The famous Klingon linguist, Whorf, has returned with his theories on linguistic relativity (I know, terrible joke).

The Largest Whorfian Study Ever. The Lousy Linguist looks at the paper Ways to go: Methodological considerations in Whorfian studies on motion events. As you can probably guess, the paper deals with the methodological issues surrounding linguistic . . . → Read More: Some Links #17: The Return of Whorf]]>

The famous Klingon linguist, Whorf, has returned with his theories on linguistic relativity (I know, terrible joke).

The Largest Whorfian Study Ever. The Lousy Linguist looks at the paper Ways to go: Methodological considerations in Whorfian studies on motion events. As you can probably guess, the paper deals with the methodological issues surrounding linguistic relativity. It’s all interesting stuff, bringing to light important questions about how the brain handles language. I’m fairly lay when it comes to this topic, so for more background on the current events, see similar posts over at Language Log: Never Mind the Conclusions, What’s the Evidence? and SLA Blog: Linguistic Relativity, Whorf, Linguistic Relativity.

But Science Doesn’t Work That Way: Miller & Chomsky (1963). Many of you who read this blog will be familiar with the position taken by Melody’s post over at Child’s Play: against a strong nativist position in language acquisition. It’s the first part in a series of posts so I’ll reserve judgement on her conclusions until she’s finished. But much of her post is drawn from a brilliant paper by Scholz and Pullum (2005): Irrational Nativist Exuberance. Key paragraph:

Do we really want to say that phonemes are ‘innate’?

I haven’t yet addressed how we know — with all but certainty — that the model Miller and Chomsky used had to be a poor approximation of human learning capabilities.  It has to do with phonemes.

Experiments have shown that people are remarkably sensitive to the transitional probabilities between phonemes in their native languages, both when speaking and when listening to speech.  If Miller and Chomsky’s assessment of probabilistic learning is correct, then the problem of “parameter estimation” should apply not only to learning the probabilities between words, but also to learning the probabilities between phonemes.  Given that people do learn to predict phonemes, Miller and Chomsky’s logic would force us to conclude that not only must ‘grammar’ be innate, but the particular distribution of phonemes in English (and every other language) must be innate as well.

We only get to this absurdist conclusion because Miller & Chomsky’s argument mistakes philosophical logic for science (which is, of course, exactly what intelligent design does).  So what’s the difference between philosophical logic and science? Here’s the answer, in Einstein’s words, “No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”

PLoS Blogs. Yet another blogging network. This time it’s with the Public Library of Science. The most notable move, for me at least, is Neuroanthropology. That move hasn’t seemed to impact upon their ability to produce good articles, the latest of which being in regards to Uner Tan Syndrome (I’m sure there was a documentary about this on BBC…).

Hap Map 3: more people ~ more genetic variation. Razib has a cool read on the new HapMap dataset. The current paper (Integrating common and rare genetic variation in diverse human populations) looked for variants across the genome in 11 populations, consisting of 1184 samples. It’s been especially useful with less common variants. As with previous versions, you can also explore the data. Here’s the conclusion from the paper:

With improvements in sequencing technology, low-frequency variation is becoming increasingly accessible. This greater resolution will no doubt expand our ability to identify genes and variants associated with disease and other human traits. This study integrates CNPs and lower-frequency SNPs with common SNPs in a more diverse set of human populations than was previously available. The results underscore the need to characterize population-genetic parameters in each population, and for each stratum of allele frequency, as it is not possible to extrapolate from past experience with common alleles. As expected, lower-frequency variation is less shared across populations, even closely related ones, highlighting the importance of sampling widely to achieve a comprehensive understanding of human variation.

Mathematics: From the Birth of Numbers. Someone gave this in to the charity store I work at: it’s a brilliant book by Jan Gullberg on (surprise, surprise) the history of mathematics. The first chapter was on mathematics and language, so I had to pick it up, and not just for that chapter alone, as there are plenty of gaps in my mathematical knowledge I’m sure this will clear up.

