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- Carral, V, et al.
(författare)
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A kind of auditory 'primitive intelligence' already present at birth
- 2005
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Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 21:11, s. 3201-3204
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Tidskriftsartikel (refereegranskat)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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| 4. |
- Kotilahti, K, et al.
(författare)
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Near-infrared spectroscopic imaging of stimulus-related hemodynamic responses on the neonatal auditory cortices.
- 2005
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Ingår i: Optical tomography and spectroscopy of tissue VI. - : SPIE. - 1996-756X .- 0277-786X. - 9780819456670 ; 5693, s. 388-395
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Konferensbidrag (refereegranskat)abstract
- We have used near-infrared spectroscopy (NIRS) to study hemodynamic auditory evoked responses on 7 full-term neonates. Measurements were done simultaneously above both auditory cortices to study the distribution of speech and music processing between hemispheres using a 16-channel frequency-domain instrument. The stimulation consisted of 5-second samples of music and speech with a 25-second silent interval. In response to stimulation, a significant increase in the concentration of oxygenated hemoglobin ([HbO2]) was detected in 6 out of 7 subjects. The strongest responses in [HbO2] were seen near the measurement location above the ear on both hemispheres. The mean latency of the maximum responses was 9.42±1.51 s. On the left hemisphere (LH), the maximum amplitude of the average [HbO2] response to the music stimuli was 0.76± 0.38 μ M (mean±std.) and to the speech stimuli 1.00± 0.45 μ± μM. On the right hemisphere (RH), the maximum amplitude of the average [HbO2] response was 1.29± 0.85 μM to the music stimuli and 1.23± 0.93 μM to the speech stimuli. The results indicate that auditory information is processed on both auditory cortices, but LH is more concentrated to process speech than music information. No significant differences in the locations and the latencies of the maximum responses relative to the stimulus type were found.
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| 5. |
- Mikkola, K, et al.
(författare)
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Neurodevelopmental outcome at 5 years of age of a national cohort of extremely low birth weight infants who were born in 1996-1997
- 2005
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Ingår i: Pediatrics. - : American Academy of Pediatrics (AAP). - 1098-4275 .- 0031-4005. ; 116:6, s. 1391-1400
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Increasing survival of extremely low birth weight (ELBW; birth weight < 1000 g) infants raises a concern regarding the risks of adverse long-term outcome such as cognitive dysfunction. Few studies have reported long-term follow-up of representative regional cohorts. The objective of this study was to assess the 5-year outcome of a prospectively followed national ELBW infant cohort. Methods. Of all live-born ELBW infants (n = 351) who were delivered in the 2-year period 1996 - 1997 in Finland, 206 (59%) survived until the age of 5 years. Of these, 103 were born at < 27 gestational weeks (GW). A total of 172 children were assessed with neurocognitive tests ( Wechsler Preschool and Primary Scale of Intelligence - Revised and a Developmental Neuropsychological Assessment [NEPSY]). Nine children with cognitive impairment and inability to cooperate in testing were not assessed. Motor development was assessed with a modified Touwen test. Results. The rate of cognitive impairment in the ELBW survivors was 9%. The rate of cerebral palsy was 14% (19% of ELBW infants who were born at < 27 GW). The mean full-scale IQ of the assessed children was 96 +/- 19 and in children of GW < 27 was 94 +/- 19. Attention, language, sensorimotor, visuospatial, and verbal memory values of NEPSY assessment were significantly poorer compared with normal population means. Four percent needed a hearing aid, and 30% had ophthalmic findings. Of 21 children who had been treated with laser/cryo for retinopathy of prematurity, 17 (81%) had abnormal ophthalmic findings. Of the whole cohort, 41 (20%) exhibited major disabilities, 38 (19%) exhibited minor disabilities, and 124 (61%) showed development with no functional abnormalities but subtle departures from the norm. Only 53 (26%) of the total ELBW infant cohort were classified to have normal outcome excluding any abnormal ophthalmic, auditory, neurologic, or developmental findings. Being small for gestational age at birth was associated with suboptimal growth at least until age 5. Conclusions. Only one fourth of the ELBW infants were classified as normally developed at age 5. The high rate of cognitive dysfunction suggests an increased risk for learning difficulties that needs to be evaluated at a later age. Extended follow-up should be the rule in outcome studies of ELBW infant cohorts to elucidate the impact of immaturity on school achievement and social behavior later in life.
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