Category: Science

Bowls made of depleted uranium, what could possibly go wrong?

Just a relatively quick post, as things are have been and are continuing to insist upon being busy – I’ve had a round of assessment for my PhD (my mid-candidature review), participated in a speaking competition about my PhD, done a talk about “seducing with neuroscience” (maybe I’ll post something about that at some stage – it’s not food-related but it is very interesting, and despite the evocative name it’s actually about how neuroscience information influences people’s judgments about the credibility of explanations), and now I’m madly analysing data to get an abstract submitted for a conference in November prior to leaving for a conference coming up in September (yep, it’s overseas-trip-time for me again, for the fourth time in 18 months – more on that later too, I guess).

SO! Another one to file away in the “how to influence people’s perception of food” category – can you influence people’s perception of food by manipulating something as simple as the weight of the dish it’s served in?

YES! It seems…

In a study by Piqueras-Fiszma and colleagues, participants were asked to rate 3 yoghurt samples in terms of flavour intensity, density, price expectation and liking. The yoghurt samples were served in three bowls that were all identical except for their weight: they were white ceramic bowls to which a hidden weight could be attached, so that the lightest bowl was 375g, the intermediate-weight bowl was 675g, and the heaviest bowl was 975g. Each bowl was used to serve a 150g sample of plain old Greek yoghurt (important information for study replication: it was purchased from Tesco!).

Participants had to hold the bowl in one hand while they sampled the yoghurt, and each bowl was taken away before the next one was given, so that there was never a chance to directly compare the weights.

Of course, it was the exact same yoghurt in each of the three samples that each participant tried – the only difference was the weight of the bowl the yoghurt was served in. But the participants didn’t know that. They probably assumed they were taste-testing different yoghurts.

Results showed that the heavier the bowl, the higher people rated the perceived density of the yoghurt when they sampled it, and the more money they expected to pay for it. Also, the heavier the bowl, the more participants liked the yoghurt. Perceived flavour intensity was not significantly affected by the weight of the bowls.

So everyone go out immediately and buy really heavy bowls and plates! Serve your things in heavy dishes all the time! Force your dinner guests to hold the crockery in their hands as they eat! Make people think your food is more fancy, more expensive, more lovely!

Or not. These results probably can’t be generalised too much – maybe you only get this effect for particular foods, and yoghurt just happens to be one of them. Maybe the effect changes depending on other properties of the food, e.g. maybe the volume of yoghurt is difficult to visually gauge because it’s just a big amorphous lump, so people’s perceptions are only influenced when the amount of food is difficult to get an idea of. Maybe putting something a bit more discrete, like an apple, into the different bowls would get a different result.

And it would be interesting to do a study investigating whether the weight of the vessel influences the amount of food eaten – maybe if the bowl is heavier, the food seems denser, and perhaps the brain is tricked into thinking the food is more calorific and so satiety occurs sooner. Who knows? I mean, there are many cues that the brain uses to determine satiety, so maybe it would be difficult to detect an effect of serving dish weight, but it is intriguing…

Anyway, it’s brownie time. Or blondie, as the case may be, I don’t know what defines one versus the other. Do blondies simply lack the predominance of cocoa or milk/dark chocolate in the batter? Anyway, the photos above are of some ridiculously delicious blondies (we’ll go with blondies for the name), featuring one of the greatest things known to humankind: peanut butter. They are peanut butter and waffle blondies (they have waffle crumbs throughout them) with dark chocolate chips. I recently made a variation of the recipe, photos of which are below: peanut butter, waffle and malt biscuit blondies with white chocolate chips and strawberries. I made those for a friend who recently endured an incredibly difficult experience (understatement of the century) and has just gotten out of hospital.

Recipe for peanut butter blondies (and variations thereof)…
Read the full article »

Panko panko panko

This might be the most difficult post I’ve ever had to write. Not because of the hours involved in devising recipes, cooking them, photographing them, going through countless databases and articles in order to find some interesting food-related scientific research to write about, actually writing the post, etc. The difficulty is mainly because of the title of the paper I’m writing about:

Overcoming the urge to splurge: Influencing eating behaviour by manipulating inhibitory control.

