Steve Jobs' gift to cognitive science

The ubiquity of iPhones, iPads and other miniature computers promises to revolutionise research in cognitive science, helping to overcome the discipline's over-dependence on testing Western, educated participants in lab settings.

That's according to an international team of psychologists who say the devices allow for experimentation on an unprecedented scale. "The use of smartphones allows us to dramatically increase the amount of data collected without sacrificing precision," say Stephane Dufau and his colleagues, "and thus has the potential to uncover laws of mind that have previously been hidden in the noise of small-scale experiments." In contrast, they argue that conducting cognitive psychology experiments over the internet has not been a great success because of problems obtaining the necessary precision of timing.

To illustrate their point, the researchers developed an iPhone/iPad App that replicates the classic "lexical decision task" used by psychologists to study the sub-second mental processes involved in reading. Participants are presented with a series of letter strings and simply have to indicate as quickly as possible whether each one is a real word or not. The App was launched as a seven-language international effort in December 2010 and after just four months data had been collected from over four thousand participants. By way of comparison, it took more than three years to collect a similar amount of data via conventional means. It will be easy to add further languages to the App, including non-Romanic alphabet languages like Chinese.

The free Science XL App presents the task to users as a test of word power and offers a choice of task lengths from two to six minutes. Once enrolled, participants use Yes/No buttons on the touch-screen display to indicate whether the letter strings that appear are real words or not. Each participant's performance stats are presented at the end and they are given the option of forwarding their results to the researchers via email. Extreme negative outliers were excluded from further analysis. There is the obvious issue of participants choosing to only send in favourable performance data. However, this doesn't spoil the ability to examine the effect of different factors on performance. For example, the data collected via the App matched many known features of lexical decision time data: reaction times were quicker for more common words and mean reaction times correlated with data collected in psychology labs.

Using smartphones "has wide multidisciplinary applications in areas as diverse as economics, social and affective neuroscience, linguistics, and experimental philosophy," say Dufau and his collaborators. "Finally it becomes possible to reliably collect culturally diverse data on a vast scale, permitting direct tests of the universality of cognitive theories."

This isn't the first time that psychology researchers have aired their excitement about the potential of mobile technologies to revolutionise their methods. A 2009 study used mobile phones to monitor participants' social movements and phone calls.
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Dufau, S., Duñabeitia, J., Moret-Tatay, C., McGonigal, A., Peeters, D., Alario, F., Balota, D., Brysbaert, M., Carreiras, M., Ferrand, L., Ktori, M., Perea, M., Rastle, K., Sasburg, O., Yap, M., Ziegler, J., and Grainger, J. (2011). Smart Phone, Smart Science: How the Use of Smartphones Can Revolutionize Research in Cognitive Science. PLoS ONE, 6 (9) DOI: 10.1371/journal.pone.0024974

-Thanks to Marc Brysbaert for the tip-off.

Post written by Christian Jarrett for the BPS Research Digest.

How a simple point of grammar could affect our voting decisions

A simple tweak in the tense of a verb could make the difference between electoral victory and defeat, according to a study by US researchers.

Imagine you encountered the following text: "Timmy Tucker is a senior politician. Last year Timmy championed human rights, and was fiddling his expenses."

Now compare with this version: "Timmy Tucker is a senior politician. Last year Timmy was championing human rights, and fiddled his expenses."

How does each version affect your view of Timmy Tucker? New findings from Caitlin Fausey and Teenie Matlock suggest that the first version is more likely to damage Timmy's re-election prospects.

The researchers found that the imperfect tense (e.g. "was fiddling") exacerbates the effect of a negative claim about a politician, compared with the perfect tense (e.g. "fiddled"). Fausey and Matlock aren't certain why this is, but they think the imperfect tense gives the sense that an action is ongoing, whereas the perfect tense brings closure.

