Symposia

How does a one-time learning experience transform into a lasting memory? With their Janus-faced property of being at once dynamic and stable, epigenetic mechanisms harbor the potential to better explain the molecular processes that convert changing environmental contingencies into lasting experiences. Accordingly, over the past 15 years, multiple studies have shown that epigenetic modifications critically contribute to learning, memory storage and memory deterioration. However, owing to a high degree of cell type heterogeneity in the brain, the precise contribution of neuroepigenetic processes to memory formation and storage still remains to be elucidated.
In this symposium, we bring together leading scientists in the field of neuroepigenetics to discuss their latest advances in this respect. Particular attention will be given to cell type-specific epigenetic processes, including those occurring in engram cells, a bona fide memory-related cell population in the brain. Thus, Ana Oliveira will demonstrate how DNA methylation strengthens engram stability and memory encoding; Angel Barco will discuss short- and long-term transcriptomic and epigenomic changes triggered by neuronal activation and involved in memory formation; Ana Pombo will highlight long-range three-dimensional chromatin interactions specific of neuronal cell types; and Johannes Gräff will show how epigenetic modifications influence cells to become allocated to the memory trace. Together, these talks will highlight the most recent, state-of-the-art findings of neuroepigenetics processes governing learning and memory, and importantly, illustrate that epigenetic modifications might indeed serve as chromatin-templated memory aids.
This symposium should be of interest to a broad audience of the EBBS meeting.

Exposure to early-life adversity (ELA) increases the risk to develop eating disorders (ED) and metabolic diseases later in life. Notably, the prevalence of these disorders varies markedly by sex. For example, eating disorders and obesity are more prevalent in women, while diabetes type 2 is more prevalent in men. There is emerging evidence that the contribution of ELA to this spectrum of disorders, depends on the characteristics and timing of the adversity, on the specific outcome measures assessed, and on inherent sex-differences in brain and body. However, the biological mechanisms underlying the contribution of ELA exposure to pre-existing sex differences in vulnerabilities to eating disorders are not well understood. In this session we will capitalize on the latest studies to shed light on the interface of ELA and eating and metabolic derangements. We discuss novel discoveries centred on the hypothalamus, key in regulating energy intake and expenditure, and on the operation of the reward circuitry, important for the hedonic aspects of food intake. Prof. Chen will start by discussing his recent findings on sex-dependent effects of prenatal stress on ED and metabolic risks, including activity-based anorexia, binge eating, adiposity upon high-fat diet (HFD), and the proposed role of central and placental microRNA in mediating the observed alterations. Next Prof. Baram will discuss recent and unpublished findings on sex-specific consequences of ELA on craving of palatable food and pro-hedonic drugs, focusing on the role of a novel stress-sensitive amygdala-nucleus accumbens projection. Dr. Ruigrok will then present her unpublished work on the sex-dependent effects of postnatal stress exposure on food preferences in a free choice high-fat high-sugar paradigm, as well as the associated changes in the reward and hypothalamic circuitry. Finally, Dr. Ozanne will discuss how maternal obesity programs metabolic functions in the offspring and how these changes can be sex-dependent. This session includes speakers from different regions, career stage and sex. It will span molecular, cellular and cutting-edge circuit approaches for understanding highly clinically-relevant normal and pathological behaviors.