The 5th word in the title: absolutely the worst word in the English language.

I hate it so much. Who would have thought that a single word, by virtue of the mere sound of its phonemes, could conjure up such grotesque imagery and such a visceral revulsion in a person? I don’t understand how that word isn’t onomatopoeic for the sound of vomiting. It makes me want to vomit, it sounds like the noise people make when vomiting – it would be put to good use if it were employed in that manner.

I also hate the meaning that it stands for: some sort of unjustified failure of self-control, a lapse in good judgement, a lack of consideration and deliberation. People use the word in and of itself to try to attempt to justify their unjustified behaviour, as if the fact that the behaviour has a name means that it’s legitimate. Oh I just spent $900 on an antique Royal Doulton “Bunnykins” tea set from 1954, someone (I don’t know who) might say, but it’s OK – it was a… splurge. OH MY GOD. I would prefer if people just owned up to it and said they made an impulsive, spontaneous, poorly informed decision, but hey, it felt good at the time. It would be even better if they just made an informed, thoughtful, deliberate decision after a long and critical analysis of the pros and cons, but hey – humans as a species are nothing if not impulsive and irrational.

And I should know. Well, I should know something about it, to some limited extent. One of the things I study in my PhD is the ability to control behaviour, albeit in a bit of a simplified way: I use simple computer-based tasks that test people’s ability to withhold a response that they’re used to making. So my research participants press a button as quickly as possible to indicate whether they’ve seen an X or an O flash up on the screen, but sometimes, infrequently, a red box flashes up around the X or the O and that means the participant has to withhold the response they were going to make. This is a measure of a person’s inhibitory control. The greater your inhibitory control, the less trouble you have inhibiting your response when you see that red box, and this is something that naturally varies from person to person. A pretty straight-forward task, seemingly, but incredibly important in daily life – you have to constantly evaluate your environment and change your behaviour accordingly. You don’t want to be driving through a red light because you have trouble inhibiting your foot from pressing the accelerator.

But wow – I never anticipated the potential power of this simple computer task to actually improve people’s inhibitory control in a way that might improve their eating habits. All I needed to do was chuck in some photos of things like cupcakes or chocolate and I could have been doing all my participants a huge favour (and simultaneously wrecking my actual PhD project).

This is what my task looks like:

On trials like the one in the top stream, an X or O pops up and the participant has to respond as quickly as possible to identify the letter. But on trials like the one in the bottom stream, an X or an O pops up followed a fraction of a second later by a red box, the stop-signal, which indicates to participants that they need to withhold the response they were going to make.

If I adapted my task to be like the one used in the urge to spl*rge study by Houben, this is what it would look like:

Sometimes participants might see the top stream – M&Ms flash up and they press a button to indicate that they’ve seen a food item (the alternative is that they might see something like a chair flash up and they press a button to indicate that they’ve seen a non-food item). Other times, participants might see the bottom stream – chips flash up and they go to press a button to indicate that they’ve seen a food item, but then they hear an auditory tone that tells them that they have to withhold that response that they were going to make (again, the stop-signal).

The manipulation here is that one of the 3 different food items that are displayed (chips, nuts or M&Ms) is always paired with the stop-signal, one is never paired with the stop-signal, and one is only paired with the stop-signal 50% of the time. This is to see if participants might be pairing their response inhibition with a particular type of food and perhaps through associative learning they might become better at inhibiting responses to that food in general – maybe if they’re used to inhibiting their response every time they see M&Ms, and you give them some real M&Ms, they won’t be so impulsive and eat so many of them. Maybe.

And yeah, you kind of get that. If you take a subset of participants who have particularly bad inhibitory control (they’re more than 1 standard deviation below average for inhibition speed), you can actually decrease their consumption of the food that was always paired with the stop signal, compared to the food that was paired with the stop-signal 50% of the time (the control condition). So if they were always inhibiting their response to M&Ms but not to chips, after the experiment, they’ll eat fewer M&Ms than they perhaps otherwise would.

