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Non-hexagonal neural dynamics in vowel space

  • Received: 29 April 2020 Accepted: 27 July 2020 Published: 04 August 2020
  • Are the grid cells discovered in rodents relevant to human cognition? Following up on two seminal studies by others, we aimed to check whether an approximate 6-fold, grid-like symmetry shows up in the cortical activity of humans who “navigate” between vowels, given that vowel space can be approximated with a continuous trapezoidal 2D manifold, spanned by the first and second formant frequencies. We created 30 vowel trajectories in the assumedly flat central portion of the trapezoid. Each of these trajectories had a duration of 240 milliseconds, with a steady start and end point on the perimeter of a “wheel”. We hypothesized that if the neural representation of this “box” is similar to that of rodent grid units, there should be an at least partial hexagonal (6-fold) symmetry in the EEG response of participants who navigate it. We have not found any dominant n-fold symmetry, however, but instead, using PCAs, we find indications that the vowel representation may reflect phonetic features, as positioned on the vowel manifold. The suggestion, therefore, is that vowels are encoded in relation to their salient sensory-perceptual variables, and are not assigned to arbitrary grid-like abstract maps. Finally, we explored the relationship between the first PCA eigenvector and putative vowel attractors for native Italian speakers, who served as the subjects in our study.

    Citation: Zeynep Kaya, Mohammadreza Soltanipour, Alessandro Treves. Non-hexagonal neural dynamics in vowel space[J]. AIMS Neuroscience, 2020, 7(3): 275-298. doi: 10.3934/Neuroscience.2020015

    Related Papers:

  • Are the grid cells discovered in rodents relevant to human cognition? Following up on two seminal studies by others, we aimed to check whether an approximate 6-fold, grid-like symmetry shows up in the cortical activity of humans who “navigate” between vowels, given that vowel space can be approximated with a continuous trapezoidal 2D manifold, spanned by the first and second formant frequencies. We created 30 vowel trajectories in the assumedly flat central portion of the trapezoid. Each of these trajectories had a duration of 240 milliseconds, with a steady start and end point on the perimeter of a “wheel”. We hypothesized that if the neural representation of this “box” is similar to that of rodent grid units, there should be an at least partial hexagonal (6-fold) symmetry in the EEG response of participants who navigate it. We have not found any dominant n-fold symmetry, however, but instead, using PCAs, we find indications that the vowel representation may reflect phonetic features, as positioned on the vowel manifold. The suggestion, therefore, is that vowels are encoded in relation to their salient sensory-perceptual variables, and are not assigned to arbitrary grid-like abstract maps. Finally, we explored the relationship between the first PCA eigenvector and putative vowel attractors for native Italian speakers, who served as the subjects in our study.


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    Acknowledgments



    Funded by Human Frontier Science Program RGP0057/2016. Discussions and assistance in particular with EEG methods by Yamil Vidal Dos Santos, Yair Lakretz, Massimiliano Trippa and others in the Human Frontier collaboration are gratefully acknowledged. Research in partial fulfillment of the requirements for the PhD degree of ZK. AT acknowledges the gracious hospitality of the Kavli Institute for Theoretical Physics in Santa Barbara, where this work was partially written up.

    Conflict of interest



    The authors declare no conflict of interest.

