Variation and Variability in Drosophila Grooming Behavior

Behavioral differences can be observed between species or populations (variation) or between individuals in a genetically similar population (variability). Here, we investigate genetic differences as a possible source of variation and variability in Drosophila grooming. Grooming confers survival and social benefits. Grooming features of five Drosophila species exposed to a dust irritant were analyzed. Aspects of grooming behavior, such as anterior to posterior progression, were conserved between and within species. However, significant differences in activity levels, proportion of time spent in different cleaning movements, and grooming syntax were identified between species. All species tested showed individual variability in the order and duration of action sequences. Genetic diversity was not found to correlate with grooming variability within a species: melanogaster flies bred to increase or decrease genetic heterogeneity exhibited similar variability in grooming syntax. Individual flies observed on consecutive days also showed grooming sequence variability. Standardization of sensory input using optogenetics reduced but did not eliminate this variability. In aggregate, these data suggest that sequence variability may be a conserved feature of grooming behavior itself. These results also demonstrate that large genetic differences result in distinguishable grooming phenotypes (variation), but that genetic heterogeneity within a population does not necessarily correspond to an increase in the range of grooming behavior (variability).

A lexical approach for identifying behavioural action sequences

Animals display characteristic behavioural patterns when performing a task, such as the spiraling of a soaring bird or the surge-and-cast of a male moth searching for a female. Identifying such recurring sequences occurring rarely in noisy behavioural data is key to understanding the behavioural response to a distributed stimulus in unrestrained animals. Existing models seek to describe the dynamics of behaviour or segment individual locomotor episodes rather than to identify the rare and transient sequences of locomotor episodes that make up the behavioural response. To fill this gap, we develop a lexical, hierarchical model of behaviour. We designed an unsupervised algorithm called “BASS” to efficiently identify and segment recurring behavioural action sequences transiently occurring in long behavioural recordings. When applied to navigating larval zebrafish, BASS extracts a dictionary of remarkably long, non-Markovian sequences consisting of repeats and mixtures of slow forward and turn bouts. Applied to a novel chemotaxis assay, BASS uncovers chemotactic strategies deployed by zebrafish to avoid aversive cues consisting of sequences of fast large-angle turns and burst swims. In a simulated dataset of soaring gliders climbing thermals, BASS finds the spiraling patterns characteristic of soaring behaviour. In both cases, BASS succeeds in identifying rare action sequences in the behaviour deployed by freely moving animals. BASS can be easily incorporated into the pipelines of existing behavioural analyses across diverse species, and even more broadly used as a generic algorithm for pattern recognition in low-dimensional sequential data.

AVATAR: AI Vision Analysis for Three-dimensional Action in Real-time

Artificial intelligence (AI) is an emerging tool for high-resolution behavioural analysis and conduction of human-free behavioural experiments. Here, we applied an AI-based system, AVATAR, which automatically virtualises 3D motions from the detection of 9 body parts. This allows quantification, classification and detection of specific action sequences in real-time and facilitates closed-loop manipulation, triggered by the onset of specific behaviours, in freely moving mice.

Narrative Aspects of Images of Spear Use in Scandinavian Rock Carvings

Researchers have long discussed whether Scandinavian rock art reflects narratives. Their interpretations have frequently been based on inspections of rock art panels combined with knowledge from ethnographic and historical sources. Here, the authors adopt a more focused narratological approach that takes the concept of (visual) narrativity into consideration and draws on studies by literary analysts, cognitive psychologists, and semioticians. Images of spear use in the provinces of Bohuslän and Östergötland in Sweden, given their diversity and indexical qualities, are well-suited to such a study. They reveal different kinds of indexical relationships, i.e. how the spears direct attention to possible targets, arguably corresponding to action scripts well-known to Bronze Age communities. Many spear images may be regarded as mini-narratives and mnemonic devices intended to represent schematized action sequences. The authors suggest that concepts such as iconicity, indexical relationships, scripts, and mini-narratives could be fruitfully employed in research on Scandinavian rock art and beyond.

