Study Of Context Effects Research Articles

Do adolescents always take more risks than adults? A within-subjects developmental study of context effects on decision making and processing

Adolescents take more risks than adults in the real world, but laboratory experiments do not consistently demonstrate this pattern. In the current study, we examine the possibility that age differences in decision making vary as a function of the nature of the task (e.g., how information about risk is learned) and contextual features of choices (e.g., the relative favorability of choice outcomes), due to age differences in psychological constructs and physiological processes related to choice (e.g., weighting of rare probabilities, sensitivity to expected value, sampling, pupil dilation). Adolescents and adults made the same 24 choices between risky and safe options twice: once based on descriptions of each option, and once based on experience gained from sampling the options repeatedly. We systematically varied contextual features of options, facilitating a fine-grained analysis of age differences in response to these features. Eye-tracking and experience-sampling measures allowed tests of age differences in predecisional processes. Results in adolescent and adult participants were similar in several respects, including mean risk-taking rates and eye-gaze patterns. However, adolescents’ and adults’ choice behavior and process measures varied as a function of decision context. Surprisingly, age differences were most pronounced in description, with only marginal differences in experience. Results suggest that probability weighting, expected-value sensitivity, experience sampling and pupil dilation patterns may change with age. Overall, results are consistent with the notion that adolescents are more prone than adults to take risks when faced with unlikely but costly negative outcomes, and broadly point to complex interactions between multiple psychological constructs that develop across adolescence.

The Shape of Things to Come in Speech Production: A Functional Magnetic Resonance Imaging Study of Visual Form Interference during Lexical Access.

Studies of context effects in speech production have shown that semantic feature overlap produces interference in naming of categorically related objects. In neuroimaging studies, this semantic interference effect is consistently associated with involvement of left superior and middle temporal gyri. However, at least part of this effect has recently been shown to be attributable to visual form similarity, as categorically related objects typically share visual features. This fMRI study examined interference produced by visual form overlap in the absence of a category relation in a picture-word interference paradigm. Both visually similar and visually dissimilar distractors led to increased BOLD responses in the left inferior frontal gyrus compared with the congruent condition. Naming pictures in context with a distractor word denoting an object visually similar in form slowed RTs compared with unrelated words and was associated with reduced activity in the left posterior middle temporal gyrus. This area is reliably observed in lexical level processing during language production tasks. No significant differential activity was observed in areas typically engaged by early perceptual or conceptual feature level processing or in areas proposed to be engaged by postlexical language processes, suggesting that visual form interference does not arise from uncertainty or confusion during perceptual or conceptual identification or after lexical processing. We conclude that visual form interference has a lexical locus, consistent with the predictions of competitive lexical selection models.

The appropriacy of averaging in the study of context effects.

Models of human decision-making aim to simultaneously explain the similarity, attraction, and compromise effects. However, evidence that people show all three effects within the same paradigm has come from studies in which choices were averaged over participants. This averaging is only justified if those participants show qualitatively similar choice behaviors. To investigate whether this was the case, we repeated two experiments previously run by Trueblood (Psychonomic Bulletin & Review, 19(5), 962-968, 2012) and Berkowitsch, Scheibehenne, and Rieskamp (Journal of Experimental Psychology, 143(3), 1331-1348, 2014). We found that individuals displayed qualitative differences in their choice behavior. In general, people did not simultaneously display all three context effects. Instead, we found a tendency for some people to show either the similarity effect or the compromise effect but not both. More importantly, many individuals showed strong dimensional biases that were much larger than any effects of context. This research highlights the dangers of averaging indiscriminately and the necessity for accounting for individual differences and dimensional biases in decision-making.

Causation From Perception

Beginning with the research of Albert Michotte, investigators have identified simple perceptual events that observers report as causal. For example, suppose a square moves across a screen and comes to a halt when it makes contact with a second square. If the second square then begins moving in the same direction, observers sometimes report that the first square “pushed” the second or “caused it to move.” Based on such reports, Michotte claimed that people perceive causality, and a number of psychologists and philosophers have followed his lead. This article examines Michotte’s hypothesis by comparing it with its chief rival: Observers possess representations of pushings, pullings, and other events in long-term memory. A Michottean display triggers one of these representations, and the representation classifies the display as an instance of pushing (or pulling, etc.). According to this second explanation, recognizing an event as a pushing is similar to classifying an object as a cup or a dog. Data relevant to this debate come from infant and animal studies, cognitive and neuropsychological dissociation experiments, and studies of context effects and individual differences. However, a review of research in these paradigms finds no reason to prefer Michotte’s theory over its competitor.

