The inflected noun system in Serbo-Croatian: Lexical representation of morphological structure

Repetition priming is examined for alternating and nonalternating morphologically related inflected nouns. In Experiments I and 2, latencies to targets in nominative and dative/locative cases, respectively, were invariant over case of prime. In Experiment 3, latencies to nominative-case nouns were the same whether the nouns were primed by forms in which the spelling and pronunciation of the common stem were shared (nonalternating) or not (alternating) with the nominative form. Results are interpreted as reflecting lexical organization among the members of a noun system. In Experiments I and 2, the pattern of latencies to primes suggests a satellite organization in which nominative forms are more strongly linked to oblique forms than oblique forms are to each other. In Experiment 3, atypical cases of alternating forms showed a different pattern of prime latencies, suggesting that the organization within a noun system may differ for alternating and nonalternating forms.     

Amplitude measures of operant response: Implementation with Apple Pascal

Because operant conditioning studies involving force of response as a dependent variable require high-speed A/D conversion, conventional operant software, which treats the input datum as a dimensionless event, is generally unsuited for this kind of work. The author describes a complete Apple-based hardware-software ensemble that measures and records on diskette the peak force, duration, time integral of force, and interresponse time for individual operant responses. Data acquisition and control programs were written in Apple Pascal linked to selected assembly language modules. The real-time base was derived from an inexpensive crystal clock interfaced     

Invariants,specifiers, cues: An investigation of locus equations as information for place of articulation

This experiment explored the information for place of articulation provided bylocus equations— equations for a line relating the second formant (F2) of a vowel at midpoint toF2 of the formant at consonant-vowel (CV) syllable onset. Locus equations cue place indirectly by quantifying directly the degree of coarticulatory overlap (coarticulation resistance) between consonant and vowel. Coarticulation resistance is correlated with place, The experiment tested predictions that when coarticulation resistance varies due to properties of the consonant other than place of articulation (in particular due to manner of articulation), locus equations would not accurately reflect consonantal place of articulation. These predictions were confirmed. In addition, discriminant analyses, using locus equation variables as classifiers, were generally unsuccessful in classifying a set of consonants representing six different places of articulation. I conclude that locus equations are unlikely to provide useful place information to listeners.     

Audiovisual integration in perception of real words

Three experiments follow up on Easton and Basala’s (1982) report that the “McGurk effect” (an influence of a visibly mouthed utterance on a dubbed acoustic one) does not occur when utterances are real words rather than nonsense syllables. In contrast, with real-word stimuli, Easton and Basala report a strong reverse effect whereby a dubbed soundtrack strongly affects identification of lipread words. In Experiment 1, we showed that a strong McGurk effect does obtain when dubbed real words are discrepant with observed words in consonantal place of articulation. A second experiment obtained only a weak reverse effect of dubbed words on judgments of lipread words. A final experiment was designed to provide a sensitive test of effects of lipread words on judgments of heard words and of heard words on judgments of lipread words. The findings reinforced those of the first two experiments that both effects occur, but, with place-of-articulation information discrepant across the modalities, the McGurk effect is strong and the reverse effect weak.     

San Diego Suicide Study: the adolescents

The San Diego Suicide Study involved psychological autopsy and toxicological examination of 283 suicides. Of the 133 consecutive cases under age 30, 14 were under age 20. In this paper, detailed data on the 14 adolescent cases are presented and the findings compared to other studies.     