Currie TE, Greenhill SJ, & Mace R (in press). Is horizontal transmission really a problem for phylogenetic comparative methods? A simulation study using continuous cultural traits. . . . → Read More: Two new Greenhill Papers]]> Simon Greenhill has just announced two new papers on applying phylogenetic techniques to the study of culture. No doubt I’ll be blogging about these at some point in the future. Below are the abstracts:

Currie TE, Greenhill SJ, & Mace R (in press). Is horizontal transmission really a problem for phylogenetic comparative methods? A simulation study using continuous cultural traits. Philosophical Transactions of the Royal Society, B:

Phylogenetic comparative methods (PCMs) provide a potentially powerful toolkit for testing hypotheses about cultural evolution. Here we build on previous simulation work by Nunn et al. (2006) to assess the effect horizontal transmission between cultures has on the ability of both phylogenetic and non-phylogenetic methods to make inferences about trait evolution.

We found that the mode of horizontal transmission of traits has important consequences for both methods. Where traits were horizontally transmitted separately PCMs accurately reported when trait evolution was not correlated even at the highest levels of horizontal transmission.

In contrast, linear regression analyses often incorrectly concluded that traits were correlated. Where simulated trait evolution was not correlated and traits were horizontally transmitted as a pair both methods showed increased levels of positive correlation with increasing horizontal transmission.

Where simulated trait evolution was correlated increasing rates of separate horizontal transmission led to decreasing levels of correlation for both methods, but that increasing rates of paired horizontal transmission did not. Furthermore, the PCM was also able to make accurate inferences about the ancestral state of traits.

These results suggest that under certain conditions PCMs can be robust to the effects of horizontal transmission. We discuss ways that future work can investigate the mode and tempo of horizontal transmission of cultural traits.

 Gray RD, Bryant D, & Greenhill SJ (in press) On the shape and fabric of human history. Philosophical Transactions of the Royal Society, B:

In this paper we outline two debates about the nature of human cultural history. The first focuses on the extent to which human history is treelike (its shape), and the second on the unity of that history (its fabric).

Proponents of cultural phylogenetics are often accused of assuming that human history has been both highly tree-like and consists of tightly linked lineages. Critics have pointed out obvious exceptions to these assumptions.

Instead of a priori dichotomous disputes about the validity of cultural phylogenetics phylogenies, we suggest that the debate is better conceptualized as involving positions along continuous dimensions. The challenge for empirical research is therefore to determine where particular aspects of culture lie on these dimensions.

We discuss the ability of current computational methods derived from evolutionary biology to address these questions. These methods are then used to compare the extent to which lexical evolution is treelike in different parts of the world and to evaluate the coherence of cultural and linguistic lineages.

Last year at Edinburgh’s Fringe Festival me and several of my friends saw this brilliant show called the Rap Guide To Evolution (which I briefly blogged about here). Well this year the same rapper, one Baba Brinkman, was back with a new show: the Rap Guide to Human Nature. Unlike most rap attempts at . . . → Read More: The Rap Guide to Human Nature]]>

Last year at Edinburgh’s Fringe Festival me and several of my friends saw this brilliant show called the Rap Guide To Evolution (which I briefly blogged about here). Well this year the same rapper, one Baba Brinkman, was back with a new show: the Rap Guide to Human Nature. Unlike most rap attempts at explaining science, it doesn’t sound like a bad Beastie Boys and Sugarhill Gang pastiche of awkward cadence and simple rhyming. Also, it includes some brilliant interludes from various scientists and researchers, including Olivia Judson and David Sloan Wilson. Here is a video of him performing at Binghampton University (I suppose his audience isn’t straight outta compton):

According to the evolutionary psychologist Geoffrey Miller and his colleagues (e.g Miller 2000b), uniquely human cognitive behaviours such as musical and artistic ability and creativity, should be considered both deviant and special. This is because traditionally, evolutionary biologists have struggled to fathom exactly how such seemingly superfluous cerebral assets would have aided our survival. By the . . . → Read More: The Problem With a Purely Adaptationist Theory of Language Evolution]]>

According to the evolutionary psychologist Geoffrey Miller and his colleagues (e.g Miller 2000b), uniquely human cognitive behaviours such as musical and artistic ability and creativity, should be considered both deviant and special. This is because traditionally, evolutionary biologists have struggled to fathom exactly how such seemingly superfluous cerebral assets would have aided our survival. By the same token, they have observed that our linguistic powers are more advanced than seems necessary to merely get things done, our command of an expansive vocabulary and elaborate syntax allows us to express an almost limitless range of concepts and ideas above and beyond the immediate physical world. The question is: why bother to evolve something so complicated, if it wasn’t really all that useful?