It is now well-established that derangement in the maturational pattern of specific cellular subtypes or brain circuits as a consequence exposure to adverse life events at different stages of development represents an important element of susceptibility to different neuropsychiatric disorders. Our symposium will bring together senior and young scientists with different but complementary expertise to discuss the most recent cellular and molecular findings linking developmental adversities with the etiology of neuropsychiatric disorders, highlighting sensitive time windows for preventive and/or therapeutic intervention.
Prof. Marco A. Riva (Italy) will show how exposure to prenatal stress produces long-lasting changes in brain function by affecting the expression and function of genes that play important roles in brain plasticity and that are closely related to glucocorticoid function and inflammation. He will also show how therapeutic intervention in selected time windows may change the trajectory and prognosis in patients affected by chronic mental illness.
Dr. Francesca Cirulli (Italy) will focus on the overlapping mechanisms engaged by psychosocial and metabolic stress in the developmental programming of the foetus. She will present preclinical findings indicating that prenatal exposure to a high-fat diet acts as a stressor, disrupting social behaviour altering genes involved in neuroendocrine function. She will show that targeting oxidative stress during foetal life represents a novel strategy to prevent the long-term effects of early life adversities.
Dr. Dwir (Switzerland) will highlight, both in a mouse model and in early psychosis patients, a mechanism (MMP9/RAGE), induced by an additional oxidative challenge during the early postnatal period, leading to a vicious cycle of processes, which affects the maturation of parvalbumin-expressing interneurons. She will show that these impairments can be rescued by an antioxidant treatment combined to an enriched environment at a precis developmental timing.
Janssen Kotah (The Netherlands) will talk about how postnatal early-life adversity (ELA) programs the brain response to later-life experiences and how this might link to later-life cognitive deficit and development of Alzheimer’s disease. The talk will highlight the roles of microglia and astrocytes in these phenotypes and how ELS alters their profiles at baseline and immune-challenged conditions. He will also talk about how fatty acids modulate these effects.

The precise function of the hippocampus in remote memory remains to be clarified. This symposium will address the role of the hippocampus in retrieving and representing remote memories of past events. In doing so, does the hippocampus act on inputs stored elsewhere (e.g., the vmPFC and posterior cortical areas) or, at least in some instances, does it draw upon information stored in the hippocampus itself about past episodes. Evidence from studies with animal models and humans will be considered, as we confront the central question of how, and for how long, does the hippocampus maintain representations of our past experiences.

Human aggressive behaviour is a social problem that has a large impact at many levels. A particular form is domestic violence, which affects the worldwide population regardless of geographic location, culture, socioeconomic status, occupation, and education levels. The prevalence is rather high, and according to the WHO, one in four women suffer some form of it along their lives. Victims, families, and the society as a whole suffer the detrimental consequences of this urgent problem that needs to be addressed. Most countries have developed intervention programs for batterers, albeit with a low success rate. This is why it is critical to go to the root of it, the brain circuits and dynamics that underlie aggressive behaviour, both in humans and in animal models. From this investigation, and that of the generation of social behaviour and empathy, scientifically based approaches should be designed towards the generation a pro-social, non-violent behaviour.
In this proposal we bring together four speakers who approach the topic of violent versus empathic behaviour from four different angles:  cognitive science and brain imaging in humans (Beatrice de Gelder), first person perspective and virtual reality therapy for offenders (Sofia Seinfeld), social behaviour and neuromodulation of aggression in animal models (Sietse de Boer) and circuits and whole brain mechanisms underlying social behaviour and aggression and its interaction with neuropsychiatric disorders (Sam A. Golden).  We expect that the discussion between these speakers will bring scientific light onto this relevant problem for humanity in the XXI century.

