Oct 1 2013

Ready to be tested?

How does the brain work? Using real and fictional characters to setup a story framework, I write about the science of the human (and sometimes animal) mind. I am a journalist rather than a neuroscientist so my approach is exploratory.

Click here to take a 10-question quiz which covers some of the topics I have discussed in my articles. To explore the subjects further, use the site search form (on the right) to find the relevant articles by using keywords from the questions and answers (e.g. enter “turmeric in the search engine to learn more about question #4).

Jul 1 2013

The BRAIN

“Why a map, Mom?”

“Well, how do people normally use a map?”

“To get oriented to a place and to use that to find their way around.” Brian thinks for a minute. “So, it’s to understand where neurons are located inside the brain and how they are connected?” He pauses. “But don’t neuroscientists and neurosurgeons already know the locations and the connections?”

“They do but the brain has more than one billion neurons–” his mom says.

“–and several trillion neural connections or roads, you can say. Wait, are the neurotransmitters like roads or like cars? I guess they are like cars.”

His mom smiles. “That’s a close analogy. How do you think they will use the map?”

Brian scratches his chin.

“There are many diseases like Alzheimer’s or Parkinsons that we don’t fully understand,” his mom says. “ Obama’s BRAIN (Brain Research through Advancing Innovative Neurotechnologies) initiative will help them develop tools that can be used to not only map the brain but to understand how the neurons behave. So, it’s not just about creating a more detailed map but it’s also about getting a dynamic view of the stuff that happens in the brain.”

“But, how, how exactly? How will they capture the messages, the path traversed by the neurotransmitters, the messengers of the brain? I mean, that’s not a static thing…”

“Good point. The current studies use fMRI technologies to measure blood flow in specific parts of the brain. This helps them locate the place where neurotransmitters are active.”

“Yes, I know that!”

“Well, the idea of BRAIN is to provide funding to create more sophisticated tools than the fMRI, to see both high-level view of the neurons and their activities and to get a more close-up view—“

“—yeah, I get it.” He says impatiently. “But how is it different than the research already happening?”

“It’s not necessarily different. It’ll build on the existing work and provide additional resources.”

“Ah, so we can learn about the brain faster.”

“Yup.”

“Mom, maybe I can get involved with the BRAIN initiative.”

“Yes, it’s a new thing. So, there will be all types of opportunities if the funding continues. But, first if you have to get qualified by studying neuroscience.”

“Maybe I can become a brain surgeon!”

“Sure, but that means you will learn and use what is already known about the brain. You won’t be making new discoveries. So you won’t be part of BRAIN.”

“So, a neuroscientist then?”

“Yes, or both,” his mom says.

“I can be like Oliver Sacks and be a brain-surgeon and a neuroscientist and a neuroscience writer.”

“Yes, you can be. But first, start exercising your brain on the math homework that’s due tomorrow.”

“Yes Mom.”

Leena Prasad has a writing portfolio at http://FishRidingABike.com. Links to earlier stories in her monthly column can be found at http://WhoseBrainIsIt.com.

Josh Buchanan, a UC Berkeley graduate, edits this column with an eye on grammar and scientific approach.

References:

Flatow, Ira, host of President Obama Calls for a BRAIN Initiative, NPR>Science>Research News, April 5, 2013, http://www.npr.org/2013/04/05/176339688/president-obama-calls-for-a-brain-initiative
Neuroscientists Weigh In on Obama’s BRAIN Initiative, Scientific American, May 2, 2013, http://www.scientificamerican.com/article.cfm?id=neuroscientists-weigh-in-obamas-brain-initiative

Nov 13 2012

Red vs. Blue

topic	politics
region	amygdala, ACC

“…My plan will continue to reduce the carbon pollution that is heating our planet – because climate change is not a hoax. More droughts and floods and wildfires are not a joke. They are a threat to our children’s future. And in this election you can do something about it,” said Barack Obama. On the contrary, Mitt Romney said, “I’m not in this race to slow the rise of the oceans or to heal the planet.”

