Variability of the MAX and MIN Statistic: A Theory of the Quantile Spread as a Function of Sample Size

The maximum and minimum of a sample from a probability distribution are extremely important random variables in many areas of psychological theory, methodology, and statistics. For instance, the behavior of the mean of the maximum or minimum processing time, as a function of the number of component random processing times (n), has been studied extensively in an effort to identify the underlying processing architecture (e.g., Townsend & Ashby, 1983; Colonius & Vorberg, 1994). Little is known concerning how measures of variability of the maximum or minimum change with n. Here, a new measure of random variability, the quantile spread, is introduced, which possesses sufficient strength to define distributional orderings and derive a number of results concerning variability of the maximum and the minimum statistics. The quantile spread ordering may be useful in many venues. Several interesting open problems are pointed out. This work was supported by an NIH Grant R01 MH57717 to the first author. Some of the collaboration took place during the year 2000 while J.T. Townsend was a Fellow at the Hanse Institute for Advanced Study (HWK), sponsored by H. Colonius at Oldenburg University.     

Spoken Idiom Recognition: Meaning Retrieval and Word Expectancy

This study investigates recognition of spoken idioms occurring in neutral contexts. Experiment 1 showed that both predictable and non-predictable idiom meanings are available at string offset. Yet, only predictable idiom meanings are active halfway through a string and remain active after the string’s literal conclusion. Experiment 2 showed that the initial fragment of a predictable idiom inhibits recognition of a word providing a congruous, but literal, conclusion to the expression. No comparable effects were obtained with non-predictable idioms. These findings are consistent with the view that spoken idiom identification differs from word recognition and occurs word-by-word, just as with other familiar, multi-lexical phrases.The present study was supported by PRIN 2003–2004. We would like to thank Corrado Cavallero, Simona Collina, Melinda Tucker and Francesco Zardon for their valuable help.     

Muscular Activity in the Arm during Lexical Retrieval: Implications for Gesture-Speech Theories

The origin and functions of the hand and arm gestures that accompany speech production are poorly understood. It has been proposed that gestures facilitate lexical retrieval, but little is known about when retrieval is accompanied by gestural activity and how this activity is related to the semantics of the word to be retrieved. Electromyographic (EMG) activity of the dominant forearm was recorded during a retrieval task in which participants tried to identify target words from their definitions. EMG amplitudes were significantly greater for concrete than for abstract words. The relationship between EMG amplitude and other conceptual attributes of the target words was examined. EMG was positively related to a word’s judged spatiality, concreteness, drawability, and manipulability. The implications of these findings for theories of the relation between speech production and gesture are discussed.This experiment was done by the first author under the supervision of the second author in partial completion of the Ph.D. degree at Columbia University. We gratefully acknowledge the advice and comments of Lois Putnam, Robert Remez, James Magnuson, Michele Miozzo, and Robert B. Tallarico, and the assistance of Stephen Krieger, Lauren Walsh, Jennifer Kim, and Jillian White.     

Processing coordinated structures: incrementality and connectedness

We recorded participants' eye movements while they read sentences containing verb-phrase coordination. Results showed evidence of immediate processing disruption when a reflexive pronoun embedded in the conjoined verb phrase mismatched the sentence subject. We argue that this result is incompatible with models of human parsing that employ only bottom-up parsing procedures, even when flexible constituency is employed. Models need to incorporate a mechanism similar to the adjoining operation in Tree-Adjoining Grammar, in which one structure is inserted into another.     

How Should a Speech Recognizer Work?

Although researchers studying human speech recognition (HSR) and automatic speech recognition (ASR) share a common interest in how information processing systems (human or machine) recognize spoken language, there is little communication between the two disciplines. We suggest that this lack of communication follows largely from the fact that research in these related fields has focused on the mechanics of how speech can be recognized. In Marr's (1982) terms, emphasis has been on the algorithmic and implementational levels rather than on the computational level. In this article, we provide a computational-level analysis of the task of speech recognition, which reveals the close parallels between research concerned with HSR and ASR. We illustrate this relation by presenting a new computational model of human spoken-word recognition, built using techniques from the field of ASR that, in contrast to current existing models of HSR, recognizes words from real speech input.     

Doctor's Expertise and Managing Discrepant Information from Other Sources in Genetic Counseling: A Conversation Analytic Perspective

The study examines a recurrent interactional pattern in genetic counseling. It describes clinical geneticists' responses in situations in which clients have presented information from other sources that is potentially discrepant with information given by the doctor. The data consists of 12 video-recorded sessions of genetic counseling in Finland, and the method is conversation analysis. There are two primary ways the doctors respond: either they accept the client's information as such, but show that it is not discrepant with the doctor's information, or they reject the client's information. In the latter case they mitigate the ‘wrongness’ of the client's information. The clinical geneticists seem to be working with a dilemma: they need to find a balance between ensuring correct understanding of the information and showing respect for the expertise of others. A particularly complex case is also analyzed and reflected on.     

发展性阅读障碍者的快速命名缺陷

快速命名任务是一种需要命名多个高熟悉项目的认知任务,尤其适合用来对成因复杂的发展性阅读障碍进行研究。许多研究者使用不同类型的快速命名任务发现,发展性阅读障碍者的快速命名缺陷在眼动过程表现为中央凹和副中央凹的加工困难,在认知过程中表现为抑制能力较差等。未来的研究中应该注意到快速命名缺陷的复杂性,采用多种方法相结合的方式来探究快速命名缺陷的本质,从而建立系统性的假说。     

The Nature and Significance of Behavioural Genetic Information

In light of the human genome project, establishing the genetic aetiology of complex human diseases has become a research priority within Western medicine. However, in addition to the identification of disease genes, numerous research projects are also being undertaken to identify genes contributing to the development of human behavioural characteristics, such as cognitive ability and criminal tendency. The permissibility of this research is obviously controversial: will society benefit from this research, or will it adversely affect our conceptions of ourselves and each other? When assessing the permissibility of this research, it is important to consider the nature and deterministic significance of behavioural genetic information. Whilst todate there has been much discussion and debate about the properties of genetic information per se and genetic determinism, this has not been applied to behavioural genetic research and its ethical implications. Therefore, this paper elucidates how behavioural genetic information can be distinguished from other types of genetic and non-genetic information and also synthesises the determinative significance of genetic factors for the development of human behavioural traits. Undertaking this analysis enables the ethical issues raised by this research to be debated in an appropriate context and indicates that separate policy considerations are warranted.

     

Changes in the structure of children's isometric force variability with practice

This study examined the effect of age and practice on the structure of children's force variability to test the information processing hypothesis that a reduction of sensorimotor system noise accounts in large part for age-related reductions in perceptual-motor performance variability. In the study, 6-year-olds, 10-year-olds, and young adults practiced on 5 consecutive days (15 trials/day), maintaining for 15-s trials a constant level of force (5 or 25% of maximum voluntary contraction) against an object using a pinch grip (thumb and index finger). With increasing age, the amount of force error and variability decreased, but the sequential structure of variability increased in irregularity. With practice, children reduced the amount of variability by changing the structure of the force output so as to be more similar to that of their older counterparts. The findings provide further evidence that practice-driven changes in the structure of force output, rather than a decline in the amount of white noise, largely account for age-related reductions in the amount of force variability.