In the last years, neuroscience research has particularly focused on understanding the neurobiological underpinnings of social behaviors. Indeed, several studies have described the neural circuits underlying behaviors such as social discrimination, mating, aggression, and affiliative social interactions. However, most of those studies were sex-biased, being conducted exclusively on male subjects. As a matter of fact, females have been rarely studied in the context of behavioral neuroscience. Taking into account that women are also if not more affected by psychiatric disorders than men and that this might impact their social interactions, more studies on the neurobiology of the female brain are urgently required. Here, we propose to explore and discuss recent and groundbreaking findings on the neurobiology of the female brain and their implications on social behavior. For doing so we selected a broad list of speakers and topics that represent the diversity of behaviors displayed by females during social interactions. Prof. Inga Neumann (Full Professor, University of Regensburg, Germany) a prominent researcher on the social behavior and neuropeptide field will host the session. Prof. Dr. Suzanna Lima (Group leader, Champalimaud Foundation, Lisbon, Portugal) will discuss the hypothalamic circuits regulating female reproduction. In detail, she will give insights into how sex hormones underly both female fertility and receptivity in mice. Following, on that topic, Dr. Mauro Silva (Postdoc fellow, French National Institute of Health and Medical Research, Lille, France) will introduce novel evidence depicting how hypothalamic NOS-expressing neurons are involved in sexual dysfunction in a mouse model of Polycystic Ovary Syndrome. Prof. Dr. Alexa Veenema (Associated Professor, Michigan State University, Michigan, USA), will introduce data showing how the developmental status as well as sex influence the ability of animals to recognize their con-specifics, focusing on the neural circuits underlying those differences. Finally, in the last session, we will explore how social interactions become disruptive and pathological, for doing so Dr. Vinicius Oliveira (Postdoc fellow, University of Regensburg, Germany) will present his recent findings on female aggression. In detail, he will show how the interplay between the neuropeptides oxytocin and vasopressin acts in specific neuronal populations within the lateral septum and central amygdala to evoke female aggression.

While the negative impact of chronic stress has long been the focus of extensive neuroscience research, surprisingly little is known about the complex events that unfold in response to an acute stressor. Acutely stressful situations call for a rapid reset of brain function. This requires circuit- and network-wide changes that redistribute resources across the entire brain, dramatically altering behavior in the process. Simultaneously, the acute stress response also sets in motion neuroendocrine cascades and a series of molecular changes on the level of protein phosphorylation, gene transcription and epigenetic regulation. These multifactorial molecular events have functional consequences, for example altering synaptic connections. As these molecular and circuit-wide changes play out dynamically over time, resilient individuals will successfully cope with the stressful event, while susceptible individuals might undergo maladaptive changes and succumb to psychiatric disease, such as post-traumatic stress disorder. Understanding how healthy coping enables an efficient termination of the stress response, and identifying checkpoints that constitute risk factors for disease is a key research challenge.
Current attempts to study and dissect these complex changes involve molecular neurobiology and circuit neuroscience in rodent models, as well as functional imaging and clinical interventions in humans. Given that the stress response is highly conserved in mammals, there is translational potential to bridge preclinical and clinical work at all levels, but direct communication between basic and applied stress research is often limited. To address this need, the central aim of this symposium is to bring together the most cutting-edge preclinical and clinical research, thus providing a multi-level approach to the acute stress response, across scales and across species. We will showcase some of the latest research into the consequences of acute stress, reaching from the level of molecules and brain circuits in animal models, to system level brain studies and clinical research into stress-related disorders in humans. Our speakers will present multi-omics and circuit/network dissection of the acute stress response, describe mechanisms underlying different trajectories of resilience and vulnerability to stress, and bridge scales in brain imaging to reveal substrates and diversity of human emotional experiences.

Social behavior is the interaction of two or more individual of the same species and encompass’ a robust behavioral continuum that includes both affiliative and antagonistic contacts between conspecifics. Sensory inputs, internal states and environmental contexts are all factors that strongly regulate social behavioural decisions, but how the brain processes this diverse information and makes these choices is largely unknown. Many of these factors are encoded and processed by different brain regions and cell-types, and the synthesis of a circuit-level hypothesis of social decision making is paramount to understanding neuropsychiatric disorders such as autism, depression and substance abuse, amongst many others. This symposium will focus on recent advances in understanding the role of some of these defined brain circuits in regulating both affiliative and antagonistic social interaction in rodents. Salvatore Lecca will present a work investigating the role of the lateral habenula (circuits and neuronal dynamics) in supporting specific parental behaviors in mice. Viviana Trezza will discuss recent finding on the neuronal mechanisms underlying social play behavior. Camilla Bellone will discuss the role of mesolimbic dopamine system in social motivation. Cristina Marquez will discuss social modulation of foraging decisions in rats.
Collectively, these data begin to provide a deeper insight into the neurocircuitry guiding myriad social behaviors, which are not only important to understanding the neural basis of complex behavior but also highlight potential dysfucntions underlying neuropsychiatric diseases.

