Visual search asymmetry with uncertain targets

The underlying mechanism of search asymmetry is still unknown. Many computational models postulate top-down selection of target-defining features as a crucial factor. This feature selection account implies, and other theories implicitly assume, that predefined target identity is necessary for search asymmetry. The authors tested the validity of the feature selection account using a singleton search task without a predefined target. Participants conducted a target-defined and a singleton search task with a circle (O) and a circle with a vertical bar (Q). Search asymmetry was observed in both tasks with almost identical magnitude. The results were not due to trial-by-trial feature selection, because search asymmetry persisted even when the target was completely unpredictable. Asymmetry in the singleton search was also observed with more complex stimuli, Kanji characters. These results suggest that feature selection is not necessary for search asymmetry, and they impose important constraints on current visual search theories.     

State Self-Esteem as a Moderator of Negative Mood Effects on Person Impression

Participants in a negative or a neutral mood performed an impression formation task in Experiment 1, a word fragment completion task in Experiment 2, and both tasks in Experiment 3. A self-referent versus other-referent sentence completion task was used to induce a negative mood. As a result, participants exhibited fewer mood-congruent effects on impression rating in the self-referent than in the other-referent mood induction condition, even though relevant traits had been equally activated across the two conditions. It was also shown that the self-referent induction procedure was accompanied by degrading of self-esteem, whereas the other-referent one was not. Taken together, the results suggest that the state self-esteem might be relevant to moderating of the negative mood effects on person impression.     

Social Exclusion and Disengagement of Covert Attention from Social Signs: The Moderating Role of Fear of Negative Evaluation

Previous research has demonstrated that social exclusion motivates individuals with low fear of negative evaluation (FNE) to pay attention to signs of social acceptance, but it does not motivate individuals with high FNE to do so. However, it remains unclear whether this finding reflects overt or covert attentional bias because the researchers employed a dot‐probe task. In order to resolve this ambiguity, the present study solely assessed disengagement of covert attention from social signs after exclusion manipulation in an experiment with university students (N = 60). As a result, exclusion delayed disengagement of covert attention from facial stimuli regardless of their types of expression for participants with low FNE, but such delay was not observed for participants with high FNE. The result indicated that social exclusion enhances attention to social information in individuals with low FNE, whereas it does not in individuals with high FNE. We discuss the possibility that a decline in inclusionary status affects overt and covert attentional processes differently.     

External source monitoring in a real‐life event: developmental changes in ability to identify source persons

The present study investigated young children's and adults' external source‐monitoring abilities with respect to facial identification accuracy for complex live events. Five‐ to 6‐ year‐olds and adults watched a magic show in which three different female magicians (i.e. source persons) performed three different kinds of magic tricks each. After approximately 1 month, the participants were asked to recognize what kinds of magic tricks had been performed, to make face identifications as to which magician had performed those magic tricks and to recognize those magicians' attributes. Results showed that both young children and adults had more difficulty with identifying source persons than recognizing them in a real‐life event in which a number of persons appeared. Especially for young children, low credibility was shown not only for the source memories but also for the recognition memories of the source person attributes. Copyright © 2007 John Wiley & Sons, Ltd.     

Understanding of speaker certainty and false‐belief reasoning: a comparison of Japanese and German preschoolers

It has been repeatedly shown that when asked to identify a protagonist's false belief on the basis of his false statement, English‐speaking 3‐year‐olds dismiss the statement and fail to attribute to him a false belief. In the present studies, we tested 3‐year‐old Japanese children in a similar task, using false statements accompanied by grammaticalized particles of speaker (un)certainty, as in everyday Japanese utterances. The Japanese children were directly compared with same‐aged German children, whose native language does not have grammaticalized epistemic concepts. Japanese children profited from the explicit statement of the protagonist's false belief when it was marked with the attitude of certainty in a way that German children did not – presumably because Japanese but not German children must process such marking routinely in their daily discourse. These results are discussed in the broader context of linguistic and theory of mind development.     