“DO I HAVE TO BE GOOD ALL DAY?” THE TIMING OF DELAYED REINFORCEMENT AS A FACTOR IN GENERALIZATION

Delayed reinforcement, sometimes delivered just after the setting in which the critical behavior had occurred (Early), and sometimes delivered only after several further settings had been encountered (Late), was used to improve a variety of behaviors in seven preschool children, and to control their generalization. Performance of those behaviors was measured in two classroom settings: the Contingent setting, within which performance of the specified behavior determined the later (Early or Late) reinforcement, and the Generalization setting, in which there were no experimental contingencies, immediate or delayed, for the performance of the same behavior. Performances by all children in the Contingent setting were controlled by delayed reinforcement, whether Early or Late. All children showed consistent generalization from the Contingent setting to the Generalization setting during the Late condition, when reinforcement was delivered at the end of the school day. Generalization did not occur during the Early condition, when reinforcement was provided immediately after the Contingent setting (prior to the Generalization setting), unless that condition had been preceded by a Late condition (as it was for S₆ and S₇). The results suggest that the Late timing of delayed reinforcement was an effective and efficient generalization-promotion technique for performances that did not generalize spontaneously.     

Primary and secondary reinforcers as distinctive cues which acquire information value in partial-reinforcement discrimination training

To assess the cue as opposed to incentive effect of reward, rats were trained on an easy visual discrimination with food contingent on 50 or 100% of the correct responses, and white-noise contingent on 0, 50 or 100% of these responses. Additionally, the 50% food and noise schedules were structured for different groups to produce positive, zero, or negative correlations of the two events. Although the addition of noise did not affect learning with 100% food, the slower learning observed with 50% food was increasingly offset by greater percentages of noise, with the 50% groups showing faster learning under the negative than zero correlation and faster under the zero than positive correlation. Together with supporting speed data, these results indicate that a “neutral” stimulus can be substituted for food with little loss in performance. Consequently, the reinforcing effect of food is attributed in part to its function as a cue which, like noise, can increase the discriminability of the alternatives and provide information about the correctness of the response.     

Converging sources of evidence on spoken and perceived rhythms of speech: cyclic production of vowels in monosyllabic stress feet

The article reviews the literature from psychology, phonetics, and phonology bearing on production and perception of syllable timing in speech. A review of the psychological and phonetics literature suggests that production of vowels and consonants are interleaved in syllable sequences in such a way that vowel production is continuous or nearly so. Based on that literature, a hypothesis is developed concerning the perception of syllable timing assuming that vowel production is continuous. The hypothesis is that perceived syllable timing corresponds to the times sequencing of the vowels as produced and not to the timing either of vowel onsets as conventionally measured or of syllable-initial consonants. Three experiments support the hypothesis. One shows that information present during the portion of an acoustic signal in which a syllable-initial consonant predominates is used by listeners to identify the vowel. Compatibly, this information for the vowel contributes to the vowel's perceived duration. Finally, a measure of the perceived timing of a syllable correlates significantly with the time required to identify syllable-medial vowels but not with time to identify the syllable-initial consonants. Further support for the proposed mode of vowel-consonant production and perception is derived from the literature on phonology. Language-specific phonological conventions can be identified that may reflect exaggerations and conventionalizations of the articulatory tendency for vowels to be produced continuously in speech.     

On the relevance of locus equations for production and perception of stop consonants

We examined the possible relevance of locus equations to human production and perception of stop consonants. The orderly output constraint (OOC) of Sussman, Frachter, and Cable (1995) claims that humans have evolved to produce speech such thatF2 at consonant release andF2 at vowel midpoint are linearly related for consonants so that developing perceptual systems can form representations in anF2 _ons-by-F2 _vowel space. The theory claims that this relationship described by locus equations can distinguish consonants, and that the linearity of locus equations is captured in neural representations and is thus perceptually relevant. We investigated these claims by testing how closely locus equations reflect the production and perception of stop consonants. In Experiment 1, we induced speakers to change their locus equation slope and intercept parameters systematically, but found that consonants remained distinctive in slope-by-intercept space. In Experiment 2, we presented stop-consonant syllables with their bursts removed to listeners, and compared their classification error matrices with the predictions of a model using locus equation prototypes and with those of an exemplar-based model that usesF2 _ons andF2 _vowel, but not locus equations. Both models failed to account for a large proportion of the variance in listeners’ responses; the locus equation model was no better in its predictions than the exemplar model. These findings are discussed in the context of the OOC.