In-situ high-voltage electron microscopy observations of reactions between molten Zn and Fe

Reactions between molten Zn and Fe have been observed directly by means of an in-situ heating experiment in a high-voltage electron microscope. In order to suppress evaporation of Zn during the in-situ heating experiment the specimen was coated with a plasma-polymerized hydrocarbon film. Mechanisms for the formation of Fe-Zn intermetallic compounds are discussed and it is concluded that all the models proposed so far are of doubtful validity.     

A high-loaded hemisphere successfully ignores distractors

We used a response competition paradigm to investigate whether a distractor is effectively rejected under conditions where it is projected to a highly-loaded hemisphere. In two experiments we asked right-handed participants to identify a target among five task-relevant letters while they ignored a distractor. We manipulated both the distractor visual-field (low-load/high-load) and the compatibility of the target and the distractor. In the low-loaded visual-field, we presented a distractor with one task-relevant stimulus to one visual-field and the remaining task-relevant stimuli to the opposite visual-field. In the high-loaded visual-field, we presented a distractor and task-relevant stimuli in reverse. In Experiment 1 (left/right), we found a compatibility effect for the low-loaded, but not for the high-loaded visual-field. In Experiment 2, this modulation of the compatibility effect did not appear when the upper/lower visual-field was manipulated. These findings demonstrate that a distractor is successfully ignored when it is presented to a highly-loaded hemisphere.     

Fitting the child's mind to the world: adaptive norm-based coding of facial identity in 8-year-olds

In adults, facial identity is coded by opponent processes relative to an average face or norm, as evidenced by the face identity aftereffect: adapting to a face biases perception towards the opposite identity, so that a previously neutral face (e.g. the average) resembles the identity of the computationally opposite face. We investigated whether children as young as 8 use adaptive norm-based coding to represent faces, a question of interest because 8-year-olds are less accurate than adults at recognizing faces and do not show the adult neural markers of face expertise. We found comparable face identity aftereffects in 8-year-olds and adults: perception of identity in both groups shifted in the direction predicted by norm-based coding. This finding suggests that, by 8 years of age, the adaptive computational mechanisms used to code facial identity are like those of adults and hence that children's immaturities in face processing arise from another source.     

Differences in State-Trait Anxiety Inventory scores for ethnically diverse adolescents in Hawaii

This study examined the association between anxiety and 5 predictor variables: ethnicity (Caucasian, Native Hawaiian/part Hawaiian, Japanese, other), gender, grade level (9-12th), main wage earners' educational level, and State-Trait Anxiety Inventory (STAI; C. D. Spielberger, R. L. Gorsuch, & R. E. Lushene, 1970) factors for a diverse group of students. Hawaiian students were found to have significantly higher levels of anxiety than Japanese students; however, ethnicity was not a significant predictor when gender, grade level, and main wage earners' education were statistically held constant. An interaction between ethnicity and STAI factor scores indicated an atypical pattern for Caucasians. Female students scored significantly higher than male students, and main wage earners' education predicted amount of anxiety. In general, these 2 associations remained significant when ethnicity and grade level were held constant. An interaction between gender and STAI factor scores indicated that the difference between female and male students was relatively larger for positively (as opposed to negatively) worded State items and for negatively (as opposed to positively) worded Trait items. Overall, the findings suggested that apparent ethnic differences in anxiety levels may be due to causal variables related to other sociodemographic variables. Factor scores in the form of positively versus negatively worded items should be considered an important variable; using only a global STAI composite as a measure of anxiety will mask the differential effects of the STAI factor scores. Further research is needed to determine the generalizability of these findings to other groups and to provide knowledge on direct causal variables that may account for a greater percentage of variance.     

A small-world network model of facial emotion recognition

Various models have been proposed to increase understanding of the cognitive basis of facial emotions. Despite those efforts, interactions between facial emotions have received minimal attention. If collective behaviours relating to each facial emotion in the comprehensive cognitive system could be assumed, specific facial emotion relationship patterns might emerge. In this study, we demonstrate that the frameworks of complex networks can effectively capture those patterns. We generate 81 facial emotion images (6 prototypes and 75 morphs) and then ask participants to rate degrees of similarity in 3240 facial emotion pairs in a paired comparison task. A facial emotion network constructed on the basis of similarity clearly forms a small-world network, which features an extremely short average network distance and close connectivity. Further, even if two facial emotions have opposing valences, they are connected within only two steps. In addition, we show that intermediary morphs are crucial for maintaining full network integration, whereas prototypes are not at all important. These results suggest the existence of collective behaviours in the cognitive systems of facial emotions and also describe why people can efficiently recognize facial emotions in terms of information transmission and propagation. For comparison, we construct three simulated networks—one based on the categorical model, one based on the dimensional model, and one random network. The results reveal that small-world connectivity in facial emotion networks is apparently different from those networks, suggesting that a small-world network is the most suitable model for capturing the cognitive basis of facial emotions.     

Exploring children’s face-space: A multidimensional scaling analysis of the mental representation of facial identity

We explored differences in the mental representation of facial identity between 8-year-olds and adults. The 8-year-olds and adults made similarity judgments of a homogeneous set of faces (individual hair cues removed) using an “odd-man-out” paradigm. Multidimensional scaling (MDS) analyses were performed to represent perceived similarity of faces in a multidimensional space. Five dimensions accounted optimally for the judgments of both children and adults, with similar local clustering of faces. However, the fit of the MDS solutions was better for adults, in part because children’s responses were more variable. More children relied predominantly on a single dimension, namely eye color, whereas adults appeared to use multiple dimensions for each judgment. The pattern of findings suggests that children’s mental representation of faces has a structure similar to that of adults but that children’s judgments are influenced less consistently by that overall structure.     

Effects of visual cue and response assignment on spatial stimulus coding in stimulus-response compatibility

Tlauka and McKenna ( 2000 ) reported a reversal of the traditional stimulus-response compatibility (SRC) effect (faster responding to a stimulus presented on the same side than to one on the opposite side) when the stimulus appearing on one side of a display is a member of a superordinate unit that is largely on the opposite side. We investigated the effects of a visual cue that explicitly shows a superordinate unit, and of assignment of multiple stimuli within each superordinate unit to one response, on the SRC effect based on superordinate unit position. Three experiments revealed that stimulus-response assignment is critical, while the visual cue plays a minor role, in eliciting the SRC effect based on the superordinate unit position. Findings suggest bidirectional interaction between perception and action and simultaneous spatial stimulus coding according to multiple frames of reference, with contribution of each coding to the SRC effect flexibly varying with task situations.     

The fractal property of internal structure of facial affect recognition: A complex system approach

Based on a circumplex model of facial affect, four inner affective circumplexes, assumed to have 100%, 75%, 50%, and 25% emotional intensities, were investigated in terms of fractal, which is a concept of complex systems. Results revealed that the perimeters of the circumplex excluding the 25% condition possessed fractal property characterised by features specific to fractals. Results also showed that fractal dimension in the 50% condition (1.58 dimension) was significantly higher than that in the 100% (1.45 dimension) and 75% (1.45 dimension) conditions, indicating that the cognitive structure of facial affect in the 50% condition was more complex than that in the 100% and 75% conditions.