Molecular Dynamics Simulations of the 136 Unique Tetranucleotide Sequences of DNA Oligonucleotides. II: Sequence Context Effects on the Dynamical Structures of the 10 Unique Dinucleotide Steps

Molecular dynamics (MD) simulations including water and counterions on B-DNA oligomers containing all 136 unique tetranucleotide basepair steps are reported. The objective is to obtain the calculated dynamical structure for at least two copies of each case, use the results to examine issues with regard to convergence and dynamical stability of MD on DNA, and determine the significance of sequence context effects on all unique dinucleotide steps. This information is essential to understand sequence effects on DNA structure and has implications on diverse problems in the structural biology of DNA. Calculations were carried out on the 136 cases embedded in 39 DNA oligomers with repeating tetranucleotide sequences, capped on both ends by GC pairs and each having a total length of 15 nucleotide pairs. All simulations were carried out using a well-defined state-of-the-art MD protocol, the AMBER suite of programs, and the parm94 force field. In a previous article (Beveridge et al. 2004. Biophysical Journal. 87:3799–3813), the research design, details of the simulation protocol, and informatics issues were described. Preliminary results from 15 ns MD trajectories were presented for the d(CpG) step in all 10 unique sequence contexts. The results indicated the sequence context effects to be small for this step, but revealed that MD on DNA at this length of trajectory is subject to surprisingly persistent cooperative transitions of the sugar-phosphate backbone torsion angles α and γ. In this article, we report detailed analysis of the entire trajectory database and occurrence of various conformational substates and its impact on studies of context effects. The analysis reveals a possible direct correspondence between the sequence-dependent dynamical tendencies of DNA structure and the tendency to undergo transitions that “trap” them in nonstandard conformational substates. The difference in mean of the observed basepair step helicoidal parameter distribution with different flanking sequence sometimes differs by as much as one standard deviation, indicating that the extent of sequence effects could be significant. The observations reveal that the impact of a flexible dinucleotide such as CpG could extend beyond the immediate basepair neighbors. The results in general provide new insight into MD on DNA and the sequence-dependent dynamical structural characteristics of DNA.

A Parameterized Representation of Uncertain Conceptual Spaces

AbstractMost conceptual modeling in geographic information science to date has used a symbolic approach with little or no recognition of the semantic uncertainty often found in geographic concepts. This work describes a concept model based on parameterized concept descriptions that uses a spatial metaphor, the conceptual space, as an organizing structure (Gärdenfors 2000). This cognitive theory of conceptual spaces is combined with a formal representation of semantic uncertainty based on rough fuzzy sets. The conceptual space then represents each concept as a collection of rough fuzzy property definitions with associated salience weights, where a property itself can be treated as a special case of a concept. Instead of explicitly defining concept hierarchies, we can allow different conceptual structures to emerge through measures of concept inclusion and similarity. A land use/land cover example demonstrates how the model represents concepts, concept similarity, hierarchical structures and the context dependence of concepts. The final section of the paper points to the need for further studies of context effects, concept similarity measures, and uncertainty representation using the proposed model.

Traps and Stepping Stones: Neighborhood Dynamics and Family Well-Being

Studies of context effects - for example, effects of neighborhoods, schools, kinship units, or all of these - on human behavior and well-being now span the social sciences and pose some of the most daunting analytic problems faced by social researchers. Understanding such effects is particularly important as metropolitan areas in the U.S. face continued economic restructuring and large-scale demographic change from migration, aging, and other forces, and as policymakers and researchers seek to understand and respond to increased economic inequality and its consequences. To date, however, almost all relevant research has either studied processes of neighborhood change (hinting at possible effects on individuals and families) or of human development (including possible effects of neighborhood characteristics). This theoretical essay argues strongly for integrating these largely separate enterprises and outlines basic frameworks for doing so. I discuss three dynamic functions - neighborhood change, individual exposure to risks and resources, and life course transitions - that contribute to neighborhood effects and use simple Markovian risk models to illustrate the importance of housing choices and outcomes over time. Neighborhoods may be thought of as traps, stepping stones, or springboards for families navigating the life course, not just stable, upgrading, or declining (in traditional terms). As such, efforts to leverage neighborhood context to improve child and family well-being must consider how housing mobility relates to other family strategies for getting by, getting ahead, and propelling the next generation.