President Obama and Governor Romney’s views represent those of their constituency. According to a 2011 Gallup poll, 70% of Democrats “Worry a great deal / fair amount” about climate change, as opposed to only 31% of Republicans. This difference in the Democratic and Republican belief systems can have significant policy impacts regarding climate change.

From a scientific perspective, some of the general differences between Democrats/liberals and Republicans/conservatives can be observed in the workings of the brain. Much of the neuroscience research, however, that has been done in this area is inconclusive, and the results are controversial. This article is not an exploration into the why or how these differences formed but it is an explanation of the differences that were discovered amongst the representative samples of subjects who self-identified as Republicans or Democrats or conservative or liberal.

A study conducted at University College of London in 2010 concluded that conservatives have a larger amygdala than liberals. The amygdala is responsible for emotional reactions that activate the fight-or-flight response. Other parts of the brain often moderate the primitive survival instincts of the amygdala and guide human behavior. The methods used for the study and the results are highly controversial and have not passed the scientific rigor of replication and peer review. Furthermore, there is no scientific correlation between the size and activity of the amygdala.

There are other studies, however, which found differences that have been replicated by many scientists. A consortium of scientists based in San Diego, discovered that when participating in risk-taking behavior, Republicans show a higher level of activity in the amygdala than Democrats. Democrats, on the other hand, show higher activity in the Anterior Cingulate Cortex (ACC) when presented with the same risk-taking tasks. The ACC is involved in many functions, both cognitive and emotional, but one of its primary jobs is to resolve conflict. A study published in Nature Neuroscience also describes higher activity in the ACC when liberals made a mistake in pattern recognition. They were able to correct the mistake and improve performance at a faster pace than their conservative counterparts.

Other parts of the brain are also involved in processing information and issues on the political spectrum. As such, these differences are not sufficient to pinpoint brain dynamics. More extensive studies are required to both understand the differences and the means for communication with brains that exhibit these differences.

For now, how do we negotiate the differences in the belief systems and find a common ground? That’s beyond the scope of this article. But, understanding some of the differences in brain structure can at least provide an insight that the differences are hardwired in the brain. There are many studies that demonstrate that brain chemistry can be changed. This means that communication and negotiation can serve a useful purpose. If Mitt Romney and President Obama cannot agree, perhaps they can find a way to talk to each other and negotiate differences with a common goal of creating a harmonious existence for all Americans.

Upcoming…

December: neuroplasticity, the brain’s ability to change

January: food for thought, i.e., the affect of food on your brain

Leena Prasad has a writing portfolio at http://FishRidingABike.com and a journalism degree from Stanford University. Links to earlier stories in her monthly column can be found at http://WhoseBrainIsIt.com.

Dr. Nicola Wolfe is a neuroscience consultant for this column. She earned her Ph.D. in Clinical Psychopharmacology from Harvard University and has taught neuroscience courses for over 20 years at various universities.

References:

1. Darren Schreiber, et al. Red Brain, Blue Brain: Evaluative Processes Differ in Democrats and Republicans, Emerging Politics, 2009, [http://www.politicsemerging.com/Publications/RedBrainBlueBrain.pdf]

2. David M. Amodio et al. Neurocognitive correlates of liberalism and conservatism, Nature Neuroscience, September 9, 2007.

3. Mooney, Chris. The Republican Brain: The Science of Why They Deny Science–and Reality. John Wiley and Sons.

4. Mitt Romney’s Climate Change Remarks On ‘Meet The Press’ Outrage Environmental Activists, Huffington Post, Sep. 10, 2012

5. Obama Counterpunches on Climate Change, New York Times, Sep 7, 2012

6. In U.S., Concerns About Global Warming Stable at Lower Level, Gallup Poll, March 14, 2011[http://www.gallup.com/poll/146606/Concerns-Global-Warming-Stable-Lower-Levels.aspx].

Oct 4 2012

Rachael’s Defenses

topic	racism
region	amygdala, pre-frontal cortex, temporal lobe
chemicals	cortisol

This article’s primary objective is the neurobiology of the brain and not the evolutionary, psychological, and social influences that might have formed the particular brain chemistry.