Miller’s solution is that our most intriguing abilities, including language, have been shaped predominantly by sexual selection rather than natural selection, in the same way that large cumbersome ornaments, bright plumages and complex song have evolved in other animals. As one might expect then, Miller’s theory of language evolution has been hailed as a key alternative to the dominant view that language evolved because it conferred a distinct survival advantage to its users through improved communication (e.g. Pinker 2003). He believes that language evolved in response to strong sexual selection pressure for interesting and entertaining conversation because linguistic ability functioned as an honest indicator of general intelligence and underlying genetic quality; those who could demonstrate verbal competence enjoyed a high level of reproductive success and the subsequent perpetuation of their genes.

There are certainly aspects of the broader argument surrounding Miller’s idea that warrant exploration, such as the idea that linguistic competence may be influenced by genetic integrity – a topic I intend to discuss in future posts. Thus, it is perhaps unfortunate that romantic appeal renders this theory the type most vulnerable to popularisation and depictions of doe-eyed cavemen and women courting one another with prose rivalling Shakespeare and cadences comparable to Beethoven. But aside from the potential to conjure sickening visions of early Homo in love to mind, there’s a much more fundamental reason why Miller’s theory isn’t viable.

Linguists have long recognised that language is made up of up of a number of independent yet integrated components (prosody, phonology, morphology, syntax, morphosyntax and semantics), all of which are important in forming the effective communication system we use today. Following on from this, the position adopted by most evolutionary linguists is that language is therefore far too complex to have evolved spontaneously, but rather, that each linguistic component evolved separately, most likely in response to differing selection pressures and at different times in human evolutionary history (linguists refer to these intermediate stages as ‘protolanguage’), becoming integrated to form fully complex language with the advent of modern Homo sapiens.

From the viewpoint of most linguists then, Miller’s theory runs into a glaring paradox: Language could not have evolved primarily as a result of pressure for verbal creativity, because language would have to evolve to a substantially sophisticated degree beforehand in order for verbal creativity to be evaluated. For example, without an evolved capacity to produce distinct meaningless units of sound (the phonological capacity) there would be no opportunity for a species to develop the ability to recombine these sounds into the meaningful combinations that we call words. Miller’s theory still remains unrealistic even if conceptualised in the context of an ancestral population of rudimentary vocabulary users, because without the existence of syntactical rules with which to order words, it is unlikely that resulting stories would have encoded sufficient semantic weight to warrant assessment for entertainment or interest value.

Language and Music: Big Lumps of Behaviour?

It soon becomes clear that the key factor influencing the nature of Miller’s idea is his purely adaptationist approach to the study of language evolution, that is, he has focused exclusively on the possible reproductive and survival payoffs that language conferred and has purposefully ignored the importance of phylogenetic inquiry i.e. what language ‘looked like’ at successive stages of its evolution. In doing so, Miller explicitly rejects the conception of language as an entity of components, viewing this as an unnecessary abstraction that obscures functional analysis. By reducing language to a ‘big lump of behaviour’ Miller has inadvertently sent his theory spiraling into difficulty.

It is worth noting that Miller has applied this same rationale to the evolution of music (see Miller 2000a), but somewhat more successfully. There is a crucial reason for this. Like language, music can be conceived of as an integrated system of components (such as pitch, melody, rhythm etc.). However, as musical components are not semantically meaningful in the same sense that language components are, explaining the function of music (as conceived as a big lump of behaviour) without referring to intermediate evolutionary stages does not create the paradox encountered by the same approach to language, and not as much is compromised at the mercy of Miller’s parsimonious ideal.

Of course, the overriding issue here is not Miller’s enthusiasm in asserting the value of the adaptationist approach, but rather, his particular use of the adaptationist approach in isolation. With regards to a trait with such inherent complexity as language, the virtue of the adaptationist approach can be realised only in light of experimental data, comparative evidence from other species and most importantly, phylogenetic scrutiny.

References

Miller, G. F. (2000a) Evolution of Human Music Through Sexual Selection. In Wallin, N. L., Merker, B. (eds.) The Origins of Music. MIT Press pp.329-360.

Miller, G.F. (2000b) The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature. New York: Doubleday.

Pinker, S. (2003) Language as an Adaptation to the Cognitive Niche. In:  Christiansen, M.H and Kirby, S (Eds.) Language Evolution (2003) Oxford: Oxford University Press. p.16-37.

I’m not normally one for violent resolutions to sloppy science, but in taking inspiration from one such perpetrator I’m promoting a Falcon Punch policy. Above is a graphical example of a successful Falcon Punch: the goal being to hurl your target onwards and upwards into a flaming ball of scientific shame.

