Tuesday, June 29, 2010

Are we conscious or unconscious consumers?

What if I put you in a brain scanner for a few minutes and told you to stare at a black square, then I looked at your neural activity, and then I told you: “You might as well stop fighting those hidden urges. Go out and splurge on that 77’ Pinto station wagon you’ve wanted all these years.”

Would you glare at me as if I were some kind of mad scientist turned psychic-wannabe? Or would you nod in embarrassment because you read about a study that was recently published in the Journal of Neuroscience showing that your neural responses to unattended products determine what you want to buy?

In the study, John-Dylan Haynes and colleagues examined brain regions that were activated with fMRI in two groups of male subjects who participated in different visual tasks. In the first group, 17 participants had their brains scanned as they viewed images of cars while actively evaluating and rating each car’s attractiveness. In the second group, 15 participants were scanned as they engaged in a visual fixation task while images of cars popped up on the screen outside their focus of attention. After scanning, the subjects were asked whether they were willing to purchase each car that was shown to them. The researchers found that decisions about purchasing could be predicted by brain activity equally well in both groups of subjects.

The results suggest that our brains may unconsciously evaluate products when we’re not attending to them. This is quite interesting as the study provides insights to consciousness and decision-making. Proponents of neuromarketing have been circulating and praising this study because they suggest it brings us closer to using fMRI to study advertising and marketing strategies (a topic I previously wrote about).

However, the study doesn’t necessarily show that our decisions are influenced by unattended, subliminal stimuli. Instead it might show that we re-evaluate unconscious images that are images we have already consciously evaluated. In fact, the subjects in the study reported that before the experiment they were familiar with 85-87% of the cars they were shown. We can’t conclude, then, that flashing products as in subliminal advertising affects our buying choices.

So how does this study help neuromarketing? New Scientist reports that Haynes says this kind of approach might be particularly useful for inferring people's opinions of products they would be reluctant to admit to buying (although he emphasises that he is unwilling to promote neuromarketing for this purpose).

It still remains to be seen, however, whether fMRI can reveal hidden information that cannot be determined from conventional marketing surveys. Perhaps Haynes’ study contributes more to our understanding of consciousness and decision-making than it does to our understanding of selling products.

Tusche A, Bode S, & Haynes JD (2010). Neural responses to unattended products predict later consumer choices. The Journal of neuroscience : the official journal of the Society for Neuroscience, 30 (23), 8024-31 PMID: 20534850

Sunday, June 20, 2010

Do video games enhance cognitive abilities?

In my last post, I discussed a debate that is going on over whether using the internet is good or bad for the brain. Those who argue against apparently harmful effects of the internet often cite studies that suggest playing video games actually enhances certain cognitive abilities. How compelling is the evidence for these purported benefits?

Well if you search the research literature, you will find a large number of studies (some in very high-impact journals) suggesting that regular video game players indeed have demonstrated a number of cognitive benefits relative to non-video game players. These include improved eye-hand coordination, visual attention, spatial abilities, visual acuity, and ability to simultaneously track multiple moving visual items. Moreover, some studies suggest that when non-video game players are trained with action video games for a relatively short period of time, they show a gain in some of the aforementioned cognitive functions.  

Let’s take a look at a recent study that examined the possibility of yet another cognitive benefit for video game players. Sarah Donohue and colleagues at Duke University assessed whether gamers demonstrate enhanced ‘multisensory processing abilities,’ which can be explained as abilities to properly integrate information from more than one sense. For example, if you’ve ever watched a badly dubbed movie in which the sound is misaligned with the video, you’ve experienced a conflict between vision and audition. What Donohue and the researchers essentially asked is: are action video game players better at identifying these sorts of multisensory conflicts than non-video game players?

The subjects in this study were all male, as the researchers had a difficult time finding females with extensive gaming experience. 18 young adults who regularly play video games such as first-person shooters, real-time strategy and sports games were compared to 18 individuals who don’t play video games at all on a test of visual-auditory multisensory processing abilities. By presenting visual and auditory stimuli either in synchrony or offset in time on a computer screen and speakers, it was found that gamers were better at identifying when sounds and pictures were presented in synchrony or asynchrony. Subjects who played the most video games scored the best on these tests.

The findings make sense, as in video games such as first-person shooters, players integrate auditory cues with visual cues to make sure they don’t get shot when they turn a corner. I would guess that gamers who play with high-quality sound and graphic systems would enjoy exaggerated benefits of these kinds.

This study has added to the growing body of literature on positive cognitive effects of video games. So perhaps technology is not all bad for the brain. This is not to suggest that video games are purely good for you, and the more you play the better off you are in life. But we at least have evidence that all those hours of game time are not necessarily a complete waste. Now if only people started doing similar studies on avid internet users versus non-internet users (there are some studies on this, but they are notoriously few in quantity)...

As for video games, the take-home message is clear: we should all be spending more money on better televisions, graphic cards, video game systems, and sound systems, and we should be encouraging girls to join in and reap the cognitive benefits.

