Irritable bowel syndrome-mens morba in corpore morbo

The stiff-upper-lips of this world will probably always claim that irritable bowel syndrome (IBS) is "just" or "only" IBS. However, this syndrome can be highly painful and even debilitating at its most severe. It is characterised by abdominal pain and bloating, as well as constipation and/or diarrhoea. It tends to be associated with high levels of stress; childhood trauma is more prevalent in people with IBS, who have also been shown to have an altered stress response to an acute stressor in not one but two studies. IBS is also comorbid with certain stress-related disorders such as depression, although the interaction between depression and IBS can sometimes be complex-see this clip with Kurt Cobain, who suffered from both IBS and suicidal ideation for an example.

Recent research from our group (particularly Paul Kennedy, who completed his PhD in this area) has suggested that people with IBS perform more poorly on a test of memory than a healthy control group. The test (paired associates learning) involves remembering the location of abstract shapes hidden behind boxes-a bit like the kind of card game one would play as a kid. It is thought to involve activation of the hippocampus, a brain region which is also involved in the regulation of the stress response. It should be noted that although the number of errors people with IBS were making was higher than the healthy group, this was a subtle difference-but a noticeable one nonetheless.

In a just published study which I had the good fortune to get involved with, we looked at the potential neurochemical underpinnings of this change in memory performance. Specifically, we looked at whether memory performance in IBS could be changed by altering tryptophan levels. Tryptophan is an essential amino acid ("essential" because we have to derive it from our diet). It's used by the body to produce serotonin-a household name among neurochemicals thanks, among other things, to the class of antidepressants known as SSRI's (selective serotonin reuptake inhibitors). HOWEVER, most tryptophan is broken down along the less-famous kynurenine pathway, where is it catabolised into kynurenine and various other neuroactive chemicals. The enzymes in our bodies which make this happen, such as IDO and TDO, have previously been found to be altered in IBS, and there is some evidence that the chemicals produced in the kynurenine system can have a negative impact on memory. This suggests the kynurenine system could play a role in IBS-related memory attenuation.

In our study we gave people with IBS and healthy controls a drink with amino acids other than tryptophan-these compete with tryptophan at the blood-brain barrier, and consequently reduce the amount of tryptophan getting through to the brain. As a control condition, on a different testing day we gave them the same drink but with tryptophan included. We then had everyone complete a series of cognitive tasks.

What the results indicated was that people with IBS did worse than healthy controls at the memory task, similar to what had been shown before. However, this only happened when they had consumed the drink containing tryptophan. Analysis of their blood samples by Gerard Clarke indicated that the drink containing tryptophan led to higher levels of kynurenine-thus breakdown of tryptophan along the kynurenine system may explain this memory difference in IBS.

As drinking a mix of amino acids can taste unpleasant I wouldn't necessarily advise people with IBS to run to the health shops to see if they have them in. I would say that one useful step people with IBS can take is to try to keep stress at a manageable level-excessive stress is likely to lead to negative impact on your cognitive performance, particularly in the case of more complex tasks such as remembering large amounts of info. Further, although there is no cure for IBS, symptoms can be managed and minimised, and avoiding too much stress is part of this process.

***UPDATE*** For those who want to know more about the science of IBS, I forgot to mention that while  I was working on this blog post Paul Kennedy et al. published a review paper looking at irritable bowel syndrome and the microbiome (i.e. the community of microorganisms living inside us humans, and their genes). Check it out!

Kennedy, P.J., Allen, A.P., O’Neill, A., Quigley, E.M.M._, Cryan, J.F., Dinan, T.G., Clarke G. (2014). Acute tryptophan depletion reduces kynurenine levels: Implications for treatment of visuospatial memory performance in irritable bowel syndrome. Psychopharmacology, doi: 10.1007/s00213-014-3767-z

Two different ways: Creativity and two modes of thought

Whenever one encounters a child genius one is tempted to think that their creativity cannot stem from "normal" thought processes, and one sometimes sees in DVD commentaries some writers and directors can have a surprising lack of insight or ability to articulate where their ideas come from-this can be the case with actors too. A lot of people assume that creativity is fundamentally mysterious-after all, they may say, if we fully understood it how would it be creative? Let's imagine one is not Mozart, but wishes to engage in a task which requires at least moderate creativity-let's say writing a script for a romcom which will hopefully earn loads of money. Is one doomed to wait upon some elusive muse, or can we think about the types of underlying thought processes one has to draw upon to complete this task?