Rachael walks into the dimly lit bar and scans the faces to locate her friend. Priya is not here yet. She recognizes a guy at the bar as someone she has seen before. She stares at him a little too long, so he looks up at her. But there is no sign of recognition in his face and he looks away.

“Rachael?”

A black man, whom she does not recognize, walks towards her. Rachael pulls at a handful of her blonde hair with a nervous tug. Her heart races slightly and her palms are a bit sweaty. She smiles and says hello. The guy, Paul, tells her that they have met before. Oh, right, she remembers, she says, but she does not recognize him.

Rachael has seen Paul more often than she has seen the guy at the bar. Why does she recognize him but not Paul? There can be many factors for this discrepancy, but one of them can be a biological one. The man at the bar is white. Rachael is white. Neurosurgeon Alexandra Golby conducted a study in which she discovered that the face recognition areas in the temporal lobe are more active when people see someone of their own race. This higher activity leads to higher recall of the faces of people of their own race. Rachael’s brain is not unique in making this discrimination.

Why does her heart race when she sees Paul? This is a slightly racist response to seeing a black man she does not recognize. But it is not a conscious one. According to studies, many white people (most of the studies have been performed on white people) show an increased activity in the amygdala when they see a black face. The degree of response varies from person to person and the intensity of the response can be matched to the degree to which the person is a racist. The racing of her heart is triggered by the higher activity in her amygdala, the area of that brain that responds to fear by activating the fight-or-flight response and places the body in a stress mode.

Priya walks in to the bar and goes towards the guy at the bar. Paul leaves Rachael and goes up to Priya and gives her a hug. Priya’s amygdala activity stays the same when she interacts with Paul or Rachael or anyone else of any race. Her mother is Japanese and her father is from Palestine. She has had an early start in being comfortable with people of different races. Environmental factors contribute significantly to a person’s racist attitudes and thus in forming the chemical patterns of their brain. This is a positive indication that racist attitudes can be changed at the biological level.

Paul is happy to get away from Rachael. She fails to recognize him despite having had several conversations with him and he feels tense around her. Her body language is aloof towards him. It could be that she does not like him but he is starting to sense that perhaps it has to do with his race. Paul is right and Rachael does have racist tendencies even though she is not a racist, per se. She has friends of other races but she is most comfortable with people of her own race and exhibits other prejudiced characteristics. Rachael’s racist response to Paul raises the cortisol, the stress hormones, in both their bodies. Thus, her response not only hurts Paul but also harms her.

If not managed properly, issues of racism can lead to unpleasant results not only for the victims but for the racist herself. If Rachael continues to think and behave in her current mode, she is setting herself up for a future of stress leading to health problems. In order to change her automatic racist responses, she will first need to become more aware of her responses and consciously work on changing them.

What can she do to change her biological response? There is another part of the brain which is also activated when a white person sees a black face. The prefrontal cortex, the region that manages information and puts a brake on the emotional responses of the amygdala, is also activated when study participants respond to a black face. This part of the brain, located in the anterior part of the frontal lobe, is involved in learning and behavior control. Thus, conscious efforts made by a person to change their behavior can train the pre-frontal cortex to manage the amygdala-responses more effectively, and thus minimize the cortisol and any other potential side effects of racism.

Rachael does not need to know the inner workings of her brain to effect change. She just needs to understand that her behavior is counterproductive not just towards herself but towards society in general. This understanding could lead to healthier brain chemistry and a better life for herself and for others around her.

References:

1. Smith, Jeremy A., Marsh, J., & Mendoza-Denton, R., Are We Born Racist? Beacon Press 2010.

2. Zimmer, Carl., This is your brain on racism. Or is that liberal guilt?, Discover Magazine, November 18, 2003

3. Miller EK, Freedman DJ, Wallis JD. The prefrontal cortex: Categories, concepts and cognition. Philos Trans R Soc Lond B Biol Sci. 2002;357:1123–1136. [http://www.ncbi.nlm.nih.gov/pubmed/12217179]

Jun 2 2012

Stop, thief!

topic	Anger
organ	amygdala
chemicals	adrenaline, dopamine, serotonin

The vibrant colors of the murals in Clarion Alley in San Francisco awaken my senses. The twilight is perfect for capturing the mood via photographs.