ResearchBlogging.orgDonohue SE, Woldorff MG, & Mitroff SR (2010). Video game players show more precise multisensory temporal processing abilities. Attention, perception & psychophysics, 72 (4), 1120-9 PMID: 20436205

Sunday, June 13, 2010

The internet: good or bad for the brain?

There has been a lot of talk in recent weeks about the effects of technology on the brain. The New York Times has published a series of articles called “Your Brain on Computers,” which features interviews with neuroscientists as well as stories of people who are so “addicted” to the internet that it’s adversely affecting their family life and parenting habits. Furthermore, Nicholas Carr’s new book The Shallows: What the Internet is Doing to Our Brains was just released, and its ideas have sparked some interesting debates.

While some agree with Carr’s thesis that information overload and multitasking habits encouraged by internet use are bad for the brain, others contend that we are actually smarter as individuals because of the internet. Arguments against Carr have come from prominent thinkers Steven Pinker and Jonah Lehrer; Carr’s responses to some of their arguments can be found here.

I won’t summarize the arguments of either side of the debate, but I will make the following conclusions after reading through the material:

There are probably both positive and negative effects of internet use on the brain. To claim that using the internet is purely good or purely bad for you is to ignore the complexity of the issue, to ignore the complexity of the brain. Whether the internet is helpful or harmful depends on how you’re using it and what you’re using it for. We should be wary of the media when we read about “internet addiction” as if it shares features with drug addiction. Likewise, we should put on our skeptic goggles when we hear that internet use improves particular cognitive abilities that haven’t yet been demonstrated to have any practical value.

Using the internet indeed rewires your brain, but there are both good and bad ways that your brain can rewired. We’re not yet at a point where we can definitely say what aspects of internet use are good or bad (at least for most aspects). This is evidenced by the fact that well-informed, intellectual thinkers have made different conclusions from the same data about the effects of internet on the brain. Clear consensuses among scientists, such as the agreement on evolutionary theory, tend to arise from clear incontrovertible bodies of evidence. The effects of internet on the brain simply have not yet been studied in such depth (hence the existence of ‘evolutionary biologists’ but not ‘cognitive internet neuroscientists’).

Given such widespread use of technology that promises to make us more productive and efficient, parsing out which aspects of internet use are positive and negative is an important endeavour. But we mustn’t lose sight of the core issues surrounding technology overuse that are already known to be harmful to the brain. For example, there appears to be no talk within the internet-brain debate about a culture of physical inactivity that is encouraged and promoted by technology. We know that physical exercise has beneficial effects on cognitive function, which is linked to changes in brain structure and function. If this debate is about how internet use and technological reliance affects the brain, we can’t ignore the harmful effects of physical inactivity that accompany internet use.

The debate has focused so much on what your brain is doing while you focus your attention from place to place on your monitor or handheld screen, but there seems to be no talk about what your body is physically doing as you browse the internet. Physical actions (or lack thereof) cannot be thought of as separate from mental processing. A discussion of physical activity and the brain should be therefore integrated into the debate if it is to be comprehensive in addressing factors that affect our brains as we surf the web and tweet.

Of all the behavioural changes from our hunter-gatherer history that have been caused by internet and technology use, our reduced level of physical activity is perhaps the most significant – and this may be exerting the most significant effect on our brains.

Thursday, June 10, 2010

The plastic brains of birds

TheThis post was  chosen as an Editor's Selection for ResearchBlogging.orgre has been a lot of talk about brain plasticity, the idea that our brains can be shaped and moulded by experience, in popular books and articles over the past several years. The notion that new neurons can be born in our brains, even in adulthood, is gripping and at times very encouraging.

However, our brains are not nearly as plastic as the more primitive brains
of fish, amphibians and birds. Some of these organisms experience fluctuations in brain volume so drastic that if they existed in humans, they would probably lead to startling changes in intelligence and behaviour throughout adult life.

In birds, changes in singing behaviour that occur as the seasons change are linked to radical changes in the size of brain regions that control singing (explained here). During mating season, when birds sing more, new neurons are born (i.e. neurogenesis) in the song control system, whereas neurons die during the offseason.

Neurogenesis occurs in widespread regions of adult bird brains, making them a good model for studying the mechanism of neuron birth. In mammals, neurogenesis has only been identified in the hippocampus and the olfactory bulb. In humans, most research attention is given to the hippocampus because of its prominent roles in memory and cognition.

David Sherry and Jennifer Hoshooley at the University of Western Ontario recently published a review on the study of plasticity/neurogenesis in the hippocampus of birds who store food during specific seasons. The authors discuss studies that show changes in hippocampal size and neurogenesis during periods of food-storing behaviour. They propose that hippocampal neurogenesis may be a consequence of the behavioural and cognitive involvement of the hippocampus in storing and retrieving food.