For an initial study, 354 participants were split into four groups, with each reading one of four versions of a description of a politician who was up for re-election. Participants who read a version in which the man was described as last year "taking hush money" were more confident that he wouldn't be re-elected and estimated that he'd taken more money, as compared with participants who read a version in which it was written that last year "he took hush money". This subtle change in verb tense made no difference to the verdict of participants who read a positive account of the politician ("was collecting donations" vs. "collected donations").

A second study with a further 127 participants was similar except this time they all read a version that featured both a positive and negative claim about the politician. Those participants who read the description featuring a negative claim in the imperfect tense with the positive claim in the perfect tense ("was removing homes and extended roads") were less likely to say he would be re-elected (40 per cent vs. 56 per cent), compared with those who read the same claims with the tenses the other way around ("removed homes and extending roads")*.

"Because scandals involving political candidates are a hot topic in media coverage and campaign ads, insight into the power of the grammar used to communicate negative information will likely improve our understanding about how linguistic media shapes voting patterns," the researchers said.
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Fausey, C., and Matlock, T. (2011). Can Grammar Win Elections? Political Psychology, 32 (4), 563-574 DOI: 10.1111/j.1467-9221.2010.00802.x

*In this example, extending roads is assumed by the researchers to be a positive activity - environmentally minded readers might not agree with that assumption!

This post was written by Christian Jarrett for the BPS Research Digest.

Your brain unscrambles words in the mirror but then switches them back again

We humans can recognise things from different angles and orientations. As Jon Duñabeitia and his colleagues observe in their new paper, a tiger is still a tiger whether you see it facing rightwards or leftwards. When it comes to words, though, this skill largely vanishes - mirror-reversed words are especially tricky to read. It makes sense that the brain becomes sensitive to orientation in this way because, unlike the tiger, a 'd' isn't a 'd' when it faces the other way: 'b' (and the same is true for other letters).

The question that Duñabeitia set out to answer is what happens, in the case of letters, to the brain's usual ability to recognise things regardless of their orientation? Is the automatic reversal process somehow unlearned for letters, or is it merely suppressed at a later stage of processing? Given how recently in our evolutionary history we started reading and writing, the latter seems more likely.

However, a recent brain imaging study using fMRI, led by Stanislas Dehaene, suggested that the automatic reversal process was completely blocked when dealing with letters. Dehaene's team found that mirror-reversed words failed to produce a priming effect, either in terms of brain activity or behavioural performance. That is, the subliminal flash of a mirror-reversed word didn't speed up participants' recognition of that same word when it subsequently re-appeared the right way around. This suggests the mirror-reversed words weren't switched around and processed normally by the brain.

But what if the temporal resolution of fMRI is too poor to detect early mirror reversal processes? Duñabeitia's team performed an experiment in which normal and mirror-reversed words were flashed up subliminally prior to repeated presentations of those same words, but they used electroencephalography (EEG) to measure their participants' brain activity. Unlike fMRI, EEG can measure changes in brain activity over sub-second periods (although its spatial resolution is much poorer).

In contrast with Dehaene, Duñabeitia did observe a priming effect for mirror-reversed words. Although at 150ms after a prime, brain activity was different between mirror-reversed and normally oriented prime words, by 250ms the brain's response to these two kinds of prime was the same. In other words, the brain detects the mirror-reversed orientation but by 250ms it has switched it around the right way. By 400ms (still less than half a second) after the prime, the pattern had changed again, so that now the mirror-reversed prime and normally oriented prime provoked different patterns of activity (located towards the back of the brain). This could be the postulated suppression process in action.

The intriguing implication of this research is that when reading mirror-reversed words your brain automatically flips them the right way around - for an imperceptible instant you have a mirror-reading ability - but then it suppresses that effect, putting the mirror reversal back in place again, hence the words appear as awkward to read. This interpretation is consistent with the finding that many young children are capable of spontaneous mirror-writing and reading, perhaps because they have yet to develop the suppression of the automatic reversal process. There are also reports of brain injury prompting the onset of mirror reading.

