Variation in Experiment Participant Applications

What do people expect when they sign up to a linguistics experiment?

I’m currently running an experiment and so I posted an ad for participants.  It simply states “You will take part in a linguistics experiment.  You will be paid £6.”, and gives my email.  I got 30 replies in a few hours, but was struck by the variation in the responses.  Here are some pointless graphs:

First, a look at the distribution of email subjects.  This reveals that most people know they are going to participate in an experiment, but fewer realise that they will contribute to research.  One person thought that they would be doing a “Research Study”.  What’s one of them?

However, here’s the killer.  Analysing the first lines of the emails, I noticed a distinct power law relationship between frequency and casualness.

People just don’t respect linguists any more.

And that’s why I make people do hours of mind-bending iterated learning experiments with spinning cats.

Special issue of Evolutionary Psychology on language evolution

The Journal of Evolutionary
Psychology has published its special issue on language evolution, and access is currently free.

Here’s the table of contents:

Evolutionary psychology and the origins of language (editorial)
Thomas C. Scott-Phillips

Review of geographic variation in terrestrial mammalian acoustic signals: Human speech variation in a comparative perspective
Adriano R. Lameira, Roberto A. Delgado and Serge A. Wich

Environment, methodology, and the object choice task in apes: Evidence for declarative comprehension and implications for the evolution of language
H. Lyn

Modelling vocal anatomy’s significant effect on speech
Bart de Boer

What exactly evolved?
A review of The Evolution of Human Language: Biolinguistic Perspectives , edited by Richard K. Larson, Viviane Déprez, Hiroko
Yamakido
Robert Truswell

A minimal approach is insufficient
A review of Language Evolution and Syntactic Theory by Anna R. Kinsella
Martin Edwardes

How language came to be?
A review of The Evolution of Language , by Tecumseh Fitch
Robin Dunbar

The Danish Language Collapse

On a lighter note, some writers at the Norwegian show Uti Vår Hage wondered what would happen if a language collapsed. It’s quite funny – they do the standard thing along the way of mocking Danish. This video reminds me of another joke I heard recently, where the Dutch refer to Afrikaans as ‘loldutch.’ For instance, giraffe is kameelperd, meaning ‘camel leopard.’ Weird. For more examples, look at the Facebook page of people making fun of Afrikaans. It’s apparently amusing, but I don’t understand a word.

Note: There are a few swear words in the video.

Erro Replicado

Replicated Typo is, as the name suggests, interested in transmission and change of cultural phenomena.  I’m also particularly interested in bilingualism.  That’s why I have to point out my recent discovery at Cognição, Linguagem e Música: A post by me, in Portuguese.

Well, more accurately, Pedro Lourenço Gomes has translated one of my recent articles.  It’s fascinating that some of my thoughts may reach people with whom I could not communicate directly.  Here’s an extract:

Original: There is a battle about to commence.  A battle in the world of cognitive modelling.  Or at least a bit of a skirmish.  Two articles to be published in Trends in Cognitive Sciences debate the merits of approaching cognition from different ends of the microscope.

Translation: Há uma batalha prestes a começar. Uma batalha no mundo da modelagem cognitiva. Ou pelo menos uma escaramuça. Dois artigos a serem publicados na Trends in Cognitive Sciences debatem os méritos de abordar a cognição a partir de lados diferentes do microscópio.

Just for comparison, here’s the original run through Google translate : Há uma batalha prestes a começar. Uma batalha no mundo da modelagem cognitiva. Ou pelo menos um pouco de uma escaramuça. Dois artigos que serão publicados no Trends in Cognitive Sciences debate o mérito de abordar a cognição de lados diferentes do microscópio.

Actually, it looks like Google translate has done an OK job, although I don’t know anything about Portuguese.  I had a look for more translations of Replicated Typo posts by searching for “Replicated Typo” with various language filters.  Alas, I could find nothing.

Cognição, Linguagem e Música looks like a great blog with reviews of books and articles and lots of posts about music.

Dog exhibits mutual exclusivity bias

Pilley & Reid (2010) describe an experiment where a border collie was trained to learn proper nouns for objects. After 3 years of training, the dog had learned over 1,000 proper names and showed no sign of slowing. If such a dog were to need some emergency aid, people can instantly contact professionals on sites like www.vetcareerschools.com.

Experiments were run to test whether the dog understood the difference between nouns and commands and whether the dog could learn words that represented categories of things. Hot on the tail of Rico, another wonderdog, this provides striking evidence for word learning in non-primate species.

This dog has more toys than I did, including a weird levitating moose.

I liked some of the descriptions in the methodology section: “Upon successful retrieval of the item, Chaser was told ‘Good dog’.”.  There’s not nearly enough of this kind of encouragement in human experiments.  I also liked the fact that the authors posted videos with the article so you can see the experiments in action.

