The intrinsic difficulty of recursive functions

This paper deals with a philosophical question that arises within the theory of computational complexity: how to understand the notion of INTRINSIC complexity or difficulty, as opposed to notions of difficulty that depend on the particular computational model used. The paper uses ideas from Blum's abstract approach to complexity theory to develop an extensional approach to this question. Among other things, it shows how such an approach gives detailed confirmation of the view that subrecursive hierarchies tend to rank functions in terms of their intrinsic, and not just their model-dependent, difficulty, and it shows how the approach allows us to model the idea that intrinsic difficulty is a fuzzy concept. Jan Zygmunt     

Departure from normal assumptions: A promise for future psychometrics with substantive mathematical modeling

Normal assumptions have been used in many psychometric methods, to the extent that most researchers do not even question their adequacy. With the rapid advancement of computer technologies in recent years, psychometrics has extended its territory to include intensive cognitive diagnosis, etcetera, and substantive mathematical modeling ha become essential. As a natural consequence, it is time to consider departure from normal assumptions seriously. As examples of models which are not based on normality or its approximation, the logistic positive exponent family of models is discussed. These models include the item task complexity as the third parameter, which determines the single principle of ordering individuals on the ability scale.     

Aggressive and affiliative behavior in green monkeys with differing housing complexity

Eleven green monkeys (Cercopithecus aethiops) were combined into three social groups (two heterosexual, one all-male) in enclosures with similar volume but different levels of environmental complexity (two or four compartments). Agonistic and affiliative interactions were recorded over a 21-week period. The two heterosexual groups had their environmental complexity reduced (number of compartments reduced by one-half and volume/floorspace reduced by one-third) for a 5-week period in the middle of the study. Rates of contact aggression were low throughout the study. In the group with complexity reduced to one compartment, rates of noncontact aggression and affiliative behavior increased, and remained high after complexity was restored. In the group reduced to two compartments, rates of affiliative behavior increased but rates of noncontact aggression decreased, trends which continued after complexity was restored. The all-male group exhibited low rates of affiliative behavior throughout. Two compartments appear to foster successful group formation, but any change in a group's enclosure can have long-term effects on rates of aggression. © 1992 Wiley-Liss, Inc.     

Effects of referential ambiguity,time constraints and addressee orientation on the production of morphologically complex words

In five experiments, participants were asked to describe unambiguously a target picture in a picture–picture paradigm. In the same-category condition, target (e.g., water bucket) and distractor picture (e.g., ice bucket) had identical names when their preferred, morphologically simple, name was used (e.g., bucket). The ensuing lexical ambiguity could be resolved by compound use (e.g., water bucket). Simple names sufficed as means of specification in other conditions, with distractors identical to the target, completely unrelated, or geometric figures. With standard timing parameters, participants produced mainly ambiguous answers in Experiment 1. An increase in available processing time hardly improved unambiguous responding (Experiment 2). A referential communication instruction (Experiment 3) increased the number of compound responses considerably, but morphologically simple answers still prevailed. Unambiguous responses outweighed ambiguous ones in Experiment 4, when timing parameters were further relaxed. Finally, the requirement to name both objects resulted in a nearly perfect ambiguity resolution (Experiment 5). Together, the results showed that speakers overcome lexical ambiguity only when time permits, when an addressee perspective is given and, most importantly, when their own speech overtly signals the ambiguity.     

Predicting stress patterns in an unpredictable stress language: The use of non-lexical sources of evidence for stress assignment in Russian

The main goal of this research was to examine how readers of Russian assign stress to disyllabic words. In particular, we tested the claim that the process of stress assignment in Russian can only be accomplished lexically. Eleven potential non-lexical sources of evidence for stress in Russian were examined in regression and factorial studies. In Study 1, onset complexity, coda complexity, the orthography of the first syllable (CVC1), of the second syllable (CVC2), and of the ending of the second syllable (VC2) were found to be probabilistically associated with stress in Russian disyllables. In Studies 2 and 3, it was shown that Russian speakers do use 3 of these cues (CVC1, CVC2, and VC2) when making stress-assignment decisions. These results provide evidence against the idea that the nature of stress in the Russian language is so unpredictable that stress assignment can only be accomplished lexically. These results also suggest that any successful model of stress assignment in Russian needs to contain mechanisms allowing these 3 orthographic cues to play a role in the stress-assignment process.     

