Time course of effects of emotion on item memory and source memory for Chinese words

Although many studies have investigated the effect of emotion on memory, it is unclear whether the effect of emotion extends to all aspects of an event. In addition, it is poorly understood how effects of emotion on item memory and source memory change over time. This study examined the time course of effects of emotion on item memory and source memory. Participants learned intentionally a list of neutral, positive, and negative Chinese words, which were presented twice, and then took test of free recall, followed by recognition and source memory tests, at one of eight delayed points of time. The main findings are (within the time frame of 2 weeks): (1) Negative emotion enhances free recall, whereas there is only a trend that positive emotion enhances free recall. In addition, negative and positive emotions have different points of time at which their effects on free recall reach the greatest magnitude. (2) Negative emotion reduces recognition, whereas positive emotion has no effect on recognition. (3) Neither positive nor negative emotion has any effect on source memory. The above findings indicate that effect of emotion does not necessarily extend to all aspects of an event and that valence is a critical modulating factor in effect of emotion on item memory. Furthermore, emotion does not affect the time course of item memory and source memory, at least with a time frame of 2 weeks. This study has implications for establishing the theoretical model regarding the effect of emotion on memory. (C) 2011 Elsevier Inc. All rights reserved

Familiarity and complexity modulate the way children imitate tool-use actions: A cross-cultural study

The effects of action complexity and familiarity on preschooler's imitation performance were investigated. Thirty-two tool-use action video clips were imitated by 32 German and 32 Chinese preschoolers. Preschoolers' imitation performance was better for familiar as compared to unfamiliar actions and for simple as compared to complex actions. Furthermore, imitation errors were classified as means (action steps to reach the goal) errors and ends (action outcomes) errors. When imitating simple actions children made more means than ends errors, whereas more ends errors were made for complex actions. We explain this by the higher demands of processing complex actions on cognitive resources. This result highlights the important role of action complexity in children's representation of the means and ends of tool-use actions. Performances showed a high cross-cultural stability, which indicates that imitation is a basic learning mechanism thereby uninfluenced by cultures

To Bind or Not to Bind? Different Temporal Binding Effects from Voluntary Pressing and Releasing Actions

Binding effect refers to the perceptual attraction between an action and an outcome leading to a subjective compression of time. Most studies investigating binding effects exclusively employ the "pressing" action without exploring other types of actions. The present study addresses this issue by introducing another action, releasing action or the voluntary lifting of the finger/wrist, to investigate the differences between voluntary pressing and releasing actions. Results reveal that releasing actions led to robust yet short-lived temporal binding effects, whereas pressing condition had steady temporal binding effects up to super-seconds. The two actions also differ in sensitivity to changes in temporal contiguity and contingency, which could be attributed to the difference in awareness of action. Extending upon current models of "willed action," our results provide insights from a temporal point of view and support the concept of a dual system consisting of predictive motor control and top-down mechanisms

Amygdala Volume Predicts Inter-Individual Differences in Fearful Face Recognition

The present study investigates the relationship between inter-individual differences in fearful face recognition and amygdala volume. Thirty normal adults were recruited and each completed two identical facial expression recognition tests offline and two magnetic resonance imaging (MRI) scans. Linear regression indicated that the left amygdala volume negatively correlated with the accuracy of recognizing fearful facial expressions and positively correlated with the probability of misrecognizing fear as surprise. Further exploratory analyses revealed that this relationship did not exist for any other subcortical or cortical regions. Nor did such a relationship exist between the left amygdala volume and performance recognizing the other five facial expressions. These mind-brain associations highlight the importance of the amygdala in recognizing fearful faces and provide insights regarding inter-individual differences in sensitivity toward fear-relevant stimuli

Electrophysiological correlates of visually processing subject's own name

We investigated the electrophysiological correlates of the processing of subject's own name (SON) in comparison to familiar and unfamiliar names in the Chinese language. The three types of names were the deviants in an oddball paradigm among lexical and non-lexical phrases. All items consisted of three characters, and the non-lexical items were the targets. All names caused a clear N170 component of identical size which we take as a correlate of structural encoding. Only SON elicited a large N250 component, reflecting attentional capturing of SON. Additionally, SON caused a larger but later peaking P300 than the other two name stimuli which we interpret as a correlate of access to self-reference information. (C) 2011 Elsevier Ireland Ltd. All rights reserved

Discriminability effect on Garner interference: evidence from recognition of facial identity and expression

Using Garner's speeded classification task existing studies demonstrated an asymmetric interference in the recognition of facial identity and facial expression. It seems that expression is hard to interfere with identity recognition. However, discriminability of identity and expression, a potential confounding variable, had not been carefully examined in existing studies. In current work, we manipulated discriminability of identity and expression by matching facial shape (long or round) in identity and matching mouth (opened or closed) in facial expression. Garner interference was found either from identity to expression (Experiment 1) or from expression to identity (Experiment 2). Interference was also found in both directions (Experiment 3) or in neither direction (Experiment 4). The results support that Garner interference tends to occur under condition of low discriminability of relevant dimension regardless of facial property. Our findings indicate that Garner interference is not necessarily related to interdependent processing in recognition of facial identity and expression. The findings also suggest that discriminability as a mediating factor should be carefully controlled in future research