It is important to note, however, that it is difficult to directly link hippocampal neurogenesis to food-storing behaviour when this type of behaviour always comes during a specific season that is associated with changes in social system, size and appearance of home range, and diet. Important evidence that supports the notion that hippocampal neurogenesis is due to food-storing behaviour alone comes from studies of food-storing birds (e.g. chickadees) versus non-storing birds (e.g. house sparrows). The non-storing birds experience the same environmental changes as food-storing birds, but the food-storing birds show much more hippocampal neurogenesis than the non-storing birds (a study that showed this was conducted by David Sherry’s group).

It thus appears that hippocampal plasticity is linked to food-storing behaviour, an activity that involves memorizing multiple locations at once – something that birds are very good at. What remains to be seen is the aspect(s) of food-storing behaviour that the hippocampus is important for. We know that a reliable way to stimulate hippocampal neurogenesis in mammals is getting them to exercise. Could it be that birds are much more physically active during food-storing season, and could this account for the birth of new neurons? Neurogenesis is extensively studied in birds, but the question of exercise and neurogenesis has not been directly investigated.

We know that we share genes with birds that control language and singing; perhaps further study of plasticity and neurogenesis will illuminate more similarities between us and our flying friends.


Sherry DF, & Hoshooley JS (2010). Seasonal hippocampal plasticity in food-storing birds. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 365 (1542), 933-43 PMID: 20156817

Hoshooley JS, & Sherry DF (2007). Greater hippocampal neuronal recruitment in food-storing than in non-food-storing birds. Developmental neurobiology, 67 (4), 406-14 PMID: 17443797

Tuesday, June 8, 2010

The neuroscience of birdsong

I’ve decided to write a couple of articles on a relatively underappreciated area of neuroscience: the study of birds. I hope to demonstrate that although the term “bird brain” is used as an insult in everyday bicker, the tiny brains of birds are more complex than they are perceived to be. Bird brains may even be able to teach us a thing or two about the brightest of human brains. In this first post, I will describe birdsong – a rare example of music production in nonhumans.

You’ve probably woken up to the high pitch of singing birds before. If you pay close attention and analyze birdsongs, you’ll find that birds are capable of producing quite complex vocal patterns. Some bird species are able to produce over 1000 song syllables! However, the most commonly studied bird in the context of birdsong is the zebra finch, because this bird is simple: it sings just one song type. Male zebra finches sing to attract female mates, whereas female zebra finches don’t sing. The brain circuitry for song control in zebra finches is well characterized.

The most studied region in the schematic above is HVC, at the top of the bird brain. A bird with a damaged HVC cannot sing, and studies on the functional role of HVC have confirmed that it is a critical area for song production/control. In zebra finches, the HVC is much larger in males who sing than in females who don’t sing.

When male zebra finches sense the presence of a female, neural signals converge at HVC, causing the male to sing. The green pathway from HVC to RA ends at the syrinx, a vocal organ situated at the top of the trachea. The green pathway must be intact for birds to properly control muscles that modulate complex sounds being produced. The other main pathway is the red one that goes from HVC to Area X. The red pathway is involved in learning songs from “tutor” birds and receiving self-feedback while singing (so birds can correct themselves when they make mistakes).

An interesting area of study is the comparison of birdsong to human language. The hypothesis that the two are analogous is rejected by critics who maintain that birdsong is a single memorized set of vocalizations, whereas language involves a set of rules that can be combined in infinite unique ways. Nevertheless, birdsong and language parallel one another in important ways. When they are learning how to sing, birds display vocalizations that are similar to human infant babbling. Furthermore, the gene FoxP2 that is involved in neural control of vocal development is active in human and zebra finch brains in strikingly similar ways. This gene is also found in other animals such as mice, but it is best to study the gene in birds because their vocal behaviours are closest to ours.

So in summary, we now know a lot about the neural substrates of birdsong, and bird vocalizations can be looked at as both a behavioural and biological model of human language development and/or dysfunction. This post was intended to be a quick summary of what’s most interesting about the study of birdsong, so keep in mind that I’ve only scratched the surface of the topic.  Perhaps the next step will be determining how birds can dance...


Brenowitz EA, Margoliash D, & Nordeen KW (1997). An introduction to birdsong and the avian song system. Journal of neurobiology, 33 (5), 495-500 PMID: 9369455

Brenowitz EA, & Beecher MD (2005). Song learning in birds: diversity and plasticity, opportunities and challenges. Trends in neurosciences, 28 (3), 127-32 PMID: 15749165

MacDougall-Shackleton SA, & Ball GF (1999). Comparative studies of sex differences in the song-control system of songbirds. Trends in neurosciences, 22 (10), 432-6 PMID: 10481186

Teramitsu I, Kudo LC, London SE, Geschwind DH, & White SA (2004). Parallel FoxP1 and FoxP2 expression in songbird and human brain predicts functional interaction. The Journal of neuroscience : the official journal of the Society for Neuroscience, 24 (13), 3152-63 PMID: 15056695