This new research is more than just curiosity, it could help further our understanding of dyslexia, which in some cases is associated with the unwelcome automatic rotation of letters and words. 'Now we know that rotating letters is not a problem that is exclusive to some dyslexics, since everybody does this in a natural and unconscious way,' said Duñabeitia. 'But what we need to understand is why people who can read normally can inhibit this, while others with difficulties in reading and writing cannot.'
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Duñabeitia, J., Molinaro, N., and Carreiras, M. (2011). Through the looking-glass: Mirror reading. NeuroImage, 54 (4), 3004-3009 DOI: 10.1016/j.neuroimage.2010.10.079 [Article pdf via author website].

Stroke cures man of life-long stammer

The cerebellum is coloured green in this model

Thanks to the success of the King's Speech movie, most of us are familiar with the 'developmental' kind of stammering that begins in childhood. However, more rarely, stammering can also have a sudden onset, triggered by illness or injury to the brain. Far rarer still are cases where a person with a pre-existing, developmental stammer suffers from brain injury or disease and is subsequently cured. In fact, a team led by Magid Bakheit at Mosley Hall Hospital in Birmingham, who have newly reported such a patient, are aware of just two prior adult cases in the literature.

Bakheit's patient, a 54-year-old bilingual man, suffered a stroke that caused damage to the left side of his brain stem and both hemispheres of his cerebellum - that's the cauliflower-shaped structure, associated with motor control and other functions, which hangs off the back of the brain. The man's brain damage left him unsteady on his feet, gave him difficulty with swallowing and his speech was slightly slurred. But remarkably, his life-long stammer, characterised by repetitions of sounds, and which caused him social anxiety and avoidance, was entirely gone - an account corroborated by his wife. By the time of his discharge from hospital, the slowing of his speech was much improved and yet thankfully his stammer remained absent.

The researchers can't be sure, but they think the remission of the man's stammer is likely related to his cerebellum damage, which may have had the effect of inhibiting excessive neural activation in that structure. This would be consistent with previous research showing that people who stammer have exaggerated activation in the cerebellum compared with controls, and with the finding that successful speech therapy is associated with reductions to cerebellum activation compared with pre-treatment. A second, related possibility is that, pre-stroke, the man's cerebellum was somehow having a detrimental effect on his basal ganglia (a group of sub-cortical structures involved in motor control and other functions) and that this adverse effect was ameliorated by the stroke-induced damage. This would be consistent with reports of stammers developing in patients with diseases, such as Parkinson's, that affect the basal ganglia.

A third and final possibility, the researchers said, is simply that the slowing of the man's speech somehow aided his stammer. Indeed, reducing the rate of speech is a therapeutic approach. However, this certainly wasn't a conscious strategy employed by the patient, and as we've seen, his stammer remained in remission even as his speech rate improved.

'The complete remission of stammering following a posterior circulation stroke in our patient suggests that the cerebellum and/or its connections with brain structures has an important role in maintaining developmental stammering,' the researchers concluded.
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Bakheit AM, Frost J, and Ackroyd E (2011). Remission of life-long stammering after posterior circulation stroke. Neurocase : case studies in neuropsychology, neuropsychiatry, and behavioural neurology, 17 (1), 41-5 PMID: 20799135

Left hemisphere already specialised for language by two months of age

It's widely known that in the majority of people the left hemisphere is dominant for language. But how early does this lateralisation of function emerge? An obvious way to find out is to put babies in a brain scanner and see if their brains show the same left-sided preference for language, compared with other auditory stimuli, as is observed in adults. Of course, from a practical perspective, that's easier said than done.

Ghislaine Dehaene-Lambertz and her colleagues scanned the brains of 24 infants, aged approximately two and a half, using fMRI. The researchers didn't cheat - no sedatives were used - although an experimenter did show the babies toys, visible via a mirror, to help keep them calm. Data from just seven of the babies was usable. As Dehaene-Lambertz and her colleagues explained: 'This high attrition rate underscores the fact that fMRI remains a challenge at this age.'

