Bob Berwick and Noam Chomsky’s new book Why Only Us: Language and Evolution has been making the rounds. I assumed this book would just be a re-hash of the fairly tiresome, hyper-sceptical ‘mystery of language evolution’ perspective the authors usually adopt. And it is in some respects. But it also includes a surprisingly decent discussion of recent literature on animal cognition. Berwick’s ideas come through more clearly throughout the text, typically backed up with the usual selection of Chomsky’s rhetoric, Martian analogies, irony and so forth. But both authors only brush over their core question of how hierarchy is actually established, pointing languidly to ‘some algorithm’ responsible for labeling (p. 10). It should be stressed I think that even Chomsky’s more recent technical work doesn’t go far beyond this ‘some algorithm’ attitude (2013, 2015). From the perspective of brain dynamics, ‘some algorithm’ becomes capable of being explored in a number of interesting ways, as I mention here and here and in upcoming papers (see also Boeckx and Theofanopolou’s useful response to the latter paper).
Neural oscillations might be a nice way of exploring mesoscopic computations across a number of cognitive faculties, as is already being done in domains outside language like working memory. Consider a relatively simple example. The model of linguistic computation I drew up here invokes a number of cross-frequency coupling operations, and I think we can use what we know about the linguistic profile of ASD and schizophrenic patients to empirically test it. It’s of interest, for instance, that schizophrenic patients showed higher γ-α cross-frequency coupling in Popov and Popova’s recent study of general cognitive performance, despite this co-varying with poorer attention and working memory capacities. This is surprising given that most studies show reduced left frontal γ in schizophrenia. The reason for this may be that the increased phase-amplitude-locking likely results in smaller ‘gamma pockets’ of working memory items (as Korotkova and colleagues argue on independent grounds) and hence low total γ power. In this instance, the size and order of working memory sequences outputted by the conceptual system is not optimally compatible with the oscillopathic profile, leading to greater rhythmic excitability and yet inhibited linguistic functionality. Global rhythmicity is consequently disrupted due to unusually strong fronto-parietal interconnectivity.
In upcoming work I suggest that this represents a genuine neural mechanism of an ‘interface’ between syntactically generated conceptual representations and external (memory) systems; a highly significant finding if corroborated by further experimental studies. Importing standard assumptions from syntax, we can think of the computational system as imposing its own conditions on the interfaces (i.e. standard minimalism). The shift in perspective to oscillatory terms allows us to reformulate this such that the neural ensembles responsible for storing representations (lexical roots) used to construct phrases require particular phase-amplitude-locking levels in order for the interconnected regions coupled with them to ‘read off’ their content. So oscillations can provide a nice way of exploring just what kind of ‘features’ (however defined) can ‘pass through’ the interfaces. And because each rhythm plays numerous, non-overlapping roles, it’s crucial for these oscillopathic studies to be accompanied by biophysical modeling and computationally explicit mesoscopic frameworks of regionally localized cross-frequency coupling functionality. Poeppel’s work, for instance, points to particular individual rhythms as entraining to certain structures, but recent work suggests that it’s not just rhythms, but crucially their coupling to other rhythms which delivers complex computations. There’s one sentence in Poeppel’s recent Nature paper about this, but it needs to be focused on much more.
Berwick’s influence is clearly strong in the book, generating less rhetorical posturing and more critical engagement and literature reviewing. Grand Chomskyan sentences like ‘Rational inquiry into the evolution of some system evidently can proceed only as far as its nature is understood’ and ‘These truisms hold of the study of the human language faculty just as for other biological systems’ are nicely supplemented by a fair amount of detail and actual proposals and directions. It’s a bit surreal having these authoritative Chomskyan phrases right next to pithy Berwickean jokes, though. But this isn’t a novel, it’s a pop-sci book, so it works well enough.
The authors hypothesize about Neanderthal braincase size, for some reason completely ignoring Boeckx and Benitez-Burraco’s important ‘globularity’ proposal, worth taking seriously. To top it off, there are quite a few typos and incorrect citations (date, ordering etc). Chomsky even incorrectly cites POP as 2012, despite being published online on January 6th 2013, and widely cited as a 2013 paper.
Berwick’s (I assume the influence is his, given Chomsky’s typically evasive responses to neuro-related Q&A sessions, i.e. ‘I will answer your question about X by briefly mentioning X-related topics before slowly beginning a monologue about Y’) approach to neurolinguistics is also hopelessly outdated. He sticks purely to localisation issues, answering the ‘How’ question of language evolution by just pointing to good old BA44 and 45. This ignores how the brain actually functions (via oscillations and their numerous coupling operations: phase-amplitude, phase-phase, etc) and keeps solely to the basic understanding we have of where in the brain complex dynamic operations centre around. They even ‘(speculatively) posit that the word-like elements, or at least their features as used by Merge, are somehow stored in the middle temporal cortex as the “lexicon”’ (p. 159). This is really quite breathtaking in its simplicity, and ignores well-accepted ‘truisms’ in cognitive neuroscience that conceptual representations are widely distributed in many other regions, even if the middle temporal cortex acts as a crucial memory buffer in phrase structure building (just as how Broca’s area is most likely a similar kind of buffer in syntactic computation, and not the ‘seat of syntax’ as Friederici has often claimed). I can guarantee that if I had put my hand up in graduate neurolinguistics classes and told everyone that the lexicon is in the middle temporal cortex (next to all the odd numbers stored in the angular gyrus and my Top 10 Tom Cruise movies somewhere between BA35 and 36), I would have been laughed out of the room.
In brief, the book is a useful guide to minimalist approaches to language evolution, and I’d most likely recommend it to an outsider. But it ignores far too much of the genetics, neurobiology, and neuropsychological literature to be taken very seriously. The book isn’t strong enough to back up its declarative Why Only Us title and should really have an accompanying ?, ideally to reflect the author’s palpable myopia concerning certain issues, along with the serious acknowledgement that most of the topics of language evolution (like language use) do indeed remain in the dark, although some – given the right multidisciplinary perspective – are becoming increasingly tractable.