The communicative function of ambiguity in language

We present a general information-theoretic argument that all efficient communication systems will be ambiguous, assuming that context is informative about meaning. We also argue that ambiguity allows for greater ease of processing by permitting efficient linguistic units to be re-used. We test predictions of this theory in English, German, and Dutch. Our results and theoretical analysis suggest that ambiguity is a functional property of language that allows for greater communicative efficiency. This provides theoretical and empirical arguments against recent suggestions that core features of linguistic systems are not designed for communication.     

Going rogue in the spatial cuing paradigm: High spatial validity is insufficient to elicit voluntary shifts of attention

Voluntary shifts of attention are often motivated in experimental contexts by using well-known symbols that accurately predict the direction of targets. The authors report 3 experiments, which showed that the presentation of predictive spatial information does not provide sufficient incentive to elicit voluntary shifts of attention. For instance, when allowed to spontaneously choose between using a 100%-valid spatial word cue versus searching without the aid of the cue, observers consistently searched for a unique target without the aid of the cue. Another experiment showed that observers' choice to use spatial word cues could be biased by providing dedicated time to process the cue before the target display appeared (i.e., nonzero, cue-target SOAs). Although this dedicated processing time has routinely been included in spatial cuing experiments, its incentive-inducing role has never been acknowledged. Implications for theories of both voluntary and involuntary control are discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Processing relative clauses in supportive contexts

Results from two self-paced reading experiments in English are reported in which subject- and object-extracted relative clauses (SRCs and ORCs, respectively) were presented in contexts that support both types of relative clauses (RCs). Object-extracted versions were read more slowly than subject-extracted versions across both experiments. These results are not consistent with a decay-based working memory account of dependency formation where the amount of decay is a function of the number of new discourse referents that intervene between the dependents (Gibson, 1998; Warren & Gibson, 2002). Rather, these results support interference-based accounts and decay-based accounts where the amount of decay depends on the number of words or on the type of noun phrases that intervene between the dependents. In Experiment 2, presentation in supportive contexts was directly contrasted with presentation in null contexts. Whereas in the null context the extraction effect was only observed during the RC region, in a supportive context the extraction effect was numerically larger and persisted into the following region, thus showing that extraction effects are enhanced in supportive contexts. A sentence completion study demonstrated that the rate of SRCs versus ORCs was similar across null and supportive contexts (with most completions being subject-extractions), ruling out the possibility that an enhanced extraction effect in supportive contexts is due to ORCs being less expected in such contexts. However, the content of the RCs differed between contexts in the completions, such that the RCs produced in supportive contexts were more constrained, reflecting the lexical and semantic content of the preceding context. This effect, which we discuss in terms of expectations/lexico-syntactic priming, suggests that the enhancement of the extraction effect in supportive contexts is due to the facilitation of the subject-extracted condition.     

Feedback Delays: How Can Decision Makers Learn Not to Buy a New Car Every Time the Garage Is Empty?

Decision makers in dynamic environments (e.g., stock trading, inventory control, and firefighting) learn poorly in experiments where feedback about the outcomes of their actions is delayed. In searching for ways to mitigate these effects, this paper presents two computational models of learning with feedback delays and contrasts them against human decision-makers' performance. The no-memory model hypothesizes that decision makers always perceive feedback as immediate. The with-memory model hypothesizes that, over time, decision makers are able to develop internal representations of the task that help them to perform with delayed feedback. As borne out by human subjects, both models predict that a display of past history improves learning with delay and that increasing delay increasingly degrades performance. Even though the length of training in this task exceeds that used in many laboratory-based dynamic tasks, neither the two models nor the subjects are able to effectively learn without decision aids when faced with feedback delays. When given an amount of training that more closely approximates that provided in functioning dynamic environments, the with-memory model predicts that human decision makers may learn without decision aids over the long term if feedback delays are simple. These results raise several issues for continued theoretical investigation as well as potential suggestions for training and supporting decision makers in dynamic environments with feedback delays. Copyright 2000 Academic Press.     

The meaning of “Evolution”

In a recent article [Mertz 2001] in this journal I argued for the virtues of a realist ontology of relation instances (unit attributes). A major strength of this ontology is an assay of ontic ('material') predication that yields an account of individuation without the necessity of positing and defending 'bare particulars'. The crucial insight is that it is the unifying agency or combinatorial aspect of a relation instance as predicable that is for ontology the principium individuationis [Mertz 2002; 1996]. Or in short, what is ontically predicable, precisely as such, is the cause of individuation. As a preface to this positive doctrine I offered arguments against the coherence of bare particulars as defended in an article by J. P. Moreland [1998]. In a reply contained in this issue Moreland and Timothy Pickavance (hereafter M/P) propose to answer my objections [2002]. The response that follows provides reasons why, I contend, M/P have not succeeded in parrying my objections to bare particulars.     

Stop With the Questions Already! Does Data Quality Suffer for Scales Positioned Near the End of a Lengthy Questionnaire?

Research questionnaires frequently include dozens—if not hundreds—of self-report items. Lengthy questionnaires, however, are often a necessity. In some cases, they are needed to assess the many variables found in a complex model; in other cases, they are the result of the inclusion of a single lengthy measure. This raises an important question: Do participants provide accurate responses to measures positioned at the end of a lengthy questionnaire? One possibility is that participants experience fatigue during questionnaire completion, leading them to engage in careless responding, and thus compromising the accuracy of their responses. Another possibility is that even the longest research questionnaires are generally too short to evoke participant fatigue. This latter possibility suggests that participants are largely able to maintain their attention while completing most questionnaires. Given the lack of clarity on this issue, we conducted two experiments (Study 1 N = 244; Study 2 N = 461) in which we randomly assigned each participant to complete a block of target scales at either the beginning or the end of a lengthy (> 300-item) questionnaire. Each participant also recruited an informant who provided reports of the participant’s personality, attitudes, and behaviors. These informant data allowed us to examine the effects of the experimental manipulation on the target scales’ convergent and criterion-related validity. The findings of both studies indicated that the target scales performed similarly across the two conditions. Given the ubiquity of lengthy questionnaires, these findings have far-reaching practical implications.