The basic paradigm involved playing the babies sentences spoken by their mother and by a stranger and comparing the activity this triggered against the activity triggered by music composed by Mozart.

Speech, but not music, triggered more activity in the left versus the right hemisphere of the babies' brains. Obviously babies can't yet understand speech. A possibility is that the left-hemisphere starts out with a bias for rapidly changing stimuli - 'a bias', the researchers explained, 'that would be rapidly extended through learning to other properties of the speech signal...'.

Another finding was that a mother's voice triggered significantly greater activity in language regions than did a stranger's voice. Dehaene-Lambertz and her co-workers said this shows the mother's voice 'plays a special role in the early shaping of posterior language areas.' A further differential effect of the mother's voice is that it led to reduced activity in emotion-related regions. Perhaps, the researchers surmised, this was the neural basis of a 'soothing effect'.

Also notable was that, as in adults, the ventral (lower) portion of the left temporal lobe, but not dorsal (upper) half, showed what's known as a 'repetition effect' when the same four-second snippets of speech were replayed several times in succession. The 'repetition effect' is a reduction in activity with repetition, betraying a kind of memory for the repeated stimulus. The fact that one region of the temporal lobe showed this effect and another region didn't suggests that by two months of age the left temporal lobe is already made up of different functional sub-regions.

'A small but growing infant neuroimaging literature points to the existence, in the first few months of life, of a well-structured cortical organisation,' the researchers concluded. However, they also cautioned that 'acknowledging the existence of strong genetic constraints' on the early organisation of language-related brain regions 'does not preclude environmental influences'. Indeed, they added that: 'The present results show clearly that learning also plays a major role in structuring the infant's brain networks, inasmuch as the mother's voice has a strong impact on several brain regions involved in emotion and communication ...'.
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Dehaene-Lambertz, G., Montavont, A., Jobert, A., Allirol, L., Dubois, J., Hertz-Pannier, L., & Dehaene, S. (2010). Language or music, mother or Mozart? Structural and environmental influences on infants’ language networks. Brain and Language, 114 (2), 53-65 DOI: 10.1016/j.bandl.2009.09.003

The links between bloggers' personalities and their use of words

You can tell a person's personality from the words they use. Neurotics have a penchant for negative words; agreeable types for words pertaining to socialising; and so on. We know this from recordings of people's speech and from brief writing tasks. Now Tal Yarkoni has extended this line of research to the blogosphere by analysing the content of 694 blogs - containing an average of 115,000 words written over an average period of about two years - and matching this with the bloggers' (predominantly female; average age 36) answers to online personality questionnaires.

Some commentators have suggested that the internet allows people to present idealised versions of themselves to the world. Contrary to that idea, Yarkoni found that bloggers' choice of words consistently related to their personality type just as has been found in past offline research.

More neurotic bloggers used more words associated with negative emotions; extravert bloggers used more words pertaining to positive emotions; high scorers on agreeableness avoided swear words and used more words related to communality; and conscientious bloggers mentioned more words with achievement connotations. These were all as expected. More of a surprise was the lack of a link between the Big Five personality factor of 'openness to experience' and word categories related to intellectual or sensory experience. Instead openness was associated with more use of prepositions, more formal language and longer words.

The sheer size of the data set at Yarkoni's disposal allowed him to look not only at links between personality factors and broad word categories (as past research has done) but to also zoom in on the usage of specific words. Among the most strong and intriguing correlations were: Neuroticism correlated with use of 'irony' and negatively correlated with 'invited'; Extraversion correlated with 'drinks' and negatively correlated with 'computer'; Openness correlated with 'ink'; Agreeableness with 'wonderful' and negatively correlated with 'porn'; and Conscientiousness correlated with 'completed' and negatively correlated with 'boring'.

