Publications by authors named "Sebastien Ballesta"
Article Synopsis
- Conflict management involves both preventing and repairing the damage from social conflicts, with a focus on understanding primates' decision-making processes related to conflict.
- A study with Tonkean macaques examined how they navigate social dilemmas, showing that they consider the costs of conflict versus rewards when making choices.
- Findings indicate that these macaques balance social hierarchy and reward value in their decisions, often prioritizing group cohesion and peacekeeping over personal gains.
Article Synopsis
- Detecting predators is crucial for survival, and the Snake Detection Theory (SDT) posits that primates evolved specialized skills to spot snakes, a longstanding threat.
- Recent research involved Tonkean and rhesus macaques to assess their abilities in identifying various predators through an oddity task that measured their reaction times and success rates over 400,000 trials.
- Findings revealed that macaques were quicker at identifying geometric shapes than animals, and showed similar detection abilities for snakes and other predators, challenging the idea that snakes uniquely capture primate attention.
Article Synopsis
- Inhibitory control helps animals resist impulsive behavior, which is crucial for navigating complex social settings, especially in species with varying degrees of social tolerance.
- The study compared inhibitory control abilities among three macaque species with different social tolerances (low, medium, and high) using touchscreen tasks.
- Results showed that macaques with higher social tolerance exhibited better inhibitory control, being less impulsive and distracted, indicating that evolution favors these skills to manage complex social interactions.
Article Synopsis
- * Researchers have identified different types of neurons in the OFC: some track the value of offers, others identify the chosen option, and some encode the value of what's chosen.
- * New findings reveal that stimulating the OFC disrupts value comparison during decision-making, suggesting that this area of the brain is key for comparing the worth of different options, rather than just assessing their individual values.
Article Synopsis
- Economic choices can be influenced by various biases, which neuroeconomics aims to better understand over time.
- In experiments with rhesus monkeys, choices were less accurate and showed biases towards the second offered juice and the monkey's preferred juice when the options were presented in sequence.
- The study revealed that these biases occurred at different stages of neuronal processing in the brain, ultimately leading to lower overall value obtained by the monkeys in their choices.
Article Synopsis
- A series of studies identified specific neuron groups in the orbitofrontal cortex (OFC) of monkeys that encode essential variables in decision-making, such as the value of options and the outcome of choices, suggesting these neurons form a decision-making circuit.
- Recent research expanded on earlier experiments by examining neuron activity in the OFC when monkeys faced sequential offers of juice, alongside simultaneous ones, to see if the neuronal responses remained consistent.
- The findings revealed a strong correspondence between neuron groups activated during simultaneous and sequential choices, indicating that the same neural circuits govern economic decision-making regardless of how options are presented.
Article Synopsis
- Dominance hierarchy is crucial in animal societies, but traditional methods of assessing it can be affected by various challenges like environmental factors and difficulties in recognizing individuals.
- This research utilized automated learning and testing machines (MALT) to track and measure the dominance dynamics among semi-free-ranging Tonkean macaques, revealing a strong correlation between MALT data and observed social interactions.
- The study confirms that MALT offers a reliable, low-labor approach for continuously monitoring dominance hierarchies, which can be beneficial for managing animal groups, even in fluctuating environments.
Article Synopsis
- In the 18th century, economists like Bernoulli, Smith, and Bentham suggested that economic decisions are based on subjective values, a theory that still influences modern behavioral economics.
- Research indicates that neurons in the orbitofrontal cortex (OFC) play a key role in encoding these subjective values and influence decision-making, but previous evidence has mostly been correlational.
- Recent experiments with electrical stimulation in rhesus monkeys revealed that stimulating the OFC can directly manipulate the subjective value of options and affect decision-making, establishing a causal link between brain activity and economic choices.
Article Synopsis
- * Researchers recorded activity from the OFC of monkeys choosing between two juices, finding that the same neural circuits are used for both simultaneous and sequential choices.
- * The study revealed that neurons in the OFC encode the identities and values of offerings, and suggested that decision-making involves circuit inhibition rather than mutual inhibition, offering a clearer understanding of the neural basis for economic choices.
Front Behav Neurosci
September 2019
Article Synopsis
- Primates, particularly long-tailed macaques, exhibit complex social behaviors influenced by past interactions, demonstrating the potential for reciprocity in their relationships.
- Controlled experiments show these monkeys can reciprocate in a social decision-making task, but mainly in scenarios involving negative outcomes (like receiving an air puff).
- The monkeys' ability to reciprocate depends on witnessing their partner's decisions, indicating that their social interactions are driven by a mix of revenge for negative experiences and gratitude for positive ones.
Article Synopsis
- Videos featuring emotional and social content lead to observable social behaviors in primates, such as eye contact and facial expression mirroring.
- When male macaques watched videos, their overall eyeblink rate decreased, but the timing of their blinks became more synchronized during specific emotional displays.
- The findings indicate that blinking in macaques is influenced by both physiological needs and social interactions, similar to human responses.
Article Synopsis
- MDMA was tested for its effects on social behaviors in young male long-tailed macaques, marking the first study of its kind on non-human primates.
- Three doses of MDMA (1.0, 1.5, and 2.0 mg/kg) were administered, revealing significant effects on behaviors like social grooming, foraging, and locomotion.
- Specifically, a 1.5 mg/kg dose increased social grooming, while doses of 1.5 and 2.0 mg/kg decreased foraging, and a 2.0 mg/kg dose increased locomotion, demonstrating MDMA's potential impact on primate social dynamics.
Proc Natl Acad Sci U S A
December 2015
Article Synopsis
- Primates, particularly macaque monkeys, live in social environments where prosocial behaviors strengthen bonds and enhance group fitness.
- The study shows that macaques consider their peers' welfare when making decisions that can lead to positive or negative outcomes for others.
- Unique behavioral cues, such as mutual gaze and eye blinking, indicate their motivations—benevolence leads to prosocial choices, while indifference or malevolence correlates with less engagement.
Article Synopsis
- Blood sampling from non-human primates (NHPs) is traditionally done from veins under restraint, causing stress and ethical issues.
- A new method collects blood from the ear of restrained NHPs using capillary devices, yielding adequate samples for common biological tests.
- This method has been validated against traditional vein sampling, showing strong correlations in blood measurements, and promotes better scientific outcomes while enhancing animal welfare.
Article Synopsis
- Many primates, particularly long-tailed macaques, engage in solitary object play, which is important for their behavior and social dynamics.
- A study introduced a unique toy to a group of these macaques, revealing that access to the toy created competition reflecting their social hierarchy.
- The findings suggest that object play and social interactions are motivated by different factors, as competition for the toy reduced social contact among the monkeys, similar to how humans perceive competitors as threats.
