Can Synesthesia Be Learned?

synesthesia1In class this week, we have been very curious about the origins of synesthesia. Synesthesia is a condition in which sensory experiences evoke other perceptual experiences that are not typically elicited in most individuals. A common example is seen in individuals who associate specific colors with certain letters or graphemes. We have been asking many questions, including: How much of synesthesia is genetic? How much is dependent on our environment? Is it dependent on exposure to certain features in our culture, possibly during a “critical period”? For example, could a person develop sound to color synesthesia with a limited exposure to sound in childhood?

A study conducted by Bor, Rothen, Schwartzman, Clayton, and Seth (2014) investigated whether or not adults without synesthesia could be trained to acquire these synesthetic experiences. These non-synesthetes were trained to learn 13 specific letter-color associations by engaging in various memory and reading tasks over the course of 9 weeks. After training, participants took a variety of tests used to measure genuine synesthesia, like the color consistency task, the synthetic Stroop task, and a classical conditioning test—and they all “passed” as actually having synesthesia! Days after training, participants showed behavioral and physiological evidence for synesthesia, reporting perceived color experiences for colorless letters. Furthermore, participants were experiencing these strong perceptions inside and outside of the lab setting and across different contexts.

However, participants gained more than these perceptions. Bor et al. (2014) also found that participants who completed training showed an increase in their IQ by an average of 12 points, compared to controls. This suggests that there is something about learning synesthetic links that can result in an enhanced cognitive ability. These results are useful and exciting to explore. It is possible that this training could help individuals at risk for dementia or other diseases that cause cognitive decline.

In Bor et al.’s study (2014), the training was intense and lasted over a period of 9 weeks. However, the researchers note that some participants demonstrated synesthesia after just 5 weeks! So, it seems that there are some aspects of synesthesia that can be learned. The “genuineness” of their synesthesia, however, is under debate. In most participants, this ability faded away over time. This study made me wonder, what else could we learn if we are committed to this sort of training? For example, could we learn other special skills that are present in conditions like Savant Syndrome?

Works Cited

Bor, D., Rothen, N., Schwartzman, D., Clayton, S., & Seth, A. (2014). Adults Can Be Trained to Acquire Synesthetic Experiences. Scientific Reports, 4. doi: 10.1038/srep07089

Exercise, Twins, & the Brain

fat-vs-thin-man-facebook

A recent study in Finland (Rottensteiner, M. et. al., 2014) examined ten pairs of male twins in their twenties who for the past three years had discordance in their physical activity habits. The sets of twins throughout their lives had shared similar levels of physical activity – for example, they played the same sports or went to the gym the same amount. However, mostly because of work or family related commitments one of the twins activity level began to decline. Not only did the researchers find that the active twin had higher cardiorespiratory fitness, lower body fat percentage, and lower insulin resistance but they also found significant brain differences.

MRI scans revealed differences in the nondominant striatum and prefrontal cortex. More specifically, the putamen in the nondominant hemisphere was larger in the active twins compared to their inactive co-twin. This is an interesting finding because previous research has found these areas are associated with physical activity. In addition, the nondominant prefrontal cortex (including the subgyral and inferior frontal gyrus) was larger in active twins. Overall, long-term physical activity has structural effects on adult brains, especially in areas involved with motor control and coordination. The study suggests that even after a short period, twins who no longer share the same amount of exercise can quickly develop differing bodies and brains.

Work Cited:

Reynolds, Gretchen. “One Twin Exercises, the Other Doesn’t.” Well. The New York Times, 04 Mar. 2015. Web. 11 Mar. 2015. <http://well.blogs.nytimes.com/2015/03/04/one-twin-exercises-the-other-doesnt/&gt;.

