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389 Neuromagnetic mismatch fields tap pre-lexical phonetic representations
150
Abstracts
/International
Journal
< sex > * < emotion valence > * < ear presentation > . This detailed consideration revealed that the noise immunity perception of speech emotional information is formed in different age periods in boys and girls and strongly depends on the emotional valence.
388 CHARACI-ERISTICS OF INFANTS VOCALIZATIONS DURING THE FIRST YEAR OF LIFE E. Lyakso Department of Physiology of Higher Nervous Activity, Institute of Physiology, University emb. 7/9 Saint-Petersburg State University, Saint-Petersburg 199034, Russia The present report represents psychophysiological longitudinal data for the non-verbal period of Russian infants’ speech development. Our research was conducted in two directions: the determination of the formation of speech-like sounds in infants during the first year of life; the explanation of; thea determination possibilities of baby’s functional status on the basis of acoustic parameters measurement. Changes in spectral and amplitude characteristics of vowellike sounds and combinations of consonant-like sounds with vowel-like ones during the first year of life were observed. It was found that the fundamental frequency in < > vocalization tends to decrease durin this period; whereas vowel-like sound characteristics approxl %!ate to characteristics of vowels uttered by adults. Comparative analysis of vocalization characteristics of healthy l-week-old infants kept with mothers just after birth versus ones of babies removed from mothers was carried out. Differences in the temporal parameters and in the types of dynamic spectrum in cries of 1,5-35 month-old orphans were revealed subject to the degree of neuropathological impairment. The results obtained might be used to reveal specific vocalization characteristics which might reflect different functional status of an infant. Data analyzed support the notion that the first year of life is crucial for the formation and training of articulation apparatus as well as articulation skills. Research is supporteh by the Russian Science Humanitarian Foundation (N 96-03-04144) and Russian Ministry of High School Education (N92).
389 NEUROMAGNETIC PRE-LEXICAL PHONETIC
MISMATCH FIELDS REPRESENTATIONS
TAP
E. Diesch*, S. Biermann Dept. of Medical Psychology and Behavioral Neurobiology, Tiibingen University, Gartenstr. 29,72074 Tiibingen, Germany The hypothesis that the phonetic representation of the speech signal contributes to the generation of the mismatch response
of Psychophysiology
30 (1998)
95-271
evoked by speech contrasts was examined by exploiting the fact that the use of phonetic information is implicated in lexical access. The speech-evoked magnetic mismatch field was measured in right-handed native speakers of German. The standard stimuli were two-syllable words in the test condition and phonological two-syllable nonwords in the control condition. The deviants were phonological two-syllable non-words that differed from the standards in the second syllable. The syllable tokens for the first and second syllable position, respectively, were equated in loudness, duration, and segmental acoustic structure. The equivalent current dipole fitted to the mismatch field was deeper inside the brain and its dipole moment was stronger for nonword than word standards. The correlation of the dipole moment and the depth of an equivalent current dipole suggested that the underlying cortical sources differed in surface area. Information to distinguish between differences in dipole moment and depth was provided by an amplitude measure of the field. The pattern of correlation of field amplitude, source dipole moment, and depth suggested that the lexical&y conditions differed in both source surface area and depth. This lexicality effect suggests that there is a prelexical, but not a postlexical effect on the magnetic mismatch field. The results are compatible with a modular rather than an interactive view of the relationship between lexical and phonetic representation.
390 SPEECH TIMING ING SUBJECTS
IN HEALTHY
AND STUl-l-ER-
K. Radilova’, A. Novak’, J. Vokral’, T. Radii** ‘Phoniatry Clinic, First Medical Faculty, Charles University, Prague, Czech Republic 21nstitute of Physiology, Czech Academy of Sciences, Videnska Str. 1083, Prague 4, 14220 Czech Republic
Two experiments were performed in healthy and stuttering subjects. In the first one the subjects had to vocalize (generating a short “pa” sound), to tap with their index finger, or to do both simultaneously, in synchrony with rhythmic sequences of tones. It was found that vocalization onsets preceded tonal onsets at the intertonal intervals of 800 ms. There existed “anticipation” for vocalization, as it existed for tapping. However, vocalization started later than tapping, usually. That meant “anticipation” was shorter for vocalization than for tapping. At intertonal intervals of 1600, and mostly 3200 ms, temporal assynchrony between vocalization, and tonal onsets (as between tapping and tonal onsets), became shifted toward positive values, i.e. stimuli preceded responses. At intertonal intervals of 3200 ms the subjects were unable to follow the rhythm, as they could not remember the position of the given tone in time till the onset of the following tone, apparently.