Cortical, hippocampal and amygdalar structures are considered the main centers in the formation and stabilization of emotional memories. However, a growing body of evidence indicates the key contribution of numerous thalamic nuclei in these processes. Here we aim to present new data showing the central role of the thalamus and its interaction with limbic areas in fear memory modulation. First, we will show two examples of thalamo-amygdala circuits functionally involved in fear learning processes: (1) prof. Jan Gründemann will present in vivo calcium imaging data, collected using a miniaturized microscope, that characterize the complex neuronal plasticity occurring in the medial geniculate body (MGB) upstream of the amygdala to support fear learning. MGB neuronal population balances experience-dependent single cell plasticity with consistent ensemble level representations of the sensory environment to support stable auditory perception with minimal affective bias. (2) prof. Ferenc Matyas, will describe the role of a genetically-defined neuronal population in the lateral thalamus that provides the amygdala with multimodal and plastic information necessary for aversive memory formation and recall.
Importantly, thalamic integration has recently emerged as a crucial process for effective consolidation and update of remote (1-month old) fear memories. In the second half of this symposium (3) prof. Gisella Vetere will share recent advances focusing on the anterodorsal and laterodorsal thalamus as key regions for fear memory stabilization. In particular, Ca2+ imaging and optogenetic manipulations suggest that the switch from recent to remote memory state requires a different engagement of these thalamic regions through direct control of hippocampal and cortical ensembles. Using a similar set of techniques (4) dr. Bianca Silva identified another higher order thalamic nucleus, the nucleus reuniens, as a central hub mediating extinction of remote fear memory through its efferent projections to the amygdala.
Collectively, this symposium aims to gather the latest advances on thalamic regulation of various aspects of emotional memory, ranging from Pavlovian fear learning to memory consolidation, generalization and extinction.

It’s clear that hippocampal neurons code for where we are in space but it is less clear how they code for where objects and goals are located relative to the subject, or for space defined by continuous abstract variables such as object features. The aim of this symposium is to shed light on how these vectors – the distance and direction from objects, goals or abstract features – are represented in mammalian brains (rats, bats and humans). All speakers (2M: 2F) are Early Career Researchers, yet present world-leading work.
Dr Steven Poulter will present his recent discovery in rats of a new type of brain cell, the Vector Trace Cell (VTC) – featured as a cover story in New Scientist (2019) – that codes for the locations of objects, and remembers those locations even when the objects are no longer present. (Poulter’s report of VTCs is accepted by Nature Neuroscience pending minor textual amendments).
Ms Ayelet Sarel will describe how navigational goals are encoded in the hippocampus of flying bats. She will present evidence of how hippocampal CA1 neurons represent vectors to spatial goals (goal-direction and goal-distance signals), suggesting a new neuronal mechanism for goal-directed navigation (Science 2017, 123 citations). Sarel will also present some of her more recent and exciting data investigating neurons coding for vectors to another conspecific.
Dr Alexandra Constantinescu will shift attention from vector coding in physical space to vectorial operations of a more abstract nature in humans. She will present her fascinating work showing that gridlike signals in the medial entorhinal cortex (MEC) can organise non-spatial information into a 2-dimensional conceptual map of space. Participants had to navigate through an abstract ‘bird space’ laid out in two continuous dimensions with bird neck length on one dimension and leg length on the other (Science 2016, 305 citations). Constantinescu will also present her latest results from a new ‘Memory Palace’ study combining spatial and non-spatial information.
Dr Andrej Bicanski will present a recent model of how egocentric vector codes interface with allocentric vector codes to enable many key aspects of spatial cognition. The model combines this insight with established knowledge and new hypotheses about how location, orientation, and surrounding environmental features are associated and represented by neural population activity (eLife 2018, 64 citations).