Rottensteiner, M. et. al., (2014). Physical activity, fitness, glucose homeostasis, and brain morphology in twins. Medicine & Science in Sports & Exercise, 47, 509-518

Image: http://authoritynutrition.com/wp-content/uploads/2014/10/fat-vs-thin-man-facebook.jpg

Figuring Out Phobia

Imagine it’s a hot day and you are standing on the edge of dock, looking down into the cool water below. You want to jump in, but you are suddenly overcome with terror at the thought of being in the water; your heart starts racing, you can barely breathe, you start sweating, and your first instinct is to run back to the safety of shore. This unreasonable fear you have in response to water is likely a phobia, aquaphobia to be exact. Phobias are an extreme and irrational fear when exposed to some specific stimulus like insects, heights, or water. Interestingly, those who suffer from phobias recognize their fear is irrational and there is no real threat of danger, yet they will still avoid any contact with their phobic trigger. This begs the questions, what causes phobias? And what is going on in the brain to cause such extreme reactions to often innocuous objects or situations? With somewhere between 5-13% of Americans experiencing a type of phobia at some point in their lives, the neurological basis of phobias and fear is certainly worth investigating. Here are some of the most common types of phobia that are encountered:

phobiasDM_468x205

 

According to the DSM-IV, there are 4 categories of phobic stimuli; animal, situational, blood injury, and nature-environment. The cause of different types of phobias is still debated though. One well proven theory is that phobias develop as a result of an unpleasant or traumatic experience in childhood. For example, if a child had an unpleasant experience in a confined space, they may develop claustrophobia. Additionally, a child may witness a family member’s phobia and develop the same phobia. Still, it cannot explain how agoraphobia or social phobia arises; the causes of these are still somewhat of a mystery. Some researchers believe the disorder could be a combination of life experience, brain chemistry, and genetics.

So now we have established that one likely cause of phobia is conditioned fear; it is learned through a family member or through a traumatic experience. So what is going on in the brain during this extreme fear response?  A lot of what happens has to do with the amygdala, which triggers the release of “fight or flight” hormones as well as areas in the frontal lobes. The anterior cingulate cortex and the medial prefrontal cortex have been shown to be involved in processing and responding to negative stimuli while the ventromedial prefrontal cortex monitors the amygdala’s response to emotional stimuli or fear. However, in patients suffering from a phobia, these areas appear to function improperly. Here is a map of some of the areas involved:

Ptsd-brain

So, rather than being a system sensitive only to harmful stimuli, the improperly functioning circuits create a fear response to neutral stimuli. As a result, when somebody with a phobia encounters their phobic trigger, the activity in their amygdala spikes. A full on fight or flight reaction occurs even if the stimuli is relatively neutral and harmless.

Want to know more about phobias and the neuroscience of fear? Check out this video!

Sources:

Stein, M. B., Goldin, P. R., Sareen, J., Zorrilla, L. T. E., & Brown, G. G. (2002). Increased amygdala activation to angry and contemptuous faces in generalized social phobia. Archives of general psychiatry, 59(11), 1027-1034.

Larson, C. L., Schaefer, H. S., Siegle, G. J., Jackson, C. A., Anderle, M. J., & Davidson, R. J. (2006). Fear is fast in phobic individuals: amygdala activation in response to fear-relevant stimuli. Biological psychiatry, 60(4), 410-417.

http://www.medicalnewstoday.com/articles/249347.php

http://brainblogger.com/2010/04/22/the-neurobiology-of-social-anxiety-disorder/

The Key to Calm a Crying Baby

Soothing a baby is any mother or caregivers’ ultimate goal when their infant is crying. Babies’ universal indication of any concern, distress, pain, hunger, or desire is communicated by crying; parents endlessly attempt comforting techniques to relieve their helpless infant. A common response is for a mother to immediately pick the crying baby up and rock or walk with them gently in her arms (Gammie, 2013). Often times, the helpless infant nearly instantly stops or reduces their cries; however, as soon as their mother again puts the baby down, often the cries once again ensue. This recurring pattern exemplifies the elicited automatic calming response that infants exhibit in response to being carried. This comforting mechanism is not selective to human parents exclusively, this dynamic interaction is a comforting method utilized by parents of various mammalian species.

