within the broader context of 20th century animal behavior research and argue that the debate persists because competing research groups are guided by different constellations of epistemic aims, theoretical commitments, preferred animal subjects, and investigative practices. The expanded history of the cognitive map provided in this paper shows that more is at stake in the cognitive map debate than the truth value of propositions characterizing insect cognition. What is at stake is the future direction of an extraordinarily productive tradition of insect navigation research stretching back to Karl von Frisch. Disciplinary labels like ethology, comparative psychology, and behaviorism became less relevant at the turn of the 21st century, but as I show, the different ways of knowing animals associated with these disciplines continue to motivate debates about animal cognition. This examination of scientific disagreement surrounding the cognitive map hypothesis also has significant consequences for philosophers' use of cognitive map research as a case study.

Systems Neuroscience of Natural Behaviors in Rodents.

Animals evolved in complex environments, producing a wide range of behaviors, including navigation, foraging, prey capture, and conspecific interactions, which vary over timescales ranging from milliseconds to days. Historically, these behaviors have been the focus of study for ecology and ethology, while systems neuroscience has largely focused on short timescale behaviors that can be repeated thousands of times and occur in highly artificial environments. Thanks to recent advances in machine learning, miniaturization, and computation, it is newly possible to study freely moving animals in more natural conditions while applying systems techniques: performing temporally specific perturbations, modeling behavioral strategies, and recording from large numbers of neurons while animals are freely moving. The authors of this review are a group of scientists with deep appreciation for the common aims of systems neuroscience, ecology, and ethology. We believe it is an extremely exciting time to be a neuroscientist, as we have an opportunity to grow as a field, to embrace interdisciplinary, open, collaborative research to provide new insights and allow researchers to link knowledge across disciplines, species, and scales. Here we discuss the origins of ethology, ecology, and systems neuroscience in the context of our own work and highlight how combining approaches across these fields has provided fresh insights into our research. We hope this review facilitates some of these interactions and alliances and helps us all do even better science, together.

Impact of natural and artificial prenatal stimulation on the behavioural profile of Japanese quail.

As the sensory systems of vertebrates develop prenatally, embryos perceive many environmental stimuli that can influence the ontogeny of their behaviour. Whether the nature and intensity of prenatal stimuli affect this ontogeny differently remains to be investigated. In this context, this study aimed to analyse the effects of prenatal auditory stimulation (natural stimulation, NS; predator vocalisations or artificial stimulation, AS; metallic sounds) on the subsequent behaviour of young Japanese quail (Coturnix coturnix japonica). For this, behavioural variables recorded during ethological tests evaluating emotional and social reactivity were analysed using a principal component analysis. This analysis revealed significant differences between the behavioural profile of stimulated chicks and that of non-exposed chicks. Indeed, chicks exposed to NS expressed more intense emotional responses in fearful situations, but less neophobia when exposed to a novel environment or object, whereas chicks exposed to AS appeared more sensitive to social isolation. Our results show that the acoustic environment of embryos can influence the way young birds subsequently interact with their social and physical environment after hatching, and face challenges in changing living conditions.

Commentary: New Directions in the History of Ethology.

This welcome set of original and instructive papers illuminates and enriches the history of twentieth-century ethology in multiple ways. It adds a wealth of actors, animals, methods, and places to those featured in previous treatments of ethology's development. Some of the papers extend the chronology beyond the heyday of ethology's disciplinary construction to consider exciting developments in the 1970s and beyond. Others consider animal behavior research programs pursued contemporaneously with but independently of mainline ethology's development from the 1930s through the 1960s. Another paper takes us inside an ethologist's archive of visual images to examine the importance of such images (and such a setting) for ethological practice. Collectively, the papers provide new opportunities to contemplate how research programs and disciplines evolve; the relations between concepts, practices, and places; ethology and politics, and much more. At the same time, the individuality of the papers is conspicuous. They have not been constructed on the same model. The authors have followed their own approaches, corresponding to their own, respective interests. A short commentary is not sufficient to do justice to each of them. Rather than attempt to review them one by one, I will consider a pair of themes that may help relate the papers to each other and to the history of ethology: (1) the ongoing challenge of defining ethology and identifying who the ethologists were (or are); (2) the practices and places of animal behavior study.

From Karl von Frisch to Neuroethology: A Methodological Perspective on the Frischean Tradition's Expansion into Neuroethology.

This paper examines a tradition of eusocial insect research stemming from the Austrian zoologist Karl von Frisch. As I show in this paper, one of the most enduring features of the Frischean tradition has been an experimental methodology developed by Frisch in the early 1910s. By tracing this methodology's use through Frisch's student, Martin Lindauer, and two of Lindauer's students, Rüdiger Wehner and Randolf Menzel, this paper illuminates a surprising aspect of ethology's development during the last half of the 20th century. Namely, it sheds light on how the Frischean tradition, a tradition that had a complicated relationship with ethology since the discipline's formation in the 1930s, produced scientists who became leading figures in neuroethology, the most prominent contemporary field of behavioral research to retain the label of "ethology." Some of the features that distinguished Frisch's training method from the program of classical ethology and the work of his contemporaries later helped his academic descendants adapt the method to the neuroethological program.

Red Foxes in the Filing Cabinet: Günter Tembrock's Image Collection and Media Use in Mid-Century Ethology.