Gravity bias in young and adult chimpanzees (Pan troglodytes): tests with a modified opaque-tubes task

Young human children at around 2 years of age fail to predict the correct location of an object when it is dropped from the top of an S-shape opaque tube. They search in the location just below the releasing point (Hood, 1995). This type of error, called a 'gravity bias', has recently been reported in dogs and monkeys. In the present study, we investigated whether young and adult chimpanzees also show such a gravity bias in a modified version of the original opaque-tube task. The original task by Hood and colleagues required the subject to search in a location after the object had fallen, while in the task reported here, subjects were required to predict the location before the object was dropped. Thus the present procedure does not involve explicit invisible displacement operations, one of the important components of the original procedure. In Experiment 1 both young (1.5-2.5-year-old) and adult chimpanzees predicted the location of falling food items below the releasing point even when crossed tubes were used. These gravity errors remained after the extensive experience of using the tubes themselves. Experiment 2 further tested adult and 4-year-old chimpanzees under the set-up in which the straight and crossed tubes were simultaneously presented. The results were the same as those in the previous test, suggesting that developmental changes and learning effect do not affect the gravity bias in chimpanzees.     

Adjustments to local friction in multifinger prehension

The authors studied the effects of surface friction at the digit-object interface on digit forces and moments when 12 participants statically held an object in a 5-digit grasp. The authors changed low-friction contact (LFC) with rayon and high-friction contact (HFC) with sandpaper independently for each digit in all 32 possible combinations. Normal forces of the thumb and virtual finger (VF), an imagined finger with a mechanical effect equal to that of the 4 fingers, increased with the thumb at LFC or with an increase in the number of fingers at LFC. When the thumb was at LFC, the thumb tangential force decreased. The VF tangential force decreased when the number of fingers at LFC increased. The interaction of the local responses to friction and the synergic responses necessary to maintain the equilibrium explain the coordination of individual digit forces.     

Language-specific and universal influences in children's syntactic packaging of Manner and Path: a comparison of English, Japanese, and Turkish

Different languages map semantic elements of spatial relations onto different lexical and syntactic units. These crosslinguistic differences raise important questions for language development in terms of how this variation is learned by children. We investigated how Turkish-, English-, and Japanese-speaking children (mean age 3;8) package the semantic elements of Manner and Path onto syntactic units when both the Manner and the Path of the moving Figure occur simultaneously and are salient in the event depicted. Both universal and language-specific patterns were evident in our data. Children used the semantic-syntactic mappings preferred by adult speakers of their own languages, and even expressed subtle syntactic differences that encode different relations between Manner and Path in the same way as their adult counterparts (i.e., Manner causing vs. incidental to Path). However, not all types of semantics-syntax mappings were easy for children to learn (e.g., expressing Manner and Path elements in two verbal clauses). In such cases, Turkish- and Japanese-speaking children frequently used syntactic patterns that were not typical in the target language but were similar to patterns used by English-speaking children, suggesting some universal influence. Thus, both language-specific and universal tendencies guide the development of complex spatial expressions.     

Human gestures trigger different attentional shifts in chimpanzees (Pan troglodytes) and humans (Homo sapiens)

Brain lateralization has been the matter of extensive research over the last centuries, but it remains an unsolved issue. While hand preferences have been extensively studied, very few studies have investigated laterality of eye use in non-human primates. We examined eye preference in 14 Campbell’s monkeys (Cercopithecus c. campbelli). We assessed eye preference to look at a seed placed inside a tube using monocular vision. Eye use was recorded for 100 independent and non-rewarded trials per individual. All of the 14 monkeys showed very strong preferences in the choice of the eye used to look inside the tube (mean preference: 97.6%). Eight subjects preferred the right eye and six subjects preferred the left eye. The results are discussed in light of previous data on eye preference in primates, and compared to data on hand preference from these subjects. Our findings would support the hypothesis for an early emergence of lateralization for perceptual processes compared to manual motor functions.