    [1] Miller GA, Nicely PE (1955) An analysis of perceptual confusions among some English consonants. J Acoust Soc Am 27: 338-352. doi: 10.1121/1.1907526
    [2] Fyhn M, Hafting T, Treves A, et al. (2007) Hippocampal remapping and grid realignment in entorhinal cortex. Nature 446: 190-194. doi: 10.1038/nature05601
    [3] Doeller CF, Barry C, Burgess N (2010) Evidence for grid cells in a human memory network. Nature 463: 657-661. doi: 10.1038/nature08704
    [4] Constaninescu AO, O'Reilly JX, Behrens TEJ (2016) Organizing conceptual knowledge in humans with a gridlike code. Science 352: 1464-1468. doi: 10.1126/science.aaf0941
    [5] Mäkelä AM, Alku P, May PJ, et al. (2005) Left-hemispheric brain activity reflects formant transitions in speech sounds. Neuroreport 16: 549-553. doi: 10.1097/00001756-200504250-00006
    [6] Skipper JI, Devlin JT, Lametti DR (2017) The hearing ear is always found close to the speaking tongue: Review of the role of the motor system in speech perception. Brain Lang 164: 77-105. doi: 10.1016/j.bandl.2016.10.004
    [7] Boë LJ, Sawallis TR, Fagot J, et al. (2019) Which way to the dawn of speech?: Reanalyzing half a century of debates and data in light of speech science. Sci Adv 5: eaaw3916. doi: 10.1126/sciadv.aaw3916
    [8] Manca AD, Di Russo F, Sigona F, et al. (2019) Electrophysiological evidence of phonemotopic representations of vowels in the primary and secondary auditory cortex. Cortex 121: 385-398. doi: 10.1016/j.cortex.2019.09.016
    [9] Scharinger M, Idsardi WJ, Poe S (2011) A comprehensive three-dimensional cortical map of vowel space. J Cogn Neurosci 23: 3972-3982. doi: 10.1162/jocn_a_00056
    [10] Balas A (2009) Why can Poles perceive Sprite but not Coca-Cola? A natural phonological account. Phonology in Perception, ch 2 Berlin: Mouton de Gruyter, 25-54.
    [11] Treves M (1954) Quali sono I dittonghi italiani. Online (2020) within Papers by Marco Treves.Available from: http://marcotreves.blogspot.com/.
    [12] Fox RA (1983) Perceptual structure of monophthongs and diphthongs in English. Lang Speech 26: 21-60. doi: 10.1177/002383098302600103
    [13] Gay T (1970) A perceptual study of American English diphthongs. Lang Speech 13: 65-88. doi: 10.1177/002383097001300201
    [14] Jezek K, Henriksen EJ, Treves A, et al. (2011) Theta-paced flickering between place-cell maps in the hippocampus. Nature 478: 246-249. doi: 10.1038/nature10439
    [15] Hafting T, Fyhn M, Molden S, et al. (2005) Microstructure of a spatial map in the enthorhinal cortex. Nature 436: 69-89. doi: 10.1038/nature03721
    [16] Fyhn M, Hafting T, Treves A, et al. (2007) Hippocampal remapping and grid realignment in entorhinal cortex. Nature 446: 190-194. doi: 10.1038/nature05601
    [17] Staudigl T, Leszczynski M, Jacobs J, et al. (2018) Hexadirectional modulation of high-frequency electrophysiological activity in the human anterior medial temporal lobe maps visual space. Curr Biol 28: 3325-3329.e4. doi: 10.1016/j.cub.2018.09.035
    [18] Maidenbaum S, Miller J, Stein JM, et al. (2018) Gridlike hexadirectional modulation of human entorhinal theta oscillations. PNAS 115: 10798-10803. doi: 10.1073/pnas.1805007115
    [19] Zwicker E (1961) Subdivision of the audible frequency range into critical bands. J Acoust Soc Am 33: 248-248. doi: 10.1121/1.1908630
    [20] Klatt DH (2013) Software for a cascade/parallel formant synthesizer. J Acoust Soc Am 67: 971-995. doi: 10.1121/1.383940
    [21] Delorme A, Makeig S (2004) EEGlab: an open source toolbox for analysis of single-trial EEG dynamics including independent component analysis. J Neurosci Methods 134: 9-21. doi: 10.1016/j.jneumeth.2003.10.009
    [22] Khalighinejad B, da Silva GC, Mesgarani N (2017) Dynamic encoding of acoustic features in neural responses to continuous speech. J Neurosci 37: 2176-2185. doi: 10.1523/JNEUROSCI.2383-16.2017
    [23] Chaumon M, Bishop DVM, Busch NA (2015) A practical guide to the selection of independent components of the eectroencephalogram for artifact correction. J Neurosci Methods 250: 47-63. doi: 10.1016/j.jneumeth.2015.02.025
    [24] Bullmore ET, Suckling J, Overmeyer S, et al. (1999) Global, voxel, and cluster tests, by theory and permutation, for a difference between two groups of structural MR images of the brain. IEEE Trans Med Imaging 18: 32-42. doi: 10.1109/42.750253
    [25] Oostenveld R, Fries P, Maris E, et al. (2011) Fieldtrip: Open source software for advanced analysis of MEG, EEG, and invasive electrophysiological data. Comput Intell Neurosci 2011: 156869. doi: 10.1155/2011/156869
    [26] Näätänen R, Picton T (1987) The N1 wave of the human electric and magnetic response to sound: a review and an analysis of the component structure. Psychophysiology 24: 375-425. doi: 10.1111/j.1469-8986.1987.tb00311.x
    [27] Woods DL (1995) The component structure of the N1 wave of the human auditory evoked potential. Electroencephalogr Clin Neurophysiol Suppl 44: 102-109.
    [28] Picton TW, Hillyard SA, Krausz HI, et al. (1974) Human auditory evoked potentials. I: Evaluation of components. Electroencephalogr Clin Neurophysiol 36: 179-190. doi: 10.1016/0013-4694(74)90155-2
    [29] Bruneau N, Roux S, Guerin P, et al. (1997) Temporal prominence of auditory evoked potentials (N1 wave) in 4-8-year-old children. Psychophysiology 34: 32-38. doi: 10.1111/j.1469-8986.1997.tb02413.x
    [30] Schwartz JL, Boë LJ, Vallée N, et al. (1997) The dispersion-focalization theory of vowel systems. J Phon 25: 255-286. doi: 10.1006/jpho.1997.0043
    [31] Kropff E, Treves A (2008) The emergence of grid cells: intelligent design or just adaptation? Hippocampus 18: 1256-1269. doi: 10.1002/hipo.20520
    [32] Ferro FE, Magno-Caldognetto E, Vagges K, et al. (1978) Some acoustic characteristics of Italian vowels. J Ital Linguist Amsterdam 3: 87-95.
    [33] Goslin J, Galluzzi C, Romani C (2014) Phonitalia: a phonological lexicon for Italian. Behav Res Methods 46: 872-886. doi: 10.3758/s13428-013-0400-8
    [34] Mesgarani N, Cheung C, Johnson K, et al. (2014) Phonetic feature encoding in human superior temporal gyrus. Science 343: 1006-1010. doi: 10.1126/science.1245994
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