| 1. |
- Carral, V, et al.
(author)
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A kind of auditory 'primitive intelligence' already present at birth
- 2005
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In: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 21:11, s. 3201-3204
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Journal article (peer-reviewed)abstract
- 'Primitive intelligence' in audition refers to the capacity of the auditory system to adaptatively model the acoustic regularity and react neurophysiologically to violations of such regularity, thus supporting the ability to predict future auditory events. In the present study, event-related brain potentials to pairs of tones were recorded in 11 human newborns to determine the infants' ability to extract an abstract acoustic rule, the direction of a frequency change. Most of the pairs (standard, P = 0.875) were of ascending frequency (i.e. the second tone higher than the first), while the remaining pairs (deviant, P = 0.125) were of descending frequency (the second tone being lower). Their frequencies varied among seven levels to prevent discrimination between standard and deviant pairs on the basis of absolute frequencies. We found that event-related brain potentials to deviant pairs differed in amplitude from those to standard pairs at 50-450 ms from the onset of the second tone of a pair, indicating the infants' ability to represent the abstract rule. This finding suggests the early ontogenetic origin of 'primitive intelligence' in audition that eventually may form a prerequisite for later language acquisition.
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| 2. |
- Ruusuvirta, T, et al.
(author)
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Newborn human brain identifies repeated auditory feature conjunctions of low sequential probability
- 2004
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In: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 20:10, s. 2819-2821
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Journal article (peer-reviewed)abstract
- Natural environments are usually composed of multiple sources for sounds. The sounds might physically differ from one another only as feature conjunctions, and several of them might occur repeatedly in the short term. Nevertheless, the detection of rare sounds requires the identification of the repeated ones. Adults have some limited ability to effortlessly identify repeated sounds in such acoustically complex environments, but the developmental onset of this finite ability is unknown. Sleeping newborn infants were presented with a repeated tone carrying six frequent (P = 0.15 each) and six rare (P similar to0.017 each) conjunctions of its frequency, intensity and duration. Event-related potentials recorded from the infants' scalp were found to shift in amplitude towards positive polarity selectively in response to rare conjunctions. This finding suggests that humans are relatively hard-wired to preattentively identify repeated auditory feature conjunctions even when such conjunctions occur rarely among other similar ones.
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| 3. |
- Ruusuvirta, T, et al.
(author)
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The newborn human brain binds sound features together
- 2003
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In: NeuroReport. - 1473-558X. ; 14:16, s. 2117-2119
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Journal article (peer-reviewed)abstract
- To process a stimulus as a holistic entity, the human brain must be able to conjoin its different features. Previous evidence suggests that this ability emerges during the first months of life, implying its considerable dependence on postnatal development. We recorded human newborn (1-3 days of age) electrical brain responses to frequently occurring (standard) sounds and to rarely occurring (deviant) sounds in a series. Responses to deviants differed from those to standards despite the fact that only the combination of sound frequency and intensity could be used as a cue for discriminating between these sound types. Our finding suggests that the human brain is ready for auditory feature binding very soon after birth.
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