Do dogs (Canis familiaris) understand invisible displacement?

Domestic dogs (Canis familiaris) perform above chance on invisible displacement tasks despite showing few other signs of possessing the necessary representational abilities. Four experiments investigated how dogs find an object that has been hidden in 1 of 3 opaque boxes. Dogs passed the task under a variety of control conditions, but only if the device used to displace the object ended up adjacent to the target box after the displacement. These results suggest that the search behavior of dogs was guided by simple associative rules rather than mental representation of the object's past trajectory. In contrast, Experiment 5 found that on the same task, 18- and 24-month-old children showed no disparity between trials in which the displacement device was adjacent or nonadjacent to the target box.     

Media ratings for violence and sex. Implications for policymakers and parents

This article reviews research on the implementation of media-rating systems, parents' use and evaluation of them, and the impact of ratings on children. Although half or more of parents report using media-rating systems, understanding of various components of the systems is low, particularly for television ratings. A meta-analysis of national polls shows that parents overwhelmingly prefer that ratings specify content, rather than giving age recommendations. A second meta-analysis, of experiments testing the effects of ratings on children's interest in programs, shows that ratings indicating restricted or controversial content have a deterrent effect for children under age 8 but that, by age 11 and especially for boys, the ratings show a small enticement effect. This effect occurs for both age-based and content-based ratings. Implications for policymakers and parents are discussed.     

A computer-graphic technique for the study of body size perception and body types

We present a novel approach for measuring body size estimation in normal and eating-disordered women and men. Clinical categories of body types were used as prototypes. By comparing the subjective appearance of a person’s body with prototypes, we can understand how different attributes of his or her body shape contribute to perception of body size. After lifelike random distortions have been applied to parts of their body image, individuals adjust their body shapes until they converge on their perceived veridical appearance. Exaggeration and minimization of particular body areas measured with respect to their true shape and with different prototypes can be expressed as numerical deviations. In this way, perceived body size and body attractiveness can be appraised during the course of diagnosis and treatment of eating disorders.     

Individual differences in the effects of spontaneous mimicry on emotional contagion

Two experiments explored the role of mimicry and self-perception processes in emotional contagion. In Study 1, 46 subjects watched two brief film clips depicting an episode of startled fear. In a separate procedure, subjects adopted facial expressions of emotion, and reported whether the expressions had caused them to feel corresponding emotions. Those who reported feeling the emotions were identified as more responsive to self-produced cues for feeling. Subjects who visibly moved to mimic the behavior of the actor were significantly more likely to be those who were more responsive to self-produced cues. In Study 2, 57 subjects watched three film clips depicting happy people. During clips when they inhibited the movements of their faces, subjects reported less happiness than during clips when they moved naturally and were able to mimic, or when they exaggerated their movements. This effect occurred only among subjects who, in a separate procedure, had been identified as more responsive to self-produced cues.The authors would like to thank Paul Ekman, Jerry Ginzburg, and an anonymous reviewer for very helpful suggestions for ways to improve the paper.     

A model theory of induction

Theories of induction in psychology and artificial intelligence assume that the process leads from observation and knowledge to the formulation of linguistic conjectures. This paper proposes instead that the process yields mental models of phenomena. It uses this hypothesis to distinguish between deduction, induction, and creative forms of thought. It shows how models could underlie inductions about specific matters. In the domain of linguistic conjectures, there are many possible inductive generalizations of a conjecture. In the domain of models, however, generalization calls for only a single operation: the addition of information to a model. If the information to be added is inconsistent with the model, then it eliminates the model as false: this operation suffices for all generalizations in a Boolean domain. Otherwise, the information that is added may have effects equivalent (a) to the replacement of an existential quantifier by a universal quantifier, or (b) to the promotion of an existential quantifier from inside to outside the scope of a universal quantifier. The latter operation is novel, and does not seem to have been used in any linguistic theory of induction. Finally, the paper describes a set of constraints on human induction, and outlines the evidence in favor of a model theory of induction.     

Interactions in processing segmental and suprasegmental features of speech

A speeded classification task was used to determine the nature of the dependency relation that exists during the processing of a segmental distinction in vowel quality and a suprasegmental distinction in pitch (Experiment 1) or loudness (Experiment 2) in a consonantvowel syllable. In both experiments, evidence was found for a mutual, symmetrical dependency between the processes underlying the analysis of the segmental and suprasegmental information in the syllable. This type of interaction pattern contrasts with the pattern of unidirectional dependency previously found for the analysis of a consonantal distinction and a suprasegmental distinction, in which the analysis of the consonantal information was found to be dependent on the analysis of the suprasegmental information (e.g., Wood, 1974). Together with these earlier findings, the present results clearly indicate that the form of the interaction between processes responsible for segmental and suprasegmental analysis is a function of the type of segmental information being analyzed. Future research must determine whether the distinct interaction patterns found thus far for consonants and vowels are due to a difference in phonetic class per se, i.e., consonant vs. vowel, or to a difference in the nature of the acoustic information specifying the consonant and vowel.     

Some effects of later-occurring information on the perception of stop consonant and semivowel

In three experiments, we determined how perception of the syllable-initial distinction between the stop consonant [b] and the semivowel [w], when cued by duration of formant transitions, is affected by parts of the sound pattern that occur later in time. For the first experiment, we constructed four series of syllables, similar in that each had initial formant transitions ranging from one short enough for [ba] to one long enough for [wa], hut different in overall syllable duration. The consequence in perception was that, as syllable duration increased, the [b-w] boundary moved toward transitions of longer duration. Then, in the second experiment, we increased the duration of the sound by adding a second syllable, [da], (thus creating [bada-wada]), and observed that lengthening the second syllable also shifted the perceived [b-w] boundary in the first syllable toward transitions of longer duration; however, this effect was small by comparison with that produced when the first syllable was lengthened equivalently. In the third experiment, we found that altering the structure of the syllable had an effect that is not to be accounted for by the concomitant change in syllable duration: lengthening the syllable by adding syllable-final transitions appropriate for the stop consonant [d] (thus creating [bad-wad]) caused the perceived [b-w] boundary to shift toward transitions of shorter duration, an effect precisely opposite to that produced when the syllable was lengthened to the same extent by adding steady-state vowel. We suggest that, in all these cases, the later-occurring information specifies rate of articulation and that the effect on the earlier-occurring cue reflects an appropriate perceptual normalization.     

Depression combined with somatic symptomatology among adolescent females who report concerns regarding maternal achievement

Recent research suggests that many females who mature during periods of great change in women's roles develop, beginning at adolescence, depressive symptomatology combined with such somatic problems as headache, dyspnea, insomnia, disordered eating, and preference for thinness. In this study of possible psychological mechanisms underlying the apparently paradoxical development of such symptomatology during periods of increased opportunity for women, 20% of females attending a suburban high school reported concerns regarding the limited achievements of their mothers and the limitations being female had placed upon their mothers. Compared to other female students, these respondents exhibited a greater correlation between depressive and somatic symptomatology and a higher prevalence of depression combined with somatic symptomatology. Prevalence of combined symptomatology was particularly high among respondents who also reported paternal biases against females and among those who indicated concerns regarding the limitations that being female had placed upon themselves.