Various other mammals, such as felines and rodents demonstrates what is called the “transport response” in which the crying young assumes an immobile posture while their mother transports them (Esposito et al., 2013). Often the response is relieved stress exhibited by reduced vocal cries. This dynamic “transport response” is also seen in species of mouth-carrying primates (galagos); how is this transport response translated to humans and what is happening in the brain to activate this soothing response?

One study at the RIKEN Brain Science Institute in Saitama, Japan explored the infant physiological responses to their mothers, aiming to further examine this effective coddling parent technique. More specifically, the response of infants under the age of 6 months was examined as their mothers’ exhibited different behaviors. This study examined the behavior, vocalization, and electrocardiogram of infants during three experimental conditions: lying in a crib, being held by their mother in a stationary crib, and being carried by their mother as she walked continuously. In comparison to being in their crib, both being held by a stationary mother, as well as being carried by a walking mother exhibited decreased voluntary movement, vocalization, as well as a rapidly declining heart rate; a similar pattern of results was shown between infants being held by a stationary mother and infants being carried by a walking mother. These results showed that physical contact from the mother elicits comfort in the infant; mobile transport combined with physical contact elicits even greater comfort.

What is happening neurologically to produce such calming responses, as exhibited both physiologically and behaviorally? Exhibited by infants in this study, heart rate analysis identified differences in parasympathetic activity based on interbeat measurements; increased duration of interbeat index measurements within the infants being carried by a walking mother indicated that infants were more relaxed. Previous research suggests that maternal physical touch combined with rocking motion provides vestibular-proprioceptive stimulation; these results suggest that walking movement has a similar stimulating mechanism, resulting in heightened calming effects on infants. Furthermore, maternal walking provides infants with calming sensory inputs in a synergic manner, eliciting possibly the most effective calming response (Esposito et al., 2013).

Works Cited:

Esposito, G., Yoshida, S., Ohnishi, R., Tsuneoka, Y., del Carmen Rostagno, M., Yokota, S., … & Kuroda, K. O. (2013). Infant calming responses during maternal carrying in humans and mice. Current Biology, 23, 739-745.

Gammie, S. C. (2013). Mother–Infant Communication: Carrying Understanding to a New Level. Current Biology, 23, R341-R343.

 

Why Do We Prefer Certain Colors?

Red_Green_Blue

After a broad introduction to synesthesia this week, it prompted me to think about color and specifically why people have a preference for a certain color or colors. Why does my favorite color happen to be red? Everyone has a difference preference for colors, which is interesting and unique. We choose colors when we choose clothes, a car, a notebook, and a water bottle; basically color is taken into consideration for almost everything we buy! We pick most things based on colors we like so why is this? There isn’t really a rational influence to our decisions other than the color evokes an emotional and physiological response in us. Ultimately we decide what colors we like because of what we associate them with and the meaning that accompanies them.

In 2007, a study was conducted by Ai Yoto to investigate the physiological effects of color stimuli on the brain. They measured the effects of color in terms of blood pressure and electroencephalogram results when subjects would look at a sheet of paper that was either red, green, or blue in a random order. Additionally, they incorporated a questionnaire to assess psychological effects. The colors showed distinctly different effects on the alpha and theta bandwidth within the EEG. The questionnaire indicated significant differences between red and blue conditions. Blue elicited a stronger arousal than red did as expressed by the results of the mean power of the alpha band in the attenuation coefficient. The bandwidth measured by the EEG showed larger values while the subjects looked at red paper. They concluded that red possibly elicited an anxiety state and therefore caused a higher level of brain activity in the areas of perception and attention as opposed to the color blue. The red paper’s effect to activate the central cortical region with regard to perception and attention was more distinguishable than the biological activating effect of blue in the study (Yoto, A et. al., 2007).

