Joan A. Sereno

Processing of English inflectional morphology

The present paper explores the representation of inflectional morphology in the English lexicon. There has been a long-standing debate about how these inflectional relationships might be involved during on-line processing. Inflected forms may be derived from an uninflected base form by rule application; by contrast, both regular and irregular inflection may be treated in the same way, with morphological patterns emerging from mappings between base and inflected forms. The present series of experiments investigated these issues using a lexical decision task. The first experiment showed that response latencies to nouns were significantly shorter than those to verbs. A possible explanation for these results can be found in differences in inflectional structure between English nouns and verbs. Namely, the relative frequency of uninflected compared with inflected forms is greater for nouns than for verbs. Two additional experiments compared noun stimuli with different inflectional structures. In all cases, differences in response latencies were predicted by the frequency of the surface form, whether uninflected or inflected. The pattern of results lends support for a unitary associative system for processing regular inflection of nouns in English and argues against the view that regular inflected plurals are derived by rule from a single, uninflected lexical entry.

fMRI Evidence for Cortical Modification during Learning of Mandarin Lexical Tone

Functional magnetic resonance imaging was employed before and after six native English speakers completed lexical tone training as part of a program to learn Mandarin as a second language. Language-related areas including Brocas area, Wernickes area, auditory cortex, and supplementary motor regions were active in all subjects before and after training and did not vary in average location. Across all subjects, improvements in performance were associated with an increase in the spatial extent of activation in left superior temporal gyrus (Brodmanns area 22, putative Wernickes area), the emergence of activity in adjacent Brodmanns area 42, and the emergence of activity in right inferior frontal gyrus (Brodmanns area 44), a homologue of putative Brocas area. These findings demonstrate a form of enrichment plasticity in which the early cortical effects of learning a tone-based second language involve both expansion of preexisting language-related areas and recruitment of additional cortical regions specialized for functions similar to the new language functions.

Incomplete neutralization and other sub-phonemic durational differences in production and perception: Evidence from Dutch

Abstract Words which are expected to contain the same surface string of segments may, under identical prosodic circumstances, sometimes be realized with slight differences in duration. Some researchers have attributed such effects to differences in the words’ underlying forms (incomplete neutralization), while others have suggested orthographic influence and extremely careful speech as the cause. In this paper, we demonstrate such sub-phonemic durational differences in Dutch, a language which some past research has found not to have such effects. Past literature has also shown that listeners can often make use of incomplete neutralization to distinguish apparent homophones. We extend perceptual investigations of this topic, and show that listeners can perceive even durational differences which are not consistently observed in production. We further show that a difference which is primarily orthographic rather than underlying can also create such durational differences. We conclude that a wide variety of factors, in addition to underlying form, can induce speakers to produce slight durational differences which listeners can also use in perception.

Graphemic, associative, and syntactic priming effects at a brief stimulus onset asynchrony in lexical decision and naming

The present set of experiments investigated graphemic, associative, and syntactic priming effects in both a lexical decision and a naming task. In all the experiments, a three-word maskng procedure (word-prime-target) with a 60-ms stimulus onset asynchrony between prime and target was used to limit strategic effects

Dichotic Perception of Mandarin Tones by Chinese and American Listeners

The dichotic perception of Mandarin tones by native and nonnative listeners was examined in order to investigate the lateralization of lexical tone. Twenty American listeners with no tone language background and 20 Chinese listeners were asked to identify dichotically presented tone pairs by identifying which tone they heard in each ear. For the Chinese listeners, 57% of the total errors occurred via the left ear, indicating a significant right ear advantage. However, the American listeners revealed no significant ear preference, with 48% of the errors attributable to the left ear. These results indicated that Mandarin tones are predominantly processed in the left hemisphere by native Mandarin speakers, whereas they are bilaterally processed by American English speakers with no prior tone experience. The results also suggest that the left hemisphere superiority for native Mandarin tone processing is similar to native processing of other tone languages.

Acoustic analyses and perceptual data on anticipatory labial coarticulation in adults and children.