Space . . . → Read More: Some Links #16: Why I want to Falcon Punch (some) BBC Science Writers]]>

I’m not normally one for violent resolutions to sloppy science, but in taking inspiration from one such perpetrator I’m promoting a Falcon Punch policy. Above is a graphical example of a successful Falcon Punch: the goal being to hurl your target onwards and upwards into a flaming ball of scientific shame.

Space is the final frontier for evolution, study claims. I had planned on writing a more substantial article on how yet another science writer, in this case one Howard Falcon-Lang, is claiming that Darwin has once again been felled by a new study. Greg Laden, however, beat me to the punch with a damning critique:

If Howard Falcon-Lang did not a) claim to be a science reporter and b) have a dumb-ass hyphenated name, I’d be nice in my critique of his recent writeup. But no. He left me no choice. I will have to take it apart red in tooth and claw.

Charles Darwin may have been wrong when he argued that competition was the major driving force of evolution.

OK, this is a little premature for me to say here, but as you read on you’ll see that my assertion is justified: Mr. Falcon-Lang is not really in a position to make any kind of claim regarding the wrongness or rightness of a genius of the level of Dr. Darwin.

He imagined a world in which organisms battled for supremacy and only the fittest survived.

No. That is the world that so many hack science writers, creationists, and various Darwin detractors imagine. Darwin wrote endlessly about differential survival, differential reproduction, mate selection, and all the myriad forces that determine selection (and randomness). He did not imagine the thing Mr. Falcon-Lang imagines him to have imagined.

The paper in question is actually a large-scale study on biodiversity, with the supposed contention arising from how ecological diversity is driven by expansion and contraction of occupied ecospace, as opposed to direct competition within existing niches. It’s hardly a new idea nor the revolutionary overthrow of all accepted knowledge on natural selection and other evolutionary processes. As Greg notes, what is new is the use of “good available data that demonstrates this concept”.

Altmann: Hauser apparently fabricated data. In keeping with the shoddy science theme… I’ve been keeping a close eye on the Hauser story, ever since it first came to my attention early this month. I’ve refrained from saying too much on the subject because I didn’t really know what was going on, other than a few of allegations being bandied about concerning said individual. Mark Liberman’s post has, for me at least, clarified my position somewhat in that it appears Hauser fabricated data; it wasn’t just some accidental coding mistake as previously suggested. So it’s looking pretty bad, even though we still know very little about the ins and outs of the situation. Another good recent article on the topic: Hausergate: Scientific Misconduct and What We Know We Don’t Know.

Scientists must fight for their funding. Former Liberal MP, Dr Evan Harris, has made an impassioned plea for British scientists and investors to make their voices heard against the prospects of significant cuts in scientific funding:

Cuts to science do not just mean a hiatus in some experiments: they force highly qualified individuals to go abroad or leave research. If they are forced to quit, the nature and speed of global research is such that these people will not be able to resume their careers a few years later when investment picks up again. The research and development labour supply is not a tap that can be turned on and off in line with short-term political decisions.

Coloured Hearing in Williams Syndrome. Kevin Mitchell over at GNXP Classic has another fascinating post, this time on Williams Syndrome and synaesthesia — and how these two conditions may share some unexpected similarities:

A recent study from Elisabeth Dykens and colleagues adds a new twist to this story. They found in a neuroimaging experiment that in addition to activating the auditory cortex, music also stimulates visual activity and perceptions in Williams patients. In fact, this is not specific to music – non-musical sounds had the same or even stronger effects.

Does Language Shape How You Think. If your after competent and consummate science journalism, then New York Times is never far from the mark: here, Guy Deutscher covers the increasingly popular topic of how language shapes our thoughts. Particularly intriguing is the section on Guugu Yimithirr; a language that’s reliant on cardinal directions rather than egocentric ones (such as left or right). Key paragraph:

