Scientists have achieved a significant breakthrough in unraveling the brain’s mechanics behind emotional connections, an advance that holds promise for understanding—and perhaps treating—conditions such as anxiety and trauma-related disorders. In a recent study published in Nature, researchers from the RIKEN Center for Brain Science in Tokyo have identified specific brain processes enabling the formation of complex emotional associations, challenging long-standing assumptions about how human and animal brains process emotionally charged experiences (Ars Technica).
This revelation is particularly relevant as mental health concerns in Thailand are growing at a rapid pace. According to data from the Department of Mental Health, millions of Thais experience anxiety, depression, or trauma-related disorders, yet effective treatments are often elusive (Mental Health Thailand). Understanding how the brain weaves together sensory information and intense emotions could pave new ways for therapy—particularly for those suffering lingering effects from traumatic events, such as road accidents, natural disasters, or interpersonal violence, all of which are prominent issues in Thai society.
The study, led by a project director at RIKEN and a lead researcher at the same center, departed from decades of classical research that focused narrowly on the brain’s basic fear and reward centers, namely the amygdala. Traditionally, scientists believed emotional associations—like fearing wasps after being stung—were encoded largely in this region. While this explained simple cause-effect fears, it failed to account for the true complexity of human emotional memory, which also links neutral associations such as locations or background sounds to trauma, increasing vulnerability to triggers and sustained anxiety.
Seeking to bridge this gap, the RIKEN team conducted a sophisticated animal study involving rats, with the aim of simulating more complex, human-like emotional learning. To do so, the researchers divided rats into two groups: one was allowed to form an association between a visual image and a sound (“paired” group), while another experienced these stimuli at separate times and could not make a connection (“unpaired” group). The next day, both groups were subjected to a fear-conditioning episode where the same image was paired with a mild electric shock. The crucial difference emerged when researchers later tested for fear responses not to the image, but to the sound itself. Only the “paired” animals, which had previously learned the image-sound association, exhibited a fear response to the sound—demonstrating that rats, like humans, can infer danger from indirectly related cues.
Delving deeper, the researchers employed an advanced calcium imaging technique to highlight which regions of the rats’ brains were active during the learning process. This cutting-edge method involved making neurons fluoresce in real time when they became active, enabling unprecedented real-time insights into how brain circuits construct emotional models. Counter to longstanding models, the researchers discovered that while the amygdala handled simple, direct emotional associations (such as image-electric shock), the complex, inferred emotional links depended on activity in the dorsomedial prefrontal cortex (dmPFC). As a research team director at RIKEN explained, the dmPFC “does not form the sensory model of the world. It only cares about things when they have emotional relevance.” In other words, the dmPFC steps in when the brain needs to connect seemingly unrelated experiences through a shared emotional thread.
When the team selectively inhibited the neurons connecting the dmPFC to the amygdala, rats lost their fear of the indirectly linked sound while retaining fear of the directly conditioned image. This shows that the amygdala alone is sufficient for basic fear learning, but the orchestration of complex, inferred fears—such as anticipating pain from a sound merely associated with danger—relies on the dmPFC’s higher-order integration (Nature, 2025). These findings provide strong evidence that complex emotional learning, a foundation of both resilience and vulnerability to mental health disorders, is built on distinct neural mechanisms.
For Thai readers, these insights could have profound implications. Youth in Thailand, for example, face stress from high-stakes exams, family expectations, and online social pressures—a unique mix of triggers that can combine to foster complex anxieties. The enhancement of complex emotional representations, as uncovered in this study, might explain why some individuals develop generalized anxiety or post-traumatic stress even when direct reminders of trauma are absent. What’s more, the research hints at new treatment opportunities: if therapies could target the specific circuits involved in complex emotional memory, such as the dmPFC, it may be possible to weaken maladaptive emotional associations without erasing core memories—a critical consideration in both clinical psychology and Buddhist philosophies of mindfulness and acceptance, which are influential in Thai mental health practice (World Health Organization Thailand).
The cultural context further deepens these findings. In Thai society, a strong emphasis on social harmony, community, and avoidance of confrontation can sometimes lead to the internalization of negative emotions or traumatic experiences. These unspoken or unprocessed traumas might manifest as physical symptoms or generalized worries, which Thai healers and mental health professionals describe as “โรคใจ” (rok jai)—illnesses of the heart-mind. Understanding that the brain actively constructs webs of emotional connections, rather than passively storing trauma, supports holistic approaches such as counseling, mindfulness-based interventions, and community mental health programs now expanding nationwide (Thai Mental Health Policies).
Nevertheless, there are many open questions left by this research. As a principal investigator at RIKEN acknowledged, the emotional models tested in rodents were relatively simple compared to human experiences. In real life, one location—for instance, a busy Bangkok intersection—may carry multiple, layered aversive associations: from bike accidents, to arguments, to memories of loss, all intertwined. Whether the dmPFC bundles these into a single, overlapping “danger zone” in the brain, or maintains separate threads for each experience, remains to be determined.
Looking to the future, the research team plans to explore how the brain binds unrelated, multimodal cues (like sounds, sights, and smells) into cohesive emotional memories—an area of special importance for individuals recovering from trauma. The hope is that, by mapping these neural connections in detail, new therapies can be devised to carefully “untie” pathological links while preserving healthy emotional learning. In Thailand, this could enhance the work of government counseling services, religious meditation retreats, and school resilience programs, offering more tailored strategies for prevention and healing.
In summary, this landmark research from RIKEN signals a new era in our understanding of how emotional memories are built in the brain—an insight as relevant to Thai families and health professionals as it is to neuroscientists worldwide. For Thai readers, practical steps include seeking support if struggling with persistent fears, engaging with available mental health resources, and considering community-based or mindfulness approaches that help reframe and process emotional memories. As science continues to uncover the roots of emotional learning, there is hope for more effective, culturally sensitive interventions that can strengthen mental resilience across generations.