I finish planning a composition and am about to click when a man on a bike rides by and snatches the camera from my hand. For a few split seconds, I do not comprehend or accept what has just happened. Then I start to scream: He stole my camera! He stole my camera!

I feel violated. I have several months of photographs in that camera. My camera!

I run after him, screaming, as he turns right onto Mission Street. I realize that I have lost my photos and will not be getting them back but I am unable to accept this fact. I continue to scream. Then a strange and unexpected series of events occur.

The man who has stolen my camera comes back into the alley on foot. He holds up the camera as if he is going to give it back to me. I reach for it, unsure as to what is going on. He runs with the camera tightly held within his large hand. What happened to his bicycle, I wonder but I do not have time to consider this. He is running now in the opposite direction from Mission and towards Valencia Street. He is running towards the Mission Police Station! I doubt that he realizes this, however.

I start screaming at the top of my lungs and run after him. I am not saying anything this time. I am simply making a deep guttural sound, primitive language-independent screams of distress.

A policeman on a bike rides by me and asks what happened. He is headed from Mission to Valencia, the same direction as the thief. I tell him and he rides after the thief, who has already disappeared around the corner on Valencia. Another policeman on a bike also chases after the thief. I wonder if this might be why the thief has abandoned his bike, to perhaps find a route that does not allow a bike passage. Or, perhaps his bike is stolen also.

Then I hear sirens.

I slow down and start walking instead of running. I am out of breath and feeling calmer. A group of people walk towards me “You are lucky, they got him,” one of them says.

Why do I react with so much aggression and without any consideration for my safety?

Surprise or fear can trigger an adrenaline rush. The quantity of the adrenaline released and thus the degree of reaction is determined by chemical factors. A low quantity of the “happy” neurotransmitters dopamine and serotonin in the brain triggers a higher degree of adrenaline production. In other words, the less happy the brain, the higher the level of adrenaline it produces.

When the thief ripped the camera from my hand, my adrenaline level probably shot up. The level of adrenaline might have been exacerbated even further by the fact that I was in an unhappy mood. I had left my apartment a few hours ago in an angry mood because I was upset with my boyfriend. This would have resulted in a depletion of dopamine and serotonin.

In a different state of mind, would I have screamed less and potentially let the thief get away? Or would I have not made the primitive guttural sounds that, in retrospect, seem to be an over-reaction to the loss of some photos, as precious as they might have been.

Low dopamine and serotonin and high adrenaline do not activate a response but only contribute to the activation. The response is activated in the limbic system specifically in the amygdala. The amygdala is one of the major organs responsible for the perception of threat and for triggering an emotional response. It can hijack the potentially rational responses from other parts of the brain and cause irrational reactions. In my case, I did not consider my own safety because I was furious that my personal space and property had been violated.

Later that day, when I am in the Police Station talking into a tape recorder and going through the story of what has happened, the police inspector asks me if I want to press charges.

“It’s wrong to steal and he should be punished. But he must have been really desperate to want to steal a camera,” my thoughts tumble out of my mouth. I decide not to press charges. Technically, it is not my decision because the district attorney will press charges anyway because the man was arrested. I did not know this at the time, however, and despite my conflict, I made a decision to not punish the thief any more than he had already been punished.

Perhaps I was being kinder because the dopamine and serotonin levels in my brain had surged back up when I found out that justice had been done and that I would get my camera back. Also, my boyfriend came to the police station and held my hand and kept me company while the inspector was talking to me. His presence might have contributed to the raised levels of the “feel good” hormones.

This is all hypothetical, of course, based on my knowledge of neuroscience and research on the neuropathy of anger. I would have had to be hooked up to an fMRI (functional magnetic resonance imager) to prove my hypothesis about the actions of the amygdala and the levels of adrenaline, serotonin, and dopamine in my brain. Nonetheless, it is fun to try to guess the biological triggers for my actions when confronted with a “fight or flight” situation.