Abstracts
/International
Journal
< sex > * < emotion valence > * < ear presentation > . This detailed consideration revealed that the noise immunity perception of speech emotional information is formed in different age periods in boys and girls and strongly depends on the emotional valence.
388 CHARACI-ERISTICS OF INFANTS VOCALIZATIONS DURING THE FIRST YEAR OF LIFE E. Lyakso Department of Physiology of Higher Nervous Activity, Institute of Physiology, University emb. 7/9 Saint-Petersburg State University, Saint-Petersburg 199034, Russia The present report represents psychophysiological longitudinal data for the non-verbal period of Russian infants’ speech development. Our research was conducted in two directions: the determination of the formation of speech-like sounds in infants during the first year of life; the explanation of; thea determination possibilities of baby’s functional status on the basis of acoustic parameters measurement. Changes in spectral and amplitude characteristics of vowellike sounds and combinations of consonant-like sounds with vowel-like ones during the first year of life were observed. It was found that the fundamental frequency in <
389 NEUROMAGNETIC PRE-LEXICAL PHONETIC
MISMATCH FIELDS REPRESENTATIONS
TAP
E. Diesch*, S. Biermann Dept. of Medical Psychology and Behavioral Neurobiology, Tiibingen University, Gartenstr. 29,72074 Tiibingen, Germany The hypothesis that the phonetic representation of the speech signal contributes to the generation of the mismatch response
of Psychophysiology
30 (1998)
95-271
evoked by speech contrasts was examined by exploiting the fact that the use of phonetic information is implicated in lexical access. The speech-evoked magnetic mismatch field was measured in right-handed native speakers of German. The standard stimuli were two-syllable words in the test condition and phonological two-syllable nonwords in the control condition. The deviants were phonological two-syllable non-words that differed from the standards in the second syllable. The syllable tokens for the first and second syllable position, respectively, were equated in loudness, duration, and segmental acoustic structure. The equivalent current dipole fitted to the mismatch field was deeper inside the brain and its dipole moment was stronger for nonword than word standards. The correlation of the dipole moment and the depth of an equivalent current dipole suggested that the underlying cortical sources differed in surface area. Information to distinguish between differences in dipole moment and depth was provided by an amplitude measure of the field. The pattern of correlation of field amplitude, source dipole moment, and depth suggested that the lexical&y conditions differed in both source surface area and depth. This lexicality effect suggests that there is a prelexical, but not a postlexical effect on the magnetic mismatch field. The results are compatible with a modular rather than an interactive view of the relationship between lexical and phonetic representation.
390 SPEECH TIMING ING SUBJECTS
IN HEALTHY
AND STUl-l-ER-
K. Radilova’, A. Novak’, J. Vokral’, T. Radii** ‘Phoniatry Clinic, First Medical Faculty, Charles University, Prague, Czech Republic 21nstitute of Physiology, Czech Academy of Sciences, Videnska Str. 1083, Prague 4, 14220 Czech Republic
Two experiments were performed in healthy and stuttering subjects. In the first one the subjects had to vocalize (generating a short “pa” sound), to tap with their index finger, or to do both simultaneously, in synchrony with rhythmic sequences of tones. It was found that vocalization onsets preceded tonal onsets at the intertonal intervals of 800 ms. There existed “anticipation” for vocalization, as it existed for tapping. However, vocalization started later than tapping, usually. That meant “anticipation” was shorter for vocalization than for tapping. At intertonal intervals of 1600, and mostly 3200 ms, temporal assynchrony between vocalization, and tonal onsets (as between tapping and tonal onsets), became shifted toward positive values, i.e. stimuli preceded responses. At intertonal intervals of 3200 ms the subjects were unable to follow the rhythm, as they could not remember the position of the given tone in time till the onset of the following tone, apparently.