Both rodents and human beings are unique in terms of their brain circuitry as well as behavior making these features fingerprints for each individual. This idiosyncratic nature of humans as well as rodents is acknowledged but also frequently sacrificed on the altar of oversimplification of experimental data for better and easier communication. The ‘Tyranny of the Golden mean’ has long plagued behavioral neuroscience data interpretation and this has at times masked our ability to appreciate that behavioral manifestation by their very nature fall on a spectrum. We are always in the pursuit of the ever elusive ‘group effect’, branding outliers as an annoyance or noise hampering the proper interpretation of our ‘expected results’. Nevertheless, there is now a growing appreciation that inter-individual differences are of vital importance and studying these specific homogenous subpopulations within a larger cohort can provide us with critical information. However, identification of these subgroups requires robust statistical methods to avoid false categorization.
In this proposed symposium, we discuss mathematically driven techniques to aid in the identification of these interindividual differences to better characterize homogeneous subgroups. We will discuss the conceptual framework and statistical approaches involved in the characterization of inter-individual vulnerability to develop compulsive drug seeking to make a distinction between the neural mechanisms of drug use and that mediating the individual vulnerability to make the transition to addiction (Dr. Maxime Fouyssac). We will then present the application of supervised and unsupervised machine learning algorithms to identify a subset of rats demonstrating higher risk of alcohol use disorder and cocaine abuse (Dr. Kshitij Jadhav). Transitioning to clinical research Dr. Marwa Mahmoud will discuss multimodal feature representation and fusion as well as deep learning techniques in the development of vision based artificial intelligence in social signal processing. Finally, Dr. Mael Lebreton will present a new normalization method for interindividual brain-behavior scaling relationship in functional imaging.

In this symposium, we will combine multiple methodologies (physiology, imaging, genetics and quantitative behaviors), across several brain regions (cortex, thalamus, habenula) in a diverse set of animal models (zebrafish, mouse, rats) in order to discuss: a) the role of neural activity and synchrony in brain development, b) developmental alterations in cognitive processes and underlying neural mechanisms, c) and the relationship between these developmental processes with brain function and neurological diseases. We expect that our symposium will attract the interest from diverse groups of scientists striving to understand the relationship between brain development and function. Finally, it is important to note that our team of 4 speakers is balanced in expertise, gender, geographical distribution and their country of origin, which is well aligned with the spirit of this international conference.

Interoception, the sensing and processing of internal bodily signals by the brain, shapes cognition, emotion and behavior. Altered interocep8on is emerging as an important factor in mental illness. However, the neural mechanisms media8ng the role of interoception in psychopathology remain poorly understood. This symposium will address the brain circuits of interoception, with a focus on the insular cortex, and their contribution to higher brain functions, behavior and disease states. We will discuss experimental and conceptual advances in this field in the light of novel findings from the speakers’ research groups. The speakers and chairpersons are early-mid career scientists who have been developing innovative and internationally recognized research on interoception with a range of approaches and models. The talks will reflect this integrative and translational approach and present findings from neuroimaging in humans (Garfinkel), large scale neurohistology in humans, non- human primates and rodents (Evrard, Lamy) and integrative and behavioral neuroscience methods in rodents (Belin-Rauscent, Lamy). Through those different perspectives, we aim at fostering the debate around important open questions including on the differences in interoceptive pathways across animal species, the translational validity of animal models and the congruence of results from different experimental approaches. Interoception has benefited from renewed attention recently in psychiatric and behavioral research, but mechanistic work has been lagging behind. This symposium will present new neuronal circuits of interoception discovered in higher brain areas with modern neuroscience methods and give an up to date perspective on the role of interoceptive mechanisms in mental health and behavior. 