However, you have to be careful with this one – it has the power for both good and evil. If you take a subset of participants who have particularly good inhibitory control (more than 1 standard deviation above average for inhibition speed), it seems there is a trend towards them eating more of the food that was never paired with a stop-signal compared to the food that was paired with the stop-signal 50% of the time. So they get used to responding quickly and maybe impulsively to a particular food, and when you actually give them that food after the task, they eat more of it than they perhaps otherwise would.

There you go – if for some reason you desperately want to improve your ability to resist a particular food (have you had to take out a personal loan to finance your Valrhona habit?), all you have to do is spend a few thousands dollars on a computer and some task-programming software like E-Prime or Presentation, spend days or possibly weeks learning how to program a response inhibition task containing photos of the food you want to resist and voilà – if you’ve got poor inhibitory control to start with, you might be better at resisting that food, at least immediately after doing that task. Who knows how long-lasting the effects are? Actually, that would be an interesting study to do.

In the meantime, here are some maple syrup and panko biscuits. For those who don’ t know, panko are Japanese breadcrumbs. Panko’s potential for use in sweet recipes was first brought to my attention by the Chuao Chocolatier panko chocolate bar I tried in San Francisco – I found the bar kind of disappointing because try as I might I could not detect the panko flavour, but I believed it could still work well if done differently, which is why I came up with these biscuits. They’re delightfully crunchy and the panko gives them a nice wheaty flavour and trust me, you do not want to inhibit your eating of them.

Recipe for maple syrup & panko biscuits…
Read the full article »

Top-down will ruin your life.

This cake is a study in information processing.

In the realm of neuroscience, “top-down” and “bottom-up” are terms that describe the direction of the flow of information. Top-down processing involves higher cognitive processes coming into play to make sense of information, whereas bottom-up processing is driven by information from the more “basic” and ostensibly “lower” level, from the level of the senses (touch, sight, hearing, etc.) without the higher levels in the more executive parts of your brain necessarily coming into play.

So bottom-up processing is the relatively simple perception of your surroundings, while top-down processing can create a kind of filter for processing information and for biasing your perception, sometimes to aid in the accomplishment of a goal.

And so my experience of this cake has been entirely ruined by top-down processing.

It’s a red velvet cake, but with the red dye left out and replaced with just water instead. It’s a non-red velvet cake. Now, I love red velvet cake. On my birthday a few weeks back, Chris made me a red velvet cake (red dye and all) and it was fantastic. This cake in the photo – it’s basically the exact same recipe, but without the dye.

And condemn it to red velvet hell forever if it doesn’t taste exactly like a normal chocolate cake and nothing like red velvet cake.

My brain perceives the colour of this non-red velvet cake and it biases me towards thinking it’s just a plain old chocolate cake, because it should taste like all the hundreds of chocolate cakes I’ve had before that look like that. And honestly – it tastes like chocolate cake. I fought my brain; I desperately tried to find some semblance of the red velvet taste in that cake. It’s just not there. It’s… kind of depressing.

Solution: eat this cake blind-folded, so the sight of it doesn’t bias me towards perceiving it as a chocolate cake, and so my experience of it is only driven by the taste and smell of it.

Stupid brain, ruining my cake.

(I’m sorry I called you stupid, brain, I love you.)

Anyway, speaking of brains, I’m going to another conference about brains and the things brains do in a few weeks’ time. And it’s in San Francisco. Hurrah!

So: recommendations of must-visit locations, must-see things, must-eat-at food places in San Francisco?

I’ll also be in New York, but I’ve already got a list of a million places I didn’t get to when I was there last year, so I’ve got it all pretty much planned out (although I’d still like recommendations if you’re just dying to tell me about somewhere in particular).

Have at it.

Chocolatuuuunnnnggghhfffffff.

