As Oct. 31 approaches, marking the end of another month in the pandemic, millions of Americans will celebrate Halloween in quarantine. Despite Halloween being a time intended to celebrate and overcome fear, we remain paralyzed as our sense of normalcy continues to be redefined. Our own anxiety has motivated our actions during COVID-19. Within the span of a year, a collective sense of fear has motivated government policies and campus-wide initiatives, transforming our society virtually overnight. We’ve adopted rituals to prevent further spread, wearing masks and washing our hands more frequently than ever before. Our fear has also served as something shared between us as a society. In response to the pandemic, stories and conversations are shared through digital platforms, voicing struggles and fears associated with navigating unfamiliar territory.

This isn’t the first time we’ve felt afraid as a society. Fear is something common to humanity across space and time, and although people in the 21st century face threats like deadlines or jumpscares more often than ferocious predators, we still feel that same tightness in our chests. This emotion is something that’s evolved with us, enabling us to recognize danger and survive as a race. But for such a simple emotion, fear isn’t well understood. How do our brains recognize fear? And how does our sense of fear, originating in other life forms billions of years ago, help move us forward in the current era?

According to Dr. Lin Mei, a professor in the Neuroscience Department at Case Western Reserve University, when we perceive a new threat, electric charges are carried across billions of cells in nanoseconds. The brain processes this reaction instantaneously, sending signals to other organs to prepare the body to deal with the threat. The heart rate rises. Breathing increases. Pupils dilate. The body enters a “fight or flight” mode, increasing performance temporarily. When our eyes or ears perceive something unfamiliar, electric signals are relayed to a portion of the brain called the amygdala: a small, walnut-shaped region primarily responsible for emotions. When our sensory organs perceive information, the amygdala translates and contextualizes these signals, sorting through prior memories to assess the severity of this threat. If it deems it life-threatening, the amygdala sends a new signal to the larger hippocampus, which gives commands to other organ systems in the body. 

All throughout the brain, neurons carry signals between regions, forming synapses to pass information quickly and efficiently to different areas. As Mei reported, “There are about 86 billion neurons in the brain cell that try to talk to each other.” Further, Mei compared neurons to trees. Similar to how plants within a forest are connected and interdependent through underground root systems, neurons connect with each other by forming synapses, or small junctions that link these brain cells together.

In his research, Mei studies these synapses and their relationship to brain disorders such as Parkinson’s disease or Alzheimer’s disease. The ability to adapt and withstand stress, or synaptic plasticity, is directly linked to our memory. On this, Mei said, “Synapse formation is critical for how the brain is wired up. So synapses are extremely important for phenomenon for synaptic plasticity. For animals to learn, to memorize, to recall the memory, this is all synaptic plasticity.”

We associate our emotions with the environment we may have first felt them in. For example, let’s say you’ve had a stressful class in a certain room. Your mind may associate that room with feelings of anxiety or stress, so, in the future, you may be predisposed to dread or anticipate a lecture taking place in that same location. Mei explained that, similarly to other emotions, fear is contextualized within an environment. Neurons have already formed synapses between them, rooting the event and environment within our memory. When someone experiences fear by being in a familiar environment, electric discharges may travel down pre-existing pathways. The amygdala is therefore predisposed to assessing that the received signal communicates fear. 

At the same time, our memory may help us overcome feelings of fear by demystifying and anticipating threats. As avid horror movie watchers know, a jumpscare is scarier the first time around, but loses its scariness in subsequent watchings. Mei explained that your brain adapts to these events. The amygdala quantifies stimuli by comparing them to prior events. Familiar events can be recognized thanks to synaptic plasticity, which helps the brain remember other fear-inducing events. Using pre-existing pathways, the amygdala can collaborate with the hippocampus to decode and understand newer signals, making a better judgement on a perceived threat.

Fear can be beneficial for us. It developed as an evolutionary advantage, helping us to both recognize and understand threats. However, Mei warned that modern civilization can cause perpetual stress, leading to neurological degradation. Our sense of fear was tailored to infrequent threats, but the perpetual stress caused by assignments, projects, anxiety, societal pressures and other stressors triggers a strikingly similar response. Currently, it’s unknown why stress and fear affects synaptic plasticity, but neuroscientists have noticed that continuous feelings of fear hinder the ability of neurons to form synapses. In the process, memory and critical thinking abilities may be permanently damaged. As Mei said, “Long-term fear will lead to stress, and fear can cause depression. The best model for depression is unpredictable chronic stress.” 

The stress associated with the pandemic may impact our society long after a cure is found. While it’s important to adjust our lifestyles to protect others around us, studies in neuroscience remind us that, in a stressful time, we must also take care of ourselves. For some, avoiding triggers may avert the associated feelings of fear and helplessness. For others, setting daily routines can reduce stress. 

Whatever the case is for you, even though the pandemic has created fear, anxiety and worry, studies in neuroscience and psychology demonstrate that there’s a lot that we can do as individuals to change our actions, looking after the functions and health of our minds in the process.