Sector search strategies for odor trail tracking

Ants, mice, and dogs often use surface-bound scent trails to establish navigation routes or to find food and mates, yet their tracking strategies remain poorly understood. Chemotaxis-based strategies cannot explain casting, a characteristic sequence of wide oscillations with increasing amplitude performed upon sustained loss of contact with the trail. We propose that tracking animals have an intrinsic, geometric notion of continuity, allowing them to exploit past contacts with the trail to form an estimate of where it is headed. This estimate and its uncertainty form an angular sector, and the emergent search patterns resemble a “sector search.” Reinforcement learning agents trained to execute a sector search recapitulate the various phases of experimentally observed tracking behavior. We use ideas from polymer physics to formulate a statistical description of trails and show that search geometry imposes basic limits on how quickly animals can track trails. By formulating trail tracking as a Bellman-type sequential optimization problem, we quantify the geometric elements of optimal sector search strategy, effectively explaining why and when casting is necessary. We propose a set of experiments to infer how tracking animals acquire, integrate, and respond to past information on the tracked trail. More generally, we define navigational strategies relevant for animals and biomimetic robots and formulate trail tracking as a behavioral paradigm for learning, memory, and planning.

Endorsing Negative Intergroup Attitudes to Justify Failure To Confront Prejudice

While most people believe they would speak up against prejudice, many fail to do so. We identify a harmful consequence of such inaction through examining its impact on bystanders’ own prejudice. Across four studies in two countries (N=1003), using a behavioral paradigm and experimental pretest-posttest design, participants witnessed prejudice and discrimination against an outgroup minority (Jewish/Roma in Hungary, Muslim/Latinx in US). Drawing on self-justification theories, we predicted and found across studies 1-3, that those who had an opportunity but did not confront, endorsed more negative intergroup attitudes following the incident both compared to their own prior attitudes and to control groups, i.e., those who witnessed the same prejudice but had no opportunity to confront, and those who did not to confront different (non-intergroup) prejudice. In study 4, the proposed effect occurred only among those who initially valued confronting. We suggest that failure to speak up amplifies prejudice in society.

Innate Preferences Affect Results of Object Recognition Task in Wild Type and Alzheimer’s Disease Mouse Models

Background: Object recognition task (ORT) is a widely used behavioral paradigm to assess memory in rodent models, due to its easy technical execution, the lack of aversive stressful stimuli, and the possibility to repeat the test on the same animals. However, mouse exploration might be strongly influenced by a variety of variables. Objective: To study whether innate preferences influenced exploration in male and female wild type mice and the Alzheimer’s disease (AD) model 3xTg. Methods: We first evaluated how object characteristics (material, size, and shape) influence exploration levels, latency, and exploration modality. Based on these findings, we evaluated whether these innate preferences biased the results of ORT performed in wild type mice and AD models. Results: Assessment of Exploration levels, i.e., the time spent in exploring a certain object in respect to the total exploration time, revealed an innate preference for objects made in shiny materials, such as metal and glass. A preference for bigger objects characterized by higher affordance was also evident, especially in male mice. When performing ORT, exploration was highly influenced by these innate preferences. Indeed, both wild type and AD mice spent more time in exploring the metal object, regardless of its novelty. Furthermore, the use of objects with higher affordance such as the cube was a confounding factor leading to “false” results that distorted ORT interpretation. Conclusion: When designing exploration-based behavioral experiments aimed at assessing memory in healthy and AD mice, object characteristics should be carefully evaluated to improve scientific outcomes and minimize possible biases.

Investigating Mindful Awareness from Moment-to-Moment in Meditation: The Mindful Awareness Task (MAT)

Buddhist and contemporary psychological theories propose that training attention and awareness in mindfulness meditation is a fundamental mechanism of mindfulness, essential for producing its salutary effects. Yet, the empirical foundation for this central idea in mindfulness science is surprisingly small due to a limited methodological capacity to measure attention and awareness during mindfulness meditation. Accordingly, we set out to study these processes (N = 143) via a novel behavioral paradigm measuring the objects and temporal dynamics of mindful awareness during meditation – the Mindful Awareness Task (MAT). Using this paradigm, we empirically characterized attention and awareness during mindfulness meditation. We provide novel behavioral evidence indicating that, as long-theorized, attention and awareness during mindfulness meditation are related to previous mindfulness meditation practice, attitudinal qualities of mindfulness, attention regulation, and mental health. We found that in contrast to widely held assumptions, sustained attention and executive functions, as measured via common cognitive-experimental tasks, may not be meaningfully related to the cognitive capacities trained and expressed in mindfulness meditation. Furthermore, we found that the accuracy of self-reported mindfulness is, paradoxically, dependent on behaviorally measured capacities for mindful awareness. Collectively, our behavioral findings reveal that, as long-theorized, attention and awareness during mindfulness meditation may indeed be fundamental to the practice, cultivation, and salutary functions of mindfulness. Findings indicate that the MAT paradigm may overcome significant limitations of extant measurement methods, and thereby enable future scientific insights into attention and awareness in mindfulness meditation and their salutary effects.