References:

Dr. Goulston, Mark,Usable Insight, The Neuroscience of Anger, Monday, April 18th, 2011, http://markgoulston.com/usable-insight-the-neuroscience-of-anger/

May 3 2012

May 2012: bi-polar

Ben has disappeared suddenly and his girlfriend Paula is feeling anxious. He has sent an email, however, to say that he is okay and will get in touch with her soon. She calls up Ben’s sister Sonia to try to understand what’s going on with him. Read more at Whose Brain Is It? column published in Synchronous Chaos magazine.

Nov 1 2011

We got sold out

topic

Money & Fear

Banks got bailed out
We got sold out!

Frida rolls down her car window. Hundreds of people are chanting, moving towards her. Not exactly towards her but she’s in a car going east on Mission Street and they are walking in the opposite lane. Motor vehicle traffic is at a standstill.

Ah, the Wall Street occupation of New York City has moved here, she thinks.

Whose streets?
Our Streets!

The people in the street chant, as if responding to her thoughts. She meets the gaze of one of the protestors. Suddenly she feels uncomfortable in her black 2011 BMW.

She panics. Frida is reacting to what she perceives as a threat to her current lifestyle, as if the people protesting on the street are going to take away what she has worked hard to achieve.

Her mind flashes back to a decade ago. Her college scholarship funding has fallen through. Her single mom works two jobs and does not have the money to pay the high tuition and expenses for the private college that she plans to attend. Frida spends the next two years working and taking out a loan to pay for college. Life at college is difficult. She is older than the other students and doesn’t have the free-flowing funds that they seem to have. Her social life is limited. Instead of enjoying college life, she is anxious to graduate with a business degree and start a new life, hopefully with one of the top business-consulting firms.

Her heart is beating faster. Her hands are clammy as she holds the steering wheel tighter.

Fear is a natural reaction to the potential threat to one’s safety. It can cause the fight or flight response leading to anxiety. This is what is happening to Frida.

The perception of danger is handled by many parts of the brain but the amygdala, a part of the limbic system of the brain, is the chief operator in initiating the fight or flight response. In Frida’s situation, fear perception leads the amygdala to send a danger message to the anterior nucleus of the hypothalamus, another part of the limbic system.

The hypothalamus manages a wide range of basic biological functions and metabolic reactions. For Frida, it initiates a chain reaction of chemicals which leads to the activation of the sympathetic nervous system. The sympathetic nervous system produces a surge of the hormone adrenaline. Frida’s heart is racing and her hands are clammy. This tension is caused by the excess adrenaline in her bloodstream.

She notices a large sign “We are the 99%.”

Frida’s hands relax on the steering wheel. She realizes that she is also in the ninety-nine percentage. This is not about semi-wealthy people like herself but about the top one percentage who own a majority of the wealth in the United States. She takes a deep breath and starts to calm down. The level of adrenaline in her bloodstream is not going up anymore. She turns on the radio and flips to her favorite classical music station. The music distracts her from here stress and sympathetic arousal, helping her to access other brain regions to restore a non-stressful state.

Links to past columns are available at WhoseBrainIsIt.com and Leena’s writing portfolio is available at FishRidingABike.com. Leena has a journalism degree from Stanford University.

Dr. Nicola Wolfe is the neuroscience consultant for this column. She earned her Ph.D. in Clinical Psychopharmacology from Harvard University and has taught neuroscience courses for over 20 years at various universities.

References for this article: Dr. Wolfe’s Neuroscience class at Berkeley extension, InnovationMagazine.com, ScholarPedia.org

Sep 1 2011

Mental Movies

topic	memory
region	Amygdala, hippocampus

She turns on the CD player in her car and “When I’m 64” streams out over the speakers. Mona starts to cry. She is on Highway 280, driving down to Palo Alto to see her brother Michael. She’s flooded by memories of her childhood with Michael. She can hear his voice and visualize him singing the song when he was 9 or 10 years old. Michael has been in a car accident and has been in a coma for several weeks. It all seems hard to believe. He’s only 24. How can this be happening?

Mel is walking around in the grocery store. He sees a ripe yellow mango with red spots on the top. He picks it up and sniffs it. “Singaporean,” he can hear his ex-girlfriend’s voice say. He can visualize her eating the mango, the juices running down her mouth as she bites into the skin. He wonders what she is doing now. Perhaps she is eating one of these; he thinks and puts it in his grocery cart.