Posttraumatic stress disorder (PTSD) is a psychiatric disorder that can develop after exposure to extreme aversive events, such as war, sexual violence, life-threatening accidents. These situations usually overcome the individual’s coping responses leading to behavioral and psychological alterations. To develop better treatments for this disorder, a greater understanding of its neural substrates is of utmost importance. Such an understanding requires a delineation of both the processes underlying the symptomatology, and those underlying the etiology of this disorder.
A cardinal feature of PTSD is a paradoxical pattern of memory with hypermnesia for salient traumatic cues that do not necessarily predict the trauma and amnesia for peritraumatic contextual cues. Clinical studies strongly suggest that a deficit in trauma contextualization might be responsible for the formation of these PTSD symptoms. Validating this hypothesis and identifying the underlying neurobiological mechanisms of such memory alteration would unveil potential therapeutic targets.
Furthermore, only a small fraction of all trauma-exposed individuals eventually develops PTSD, whereas the rest is resilient. Understanding the differences between a vulnerable and a resilient brain, along with the factors that can induce this vulnerability thus constitutes a major challenge to target prevention and develop directed treatments.
In this context, the aim of this symposium is to gather scientists who work in Human or rodents and develop complementary approaches and models in order to tackle these two issues. We expect it to bring highlights on our current understanding of this pathology, which is a crucial step towards targeted treatments.

The aim of this symposium is to provide an update of different perspectives on assessing neurobiological underpinnings of psychiatric disorders and their treatments. The first presentation puts forward a task based on social geometry to explore the neural and computational bases of social decision-making and real-world social function. This is particularly important for assessing social dysfunction in schizophrenia, borderline personality disorder and social anxiety and is relevant for assessing treatment. The second presentation explores the proof-of-principle of novel imaging techniques that aim at the assesssment of mood-dependent changes in the brain, by using techniques that are sensitive to myelin, iron and tissue free water content. The third presentation will put forward the formal validation of a task assessing emotional processing from an individualized perspective on a neural level, by taking into account behavioral activations assessed in a specific emotion-focused task. The third presentation discusses psychotherapy changes on a neural basis for patients with borderline personality disorder when the individual’s experience is taken into account on the level of the neural activations. These BOLD changes will be related to psychotherapy outcomes and discussed in the context of a model of enhancement of social function in psychiatric disorders.

When considering higher-level cognition, the cortex always features, while subcortical regions are often overlooked or downplayed. The aim of our symposium is to highlight subcortical structures and their integrative crosstalk with cortical regions. Our speakers focus on different cognitive abilities, from learning and memory to decision-making, navigation, and adaptive behaviours. We will provide a comprehensive overview of the critical roles played by subcortical-cortical interactions while also considering the affective dimensions of these processes. Rodent (Mathieu Wolff) and primate (Anna Mitchell) animal models will feature to illustrate how thalamic nuclei critically contribute to cortical functions. We also aim to broaden the frontiers of thalamocortical circuits by considering subcortical thalamic afferents that have been to date largely ignored, again from both rodent (Seralynne Vann) and primate perspectives (Helen Barbas, Seralynne Vann, Anna Mitchell).
Our symposium will emphasize a coherent message that to fully understand the underlying mechanisms in processes such as decision-making and spatial processing, we need to look beyond the cortex and hippocampus and consider a wider cast of contributors. Furthermore, many of the pathways under discussion have been linked to neurological and psychotic disorders and disease, highlighting why understanding these mechanisms is vital in healthy functioning and in disease states. An important expected outcome of this symposium is to provide the audience with a synthetic perspective on current understanding of the circuit-level underpinning of affective cognition, consistent with the well cited track record of each participant.
Our symposium contributors have been chosen with inclusivity and diversity in mind, both in terms of their research and the speakers themselves. For research areas, we present data from different experimental models used including rodents and non-human primates; and there is a focus on different brain regions and a range of experimental techniques to probe the specific questions. This diversity will be of interest to a wide audience. The panel includes both female (3) and male (1) speakers of which one is a senior principal investigator and three are mid-career principal investigators. Within our panel we have a physically disabled scientist and scientists with caring responsibilities. Our panel line-up includes speakers based in Europe and the United States.