Commanding or being a simple intermediary: how does it affect moral behavior and related brain mechanisms?

History has shown that fractioning operations between several individuals along a hierarchical chain allows diffusing responsibility between components of the chain, which has the potential to disinhibit antisocial actions. Here, we present two studies, one using fMRI (Study 1) and one using EEG (Study 2), designed to help understand how commanding or being in an intermediary position impacts the sense of agency and empathy for pain. In the age of military drones, we also explored whether commanding a human or robot agent influences these measures. This was done within a single behavioral paradigm in which participants could freely decide whether or not to send painful shocks to another participant in exchange for money. In Study 1, fMRI reveals that activation in social cognition and empathy-related brain regions was equally low when witnessing a victim receive a painful shock while participants were either commander or simple intermediary transmitting an order, compared to being the agent directly delivering the shock. In Study 2, results indicated that the sense of agency did not differ between commanders and intermediary, no matter if the executing agent was a robot or a human. However, we observed that the neural response over P3 was higher when the executing agent was a robot compared to a human. Source reconstruction of the EEG signal revealed that this effect was mediated by areas including the insula and ACC. Results are discussed regarding the interplay between the sense of agency and empathy for pain for decision-making.

Rabbits use both spectral and temporal cues to discriminate the fundamental frequency of harmonic complexes with missing fundamentals

The pitch of harmonic complex tones (HCT) common in speech, music and animal vocalizations plays a key role in the perceptual organization of sound. Unraveling the neural mechanisms of pitch perception requires animal models but little is known about complex pitch perception by animals, and some species appear to use different pitch mechanisms than humans. Here, we tested rabbits' ability to discriminate the fundamental frequency (F0) of HCTs with missing fundamentals using a behavioral paradigm inspired by foraging behavior in which rabbits learned to harness a spatial gradient in F0 to find the location of a virtual target within a room for a food reward. Rabbits were initially trained to discriminate HCTs with F0s in the range 400-800 Hz and with harmonics covering a wide frequency range (800-16,000 Hz), and then tested with stimuli differing either in spectral composition to test the role of harmonic resolvability (Experiment 1), or in F0 range (Experiment 2), or both F0 and spectral content (Experiment 3). Together, these experiments show that rabbits can discriminate HCTs over a wide F0 range (200-1600 Hz) encompassing the range of conspecific vocalizations, and can use either the spectral pattern of harmonics resolved by the cochlea for higher F0s or temporal envelope cues resulting from interaction between unresolved harmonics for lower F0s. The qualitative similarity of these results to human performance supports using rabbits as an animal model for studies of pitch mechanisms providing species differences in cochlear frequency selectivity and F0 range of vocalizations are taken into account.

Sex Differences in Behavior and Molecular Pathology in the 5XFAD Model

Background: The prevalence of Alzheimer’s disease (AD) is greater in women compared to men, but the reasons for this remain unknown. This sex difference has been widely neglected in experimental studies using transgenic mouse models of AD. Objective: Here, we studied behavior and molecular pathology of 5-month-old 5XFAD mice, which express mutated human amyloid precursor protein and presenilin-1 on a C57BL/6J background, versus their wild-type littermate controls, to compared both sex- and genotype-dependent differences. Methods: A novel behavioral paradigm was utilized (OF-NO-SI), comprising activity measures (Open Field, OF) arena, followed by Novel Object exploration (NO) and Social Interaction (SI) of a sex-matched conspecific. Each segment consisted of two repeated trials to assess between-trial habituation. Subsequently, brain pathology (amyloid load, stress response and inflammation markers, synaptic integrity, trophic support) was assessed using qPCR and western blotting. Results: Female 5XFAD mice had higher levels of human APP and amyloid-β and heightened inflammation versus males. These markers correlated with hyperactivity observed in both sexes, yet only female 5XFAD mice presented with deficits in object and social exploration. Male animals had higher expression of stress markers and neurotrophic factors irrespective of genotype, this correlated with cognitive performance. Conclusion: The impact of sex on AD-relevant phenotypes is in line with human data and emphasizes the necessity of appropriate study design and reporting. Differential molecular profiles observed in male versus female mice offer insights into possible protective mechanisms, and hence treatment strategies.