Chocolate! Oh my god, chocolate. Chocolate! Master/mistress of our hearts! Emperor/empress of all sweet things! Ruler of our minds! Don’t you know, it has chemicals that make us happy! It has compounds that are the ones that also flood your brain when you’re in love! Or during moments of passion! Chocolate contains chemicals of passion! And love! And happiness! And joy! And all of that! Right? Right?

(Can you just imagine my withering gaze right now? You should get a chill up your spine.)

It’s not right, actually. Of course it isn’t. Of course. It’s never that simple. But saying that chocolate contains happy/lovey-dovey/alluring chemicals is a nifty thing to say, even if it’s not necessarily true, or not true to the extent we think it is. It plays into our beliefs, seems to confirm our existing expectations, and makes us all feel warm and fuzzy and comforted – chocolate will always be there for us, to hold us and nurture us and to spur us to neglect urgent work in favour of going on an epic mission to find chocolate, to console ourselves in its melty embrace, to search desperately through the pantry until we are totally convinced there’s not any chocolate in there, and then to search again just to make sure, and then to walk or drive or ride in a horse-drawn carriage to an appropriate vendor of chocolate-related delights.

But what say you, Science? (Science should be the true master/mistress of everyone’s hearts, OK?)

Science says things just aren’t that clear. Unsurprisingly. Oh, Science. Oh, oh, Science.

Firstly, the most widespread inaccuracy: that a chemical in chocolate – phenylethylamine – is the chemical that also responsible for the feeling of love in the brain, or the feeling of passion, or whatever the latest churnalism article in the Daily Mail (yeah, I’m not even in the UK and I’m going to point my finger at it) or whatever hobbling excuse for a newspaper has regurgitated.

While it is true that chocolate contains phenylethylamine, and that phenylethylamine may have effects on cognition, mood and emotion, very little of the chemical could ever get to the brain, since when it is consumed, most of it is converted into a different chemical by the protein monoamine oxidase-B (Suzuki et al. 1981). Barely any phenylethylamine makes it into circulation in the blood and from there into the brain.

Oh and high levels of phenylethylamine are associated with psychosis, particularly in certain individuals with paranoid schizophrenia (Janssen et al. 1999). Just out of interest.

So everyone can quit jabbering about phenylethylamine. It is really not the magical aphrodisiac love-drug that people make it out to be.

Right, moving on. Theobromine! That’s the next chemical to which people ascribe chocolate’s beautiful, bewitching powers.

There’s actually a little bit more validity in that one, although it’s still not totally resolved and is open to debate.

In one study (Smit et al. 2004), participants were given either:
a) pills containing an amount of cocoa power that would have the same theobromine and caffeine amounts as a 50g bar of chocolate
b) pills containing the same amount of theobromine and caffeine as a 50g bar of chocolate (plus some inactive cellulose as filler)
c) pills containing just inactive cellulose as filler (the placebo condition, naturellement)

Participants in conditions (a) and (b) had faster simple reaction times and reported feeling more energetic than those in the (c) condition. That certainly suggests that theobromine and/or caffeine could be having psycho-active effects: they’re doing something to the brain. But it remains unclear whether it’s just theobromine that’s responsible for the effect, just caffeine, or a combination of both.

To make the conditions of the study a little more relevant to the real-world, doses of theobromine/caffeine were also administered in a second experiment using actual pieces of chocolate. The chocolate was made so that it either had no theobromine/caffeine in it (like white chocolate), a small amount of theobromine/caffeine (the same as milk chocolate), or a larger amount of theobromine/caffeine (the same as dark chocolate). When participants ate the chocolate with the large amount of theobromine/caffeine, it greatly improved reaction time. Chocolate with the small and large amounts of theobromine/caffeine improved working memory (tested by getting participants to press a button when they saw 3 odd or even numbers flash up in a row in a constant stream of numbers on a computer screen). The large and small doses of theobromine/caffeine did not result in participants feeling more energetic compared to the chocolate with no theobromine/caffeine or compared to placebo.

