Gray Matter Volume and The New York City Flyover: Are We Protecting a Major Cultural Icon Enough?

05/05/2009 10:53 am ET | Updated Nov 17, 2011

New York is an icon among American cities. It houses the most people of any city in America, and is internationally recognized for its impact on fashion, entertainment, finance and culture. It is a hub of activity that many people have come to identify with America and its potential impact on the world. While the city and its inhabitants continue to thrive, 9/11 has left a bitter taste in the mouth of all Americans and a tangible impact on the brains of New Yorkers. In this column, I will review the effects of 9/11 on the brains of New Yorkers close to and far from the horrific event three years later, and raise concerns about the depth of our handling of this matter in the light of the recent New York City flyover that caused a big enough stir to stimulate an investigation by President Obama.

Last week, one of President Obama's official airplanes was sent on a low-flying photo mission past the New York City skyline. One of the Boeing 747s used by the President and an F-16 jet circled the Statue of Liberty, causing an uproar amongst workers in Manhattan who were alarmed about having to re-experience another terrorist attack like 9/11. But was this really cause for alarm, and if so why?

When a situation resembling a prior trauma is re-experienced, this stimulates old memories of the trauma, flooding the brain with all kinds of terror. The resulting anxiety is crippling and can hugely impact the brains of those who experienced 9/11. A study by Ganzel and colleagues (2008) found that more than three years later, adults who were closer to the 9/11 terrorist attacks had lower gray matter volume in several brain areas related to attention, conflict, emotion and memory including the amygdala and hippocampus. For those who had previously experienced more trauma, amygdala volume, blood flow and anxiety were all correlated, suggesting that these structural changes in the brain affected the ways in which their brains functioned.

In fact, an earlier study by Ganzel and colleagues (2007) compared the brains of those who were within 1.5 miles of the 9/11 terrorist attacks and those who were living more than 200 miles away. This study found that the brains (amygdala) of people who were closer were more reactive to fear than those living further away, suggesting that even three years later, this effect persisted. These findings were confirmed in a study by Sharot and colleagues (2007) who found that people who were Downtown during the attacks reacted differently from people who were Midtown three years later. The Downtown participants specifically activated the amygdala when shown pictures of the attacks but not when they were shown other pictures. This was not true for Midtown participants. The Downtown participants also recalled the horror more vividly.

While we don't know precisely what their brains would look like eight years later, these studies suggest that we cannot just arbitrarily choose a time to stop paying attention to our citizens in the aftermath of a trauma. If the brains of a definitive population are set on high sensitivity to fear in the most populous area of America, how should we be thinking about addressing this in an ongoing way? What happens to these brains when a low-flying 747 and F16 are seen flying too close to the skyline eight years later, and how does this impact gray matter and fear sensitivity? What are the implications of this?

1. It is important to continue to understand brain-related changes in the wake of trauma reminders like the Hudson River crash and now the New York City flyover. We have to keep our fingers on the pulse (and brains) of people who are affected and offer continued supportive services, even years later. Similarly, people who are involved in such traumas should seek help for a longer period to try to reverse these brain changes.

2. We may not be able to feel the impact of these kinds of events because our brains are not wired for sensitivity to these events, the way that downtown New York residents may be. If we think that we're making too much of a big deal of this, we may want to consider that our brains are registering these events differently than those in downtown Manhattan.

3. The heightened sensitivity of brains to fear is an important factor in thinking about a community at large. Fear makes anybody's amygdala light up, but more so if you have been traumatized in the past. This extreme level of activation can disrupt thinking, cause a hypersensitivity to anything that is startling, and also start to affect people who are around.

4. Fear is "contagious". If we are around fear, it can activate the amygdala even when it occurs completely outside our awareness. There are several decision-making bastions of the New York (and international) economy that reside in New York: The UN Headquarters and Wall Street being just two of them. While the UN Headquarters complex is in Midtown, for those who are afraid of the subliminal impact of advertising on the brains of people, what about the subliminal impact of fear? Fear can disrupt attention, affect decision-making and also affect stress levels in significant ways. (In fact, a recent study by Yehuda and colleagues has shown that genes related to the body's stress system are affected in those traumatized by 9/11). These are good reasons for those who have felt especially vulnerable to the 9/11 attacks and subsequent reminders to take care of themselves and continue to reverse disruptive fear processes.

The resilience of people in New York is beyond any doubt. The cultural and architectural growth is staggering. Out of fear and terror, creativity can blossom and people can find themselves filled with a sense of purpose when confronted by their own mortality. But if our research is showing long-term effects of trauma on genes and brains, do we need to change how we are thinking, and broaden our understanding of longer-term interventions and fear-based thinking so that we are not just a sensation-responsive nation but one that recognizes and carefully analyzes the evolving temperament of a nation over time?