'The results underscore the importance of studying the influence of personality on word use at multiple levels of analysis,' Yarkoni concluded, 'and provide a novel approach for refining existing categorical word taxonomies and identifying new and unexpected associations with personality.'
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Yarkoni, T. (2010). Personality in 100,000 Words: A large-scale analysis of personality and word use among bloggers. Journal of Research in Personality, 44 (3), 363-373 DOI: 10.1016/j.jrp.2010.04.001

On a related note, don't forget our recent Bloggers Behind the (psychology) Blogs interview series.

How language reflects the balance of good and bad in the world

Imagine a garden filled with sweet smelling flowers and weeds. The flowers vastly outnumber the weeds, but the latter are more varied. And there's another asymmetry - whereas the flowers have a pleasant scent, the weeds aren't just scent-less, they're poisonous, they can kill. According to a new study, life is like this garden. Positive events outnumber negative events, but negative events are more varied and potent. Paul Rozin and colleagues say that the English language reflects this state of affairs and so do at least twenty other languages.

Rozin's team began by analysing a corpus of 100 million words of spoken and written English and found that positive words are used far more often than negative words - just as you'd expect if positive events are more common (to take one example, 'good' is mentioned 795 times per million words compared with 153 mentions per million for 'bad').

Moreover, the researchers say we've adopted a number of habits of convenience that reflect the frequent use of positive words in our language (in turn reflecting the greater frequency of positivity in the world). For example, positive words tend to be 'unmarked' - that is, the positive is the default (e.g. 'happy') whereas the negative is achieved by adding a negating prefix (i.e. 'unhappy'). Rozin cites four more such habits. Here's one more: when stating pairs of good and bad words together, it's nearly always the convention to mention the positive word first: as in 'good and bad' and 'happy and sad' rather than the other way around.

Turning to the dark side, the greater variety of negative events in the world is also reflected in English usage. For example, many negative words don't have an opposite: 'sympathy' (i.e. there's no word for sympathising about another person's good fortune), 'murderer' (there's no word for giver of life), 'risk', 'accident' etc.

To see if these patterns are reflected in other languages, Rozin's team interviewed the speakers of twenty languages (one speaker per language): Mandarin, Cantonese, Japanese, Korean, Vietnamese, Thai, Tagalog, Ibo, Arabic, Turkish, Tamil, Hindi, German, Icelandic, Swedish, French, Portugese (Brazilian), Spanish, Russian, and Polish.

Overwhelmingly, the patterns found for English also applied in these other languages. For instance, for eight sample adjectives, including 'pleasant', 'dirty', 'disgusting' and 'pure', it was the convention in 83.9 per cent of cases across all 20 languages for the positive word to be stated first alongside its negative opposite. Likewise, the negative words 'sympathy', 'murderer', 'risk', and 'accident' nearly always lacked a positive opposite.

'We hope that this study calls the attention of emotion researchers to some interesting and widespread valenced biases in the use of language,' the researchers said. 'We believe these biases are adaptive responses to asymmetries in the world, as it interacts with organisms.'
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Rozin, P., Berman, L., & Royzman, E. (2010). Biases in use of positive and negative words across twenty natural languages Cognition & Emotion, 24 (3), 536-548 DOI: 10.1080/02699930902793462

Inner words spoken in silence

As the the words fall from your lips, it's the first you've heard of them. That is, you don't have a sneak preview of what your own words sound like before you utter them. That's according to Falk Huettig and Robert Hartsuiker who say their finding has implications for our understanding of the brain's internal monitoring processes.

The researchers took advantage of an established effect whereby the sound of a spoken word draws our eyes automatically towards written words that sound similar. Forty-eight Dutch-speaking undergrads were presented with a succession of line drawings, each of which appeared alongside three written words. The participants' task was to name out loud the objects in the drawings. Meanwhile the researchers monitored their eye movements.