Flavor Fatigue: Cognitive Depletion Influences Consumer Enjoyment of Complex Flavors

Surprisingly, little research has examined how consumer responses to specific flavor characteristics of food are formed or how they may fluctuate situationally. We address this lacuna in the literature on the hedonic appreciation of food by demonstrating that enjoyment along one important gustatory dimension, flavor complexity, varies with the degree to which consumers are mentally depleted. Specifically, showing that gustatory sensations are more cognitively demanding than previously thought, findings from three studies evince that cognitive depletion reduces consumer enjoyment of complex‐flavored (but not simple‐flavored) foods via a reduction in pleasure that otherwise can be derived from complex flavors. We establish this effect across three different food categories and provide preliminary evidence for consumers’ ability to identify flavors as the underlying process. Our findings offer theoretical contributions and avenues for future research.     

不同心理弹性者的日常情绪特征:结合体验采样研究的证据

结合体验采样法和问卷法,分别考察了从252名上海高校大学生中甄别出的100名高、中、低心理弹性者在日常情绪状态和情绪复杂性、情绪调节方式上的差异态势。结果发现,不同心理弹性大学生:(1)在日常情绪状态上存在差异。高心理弹性组积极情绪的总分、强度和频率都显著高于低弹性组;高心理弹性组的积极情绪在日常情绪构成中所占的比重显著大于中、低弹性组。(2)在情绪复杂性的4个维度有不一致的表现。高心理弹性组拥有更高的积极情绪细腻度,3组在其他维度上没有发现差异。(3)积极情绪调节中,高心理弹性组多采用宣泄而少用抑制策略;消极情绪调节中,低心理弹性组多采用认知重视调节。这提示,积极情绪是与个体适应发展密切相关的内部因素,也是促进心理弹性发展的重要资源,个体对积极情绪的体验和觉察对心理弹性有重要影响。针对情绪觉察与调节的指导训练有望提升个体心理弹性。     

汉字材料的性质对视觉短时记忆广度影响的实验研究

汉字材料的熟悉性和复杂性对视觉短时记忆（ＶＳＴＭ）广度的影响研究存在分析。本研究在实验设计上区分了汉语字词的熟悉性和复杂性维度,探讨了它们对ＶＳＴＭ广义的不同影响程度,结果表明：（１）材料的熟悉性是影响汉语字词ＶＳＴＭ广度的最重要因素,材料的复杂性影响不大;（２）在材料熟悉程度一致,被试在１１－２０岁年龄范围条件下,汉语字词ＶＳＴＭ广义将保持相对恒定（３）在承认“组块假说”的前提,汉语字词ＶＳＴＭ     

Schizophrenia Epigenesis?

I begin by examining how genetics drivesschizophrenia research, and raise both familiar andrelatively novel criticisms of the evidence putativelysupporting the genetic basis of schizophrenia. Inparticular, I call attention to a set of concernsabout the effects of placentation on concordance ratesof schizophrenia in monozygotic twins, which furtherweakens the case for schizophrenia's so-called stronggenetic component. I then underscore two criticalpoints. First, I emphasize the importance of takingseriously considerations about the complexity of bothontogenesis and the development of hereditarydiseases. The recognition of developmentalconstraints and supports is crucial, for attention todevelopment exposes the naivete of too many models ofgene action in the aetiology of disease. Secondly, Iattend to those schizophreniologists who ignoremethodological criticisms and thus presume a geneticbasis for schizophrenia, and then seek the schizophrenic genotype lacking an adequatephenotype. In response I attempt to demonstrate thenecessity of a sustained effort at characterizing thephenotype of schizophrenia as an enabling conditionfor the whole enterprise of psychiatric genetics – andfor psychiatry itself. Without the organism-levelphenotype, research at the level of genes will remainunproductive – assuming of course that research at thegenetic level is appropriate at all.     

The complex challenges of ethical choices by engineers in public service

This paper proposes that engineers in public service are confronted with unavoidable complexity in their ethical considerations. The complexity begins with interactions among venues of ethical choices. Engineers must make ethical choices simultaneously at the individual, professional, organizational and societal levels. These ethical domains often conflict. The complexity also stems from situations in which physical properties may remain stable, but important social, economic, institutional and political conditions can change substantially. The paper proposes that the reflective learning approach of pragmatism can help with these challenging situations. This approach depends upon employing Dewey’s five stage process of inquiry to engage the ethical complexity inherent in the practice of engineering in the public service. An earlier version of this paper was presented at the 2005 conference, Ethics and Social Responsibility in Engineering and Technology, Linking Workplace Ethics and Education, co-hosted by Gonzaga University and Loyola Marymount University, Los Angeles, CA, USA, 9–10 June 2005.