The present study investigated anticipatory labial coarticulation in the speech of adults and children. CV syllables, composed of [s], [t], and [d] before [i] and [u], were produced by four adult speakers and eight child speakers aged 3-7 years. Each stimulus was computer edited to include only the aperiodic portion of fricative-vowel and stop-vowel syllables. LPC spectra were then computed for each excised segment. Analyses of the effect of the following vowel on the spectral peak associated with the second formant frequency and on the characteristic spectral prominence for each consonant were performed. Perceptual data were obtained by presenting the aperiodic consonantal segments to subjects who were instructed to identify the following vowel as [i] or [u]. Both the acoustic and the perceptual data show strong coarticulatory effects for the adults and comparable, although less consistent, coarticulation in the speech stimuli of the children. The results are discussed in terms of the articulatory and perceptual aspects of coarticulation in language learning.

The role of linguistic experience in the hemispheric processing of lexical tone

This study investigated hemispheric lateralization of Mandarin tone. Four groups of listeners were examined: native Mandarin listeners, English‐Mandarin bilinguals, Norwegian listeners with experience with Norwegian tone, and American listeners with no tone experience. Tone pairs were dichotically presented and listeners identified which tone they heard in each ear. For the Mandarin listeners, 57% of the total errors occurred in the left ear, indicating a right-ear (left-hemisphere) advantage. The English‐ Mandarin bilinguals exhibited nativelike patterns, with 56% left-ear errors. However, no ear advantage was found for the Norwegian or American listeners (48 and 47% left-ear errors, respectively). Results indicate left-hemisphere dominance of Mandarin tone by native and proficient bilingual listeners, whereas nonnative listeners show no evidence of lateralization, regardless of their familiarity with lexical tone.

Phonological neutralization by native and non-native speakers: The case of Russian final devoicing

The present study investigates the extent of word-final devoicing in Russian for three groups of speakers: monolingual native Russian speakers (4 Ss), native Russian speakers with knowledge of English (7 Ss), and American English learners of Russian (9 Ss). Thirty-four minimal pairs of Russian words differing in the underlying voicing of word-final obstruents were recorded. Acoustic analysis focused on four measures: preceding vowel duration, closure/frication duration, duration of voicing into closure/frication, and duration of release portion. Results indicate the absence of complete neutralization of underlying voicing for all three groups. Native Russian speakers showed sizeable differences in each of the four measures. While Russian monolingual speakers produced significant durational differences in closure/frication duration and release duration, native Russians with knowledge of English in addition maintained a difference through vowel duration and duration of voicing into closure/frication. Moreover, correlations indicated that speakers with higher English proficiency produced greater differences for vowel duration. In addition, native speakers of English learning Russian also distinguished final obstruents in terms of preceding vowel duration, closure/frication duration, duration of voicing into closure/frication, and duration of release portion, with greater durational differences for these second language learners than for Russian native speakers. The more proficient speakers of Russian decreased the durational differences and the most proficient second language learners were closer to complete neutralization than monolingual speakers of Russian. The neutralization data will be discussed in terms of the interaction between first and second language in the production of final devoicing.

Effects of Acoustic Variability in the Perceptual Learning of Non-Native-Accented Speech Sounds

This study addressed whether acoustic variability and category overlap in non-native speech contribute to difficulty in its recognition, and more generally whether the benefits of exposure to acoustic variability during categorization training are stable across differences in category confusability. Three experiments considered a set of Spanish-accented English productions. The set was seen to pose learning and recognition difficulty (experiment 1) and was more variable and confusable than a parallel set of native productions (experiment 2). A training study (experiment 3) probed the relative contributions of category central tendency and variability to difficulty in vowel identification using derived inventories in which these dimensions were manipulated based on the results of experiments 1 and 2. Training and test difficulty related straightforwardly to category confusability but not to location in the vowel space. Benefits of high-variability exposure also varied across vowel categories, and seemed to be diminished for highly confusable vowels. Overall, variability was implicated in perception and learning difficulty in ways that warrant further investigation.

Categorization of sounds

The authors conducted 4 experiments to test the decision-bound, prototype, and distribution theories for the categorization of sounds. They used as stimuli sounds varying in either resonance frequency or duration. They created different experimental conditions by varying the variance and overlap of 2 stimulus distributions used in a training phase and varying the size of the stimulus continuum used in the subsequent test phase. When resonance frequency was the stimulus dimension, the pattern of categorization-function slopes was in accordance with the decision-bound theory. When duration was the stimulus dimension, however, the slope pattern gave partial support for the decision-bound and distribution theories. The authors introduce a new categorization model combining aspects of decision-bound and distribution theories that gives a superior account of the slope patterns across the 2 stimulus dimensions.