In the context of perceiving individuals within and outside of social groups, there are distinct cognitive processes and mechanisms in the brain. Extensive research in recent years has delved into the neural mechanisms that underlie differences in how we perceive individuals from different social groups. To gain a deeper understanding of these neural mechanisms, we present a comprehensive review from the perspectives of facial recognition and memory, intergroup identification, empathy, and pro-social behavior. Specifically, we focus on studies that utilize functional magnetic resonance imaging (fMRI) and event-related potential (ERP) techniques to explore the relationship between brain regions and behavior. Findings from fMRI studies reveal that the brain regions associated with intergroup differentiation in perception and behavior do not operate independently but instead exhibit dynamic interactions. Similarly, ERP studies indicate that the amplitude of neural responses shows various combinations in relation to perception and behavior.

In recent years, cross-regional waste management has garnered significant academic interest, yet systematic reviews of related research remain scarce. Therefore, this study employed the PRISMA methodology to conduct a systematic review of 58 papers from the Web of Science and Scopus databases, aiming to clarify the current state of research in this field and explore future directions. Through analysis, five research themes were identified: management characteristics, core challenges, policy and regulation, technological innovation, and impact assessment. Research findings indicate that quantitative analysis constitutes 60% of the literature, representing the core methodology used in studies of cross-regional waste management. The challenges encountered in cross-regional waste management primarily manifest in three areas: environmental impacts, stakeholder relationships, and policy frameworks. Achieving cross-regional coordination necessitates collaborative efforts from governments, corporations, and society. This study further proposes future research directions providing support for future investigations by governments, universities, and corporate personnel.

Social identity differences are crucial for gregarious animals, impacting survival and social development. This is particularly evident in humans, where social stratification, cultural divides, and ethnic differences influence societal dynamics. Social recognition memory plays a central role in this process, maintaining social order by allowing individuals to distinguish familiar members within their group. Notably, social recognition memory exhibits differences: within a group, individuals form detailed memories of each member (individualized memory), while for out-group members, a more generalized memory of the entire group forms (categorized memory). Although this phenomenon has been explored in human studies, current research techniques and methods have limited investigations into the underlying neural mechanisms, especially their plasticity and regulatory mechanisms. This study utilizes mice to establish an experimental model for investigating differences in social recognition memory and its neural basis. We demonstrate that mice also exhibit social identity-driven memory recognition patterns. Mice form individualized memories for same-strain individuals but categorized memories for different strains, and the type of social recognition memory could be regulated by oxytocin level of ventrolateral periaqueductal gray. These findings demonstrate that oxytocin and its receptors in the ventrolateral periaqueductal gray are essential for constructing and plastically regulating intergroup social memory in mice.

Understanding how lockdown, a strict epidemic prevention policy, affects people’s risk attitudes is an interesting and fundamental issue. Behavioural experiments constitute one of the mainstream methods for measuring such microscopic effects. However, since epidemics are emergent events, their occurrence time is almost unpredictable; thus, obtaining comparative data before and after the implementation of a lockdown is difficult. Fortunately, in this study, we obtained a pair of controlled experimental data before and after the lockdown policy was implemented from the bordering town of Gengma in Yunnan Province, China. In 2018, we conducted risk preference behaviour experiments in various regions of Yunnan Province, including one experiment involving 65 residents of Gengma County, which became our first round of experiments. In November 2020, Gengma was locked down because of the COVID-19 pandemic. Immediately after the lockdown was lifted, we conducted another risk preference experiment, recruiting 55 residents, 39 of whom also participated in the first round of experiments, and this became our second round of experiments. Thus, we can better analyse how strict epidemic prevention policies change people’s risk attitudes. We found that before the COVID-19 lockdown policy was implemented, the participants’ risk attitudes fit well with the fourfold risk attitudes predicted by the Prospect Theory (PT). However, after a 14-day lockdown, Gengma residents’ risk attitudes significantly changed. They became more risk seeking for moderate-probability gains and risk averse for moderate-probability losses, which is contrary to PT’s prediction and contrary to their risk attitudes before the lockdown. These findings may serve as important references for policies related to epidemic prevention, community management, social security, and more in the post-COVID-19 era.