Another study conducted in 2000 by Thomas Madden, Kelly Hewett and Martin Roth looked at the impact of color cross culturally and how this correlated with meanings and preferences. Through their research they explored these preferences and meanings from respondents of eight countries who evaluated ten colors. The respondents rated the colors with an association of meaning and how much they liked the color and what color combinations they preferred. Their results showed that the colors blue, green, and white were all rated fairly high across countries and shared similar meanings. Black and red also received high liking ratings but their meanings varied. When relating this to consumers, it shows that in many parts of the world consumers have similarities in color liking and color meaning associations. They associate red with Coca-Cola, blue with IBM, and green and white with Canada Dry ginger ale. The differences across nationalities would explain the image perception of the brands and companies due to their regional location and presence of the brand. It is important to take color into account and their results suggest that color can be a valuable, controllable marketing variable for managing image standardization (Madden et al., 2000).

These studies help to show that color does evoke a physiological arousal within us and can show that we have specific preferences and associations for color. We choose certain brands because we have learned to associate them with a color and a meaning due to our environment and society.

Research Articles:

Madden, T. J., Hewett, K., & Roth, M. S. (2000). Managing images in different cultures: A cross-national study of color meanings and preferences. Journal of International Marketing, 8(4), 90-107.

Yoto, A., Katsuura, T., Iwanaga, K., & Shimomura, Y. (2007). Effects of object color stimuli on human brain activities in perception and attention referred to EEG alpha band response. Journal of Physiological Anthropology, 26(3), 373-379.

 

Today Human, Tomorrow machine

The Cyborg, short for cybernetic organism has always captured the minds of futurists and Trekkies, , and are portrayed as a combination of fictional character/ being of tomorrow.  But are we about to stumble into tomorrow; are cyborgs all that fantastical? Kevin Warwick, hailed as “Captain Cyborg” argues that we have already stepped into the age of the cyborg using himself as an example. In 2002, Warwick had a small chip surgically inserted into the median nerve fibers in his left wrist.  Post-surgery, Warwick could control an artificial mechanical hand and electric wheelchair.  However, Warwick could not only produce signals, but receive signals from the small micro array in his arm creating an artificial sensation.  A similar microarray was inserted into his wife’s hand, so he would sense when her hand was gripped, or being shaken.

Warwick wants to redesign communication so that we are not relying on sound waves (talking on the phone, or conversing with someone) to communicate with someone, instead he believes the next stage of human communication evolution will be a sort of telepathy through microarrays such as the one implanted in his arm.

In another of Warwick’s quirky experiments, he integrated Rat neurons onto a circuit board that was attached to a small robot, roughly the size of a toycar.  The rat-bot navigated a space with obstacles in it, avoiding and turning when it came across anything obstructing its path.  Electrical signals relayed to the neurons are then interpreted and commands are sent out to the device.  The neurons can reorganize so the rat-bot  improves its ability to avoid walls; effectively the rat-bot is learning about its environment and how to use its “body’ more efficiently.

Warwick’s work and research could has biomedical benefits and work regulating Parkinson’s syndrome is currently underway.  However, ethical questions arise as the neuron cultures get larger and the mechanical systems more complicated.  Not to fall back on science fiction, but what about the bi-directional really of information that Warwick mentioned concerning his arm implant.  If a circuit board complex enough, and “intelligent” to a certain point, integrated into the human nervous system, could it possibly overpower the brain?  Additionally, out of curiosity what would it feel like to have a novel sensation that was not produced by your boday, but a piece of computer hardware.  Warwick’s work is promising and exciting, and we look forward to seeing what he decides to implant next into his body.

Works consulted

“Innovation Isn’t Safe: The Future According To Kevin Warwick.” Forbes. Forbes Magazine, n.d. Web. 13 Mar. 2015.
“Kevin Warwick – Home Page.” Kevin Warwick – Home Page. N.p., n.d. Web. 13 Mar. 2015.
“Kevin Warwick, Once a Cyborg, Now Prophet of the Man-Machine Future.” Singularity HUB. N.p., 09 Mar. 2010. Web. 13 Mar. 2015.
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