But there is more to the effects of a geographic language, for the sense of orientation has to extend further in time than the immediate present. If you speak a Guugu Yimithirr-style language, your memories of anything that you might ever want to report will have to be stored with cardinal directions as part of the picture. One Guugu Yimithirr speaker was filmed telling his friends the story of how in his youth, he capsized in shark-infested waters. He and an older person were caught in a storm, and their boat tipped over. They both jumped into the water and managed to swim nearly three miles to the shore, only to discover that the missionary for whom they worked was far more concerned at the loss of the boat than relieved at their miraculous escape. Apart from the dramatic content, the remarkable thing about the story was that it was remembered throughout in cardinal directions: the speaker jumped into the water on the western side of the boat, his companion to the east of the boat, they saw a giant shark swimming north and so on. Perhaps the cardinal directions were just made up for the occasion? Well, quite by chance, the same person was filmed some years later telling the same story. The cardinal directions matched exactly in the two tellings. Even more remarkable were the spontaneous hand gestures that accompanied the story. For instance, the direction in which the boat rolled over was gestured in the correct geographic orientation, regardless of the direction the speaker was facing in the two films.

Drift

An important point which has not been highlighted in the . . . → Read More: Evolution of Colour Terms: 10 Universal Patterns are not Evidence for Innate Constraints]]> In a series of posts, I’ve been discussing constraints on the evolution of colour terms. Here, I discuss the role of drift and also argue that universal patterns are not necessarily good evidence for innate constraints. For the full dissertation and references, go here.

Drift

An important point which has not been highlighted in the literature is the drift introduced by cultural transmission.  Perceptual systems are noisy, and change over lifetimes.  Therefore, systems of categorising these perceptions may drift over time.  However, if concepts are shared, this drift is influenced by more than one system.  This may cause a different kind of drift from a stand-alone system for self-thought.  Communication has an additional semantic bottleneck which self-though does not have.  Using language for self thought, if you don’t know a label, you can make one up.

However, for communication, this won’t work.  For example, in models of cultural transmission (e.g., Steels & Belpaeme, 2005) agents do create new labels but, importantly, accept the speaker’s label when available.  That is, communicative systems are more flexible than systems for self-thought (communicators must be more willing to change their minds), and so are more subject to drift.  The drift allows the system to move around the possible space of coding efficiency and object categorisation efficiency.  Peaks in these landscapes will attract the drift, hence environmental and perceptual constraints being projected into language.

Although systems of colour categorisation for self-thought may be more efficient if they were constrained by the environment, shared cultural systems are more likely to reflect constraints in the environment because they are more flexible.  That is, perceptual constraints have projected themselves into language because of a communicative pressure, rather than a perceptual or environmental pressure.

I suggest that this drift, together with an ability for categories to warp perceptual spaces, would mean that individuals converge on a shared perceptual system.  If comprehension involves the activation of perceptual representations, then communication involves individuals reaching similar perceptual representations or, in a perfect world, activation of the same neural substrates.  Therefore, a population with a shared perceptual system would be able to communicate much more effectively.  In this sense, Embodied systems improve communicative success, whereas the same effect is not necessarily true of Symbolist systems. Furthermore, this drift means that populations can still converge on similar solutions, without having to assume that Universal biases are the main driving force.  It has been argued that the similarities in colour categorisation between cultures contradicts Relativism, which would predict a large variation in colour categorisation between cultures (e.g., Belpaeme & Bleys, 2005).  I argue that this inference is not necessarily valid.

Summary

This series of posts has shown that a wide range of factors constrain the categorisation of colour, including the physiology of perception, the environment and cultural transmission.  Why is there evidence for Colour Terms being adapted to so many domains?

This study considered the idea that categorisation acquired by individuals can feed back into perception and itself become a constraint both on the development of categorisation, the environment and genetic inheritance.  In this sense, the feedback from categorisation allows Niche Construction dynamics to apply to linguistic categorisations.  It was argued that this dynamic fits with the Cultural implication of an Embodied account of language comprehension.  That is, this study has concluded, similarly to Kirby et al. (2007), that universal patterns across populations do not necessarily imply strong innate biases.  This was done by arguing that Cultural, Embodied systems tend to drift towards better representations of the real world, which involves better coherence with perceptual and environmental constraints, creating cross-cultural patterns.  Furthermore, an Embodied approach to cultural dynamics incorporating a mechanism for perceptual warping predicts that the perceptual spaces of individuals can be synchronised through language to achieve better communication.

