Monday, December 31, 2012

Interested in a PhD fellowship in Amsterdam?

The Institute for Logic, Language and Computation (ILLC) currently has a PhD fellowship available at the Faculty of Humanities starting on 1 September 2013. Applications are now invited from excellent candidates wishing to conduct research in an area in which either the Logic and Language group or the Language and Computation group at ILLC are active, such as the computational modeling of human information processing, especially natural language and music (LaCo) and/or foundational issues in mathematics and computer science (LoCo). For more information, see here. Deadline for applications is 14 January 2013.

Saturday, December 15, 2012

Perfect Pitch: Is this for real?

Absolute Pitch (AP; Or Perfect Pitch, as some prefer to call it) is common throughout the animal world.*

However, the demonstration below is almost too good to be true. Is the dog like Clever Hans, picking up unconscious cuing, or is he indeed listening and converting the sounding pitches to key presses? 

My prediction: the dog primarily watches the eyes and other body movements of the trainer, and does not really listen. A curtain between the owner and the dog would confirm this.

N.B. See below for a composition by Brechtje van Dijk broadcasted by Vrije Geluiden in May 2013, with the two dogs. Look closely: they look carefully, but do they listen?

* N.B. Relative pitch is far more special, see earlier blogs.

Wednesday, December 12, 2012

Can rhesus monkeys detect the beat in music?

Beat induction, the ability to pick up regularity – the beat – from a varying rhythm, is not an ability that rhesus monkeys possess. These are the findings of researchers from the National Autonomous University of Mexico (UNAM) and our group in Amsterdam, which are published today in PLOS ONE.

It seems a trivial skill: children that clap along with a song, musicians that tap their foot to the music, or a stage full of line dancers that dance in synchrony. And in way, it is indeed trivial that most people can easily pick up a regular pulse from the music or judge whether the music speeds up or slows down. However, the realisation that perceiving this regularity in music allows us to dance and make music together makes it less trivial a phenomenon.

Previous research showed that not only adult humans, but also newborn babies can detect the beat in music. This proved that beat induction is congenital and can therefore not be learnt. In their experiments with rhesus monkeys, the researchers used the same stimuli and experimental paradigms from previous research conducted on humans and babies. They measured electrical brain signals using electrodes while the participants were listening.

These research results are in line with the vocal learning hypothesis, which suggests that only species who can mimic sounds share the ability of beat induction. These species include several bird and mammal species, although the ability to mimic sounds is only weakly developed, or missing entirely, in nonhuman primates.

In addition, the results support the dissociation hypothesis, which claims that there is a dissociation between rhythm perception and beat perception. This new research suggests that humans share rhythm perception (or duration-based timing) with other primates, while beat induction (or beat-based timing) is only present in specific species (including humans and a selected group of bird species), arguably as a result of convergent evolution.

ResearchBlogging.orgHoning, H., Merchant, H., Háden, G., Prado, L., & Bartolo, R. (2012). Rhesus Monkeys (Macaca mulatta) Detect Rhythmic Groups in Music, but Not the Beat PLoS ONE, 7 (12) DOI: 10.1371/journal.pone.0051369

Tuesday, December 11, 2012

Hebben apen maatgevoel? (Deel 2) [Dutch]

Fragment uit 'Op zoek naar wat ons muzikale dieren maakt':

"Leipzig, 15 juli 2011. Op het Max Planck Instituut in Leipzig woon ik de internationale Ritme, Perceptie en Productie Workshop (RPPW) bij. Het is een relatief kleine, tweejaarlijkse bijeenkomst waar zo’n dertig onderzoekers uit verschillende disciplines bij elkaar komen om het over ritme en verschillende ritmische activiteiten te hebben, zoals roeien, golfen, lopen, spreken en muziek maken. Het is voor mij een bijzondere workshop. Ik bezocht hem als student voor het eerst in 1988, en de onderzoekers die ik daar ontmoette (o.a. Christopher Longuet-Higgins en Eric Clarke) maakten destijds een onuitwisbare indruk op me. Door hun passie en fascinerende onderzoek wist ik dat ik ook de wetenschap in wilde. Sindsdien heb ik nagenoeg alle RPPW bijeenkomsten bijgewoond.