On each trial, one of the written words sounded like the name of the drawn object - for example, for a drawing of a heart ('hart' in Dutch), the accompanying words were: harp (also 'harp' in English), zetel ('couch') and raam ('window'). As expected, after saying the word 'hart', the participants eyes were drawn to the word 'harp'. The key question was whether this happened earlier than in previous studies in which participants heard the target words spoken by someone else rather than by themselves. If we hear our own speech internally, before we utter it, then the participants' eyes should have been drawn to the similar sounding words earlier than if they'd heard another person's utterances.

In fact, the participants' eyes were drawn to the similar sounding words with a latency (around 300ms) that suggested they'd only heard their own utterances once they were public. There was no sneak internal perceptual preview.

It's important to clarify: we definitely do monitor our speech internally. For example, speakers can detect their speech errors even when their vocal utterances are masked by noise. What this new research suggests is that this internal monitoring isn't done perceptually - we don't 'hear' a pre-release copy of our own utterances. What's the alternative? Huettig and Hartsuiker said error-checking is somehow built into the speech production system, but they admit: 'there are presently no elaborated theories of [this] alternative viewpoint.'
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Huettig, F., & Hartsuiker, R. (2010). Listening to yourself is like listening to others: External, but not internal, verbal self-monitoring is based on speech perception Language and Cognitive Processes, 25 (3), 347-374 DOI: 10.1080/01690960903046926

We're slower at processing touch-related words than words related to the other senses

People are slower at responding to tactile stimuli than to input from the other senses. It's not immediately obvious why this should be. It's unlikely to be for mechanical reasons: the retina in the eye is slower at converting input into a neural signal than is the skin. Psychologists think the answer may have to with attention. Perhaps we're not so good at keeping our attention focused on the tactile modality compared with the others. Now Louise Connell and Dermot Lynott have added to the picture by showing that the tactile disadvantage extends to the conceptual domain. That is, we seem to be slower at recognising when a word is tactile in nature than we are at recognising whether words are visual, to do with taste, sound, or smell.

The researchers had dozens of participants look at words on a screen, presented one at a time, and press a button to say if they were related to the tactile modality (e.g. 'itchy') or not. Some words were tactile-related whilst others were fillers and related to the other senses.

The same task was then repeated but with participants judging whether the words were visual-related, auditory and so on, with each sense dealt with by a new block of trials. The key finding is that participants were much slower at this task in the tactile condition than for the other senses. This was the case even when words were presented for just 17ms, which is too fast for conscious detection but long enough for accurate responding.

To make sure the slower performance in the tactile condition wasn't to do with the response requiring a button press (which inevitably causes tactile stimulation), the researchers repeated the experiment with vocal responding via a microphone. The results were pretty much the same.

Ensuring they left no stone unturned, Connell and Lynott also conducted a final experiment to check that there isn't something about tactile words, besides their touchiness, that makes them slower to process. To do this they used words that have both visual and tactile qualities - examples include shaggy and spiky - and they mixed these in among filler words that related to the other senses. The same words were used in the tactile condition (in which participants had to say whether each word was tactile-related or not) and a visual condition. Once again, participants were significantly slower in the tactile condition.

Connell and Lynott say their findings provide further evidence for the tactile sense having a processing disadvantage relative to the other senses. They think this is because there's little evolutionary advantage to sustaining attention to the tactile modality whereas there are obvious survival advantages with the other senses, for example: '...in hunting, where efficacious looking, listening and even smelling for traces of prey could afford an advantage.' You may think of pain and damage detection as reasons for paying sustained attention to the tactile domain, but remember these are served by spinal reflexes. 'We do not wait for the burning or stinging sensation to register with the attentional system before responding,' the researchers said.
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Connell L, & Lynott D (2010). Look but don't touch: Tactile disadvantage in processing modality-specific words. Cognition, 115 (1), 1-9 PMID: 19903564