Human FOXP2 "Knock-in" Mice

In chapter 2 of NOT A CHIMP I report that Wolfgang Enard, at the Max Planck Institute for Evolutionary Anthropology in Leipzig, was about to do experiments where the human version of the FOXP2 "language gene" has been "knocked in" to mice. The human FOXP2 protein differs from the version in chimps by two amino-acid substitutions. Interestingly they now report, in the May 29th edition of Cell, that the "mice with the human FOXP2 show changes in brain circuits that have been previously linked to human speech. Intriguingly enough, the genetically altered mouse pups also have qualitative differences in ultrasonic vocalizations they use when placed outside the comfort of their mothers' nests". Enard's "knock in" research nicely mimics Joseph Buxbaum's "knock out" research, reported in my book, where he knocked out the murine FOXP2 from mice and noticed severe developmental abnormalities when both copies of the gene were knocked out, but when only one copy was removed the pups failed to produce the same ultrasonic distress calls noted by Enard. Physorg reports Enard's group as saying: "Since patients that carry one nonfunctional FOXP2 allele show impairments in the timing and sequencing of orofacial movements, one possibility is that the amino acid substitutions in FOXP2 contributed to an increased fine-tuning of motor control necessary for articulation, i.e. the unique human capacity to learn and coordinate the muscle movements in lungs, larynx, tongue and lips that are necessary for speech."

Stretching Your Mouth Affects What You Hear

In my chapter INSIDE THE BRAIN I explain how the operation of certain mirror neurons in turning perception of speech in others into your own speech production was, in effect, a demonstration of the so-called motor theory of speech. Here, in this Scientific American piece, is a fascinating bit of support for this theory from David Ostry, a neuroscientist from McGill University, Montreal. Ostry used a robotic device to pull and tug areas around the mouth when volunteers synchronously heard speech sounds. So, for instance, when the volunteer heard a speech sound that could have been "head" or had" he was more likely to interpret that sound as "head" if his mouth was stretched upwards slightly toward the position he would use if he were saying the word "head". Ostry's work not only supports the idea that we use mirror neurons to learn how to speak by monitoring others' speech and reproducing those sounds for ourselves, it supports the idea that speech and language and speech production use the same motor circuits in the brain. This might help us to understand why the speech impediments in the KE family, which I report in Chapter 2 of NOT A CHIMP, are also associated with certain grammar deficits.

Mirror Neuron Theory Under Fire

I deal with mirror neurons in my chapter Inside The Brain, and slid in a short mention that not everyone in the world of neuroscience is a firm believer that mirror neurons exist and are the fundamental plank of much social cognition. Here New Scientist reports the work of Alfonso Caramazza, of Harvard University, who argues that neurons should adapt to repeated stimulation by reducing successive responses. If mirror neurons, which are said to fire both when you observe an action in the outside world and when you perform the similar action (a hand gesture for instance) for yourself, really do exist they should adapt therefore to both observation and performance - but they do not. He found only that they adapted when gestures were observed then enacted, but not the other way round. Mirror neuron afficionado Marco Iacoboni, however, is not impressed, claiming that mirror neurons are different to most classes of neurons in that they do not adapt. This would seem to be a space to watch. Mirror neuron skepticism is not going to go away.

Rooks Make and Use Tools

Rooks are not observed using tools in the wild, which makes this discovery by Nathan Emery and the appropriately named Christopher Bird (see my chapter Clever Corvids) all the more interesting because they prove to be adept tool users and makers in the laboratory setting. We need an explanation for this "latent" form of cognition. As the BBC article explains, they perform on first trial without intensive learning. They prove able to select an appropriate stone for diameter to push into a tube to release a trap-door and thus the food, and they fashion appropriate hooks from straight pieces of metal to fish for food in a bucket in a perspex well. They have also been seen to make tools involving two steps. This is immensely important because it means that the rooks are not operating under some simple behavioural rule which rewards with instant gratification but can use a tool to make a tool to get the reward - a much more impressive feat. This is called metatool use and was previously thought to be unique to hominins. Rooks have now joined New Caledonian crows as the master tool-makers of the animal world showing, again, that big-brained corvids are a match for chimps in this area at least. You can find he abstract to their paper in PNAS at http://www.pnas.org/content/early/2009/05/28/0901008106.abstract?etoc=

The Oxytocin Receptor and Human Altruism

In "Not A Chimp" I explain how vasopressin, specifically the activity of variants of the vasopressin receptor gene in the brain, relate to monogamy, pair-bonding, social affiliation and altruism. Now the same research group involved in the vasopressin-altruism research, led by Richard Ebstein of the Hebrew University, Jerusalem, have extended their work, using the Dictator Game as a proxy for altruism, to the other half of the "cuddle" hormone duo - oxytocin. How generous you are to your partner on the game relates to whether you are prosocial, proself, or ruthlessly selfish. They discovered a number of polymorphisms of the oxytocin receptor gene that were strongly associated with prosocial, altruistic behaviour. This list of gene variants strongly associated with human variation for different aspects of social behaviour is growing all the time!

Musical Aptitude linked to Vasopressin Receptor Gene Variants

In the penultimate chapter of "Not A Chimp" I fashion the beginnings of a biosocial science to human nature founded on genetic variants for a number of neurotransmitters and hormones including dopamine, serotonin and vasopressin. Here a group from Finland look at the same variants of the vasopressin receptor gene avpr1a that had been previously linked to ability for creative dance by Rachel Bachner-Melman. They have shown that aptitude for structuring music, time and pitch are all significantly associated with certain of these variants. Although it's difficult to pin down, they say, the precise selective advantage to humans of musical ability, it is clearly a social exercise, might make you attractive to the opposite sex, and is an important element of group cohesion and collective ritual. We have to be a bit careful of these results because the scores for the various aspects of musical ability were compiled from Internet questionnaires and there is always the possibility of self-reporting bias creeping in. Nevertheless, a nice addition to this burgeoning field.