Aan het conferentiediner zit ik naast Hugo Merchant, een energieke Mexicaan die de dag ervoor een lezing gaf over zijn recente onderzoek naar de representatie van tijd en ritme in de hersenen. Een geavanceerd verhaal met verrassende uitkomsten: in de hersenen blijken verschillende soorten timers traceerbaar te zijn. De hersenen van resusaapjes wel te verstaan, die in dit onderzoek als model dienen voor de hersenen van mensen. Hugo liet zien dat bij resusaapjes specifieke hersencellen actief zijn bij het aftellen totdat er iets moet gebeuren en bij cellen die de verstreken tijd meten nadat er iets is gebeurd.

Gedurende de avond praten we uitgebreid over de interpretatie en allerhande consequenties van de resultaten, zoals het schatten van tijd, het idee van een mentale klok (centraal dan wel gedistribueerd over de hersenen) en het mogelijke verschil tussen interval-gebaseerde timing (het herkennen van ritmes) en beat-gebaseerde timing (het herkennen van regelmaat).

Op een gegeven moment vraag ik Hugo op de man af: denk je dat het mogelijk is om bij resusaapjes een EEG te meten? That’s an empirical question, antwoordt hij uitdagend. En nadat we er nog wat langer over hebben gepraat, zegt hij: Let’s do it!"

A.s. zondag, in de uitzending van Vpro's Vrije Geluiden, meer over het onderzoek naar maatgevoel bij resusaapjes.

Monday, December 10, 2012

Do music and language share the same resources?

The interest in the relationship between music and language is a long-standing one. While Lerdahl & Jackendoff in their seminal book on the generative theory of tonal music built mostly on insights of metrical phonology of the time, more recent studies draw attention to the parallels with current minimalist syntactic theory rather than phonology. However, there are compelling reasons to consider music and language as two distinct cognitive systems. Recent findings in the neuroscience of music suggest that music is likely a cognitively unique and evolutionary distinct faculty (e.g., Peretz & Colheart 2003). This is referred to as the modularity-hypothesis.

This position can be contrasted with the resource-sharing hypothesis that suggests music and language share processing mechanisms, especially those of a syntactic nature, and that they are just distinct in terms of the lexicon used (Patel 2003). For this hypothesis there is now quite some evidence (see, e.g., Slevc et al., 2009). That study showed enhanced syntactic garden path effects when the sentences were paired with syntactically unexpected chords, whereas the musical manipulation had no reliable effect on the processing of semantic violations.

However, last week a new study was published in Psychonomic Bulletin & Review (Perruchet & Poulin-Charronnat, 2012) that not only replicated the results of the former study, but also tested semantic garden paths, with – surprisingly – similar effects. The researchers suggest that the mechanism that might in fact underpin these interactions is the ‘garden path configuration’, rather than the implication of an alleged syntactic module (as is suggested by the resource-sharing hypothesis). It might well be that a different amount of attentional resources is recruited to process the linguistic manipulations and as such modulating the resources left available for the processing of music.

 ResearchBlogging.orgPerruchet P, & Poulin-Charronnat B (2012). Challenging prior evidence for a shared syntactic processor for language and music. Psychonomic Bulletin & Review PMID: 23180417

ResearchBlogging.orgPeretz, I., & Coltheart, M. (2003). Modularity of music processing Nature Neuroscience, 6 (7), 688-691 DOI: 10.1038/nn1083 Patel, A. (2003). Language, music, syntax and the brain Nature Neuroscience, 6 (7), 674-681 DOI: 10.1038/nn1082