Linear correlates in the speech signal: the orderly output constraint

Neuroethological investigations of mammalian and avian auditory systems have documented species-specific specializations for processing complex acoustic signals that could, if viewed in abstract terms, have an intriguing and striking relevance for human speech sound categorization and representation. Each species forms biologically relevant categories based on combinatorial analysis of information-bearing parameters within the complex input signal. This target article uses known neural models from the mustached bat and barn owl to develop, by analogy, a conceptualization of human processing of consonant plus vowel sequences that offers a partial solution to the noninvariance dilemma--the nontransparent relationship between the acoustic waveform and the phonetic segment. Critical input sound parameters used to establish species-specific categories in the mustached bat and barn owl exhibit high correlation and linearity due to physical laws. A cue long known to be relevant to the perception of stop place of articulation is the second formant (F2) transition. This article describes an empirical phenomenon--the locus equations--that describes the relationship between the F2 of a vowel and the F2 measured at the onset of a consonant-vowel (CV) transition. These variables, F2 onset and F2 vowel within a given place category, are consistently and robustly linearly correlated across diverse speakers and languages, and even under perturbation conditions as imposed by bite blocks. A functional role for this category-level extreme correlation and linearity (the "orderly output constraint") is hypothesized based on the notion of an evolutionarily conserved auditory-processing strategy. High correlation and linearity between critical parameters in the speech signal that help to cue place of articulation categories might have evolved to satisfy a preadaptation by mammalian auditory systems for representing tightly correlated, linearly related components of acoustic signals.     

The Relations of Pro-Drug-Use Myths With Self-Reported Drug Use Among Youth at Continuation High Schools1

Drug-use myths, questionable beliefs regarding the effects of drug use, may help to explain why people engage in self-injurious drug-use behavior. While clinicians and applied social researchers have used this concept of drug-use myths extensively when developing substance abuse prevention or cessation programs, drug belief-type myth measures have not been investigated empirically. The present study examined the internal consistency and discriminant validity of a drug-use myth measure among 362 continuation (alternative) high school youth and found it to be discriminable from demographic, drug use, and other psychosocial measures. Controlling for its relations with its correlates, social desirability, perceived friends' drug use, ethnicity items, and gender, the myth measure remained significantly associated with 4 drug-use measures. Future research regarding drug use myths as predictors of drug use is encouraged based on these results.     

Bilingual speech: Bilateral control?

Forty bilinguals from several language backgrounds were contrasted to a group of English-speaking monolinguals on a verbal-manual interference paradigm. For the monolinguals, concurrent finger-tapping rate during speech output tasks was disrupted only for the right hand, indicating left-hemisphere language dominance. Bilingual laterality patterns were a function of language used: native (L1) versus second acquired (L2), and age of L2 acquisition. Early bilinguals (L1 + L2 acquisition prior to age 6) revealed left-hemisphere dominance for both languages, whereas late bilinguals (L2 acquired beyond age 6) revealed left-hemisphere dominance only for L1 and symmetrical hemispheric involvement for L2.     

Pro-drug-use myths and competing constructs in the prediction of substance use among youth at continuation high schools: a one-year prospective study

Experimentation with drugs among adolescents often is preceded by faulty beliefs (myths) regarding drug effects. The present study provides empirical demonstration of the utility of a drug use myths index in the prediction of subsequent drug use in a prospective study of substance use among high-risk adolescents. Drug use was measured as an index of recent cigarette, alcohol and marijuana use. A belief-type drug use myths index was compared as a predictor of drug use with four other frequently researched correlates of drug use. The other measures were of social influence, outcome expectancies, attitudes toward wrongness of drug use and sensation seeking. The belief-type drug use myths, attitudes toward wrongness and sensation seeking indices were found to be significant predictors of drug use among our sample of 1074 youth when controlling for gender, ethnicity and prior drug use. These findings have implications for understanding factors contributing to individual differences in drug use behaviors and could benefit the development of drug education programs for high-risk individuals.     