Mina passes by Dosa on Valencia Street. She remembers the time she went in there with her aunt, who was visiting from India. She remembers that day and how much fun it was to have dosa in her own neighborhood with her favorite aunt from India.

It’s not difficult to guess that the music, the scent, the visual cues produce emotional reactions in the brain of these people. But, what exactly happens in the brain when we store and retrieve a memory?

“What seems to happen is that a piece of familiar music serves as a soundtrack for a mental movie that starts playing in our head,” according to Petr Janata, a cognitive neuroscientist at University of California, Davis. “It calls back memories of a particular person or place, and you might all of a sudden see that person’s face in your mind’s eye.”

Familiar with studies of brain areas activated during recall of autobiographical stories, Janata theorized that the brain area behind the forehead is responsible for recalling memories associated with music. This area is called the medial pre-frontal cortex. He conducted a study in which he had college students listen to top-40 music when the students would have been between the ages of 8-18. Using fMRI brain scan, he noted the music was associated with mental activity spikes in the medial pre-frontal cortex of the subjects’ brain. The subjects later wrote down the memories recalled by the music.The vividness of the memory recalled was proportional to the intensity of activity in the medial pre-frontal cortex.

This area of the brain is just one of the many areas involved in long-term memory and one of the areas associated with Mona’s recall of her childhood memories of her brother.

The hippocampus, a tiny structure that resembles a sea horse and curls near the center of the brain, is one of the primary regions involved in orchestrating the storage of information from short-term memory to long-term memory. As Mona and her brother listen to “The Beatles” and their eyes and ears register the event, the hippocampus harmonizes the visual and auditory sensations into one “event”. The event is stored as a pattern of biochemical changes in nerve cell networks. Later the hippocampus will manage the retrieval and re-play of the event.

Over time and with repetitions of the stored events in the brain, other parts of the brain eventually do not need the hippocampus to manage them and can recall the information on their own. In Mona’s case and in the case of the college students in the experiment, the memory has been in the brain for so long that the hippocampus is probably no longer required to manage the recall. Depending on how long ago it was that Mel’s ex-girlfriend told him about the Singaporean mango and how often he has replayed that memory in his head, his hippocampus might or might not still be involved in recalling this memory. Same applies to Mina’s memories of her aunt.

All the memories presented here (Mona’s of her brother, Mel’s of his ex-girlfriend, and Mina’s of her aunt) have emotional context. This suggests the involvement of a region of the brain called the limbic system and one particular organ called the amygdala. Often referred to as amygdala, there are actually two of them in the brain. They are almond shaped with a diameter of about an inch but the size can vary from person to person. The amygdala assists in deciding as to whether an experience has emotional significance and prioritizes the event in terms of importance for storing in long-term memory.

The memories discussed here are all associated with storage of emotionally significant events. In each of these three examples the memory can be triggered by sensual clues: the sound of the music, the feel and smell of a mango, the taste of Indian dosa. Mona and her brother listen to music as he sings the lyrics and they both activate their auditory senses. Mel’s girlfriend picks out a mango and tells him about it. He smells it. Later, she eats it in a way that’s unfamiliar to him, without peeling and cutting it. His auditory and olfactory senses are activated. Mina has an enjoyable dinner with her aunt. Her olfactory senses are activated and so are her taste buds. In all these case, the visual senses are also activated. The combination of activities creates an event that is prioritized by the amygdala and managed by the hippocampus for storage in long-term memory. Later, the network of brain cells in various locations in the brain will synchronize to retrieve the memory.

Although there have been tremendous advances in the biochemistry and anatomy of long-term memory, much remains unknown. There is a strong indication, however, that it’s the result of team-work amongst complex networks of nerve cells and organs that provides human beings with the ability to replay events from their life based on retrieval cues that are picked up by the senses.

References for this article: http://www.livescience.com, http://www.thebrain.mcgill.ca, Dr. Wolfe’s Behavioral Psychology class at Berkeley extension.