Human evolution has been marked by a striking increase in total brain volume relative to body size. While most work has focused on disproportionate expansion of certain regions of association cortex across our evolutionary lineage, descent with modification is apparent across all neural systems in both human and non-human primates. However, despite growing evidence for the ubiquitous and complex influence of evolutionary forces on brain biology beyond the cortex, the vast majority of the literature on human brain evolution remains excessively corticocentric.
Here we present recent work examining how evolutionary processes have modified the anatomical and functional systems that make up the human brain. First, we show how mammalian brain evolution involves selective change in the components of neural systems that are distributed throughout the brain. Second, we highlight the importance of the relative expansion of the lateral cerebellum in the augmentation of the dimensionality of human cognitive capacities. Third, we present data demonstrating that molecular methods such as single cell RNA sequencing across humans, nonhuman primates, and other species reveals the sometimes surprising ways that cell types have evolved across brain structures. Finally, we conclude with a discussion of how brain evolution can be viewed as a process of reorganization of large-scale circuits instead of the simple “addition of parts”.
Our talks will cover multiple domains of evolutionary neuroscience, but are aligned with a common focus. Specifically, our perspectives together challenge the systemic mischaracterization of human cognition and behavior as a competition that pits phylogenetically recent cortical territories against evolutionarily ancient subcortical and cerebellar systems. In stark contrast, we propose a more comprehensive view of human brain evolution that stretches across multiple scales and regions within the central nervous system. This new perspective offers important insights into theory development, as well as the study of behavior across health and disease.

Face to face social interactions are important in learning and building social bonds, and atypical interactions are characteristic of many psychiatric disorders. However, it is hard to capture the dynamic, interactive nature of real-world social interactions in a static isolated MRI scanner. Functional near-infrared spectroscopy (fNIRS) is an emerging brain-imaging modality which allows us to measure cortical blood flow as a proxy for neural activity in freely moving children and adults engaged in natural dynamic social interactions. This symposium presents cutting-edge research in fNIRS which explores the basic mechanisms of human social interaction and their development.
Using hyperscanning methods, Hirsch presents data on how socioeconomic disparity impacts on the neural mechanisms engaged in dialogue between pairs of participants. Results show stronger engagement of prefrontal mechanism when participants converse with an out-group member. Pinti also uses hyperscanning to explore brain mechanisms involved in lying and lie detection as participants play a card game like Poker. The results show specific mechanisms engaged when participants intend to deceive their partner. These two studies illustrate how fNIRS can provide new insights into the fundamental mechanisms of human social engagement. Moving to developmental studies, Bulgarelli presents data from 18 month old infants, tracking the development of connectivity patterns and how these relate to the infant’s emerging sense of self. Results show a strengthening of frontoparietal connectivity associated with passing a mirror self-recognition test. Finally, Hamilton examines brain activity while participants with autism engage in a live interaction task that invites spontaneous imitation. Results show differences in patterns of brain activity in the autistic participants, despite similar behavioural performance. These two studies illustrate the value of using fNIRS to explore social interaction in developing and atypical populations for whom fMRI is not accessible.
Overall, these studies showcase the advances which are being made in the domain of interactive social neuroscience. As researchers increasingly look to study the diversity of dynamic social behaviour in ecologically valid contexts, fNIRS can help us track the neural mechanisms which support these interactions.