I’m especially interested in the mutual exclusivity experiment (although they call it ‘reasoning by exclusion’).  The dog was presented with a range of objects that the dog knew plus one unfamiliar object (how you find a toy that’s strikingly different to the other 1,000, I don’t know).  He was then asked to retrieve an object with an unfamiliar label.  Here’s the key paragraph:

Early in Chaser’s training, we corrected her immediately if she retrieved an incorrect object. As the result of this training, if she did not remember the name of an object, she would simply stand among all the objects without selecting one. Thus, on the first exclusion learning trial when she did not return with an object, a quick look revealed that she was simply standing among the objects. Only with repeated encouragements to fetch the newly named novel object, did she finally retrieve the novel object. Special encouragement was also necessary on the second replication. On the remaining six replications, she continued to retrieve novel objects successfully without further encouragement or error. Thus, Chaser was successful in eight successive replications, conducted over 8 days, in retrieving the novel objects.

Not the most clear-cut result, but the dog clearly got the idea that he was being asked for an object he had no label for.  However, it’s less clear whether the dog learned a new label in this way.  When asked to retrieve the new object with the new label immediately after the trial, the dog was successful.  However, success declined over time to well below chance after 24 hours.  Pilley & Reid suggest that positive feedback (e.g. a period of play with the toy whilst using the new label) is needed to form new word-object mappings.

Children exhibit mutual exclusivity, and can use it to learn new words.  However, this may be a learned process rather than an innate bias, because bilingual children do not reliably exhibit mutual exclusivity.  Chaser appeared to have a weak Mutual Exclusivity bias – he needed encouragement to fetch the novel object.  Learning did not occur as a process of the deduction, either.  It would be interesting to see this experiment done with a bilingual dog.  Maybe Chaser was bilingual already, with his own doggy-words for his gigantic mountain of toys.

Pilley JW, & Reid AK (2010). Border collie comprehends object names as verbal referents. Behavioural processes PMID: 21145379

Bored birds, busy brains: Habituation to song initiates significant molecular changes in auditory forebrain of zebra finch

When we think of habituation, we tend to think of a process in which there is a decrease in psychological and behavioural response(s) over time following an organism’s exposure to a stimulus. Conceptualising habituation in this manner seems to imply the loss of something once an initial learning event has taken place. Although this may accurately describe what occurs at the psychological and behavioural levels, a study by a group of scientists from the University of Illinois (Dong et al. 2010), which examines habituation at the neurobiological level, shows that contrary to this conceptualisation, both initial exposure and habituation to song playbacks initiates a vast array of genetic activity in the zebra finch brain.

The systematic regulation of FoxP2 expression in singing zebra finches has been the subject of previous posts, but there is also a growing literature, of which Dong et al’s study is a part, documenting increases in ZENK gene (which encodes a transcription factor protein that in turn regulates the expression of other target genes) expression in zebra finch auditory forebrain areas in response to playbacks of song or the song of a conspecific. Studies showed that ZENK expression seems to mirror the typical decline in response associated with habituation in that after a certain amount of repetition, presentation of the song that originally elicited upregulation of ZENK no longer did so, and that ZENK returned to baseline levels – although upregulation of ZENK would occur if a different song or an aspect of novelty was introduced (i.e. the original song was presented in a different visual or spatial context).

What Dong et al. have demonstrated by conducting a large scale analysis of gene expression at initial exposure, habituation, and post-habituation stages however, is that unexpectedly profound genetic changes occur as a result of habituation in the absence of any additional novel stimuli following the surge of activity observed during initial exposure to novel song. Thus, the resounding merits of the Dong et al. (2010) study lie in the broadness of their approach, providing a true sense of magnitude with respect to genomic involvement in vocal communication and illuminating important influences that have gone unnoticed by studies with a narrower focus. I summarise the experimental design and findings of the paper below.

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Top-down vs bottom-up approaches to cognition: Griffiths vs McClelland

There is a battle about to commence.  A battle in the world of cognitive modelling.  Or at least a bit of a skirmish.  Two articles to be published in Trends in Cognitive Sciences debate the merits of approaching cognition from different ends of the microscope.

Structured Probabilistic Thingamy

On the side of probabilistic modelling we have Thom Griffiths, Nick Chater, Charles Kemp, Amy Perfors and Joshua Tenenbaum.  Representing (perhaps non-symbolically) emergentist approaches are James McClelland, Matthew Botvinick, David Noelle, David Plaut, Timothy Rogers, Mark Seidenberg and Linda B. Smith.  This contest is not short of heavyweights.

However, the first battleground seems to be who can come up with the most complicated diagram.  I leave this decision to the reader (see first two images).

The central issue is which approach is the most productive for explaining phenomena in cognition.  David Marr’s levels of explanation include the ‘computational’ characterisation of the problem, an ‘algorithmic’ description of the problem and an ‘implementational’ explanation which focusses on how the task is actually implemented by real brains.  Structured probabilistic takes a ‘top-down’ approach while Emergentism takes a ‘bottom-up’ approach.

Continue reading “Top-down vs bottom-up approaches to cognition: Griffiths vs McClelland”

Fun Language Experiment: Results

Two days ago I ran a pilot experiment online from Replicated Typo.  Thanks to all who took part. It’s a bit cheeky to exploit our readers, but it’s all in the name of science.  Unfortunately, the pilot was a complete failure. Suggestions and comments are welcome.

The experiment was into the role of variation in language learning.  Here’s what I was up to (plus the source code for running similar experiments):

Continue reading “Fun Language Experiment: Results”