In discussing this I draw on a distinction from the broader literature on thinking and reasoning. There has been a lot of interest in type 1 and type 2 thinking, which have been popularised in a recent book by behavioural economist extraordinaire Daniel Kahenman. A bat and a ball cost 1.10 - if the bat costs one euro more than the ball, how much do they cost? Type 1 thinking is fast and automatic (it shouts out "the bat's one euro and the ball's ten cent!), type 2 is slower and sequential (it realises that one euro is not one euro more than ten cent, so you have to adjust the estimate-it's actually 1.05 for the bat and five cent for the ball). I like to remember which is which by thinking of type 1 as the type which arrives first, because of its speed, and vice versa. The mysterio approach to creativity would seem to favour the account that, inasmuch as creativity is a thought process, it should therefore by type 1 (indeed, so fast that it is not accessible to conscious introspection). 

When working through creative projects, one tends to go through stages-firstly, you prepare the groundwork; say, checking out the other films in the genre to see if you are sinking into cliché (or committing outright plagiarism). There often follows an impasse, where one is stuck on what to do next-where to go relative to what's gone before (how many ways can you get two kooky singletons to go through the will-they/won't-they and maintain tension in the audience?). Following a period of "incubation" with a bit of luck there is then insight; the aha! moment when it occurs to you how to move past the mental block (the unique selling point of the script is the male lead is actually a salmon trapped in the body of a windsurfing CEO played by Matthew McConaughey). But often the creative process doesn't end there- you then have evaluation of the idea ("the salmon thing isn't realistic, but is it compelling?") and then dissemination (having the script sent to directors/producers who realise your meisterwork on the big screen). There are other accounts of creativity that propose more stages, but I think this broad framework is a nice place to start.

I have argued previously in an article with Kevin Thomas that both type 1 and type 2 thinking are important at various stages of creative thinking. During the preparation phase, ideas for creative projects can come through applying simple heuristics (e.g. "do the opposite of what they've done") or through careful consideration of what your predecessors have done. Insight can be a very sudden thing (many riddles used in psychology experiments can be like this) or it can occur through a more gradual process of working through concepts (consider the process of composing a score for a film; there are many points at which you have to decide which ntoes to use next). Evaluation can be type 1 ("does the script for the romcom look okay?") or type 2 ("how exactly should I phrase the funeral speech to avoid undermining the frothy comedy?") 

It's always flattering when one's work is cited and it was cool to see our paper get cited in a recent article in Thinking & Reasoning which indicated that people prone to engage in type 2 thinking perform better at the remote associates test (e.g. "what word connects the three words HOUSE, APPLE and SURGEON?") This test is thought to tap into the slope of one's associative hierarchy (basically, the ease with which one can draw connections between concepts which, at first glance, may seem unconnected). Such a skill is surely important for the striking juxtapositions that can create a great scene in a novel or film. At the same time, the remote associates test is very quick- in terms of stages of the creative process it tends to be associated with a very sudden moment of insight and very little evaluation. It would be interesting to see more research being done on the more long-term creative thinking projects that artists engage in, where insight happens at a more gradual pace (e.g. choosing various chords in the writing of a song) and evaluation of a larger set of ideas must be carried out (e.g. honing the phrasing of the quips Jennifer Lawrence speaks as her six-packed beau flounders on the beach in salmon-brained lunacy). 

Since writing the paper with Kevin Thomas, I also came across evidence that what can aid creativity is using whichever type of thought one is less likely to rely upon generally. It seems that maybe it is not just the ability to use both slow, logical reasoning and fast simple heuristics, but the ability to switch between the two that can help the creative thought process. When the deadline for the romcom script roles around you'll have to tap into faster thinking processes. 

Will the project of understanding the underlying cognitive psychology of creativity effectively undermine the existence of creativity itself? I don't think so. The technological, social and ecological sands shift beneath our feet, and even when the process of creative thinking is understood, this process will still have to be applied to novel problems requiring different solutions-and of course the process itself may need to be tweaked in future. Perhaps the romcom will be replaced by a greater form of light romantic titillation, and new tropes will have to be negotiated. (If you didn't get it, the answer is TREE-or at least TREE is one possible answer).

Allen, Andrew P., and Kevin E. Thomas. (2011). "A dual process account of creative thinking." Creativity Research Journal 23(2), 109-118.

Blurred lines: A review of "Intuition Pumps" by Daniel Dennett

Just finished reading "Intuition Pumps" by Daniel Dennett. Although Dennett is perhaps best known as one of the so-called "New Atheists", along with Sam Harris and Richard Dawkins (the latter seems to be a chum of his), he has perhaps made the biggest contribution in the area of philosophy of mind. Besides being a philosopher of mind, Dennett takes a great interest in relevant disciplines such as biology and psychology. He is also a charming, avuncular storyteller, which probably does no harm to his relatively broad appeal, and he aims for a non-specialist audience with this latest offering.