The orbitofrontal cortex (OFC) is a part of the prefrontal neocortex that, in mammals, plays a central role in cognition; flexibly decoding, integrating, processing, and routing information to other cortical and subcortical structures. How does OFC connectivity and physiology enable configuration and coordination of inputs for local circuit computations, as well as diverse, top-down outputs to distributed brain areas to influence learning and cognitive behaviour? This symposium will bring together a range of early-career and experienced researchers harnessing rodent models to understand the roles of the OFC in cognitive behaviour by studying the plasticity, computational capabilities, and behavioural impact of OFC circuits.
The first speaker, Prof. Geoffrey Schoenbaum (NIDA, USA), is a prominent researcher in the field whose lab has studied the role of OFC in decision-making for decades. He will introduce the topic and further discuss his latest work on the computations in OFC that subserve value-based decisions and when and why the OFC is important to such decisions.
Next, Dr Fanny Cazettes (Champalimaud Centre for the Unknown, Portugal) will discuss how state-representations build up in the frontal cortex during a decision-making task in mice and highlight how the availability of multiple state representations may offer simple solutions for changes in behavioral strategies, providing a powerful form of cognitive flexibility.
Following on from this, Dr Banerjee (Newcastle University, UK) will highlight how specific long-range cortical projections from the OFC contribute to top-down cognitive control in flexible remapping of sensory responses guiding adaptive behaviour.
Finally, Dr Christine Constantinople (NYU, USA) will describe her work on the contributions of OFC to value-based decision-making and learning. She will discuss recent physiological results from OFC populations in rats performing a task in which they choose between explicitly described lotteries.
The researchers assembled for this symposium are at the forefront of their respective fields and will therefore provide a state-of-the-art account of ongoing work in their labs. The line-up includes early-career, gender-balanced, and geographically representative speakers. The topic will be of broad interest to a wide range of neuroscientists interested in cellular and circuit mechanisms in the prefrontal cortex underlying complex forms of learning and decision-making.

Adaptive decision-making depends on the interaction between goal-directed and habitual processes. An imbalance between these processes with a bias toward habit is observed in several psychopathologies. Better conceptualizing habit and understanding how our brain arbitrates between these processes may eventually reveal how the balance get tilted toward habit in these disorders. Indeed, the habit construct is impeded by methodological limitations and poor translational validity. The goal of this symposium is to gather researchers studying decision-making processes, but questioning models typically used to investigate habits.
The habit construct is limited by its operationalization as an absence of goal-directed behavior. Thus, it is not possible with current models to determine whether an imbalance in behavioral control results from abnormal habit or reduced goal-directed control. Dr Willuhn developed a new instrumental task aimed at positively identifying automated habit-like behavior and tracking its evolution across training. Another limit in habit models is that our tests typically answer a yes-or-no question when habitual and goal-directed control are likely involved along a continuum. Dr Keramati will review several neurocomputational models that he and others have developed to determine how the brain arbitrates between habitual and goal-directed processes. Although habit is defined as a stimulus-response association, the role of Pavlovian cues in behavioral control remains largely overlooked in free-operant schedules typically used to study habits. Dr Vandaele will show that increasing reward predictability by providing Pavlovian discriminative cues promotes behavioral chunking and habitual learning. Finally, although habits are ubiquitous in our everyday lives, induction of habits in laboratory tasks with human participants has proven difficult. Dr Hardwick will present a new theory suggesting that habits may be present, but masked by the execution of delayed goal-directed responses.
This symposium is transdisciplinary and should catalyze insightful discussions about the concept of habit that will be addressed under multiple complementary perspectives, from computational and animal modeling to translation in human research on decision-making. It will open new perspectives toward a fine-grained conception of habit ultimately allowing us to better address its role in psychopathologies.

A fundamental goal in studying brain and behavior is to identify cells controlling behavior responses in health and disease. Recent advances in single-cell omic technologies produced comprehensive brain atlases that link cellular states with behavioral outcomes. Here, we like to bring young group leaders who are spearheading integrating single-cell omic technologies to behavior both in health and disease. Our symposium creates a platform to discuss recent progress and challenges, as well as the opportunities that emerge when single-cell omics technologies meet with behavioral studies.