Both of the experiments also found, or rather, didn’t find, something rather interesting: there was no strong, clear effect of theobromine/caffeine on “hedonic tone”, a measure of the participants’ levels of contentment and pleasure. So it seems a bit tenuous that theobromine is this magical chemical that so many people assume must be in chocolate in order for chocolate to exert its effects upon us. But people want there to be a chemical in chocolate that explains why so many people love it – I think people get a kick out of imagining that they’re messing with their brain chemistry in order to elevate their mood or to experience enjoyment, thereby associating chocolate consumption (rather loosely) with illicit drug-taking and getting a kick out of the fact that they’re doing something vaguely taboo like that, albeit on a very diluted scale.

Maybe we should, then, look at what other possible ways chocolate could have established its lauded position as reliable and beloved comforter to many. Is it the chemicals? Or is it something else? Or is it the chemicals and something else?

But maybe I’ll get into that next time.

(See, if I leave you with this tremendously epic cliff-hanger, I’ll feel bad for not following it up again soon, so that will give me the impetus to blog again. It’s like training a puppy! But not really like that at all.)

The photos in this post are of the birthday cake I made for Dr Tash PhD last year, and I tried to make said cake as sour as possible (per her predilection for sourness). I can’t actually remember how I made this cake – I think it was a lemon drizzle cake sandwiched in between two layers of white chocolate mud cake, but I could be wrong. I also have no idea what the purple stars are, except that they were some sort of sour agar gel I made and are not, contrary to appearances, slices of beetroot. Just so you know.

References
Suzuki et al. 1981. Oxidation of beta-phenylethylamine by both types of monoamine oxidase: examination of enzymes in brain and liver mitochondria of eight species. Journal of Neurochemistry, 36(3), 1298-1301.
Janssen et al. 1999. Does phenylethylamine act as an endogenous amphetamine in some patients? International Journal of Neuropsychopharmacology, 2(3), 229-240.
Smit et al. 2004. Methylxanthines are the psycho-pharmacologically active constituents of chocolate. Psychopharmacology, 176(3-4), 412-419.

The grand monkey gland

To tide you over until the imminent cessation of this blog’s unexpected hibernation, here’s some of what you come here for: food and science. Well it’s drink and science in this case. And the science part is that there are beakers and gloves involved. And that most of the people at the table were scientists.

May I present the Monkey Gland Hand, a cocktail at Salon Lounge here in Brisbane. I went there with a group of friends for my birthday very recently and we partook of some rather elaborate and creative cocktails.


(Harvesting the Monkey Gland Hand is a precision operation.)

The Monkey Gland Hand is Beefeater gin, Kubler Swiss absinthe, blood orange juice and homemade grenadine glaze: a slight variation of the original Monkey Gland cocktail, served as you can see in a surgical glove, on a surgical tray, with surgical scissor and a beaker. The person who served it to us also gave us a slightly garbled version of this Wikipedia article on Serge Voronoff as an explanation for the drink’s origins (short version: attaching monkey testicles to people for purportedly therapeutic purposes in the 1920s – of course).

Above is The Ego, inspired by The Strange Case of Dr Jekyll and Mr Hyde. It contained Beefeater 24 gin, white chocolate liqueur, oolong tea, vanilla syrup, lemon juice, pear juice and cucumber foam. I had its complementary drink, The Alter Ego, which was Beefeater 24 gin, peach liqueur, orange bitters, mandarin glaze, lychee juice, mandarin juice, lemon juice and a frozen liquid nitrogen crust.

Espresso Head: Havana Club Anejo Reserva rum, Pernod Ricard, tonka bean sugar syrup and espresso, topped with vanilla and milk foam.

If you’re now in the mood for cocktails but the contents of these seem a bit too encyclopaedic or unattainable or hatefully complex, don’t forget 12 Bottle Bar for something maybe a tiny bit more simplified, but just as effective.

However, you must always consider surgical gloves as serving vessels for all imbibable liquids, from this day forth. I know I will.