Steels, L., & Belpaeme, T. (2005). Coordinating perceptually grounded categories through language: A case study for colour Behavioral and Brain Sciences, 28 (04) DOI: 10.1017/S0140525X05000087

Belpaeme, T. (2005). Explaining Universal Color Categories Through a Constrained Acquisition Process Adaptive Behavior, 13 (4), 293-310 DOI: 10.1177/105971230501300404

Kirby, S., Dowman, M., & Griffiths, T. (2007). Innateness and culture in the evolution of language Proceedings of the National Academy of Sciences, 104 (12), 5241-5245 DOI: 10.1073/pnas.0608222104

This section reiterates how a link between linguistic categories and perception fits into Niche Construction Theory.  If concepts can influence perception, and people share the same concepts, their perceptions will . . . → Read More: Evolution of Colour Terms: 9 Niche Construction]]> In a series of posts, I’ve been discussing constraints on the evolution of colour terms. For the full dissertation and references, go here.

This section reiterates how a link between linguistic categories and perception fits into Niche Construction Theory.  If concepts can influence perception, and people share the same concepts, their perceptions will become synchronised.  This would render them more effective at communication, since referents would be perceived as similar (‘red’ can refer to the same domain of entities for each individual).  Furthermore, it may render them more able to co-operatively build a better model of the actual environment (for instance, describing an unseen danger, or researching physics).  However, this will only be true if language is grounded in constraints that come from the actual environment.  If this were not the case, apart from being inefficient at describing the actual environment, a language may drift to influence the perceived environment in a way that results in a worse fit with the actual environment.

Returning to the constraints diagram (above), note that the influence of categorisation continues, through action, to change the environment.  In other words, if language influences the perceived environment and facilitates communication, then it may also facilitate the way we change the actual environment.  In this sense, language’s influence on perception can be regarded as a form of Niche Construction (Laland, Odling-Smee & Feldman, 2000).  Therefore, not only does language become better at describing the actual environment, but the environment becomes better suited to being described by language.  This creates a better fit between perceived and actual environments and possibly increases the fitness of language users.  Essentially, then, this study presents evidence for language-specific niche construction where language can influence the environment.  This dynamic would be a consequence of an Embodied system, and more efficient as part of an Embodied system than a Symbolist account.  I therefore argue that the Embodied account is supported.

As an example of this dynamic, Hansen et al. (2006) showed that perception is affected by semantic knowledge, specifically that achromatic bananas look yellow.  However, bananas are domesticated (Heslop-Harrison & Schwarzacher, 2007).  The link between a banana’s structure and colour, therefore, is a constructed niche – cultivators fertilise the ‘best’ bananas, which go on to influence the way they perceive bananas, which affects which bananas they fertilise, and so on.  This means that the effect found in Hansen et al. cannot be innate, since the colour and structure of a banana have changed (see below).  Modulating perception with flexible, high-level categories is a way of keeping up with rapidly changing environments.

Differing structures and colours of six species of banana, all ripe. Top left: Musa balbisiana, ancestor of modern cultivated bananas. Top right: Pink Banana (Musa velutina). Bottom, from left to right: Plantains (Musa paradisiacal), red bananas (Musa rutilus), Bananito (Musa acuminate) and Cavendish bananas (Musa cavendishii). Images from Wikimedia Commons, http://commons.wikimedia.org

Less anecdotally, Griffin’s (2006) model, which classified objects using colour (see section 5.2.2), found that natural colour categories optimally aid the identification of objects.  Furthermore, the model performed equally well for natural and manufactured objects.  That is, manufactured objects have been coloured to be maximally classifiable by colour, according to linguistic colour categorisations.  This would be an intuitive and efficient tactic if, as Embodied Cognition suggests, comprehension is scaffolded onto systems of object recognition (MacWhinney, 1999).  There would be no advantage in doing this in a Symbolist system where perceptions and concepts have arbitrary connections.

Next, why universal patterns are not evidence for innate constraints ->

Laland, K., Odling-Smee, J., & Feldman, M. (2000). Niche construction, biological evolution, and cultural change Behavioral and Brain Sciences, 23 (1), 131-146 DOI: 10.1017/S0140525X00002417

Hansen, T., Olkkonen, M., Walter, S., & Gegenfurtner, K. (2006). Memory modulates color appearance Nature Neuroscience, 9 (11), 1367-1368 DOI: 10.1038/nn1794

Heslop-Harrison, J., & Schwarzacher, T. (2007). Domestication, Genomics and the Future for Banana Annals of Botany, 100 (5), 1073-1084 DOI: 10.1093/aob/mcm191

Griffin, L. (2004). Optimality of the Basic Colours Categories Journal of Vision, 4 (8), 309-309 DOI: 10.1167/4.8.309