HyunJung Shin

Rules and Exemplars in Categorization, Identification, and Recognition

Subjects learned to classify perceptual stimuli varying along continuous, separable dimensions into rule-described categories. The categories were designed to contrast the predictions of a selective-attention exemplar model and a simple rule-based model formalizing an economy-of-description view. Converging evidence about categorization strategies was obtained by also collecting identification and recognition data and by manipulating strategies via instructions. In free-strategy conditions, the exemplar model generally provided an accurate quantitative account of identification, categorization, and recognition performance, and it allowed for the interrelationship of these paradigms within a unified framework. Analyses of individual subject data also provided some evidence for the use of rules, but in general, the rules seemed to have a great deal in common with exemplar storage processes. Classification and recognition performance for subjects given explicit instructions to use specific rules contrasted dramatically with performance in the free-strategy conditions and could not be predicted by the exemplar model.

Similarity-scaling studies of dot-pattern classification and recognition

Classification performance in the dot-pattern, prototype-distortion paradigm (e.g., Posner & Keele, 1968) was modeled within a multidimensional scaling (MDS) framework. MDS solutions were derived for sets of dot patterns that were generated from prototypes. These MDS solutions were then used in conjunction with exemplar, prototype, and combined models to predict classification and recognition performance. Across 3 experiments, an MDS-based exemplar model accounted for the effects of several fundamental learning variables, including level of distortion of the patterns, category size, delay of transfer phase, and item frequency. Most important, the model quantitatively predicted classification probabilities for individual dot patterns in the sets, not simply general trends of performance. There was little evidence for the existence of a prototype-abstraction process that operated above and beyond pure exemplar-based generalization.

Detecting affiliation in colaughter across 24 societies

Significance Human cooperation requires reliable communication about social intentions and alliances. Although laughter is a phylogenetically conserved vocalization linked to affiliative behavior in nonhuman primates, its functions in modern humans are not well understood. We show that judges all around the world, hearing only brief instances of colaughter produced by pairs of American English speakers in real conversations, are able to reliably identify friends and strangers. Participants’ judgments of friendship status were linked to acoustic features of laughs known to be associated with spontaneous production and high arousal. These findings strongly suggest that colaughter is universally perceivable as a reliable indicator of relationship quality, and contribute to our understanding of how nonverbal communicative behavior might have facilitated the evolution of cooperation. Laughter is a nonverbal vocal expression that often communicates positive affect and cooperative intent in humans. Temporally coincident laughter occurring within groups is a potentially rich cue of affiliation to overhearers. We examined listeners’ judgments of affiliation based on brief, decontextualized instances of colaughter between either established friends or recently acquainted strangers. In a sample of 966 participants from 24 societies, people reliably distinguished friends from strangers with an accuracy of 53–67%. Acoustic analyses of the individual laughter segments revealed that, across cultures, listeners’ judgments were consistently predicted by voicing dynamics, suggesting perceptual sensitivity to emotionally triggered spontaneous production. Colaughter affords rapid and accurate appraisals of affiliation that transcend cultural and linguistic boundaries, and may constitute a universal means of signaling cooperative relationships.

Cross-Cultural Differences in Consistent Mapping Effects of Targets and Distractors

Previous cross-cultural studies have shown that East Asians pay more attention to the background information and European Americans more to the focal object. However, it has not been well investigated what cognitive benefits can be achieved with these different attention allocation strategies. In the current study, we examined whether Koreans and European Americans differ in utilizing the regularity in targets and distractors by comparing consistent mappings (CMs) with varied mappings (VMs) of stimuli. Two experiments consistently revealed that European Americans showed a greater performance benefit with the consistency embedded within the targets (i.e., the CM target effect) but not within the distractors. In contrast, Koreans showed a greater performance benefit with the consistency within the distractors (i.e., the CM distractor effect), but not within the targets. These results imply that the East–West differences in attention allocation strategies reflect the cultural differences in utilizing the information that is potentially beneficial for task performance. We discuss what kinds of cognitive benefits can be achieved by differentially paying attention to the target and the background.

A Model on the Processing of Noun-Noun Conceptual Combination and Its Verification

In this study, a model on the processing of noun-noun conceptual combination was proposed and an experiment was conducted to verify it. The model suggests that thematic-relation interpretation can be facilitated when there are any salient external properties in the head and the modifier is relevant to one of them. On the other hand, property-mapping interpretation can be facilitated when there are any salient internal properties in the modifier and the head has any relevant slot (dimension) to one of them. The experiment examined whether external/internal properties in the heads/modifiers and relevance between modifier and head can facilitate property or relation interpretation by measuring interpretation times and degrees of interpretation convergency. The results showed that the interpretation time is faster and the interpretation convergency is higher when there are external or internal properties and their relevant slots as well.

The Perception of Spontaneous and Volitional Laughter Across 21 Societies

Laughter is a nonverbal vocalization occurring in every known culture, ubiquitous across all forms of human social interaction. Here, we examined whether listeners around the world, irrespective of their own native language and culture, can distinguish between spontaneous laughter and volitional laughter—laugh types likely generated by different vocal-production systems. Using a set of 36 recorded laughs produced by female English speakers in tests involving 884 participants from 21 societies across six regions of the world, we asked listeners to determine whether each laugh was real or fake, and listeners differentiated between the two laugh types with an accuracy of 56% to 69%. Acoustic analysis revealed that sound features associated with arousal in vocal production predicted listeners’ judgments fairly uniformly across societies. These results demonstrate high consistency across cultures in laughter judgments, underscoring the potential importance of nonverbal vocal communicative phenomena in human affiliation and cooperation.