Recognition of word and nonsense syllables in noise

In the recognition of human speech, listeners use sensory information from the speech signal as well as signal-independent information, such that acoustic-phonetic salience, lexical status, frequency of usage, and neighborhood density interact in speech recognition. This paper presents detailed results from a replication of a study of context effects reported by Boothroyd and Nittrouer [J. Acoust. Soc. Am. 84, 101–108 (1988)]. 240 phonetically matched word and nonsense CVC syllables at different SNRs were presented to 32 listeners for identification. The results are consistent with the original study, with greater accuracy for words than nonsense items as quantified by a j-factor analysis according to lexical status. Online response collection enabled detailed analyses not reported in the original study. Values for the j-factor according to usage frequency and phonetic confusability are presented. Confusion matrices of the phonemes are presented, and are largely consistent with previous studies for the initial consonants and vowels. Accuracy in the final consonants of nonsense syllables is substantially lower than the corresponding phonemes of words or than the initial consonants of nonsense syllables. Final nasals were particularly difficult to identify.

A study of context effects on phychological response caused by meaningless random noise in the case of listening to speech

A study of context effects on phychological response caused by meaningless random noise in the case of listening to speech

Comments on "Acoustic Measurements of Men’s and Women’s Voices: A Study of Context Effects and Covariatlon"

Comments on "Acoustic Measurements of Men’s and Women’s Voices: A Study of Context Effects and Covariatlon"

A Case Study of Context Effects and Residential Area Evaluation in Hamilton, Canada

Context effects which describe how the characteristics of residential alternatives affect evaluation and residential choices are examined empirically. The extent that people use different criteria to cognize dissimilar residential areas is investigated with survey data from Hamilton, Canada. For nine residential areas, individual differences in cognition and context effects are evaluated by a two-way analysis of variance of attribute ratings. No significant individual differences emerged for fourteen of the sixteen attributes. They are retained in the subsequent derivation of evaluative criteria. These criteria vary among areas, but context effects are comparatively weak. Context effects are reduced by removing individual differences in the cognition of residential area attributes.

Social facilitation: A self-presentational view.

This article offers a self-presentat ional account of performance in others' presence. The account attributes social facilitation to the performer's active regulation of a public image, and it attributes social impairment to embarrassment following loss of public esteem. Individuals lose esteem by making numerous errors on difficult tasks. This self-presentational analysis is tested in a study of context effects in verbal learning. Two tasks are studied: a difficult task that includes a few simple items and an easy task that includes a few complex items. Consistent with the self-presentational analysis (but not with drive theories of social facilitation), the presence of an observer impairs the learning of simple items if those items are embedded within a difficult task. Also, an observer's presence does not impair the learning of complex items if those items are embedded within an easy task. Questionnaire responses suggest a naturally occurring confound between task difficulty and perceived failure. The influence of the presence of others on individual behavior, a classic topic in social psychology, was studied extensively in the early 1900s (Dashiell, 1935). Contemporary interest in the topic derives from Zajonc's proposal (1965) that the presence of others acts as a source of generalized drive (Spence, 1956), and energizes the dominant response tendency to the exclusion of competing responses. Cottrell (1972) amended Zajonc's theory, contending that the presence of others arouses apprehension over evaluations. He claimed evaluation apprehension as a source of generalized drive. This article proposes an alternative analysis of behavior in others' presence. Following Cottrell, the analysis attributes the influence of others' presence to the potential that presence gives them for evaluation. But Cottrell seemed to ignore the fact that the object of evaluation is the individual's perThis article is based on a dissertation submitted to Duke University in partial fulfillment of the requirements for the PhD. I am grateful to Alan Levy, my dissertation adviser, for his guidance and to Mike Gottesman for help with this research.