Before grappling with some larger topics, the book opens with some general "thinking tools". I read through this section of the book in no time-it's a great little page-turning pamphlet in itself, even if a few of the ideas (or versions thereof) are probably already in many intelligent people's arsenals. A personal favourite is his point about the phrase surely, which he suggests is often used when someone kind of realises that their argument is just about obvious enough that they shouldn't have to justify/explain it too much (although maybe they should!)

His interest in biology is evident in his discussion of evolution, an engaging enough read (I say this as someone who knows very little about evolution). However, it is his discussion of consciousness (an area I've recently become interested in) that I was most interested in checking out. My first experience of Daniel Dennett was reading (a chunk of) his "Consciousness Explained". With the advent of fMRI allowing researchers to observe blood flow to specific regions of the brain in response to thinking tasks, one might be tempted to look into "pinning" consciousness on a particular part of the brain. Although fMRI has been used to assess whether people are conscious of certain things, in very interesting circumstances, in "Consciousness Explained" Dennett came out against the implication that there is some endpoint in the brain where consciousness occurs, suggesting instead that it is something which is sorta (a word he uses a lot in "Intuition Pumps") present at some level in one part of the brain before becoming more present at a "later" part. This approach to having conscious experience leaves a lot of people cold, as far as I can see, but I must say I'm biased towards Dennett's view on consciousness; when I hears thinkers talk about consciousness as an indivisible, all-or-nothing process it doesn't really appeal to me at an intuitive level-don't we all have experience of our level of awareness diminishing as sleep sets in?

Having been drawn in by the previous book, I was keen to take in the section in this book dealing with consciousness. Here Dennett takes on classic philosophical problems such as zombies (i.e. people who behave as if they are conscious, but are not) and Searle's infamous Chinese Room. Unfortunately, the book gets a little too quick to refer the reader on to other sources at times in this section, although the chapter "The Tuned Deck" may be one of the most entertaining parts of the book (I won't spoil it for you), if a little vague on detail. In some ways this book's section on artificial intelligence seems to say more about consciousness than the section entitled "Tools for thinking about consciousness". Here, Dennett dissects how bits of information, too simplistic by themselves to represent anything in the world, can be gradually combined with extremely simple operators to complete tasks such as addition and subtraction (he even sets a homework assignment to be done using a computer program which allows you to design these types of operations from the bottom up, which I'll admit I didn't do). Reading this section I got a gut feeling for how an incredibly simple process, such as a neuron firing or not, when combined with billions of other neurons in a vast interacting (and sometimes self-referential?...) networks could gradually build up to something complex enough to be capable of self-awareness. I would be curious what Dennett thinks/would say about recent developments in robotics, with robots being created that appear to have some degree of self-awareness.

Turning towards the topic of free will, Dennett takes a compatabilist viewpoint (i.e. that free will and determinism are compatible). Similar to his sorta approach to consciousness, he argues that the idea that determinism rules out free will is based on an idea of free will which is too absolutist. Again, I found this intuitively appealing-I feel that I have a greater amount of free will about things I think of doing tomorrow compared to what I do a few seconds from now. However, I still found this part of the book a little difficult to swallow-I may need to read it a second time, but he seems to put the burden of proof on those who think determinism rules out free will without being 100% clear as to why a sorta free will would allow for determinism-does determinism then become sorta determinism?

Dennett closes with some words on being a philosopher. He suggests that pursuing a more long-term problem in philosophy may be a more fruitful approach in the long run than grappling with a "hot" topic-he quips that these are the quickest to burn out. Probably true in psychology, although this is advice which is easier to give than follow when one is a junior thinker chasing funding/job opportunities...

http://www.amazon.com/Intuition-Pumps-Other-Tools-Thinking/dp/0393348784/ref=sr_1_1?ie=UTF8&qid=1409346685&sr=8-1&keywords=intuition+pumps

The perks of a pack of gum

Besides drinking caffeine-rich beverages, I've heard anecdotally that some long-distance drivers will chew gum behind the wheel to avoid paying an untimely visit to the land of snooze. A recent research article has looked at the potential alerting effect of gum in the lab, looking not only at feelings of alertness and associated attention performance, but also at brain activity and heart rate changes which can give a broader picture of what's happening.

We had participants complete a task where they watched a stream of 3-digit numbers-generally each number differed from the previous one, but every so often there would be a repetition (a bit like a quality control job on a production line). A vigilance task (i.e. sustained attention to rare target stimuli) such as this tends to be associated with a vigilance decrement (i.e. you perform more poorly at the task as time goes on). A previous paper indicated that chewing gum could improve performance on this type of task, but only after a certain amount of time performing it-that is, as eyes were starting to droop. In this study we looked at chewing gum on the same vigilance task, but this time we also measured electroencephalography (EEG) as well as heart rate, to see what physiological changes might accompany such effects. The vigilance decrement was probably enhanced by the fact that having the EEG equipment set up can take a longish while of sitting still (as anyone who has taken part in this study will attest to).