This paper considers the epistemic career of visual media in ethology in the mid-20th century. Above all, ethologists claimed close contact with research animals and drew scientific evidence from these human-animal communities, particularly in public relations. However, if we look into the toolboxes of comparative behavioral biologists, it becomes evident that scientifically valid research results were primarily obtained by experimenting with model images. These visual specimens tell a technical story of the methodological requirements in behavioral science necessary to bridge everyday observations between the laboratory and the field. By neutralizing individual traces of animal bodies as well as their observers, they prompted the abstraction of ethological hypotheses. The case study of East-German biologist Günter Tembrock (1918-2011), who maintained his own collection of newspaper clippings, drawings, photographs, and films, offers a new perspective on the methodological development of this field. Furthermore, this article contributes to a scholarly discussion geared toward expanding the spaces of ethological research. My analysis of the image collections of the Forschungsstätte für Tierpsychologie presents the archive as a relevant site of study in the history of ethology.

Landscapes of Time: Building Long-Term Perspectives in Animal Behavior.

In the 1960s, scientists fascinated by the behavior of free-living animals founded research projects that expanded into multi-generation investigations. This paper charts the history of three scientists' projects to uncover the varied reasons for investing in a "long-term" perspective when studying animal behavior: Kenneth Armitage's study of marmots in the Rocky Mountains, Jeanne Altmann's analysis of baboons in Kenya, and Timothy Hugh Clutton-Brock's studies (among others) of red deer on the island of Rhum and meerkats in the Kalahari. The desire to study the behavior of the same group of animals over extended periods of time, I argue, came from different methodological traditions - population biology, primatology, and sociobiology - even as each saw themselves as contributing to the legacy of ethology. As scientists embraced and combined these approaches, a small number of long-running behavioral ecology projects like these grew from short pilot projects into decades-long centers of intellectual gravity within behavioral ecology as a discipline. By attending to time as well as place, we can see how this long-term perspective was crucial to their success; they measured evolutionary changes over generations of animals and their data provided insights into how the animals they studied were adapting (or not) to changing local and global environmental factors.

"It Felt More like a Revolution." How Behavioral Ecology Succeeded Ethology, 1970-1990.

As soon as ethology's status diminished in the early 1970s, it was confronted with two successor disciplines, sociobiology and behavioral ecology. They were able to challenge ethology because it no longer provided markers of strong disciplinarity such as theoretical coherence, leading figures and a clear identity. While behavioral ecology developed organically out of the UK ethological research community into its own disciplinary standing, sociobiology presented itself as a US competitor to the ethological tradition. I will show how behavioral ecology took the role of legitimate heir to ethology by rebuilding a theoretical core and an intellectual sense of community, while sociobiology failed to use its public appeal to reach disciplinary status. Meanwhile, ethology changed its disciplinary identity to encompass all biological studies of animal behavior.

Ethologists in the Kindergarten: Natural Behavior, Social Rank, and the Search for the "Innate" in Early Human Ethology (1960s-1970s).

During the 1970s, ethologists at the German Max Planck Institute for Behavioral Physiology in Seewiesen started a series of research projects at several regional kindergartens in search of natural predispositions in human behavior. This so-called "Kindergarten Project" became one of the pillars of research activity at the newly founded Forschungsstelle für Humanethologie (Research Center for Human Ethology) where Irenäus Eibl-Eibesfeldt and a team of researchers set out to explore new fields of research for the discipline of ethology. Taking the research project conducted by biologist Barbara Hold on ranking behavior among kindergarten children as a vantage point, this paper explores the shift in ethology from animal to human behavior which occurred during the 1960s and 1970s. It analyzes how human ethologists coped with the methodological, conceptual, and ethico-political challenges which arose from crossing the human-animal divide. This article thus sheds light on the hitherto unwritten history of human ethology as it was developed at the MPI since the late 1960s.

Steps towards a computational ethology: an automatized, interactive setup to investigate filial imprinting and biological predispositions.

Soon after hatching, the young of precocial species, such as domestic chicks or ducklings, learn to recognize their social partner by simply being exposed to it (imprinting process). Even artificial objects or stimuli displayed on monitor screens can effectively trigger filial imprinting, though learning is canalized by spontaneous preferences for animacy signals, such as certain kinds of motion or a face-like appearance. Imprinting is used as a behavioural paradigm for studies on memory formation, early learning and predispositions, as well as number and space cognition, and brain asymmetries. Here, we present an automatized setup to expose and/or test animals for a variety of imprinting experiments. The setup consists of a cage with two high-frequency screens at the opposite ends where stimuli are shown. Provided with a camera covering the whole space of the cage, the behaviour of the animal is recorded continuously. A graphic user interface implemented in Matlab allows a custom configuration of the experimental protocol, that together with Psychtoolbox drives the presentation of images on the screens, with accurate time scheduling and a highly precise framerate. The setup can be implemented into a complete workflow to analyse behaviour in a fully automatized way by combining Matlab (and Psychtoolbox) to control the monitor screens and stimuli, DeepLabCut to track animals' behaviour, Python (and R) to extract data and perform statistical analyses. The automated setup allows neuro-behavioural scientists to perform standardized protocols during their experiments, with faster data collection and analyses, and reproducible results.