De ira III, 2: fonti dossografiche e analogie con il moderno paradigma cognitivo-comportamentale

This paper aims to analyse a dense passage of De ira by Seneca (III, 2) that, considering its structural and thematic relevance in the architecture of the tractate, gives rise to interesting and valuable considerations to understand more deeply the nature of the work. First, the extract under examination is crucial since enables to identify the dossographic sources that the author drew on to develop the therapeutic strategy adopted for the treatment of anger in the third book of the work. Furthermore, an overall interpretation of the essay, based on a passage so rich in literary and philosophical implications, will be provided. Eventually, we will deal with the therapeutic approach selected by the philosopher and its analogies with the ancient Cynic-Stoic ἐπιλογισμός and the modern cognitive-behavioral paradigm. Il presente articolo si propone di esaminare un passo del De ira di Seneca (III, 2) che, in virtù della sua rilevanza strutturale e tematica all’interno dell’architettura dell’opera, si presta a sviluppare una serie di interessanti considerazioni, senz’altro utili per comprendere più a fondo la natura complessiva del trattato. Il passaggio in questione si rivela anzitutto cruciale poiché consente di tracciare le fonti dossografiche a cui l’autore si è ispirato per mettere a punto la strategia terapeutica adottata per la cura dell’ira, accuratamente illustrata proprio nel terzo libro dell’opuscolo. Sulla scorta inoltre di un passo così denso di implicazioni filosofico-letterarie, si avanzerà una proposta di interpretazione complessiva dell’opera e degli intenti che la sostenziano . Infine, si passerà ad analizzare l’approccio terapeutico prescelto dal filosofo, e si mostrerà come esso si collochi al confine fra l’antico ἐπιλογισμός cinico-stoico e il moderno paradigma cognitivo-comportamentale.

Affective theory of mind impairments underlying callous-unemotional traits and the role of cognitive control: A pilot study

Affective theory of mind (aToM) impairments predict antisocial behavior above clinical rating of the youth antisocial phenotype callous-unemotional (CU) traits. Adolescents with CU traits demonstrate specific impairments in cognitive control; and cognitive control modulates aToM. Adolescents with CU traits specifically demonstrate aToM impairments during complex, but not basic, emotions, which require greater cognitive control to process. What is less understood is how cognitive control impacts complex aToM in relation to CU traits. Such investigations demonstrate promise for understanding modifiable mechanisms underlying core impairments of CU traits. To examine this, 81 participants (ages 12-14, Female = 51.8%, Male= 48.2%) were recruited to complete a behavioral paradigm that involved an initial aToM task followed by placing additional demands on cognitive control and a final repeat of the same aToM task. Results indicate higher CU traits associated with greater sensitivity to cognitive demands and that placing demands on cognitive control resulted in additional decrements in complex aToM. These preliminary results suggest that the cognitive control vulnerabilities associated with CU traits impact complex aToM. This may partially explain why youth with CU traits persist in antisocial behavior and warrants further investigation.

A Novel Assay Allowing Drug Self-Administration, Extinction, and Reinstatement Testing in Head-Restrained Mice

Multiphoton microscopy is one of several new technologies providing unprecedented insight into the activity dynamics and function of neural circuits. Unfortunately, some of these technologies require experimentation in head-restrained animals, limiting the behavioral repertoire that can be integrated and studied. This issue is especially evident in drug addiction research, as no laboratories have coupled multiphoton microscopy with simultaneous intravenous drug self-administration, a behavioral paradigm that has predictive validity for treatment outcomes and abuse liability. Here, we describe a new experimental assay wherein head-restrained mice will press an active lever, but not inactive lever, for intravenous delivery of heroin or cocaine. Similar to freely moving animals, we find that lever pressing is suppressed through daily extinction training and subsequently reinstated through the presentation of relapse-provoking triggers (drug-associative cues, the drug itself, and stressors). Finally, we show that head-restrained mice will show similar patterns of behavior for oral delivery of a sucrose reward, a common control used for drug self-administration experiments. Overall, these data demonstrate the feasibility of combining drug self-administration experiments with technologies that require head-restraint, such as multiphoton imaging. The assay described could be replicated by interested labs with readily available materials to aid in identifying the neural underpinnings of substance use disorder.