Working memory capacity moderates the predictive effects of drug-related associations on substance use

Some theories suggest that spontaneously activated, drug-related associations in memory may have a "freer reign" in predicting drug use among individuals with lower working memory capacity. This study evaluated this hypothesis among 145 at-risk youth attending continuation high schools (CHS). This is the 1st study to evaluate this type of dual-process interaction in the prediction of drug use among a sample of at-risk adolescents. The CHS students completed assessments of drug-related memory associations, working memory capacity, and drug use. Control variables included age, gender, ethnicity, and acculturation. Robust multiple regression using least trimmed squares estimation indicated that there was a significant linear by linear interaction between working memory capacity (assessed with the self-ordered pointing task) and drug-related associations (assessed with verb generation and cue-behavior association tasks) in the prediction of alcohol and cigarette use. Consistent with dual-process cognitive theories, drug-related associations in memory predicted drug use more strongly in students with lower levels of working memory capacity. These findings add to the literature implicating the influence of dual cognitive processes in adolescent risk behaviors.     

Apples and oranges? Comparing indirect measures of alcohol-related cognition predicting alcohol use in at-risk adolescents.

Recently, there has been increased interest in the role of implicit cognitive processes in the development of addictive behaviors. In this study, the authors compared 3 indirect measures of alcohol-related cognitions in the prospective prediction of alcohol use in at-risk adolescents. Implicit alcohol-related cognitions were assessed in 88 Dutch at-risk adolescents ranging in age from 14 to 20 years (51 males, 37 females) by means of varieties of word association tasks, Implicit Association Tests, and Extrinsic Affective Simon Tasks adapted for alcohol use. Alcohol use and alcohol-related problems were measured with self-report questionnaires at baseline and after 1 month. Results showed that the indirect measures predicted unique variance in prospective alcohol use after controlling for the direct measure of alcohol-related cognitions and background variables. The results indicate that the word association tasks were the best indirect measure of alcohol-related cognitions. These indirect measures appear to assess cognitive motivational processes that affect behavior in ways not reflected by direct measures of alcohol-related cognitions.     

Assignment of reference to reflexives and pronouns in picture noun phrases: evidence from eye movements

Most structural Binding Theories predict a complementary distribution between reflexives and pronouns in picture noun phrases containing possessors (e.g. "Ken's picture of himself/him"). In two head-mounted eye-tracking experiments, listeners frequently violated Binding Theory predictions for reflexives, often interpreting the reflexives as taking an antecedent outside of the binding domain, and violating complementarity assumptions. Moreover, the pattern and timing of the eye movements showed Binding Theory violations for reflexives during the earliest moments of reference resolution. The results demonstrate that either binding constraints must be reformulated to decouple pronouns and reflexives or all reflexives in picture noun phrases must be treated as logophors, and thus exempt from structural Binding Theory.     

Processing reflexives and pronouns in picture noun phrase

Binding theory (e.g., Chomsky, 1981) has played a central role in both syntactic theory and models of language processing. Its constraints are designed to predict that the referential domains of pronouns and reflexives are nonoverlapping, that is, are complementary; these constraints are also thought to play a role in online reference resolution. The predictions of binding theory and its role in sentence processing were tested in four experiments that monitored participants' eye movements as they followed spoken instructions to have a doll touch a picture belonging to another doll. The instructions used pronouns and reflexives embedded in picture noun phrases (PNPs) containing possessor phrases (e.g., Pick up Ken. Have Ken touch Harry's picture of himself). Although the interpretations assigned to pronouns were generally consistent with binding theory, reflexives were frequently assigned interpretations that violated binding theory. In addition, the timing and pattern of eye movements were inconsistent with models of language processing that assume that binding theory acts as an early filter to restrict the referential domain. The interpretations assigned to reflexives in PNPs with possessors suggest that they are binding-theory-exempt logophors, a conclusion that unifies the treatment of reflexives in PNPs.