When participants chewed gum during the first stage of the vigilance task, they showed less of a post-baseline decrement on the vigilance test compared to those who did not chew gum (interestingly enough, this difference was still evident when further vigilance tasks were completed post-chewing). 

The EEG indicated that beta activity (which is associated with an alert state) was heightened at frontal and temporal areas following chewing gum; this effect was strongest straight after chewing, although it seemed to persist post-chewing. Furthermore, chewing gum was also associated with heightened heart rate, although this effect on heart rate seemed to dissipate quite quickly once chewing ended. It may be the case that central nervous system activity is a more likely explanation of ongoing effects of chewing than sympathetic nervous system activity (i.e. heart rate).

The study adds to a growing amount of evidence suggesting that chewing gum can enhance not only subjective alertness but also sustained attention. There has been some evidence that this can occur even in the absence of a vigilance decrement; I would speculate that this may have happened in the linked study as they used a task which I believe requires much more frequent responses to stimuli-this may reduce the extent of the decrement somewhat, compared to the vigilance task we used. (Consider running quality control on a production line where you have to spot the occasional mistake -vigilance- versus an assembly task whereby you have to continuously perform an operation on each passing piece of equipment -continuous performance. I think it's easier to tune out when you only have to do something every so often than when the default mode is responding to stimuli). 

Have I tested this on myself? I can recall attending one lecture where what I'll generously call a vigilance decrement (there was nodding involved) started to set in. This affliction was relieved to some extent by chewing some gum for a few minutes-thereby just about preventing an embarrassing collision of my head and the seat in front of me. Just don't go on an three-night, no-sleep road trip and blame me if anything goes wrong!

Allen, A.P., Jacob, T.J.C., Smith, A.P. (2014). Effects and after-effects of chewing gum on attention, heart rate, EEG and mood. Physiology & Behavior, 133, 244-251. 

Rant: On established validity and good questions

When using psychological tests, it is important to ascertain if they have good validity (i.e. test the concepts they claim to test). Obviously, if a test has already undergone evaluation to show that it has good validity (e.g. it correlates well with other measures assessing the same concept) then this can be a great time saver for you. However, I've recently been struck by a few measures which, while having previously undergone testing to examine validity, seem a priori to either be muddled or downright contradictory. (No doubt more seasoned psychologists than me can think of other examples).

A while back I completed an online survey whereby one was asked to place oneself in an imaginary scenario (stage 1). One is asked to imagine oneself committing a crime (let's say robbing a bank). In this story one is requested to imagine that one feels a sense of excitement and enjoyment in committing this crime. After having read (and presumably daydreamed about) this scenario, there are a series of follow-up questions (stage 2). One of these questions asks you to indicate how much one would enjoy robbing the bank (with the option of saying "not at all"). But you have already been told to imagine that you do enjoy it at stage 1. The question can't really be probing how much the respondent would actually enjoy such an scenario, as the survey as a whole is telling the person that they would enjoy it in this imaginary world. On mentioning this to a researcher using these questions he pointed out that he had previously noticed this shortcoming and was working on re-validating the questions-it annoyed me that he was left doing this as the original designers had not taken more care to ensure that the questions made sense in light of the scenarios that went with them.

A second example is perhaps less irritating, as the question that annoyed me was not necessarily contradictory but rather a bit muddled. However, the response to my griping from the author who used it was telling. An example question they mentioned was a triple-barrel question, let's say along the lines of "In order to enhance economic growth, our nation should cut corporation tax, reduce workers' rights and abolish the minimum wage". When I pointed out that this was a triple-barrel question which didn't allow for people having differing views on the impact of minimum wage versus the impact of corporation tax on economic growth, the person using the scale pointed out that as the validity and reliability of the questionnaire had been assessed in that format, they were sticking with it.

Why rush into spending the time and effort of collecting a large set of data to ensure the validity of a measure when it only takes an intelligent person in a room to see whether or not the questions actually make sense and are clear-cut?

Greetings

Congratulations! You have entered the world of my blog, Andrew's Psychology Archive.

I (Andrew Patrick Allen) am a psychological researcher interested in the psychology of stress, cognition, drugs effects (e.g. alcohol/hangover), foodstuffs (e.g. probiotics), the brain-gut axis, behavioral economics, philosophy of mind and a host of other fascinating aspects of human experience.

I am currently working in University College Cork (UCC), working with a multidisciplinary group investigating the brain-gut axis. With the Department of Psychiatry at UCC I am also doing some work looking at depression biomarkers (e.g. the cortisol awakening response, a rise in the stress hormone cortisol following awakening that is altered by different forms of depression) and how these might be affected by treatments for depression.

Should be bringing you plenty of ideas concerning my research as well as that of others over the coming months, maybe years. Stay tuned.