Learning to solve sequential physical reasoning problems from a scene image

In this article, we propose deep visual reasoning, which is a convolutional recurrent neural network that predicts discrete action sequences from an initial scene image for sequential manipulation problems that arise, for example, in task and motion planning (TAMP). Typical TAMP problems are formalized by combining reasoning on a symbolic, discrete level (e.g., first-order logic) with continuous motion planning such as nonlinear trajectory optimization. The action sequences represent the discrete decisions on a symbolic level, which, in turn, parameterize a nonlinear trajectory optimization problem. Owing to the great combinatorial complexity of possible discrete action sequences, a large number of optimization/motion planning problems have to be solved to find a solution, which limits the scalability of these approaches. To circumvent this combinatorial complexity, we introduce deep visual reasoning: based on a segmented initial image of the scene, a neural network directly predicts promising discrete action sequences such that ideally only one motion planning problem has to be solved to find a solution to the overall TAMP problem. Our method generalizes to scenes with many and varying numbers of objects, although being trained on only two objects at a time. This is possible by encoding the objects of the scene and the goal in (segmented) images as input to the neural network, instead of a fixed feature vector. We show that the framework can not only handle kinematic problems such as pick-and-place (as typical in TAMP), but also tool-use scenarios for planar pushing under quasi-static dynamic models. Here, the image-based representation enables generalization to other shapes than during training. Results show runtime improvements of several orders of magnitudes by, in many cases, removing the need to search over the discrete action sequences.

Illuminating the prefrontal neural correlates of action sequence disassembling in response–response binding

Execution of two independent actions in quick succession results in transient binding of these two actions. Subsequent repetition of any of these actions automatically retrieves the other. This process is probably fundamental for developing complex action sequences. However, rigid bindings between two actions are not always adaptive. Sometimes, it is necessary to repeat only one of the two previously executed actions. In such situations, stored action sequences must be disassembled, for the sake of flexibility. Exact mechanisms that allow for such an active unbinding of actions remain largely unknown, but it stands to reason, that some form of prefrontal executive control is necessary. Building on prior neuronal research that explored other forms of binding (e.g. between distractors and responses and abstract representations and responses), we explored middle and superior frontal correlates of -response binding in a sequential classification task with functional near-infrared spectroscopy. We found that anterior dorsolateral prefrontal cortex activity varied as a function of response–repetition condition. Activity in the right anterior dorsolateral prefrontal cortex correlated with changes in reaction times due to response–response binding. Our results indicate that the right anterior dorsolateral prefrontal cortex dismantles bindings between consecutive actions, whenever such bindings interfere with current action goals.

Through the looking glass: The Matrix franchise and interpretation

<p>This thesis analyses the reception of the Matrix trilogy by paying close attention to the work of film reviewers, and academic commentators who interpret the films from a religious perspective. The methodology of the project involves using a historical reception studies approach based on the work of Janet Staiger. The film reviews display an interest in the trilogy’s action sequences and its numerous cultural references. As the trilogy proceeds, the reviewers become increasingly concerned about the emphasis on spectacle. I argue that these interests can be understood in terms of debates in Film Studies around the 'cinema of attractions' and the tensions between narrative and spectacle in contemporary Hollywood cinema. The Christian, Buddhist and Gnostic religious academic commentaries all utilise an allegorical approach to the trilogy. As a result, they interpret the films through the prism of good versus evil. They also stress the importance of the acquisition of knowledge. In my opinion, the film reviews and religious interpretations share an interest in unity or singularity. This parallels the narrative of the trilogy, specifically the quest for 'the One'.</p>

Through the looking glass: The Matrix franchise and interpretation

<p>This thesis analyses the reception of the Matrix trilogy by paying close attention to the work of film reviewers, and academic commentators who interpret the films from a religious perspective. The methodology of the project involves using a historical reception studies approach based on the work of Janet Staiger. The film reviews display an interest in the trilogy’s action sequences and its numerous cultural references. As the trilogy proceeds, the reviewers become increasingly concerned about the emphasis on spectacle. I argue that these interests can be understood in terms of debates in Film Studies around the 'cinema of attractions' and the tensions between narrative and spectacle in contemporary Hollywood cinema. The Christian, Buddhist and Gnostic religious academic commentaries all utilise an allegorical approach to the trilogy. As a result, they interpret the films through the prism of good versus evil. They also stress the importance of the acquisition of knowledge. In my opinion, the film reviews and religious interpretations share an interest in unity or singularity. This parallels the narrative of the trilogy, specifically the quest for 'the One'.</p>

Dorsal striatum coding for the timely execution of action sequences

The automatic initiation of actions can be highly functional. But occasionally these actions cannot be withheld and are released at inappropriate times, impulsively. Striatal activity has been shown to participate in the timing of action sequence initiation and it has been linked to impulsivity. Using a self-initiated task, we trained adult rats to withhold a rewarded action sequence until a waiting time interval has elapsed. By analyzing neuronal activity we show that the striatal response preceding the initiation of the learned sequence is strongly modulated by the time subjects wait before eliciting the sequence. Interestingly, the modulation is steeper in adolescent rats, which show a strong prevalence of impulsive responses compared to adults. We hypothesize this anticipatory striatal activity reflects the animals' subjective reward expectation, based on the elapsed waiting time, while its steeper waiting modulation in adolescence reflects age-related differences in temporal discounting, internal urgency states or explore-exploit balance.