Phase-dependent synaptic changes in the hippocampal CA1 field underlying extinction processes in freely moving rats

Recent studies focus on the functional significance of a novel form of synaptic plasticity, low-frequency stimulation (LFS)-induced synaptic potentiation in the hippocampal CA1 area. In the present study, we elucidated dynamic changes in synaptic function in the CA1 field during extinction processes associated with context-dependent fear memory in freely moving rats, with a focus on LFS-induced synaptic plasticity. Synaptic transmission in the CA1 field was transiently depressed during each extinction trial, but synaptic efficacy was gradually enhanced by repeated extinction trials, accompanied by decreases in freezing. On the day following the extinction training, synaptic transmission did not show further changes during extinction retrieval, suggesting that the hippocampal synaptic transmission that underlies extinction processes changes in a phase-dependent manner. The synaptic potentiation produced by extinction training was mimicked by synaptic changes induced by LFS (0.5 Hz) in the group that previously received footshock conditioning. Furthermore, the expression of freezing during re-exposure to footshock box was significantly reduced in the LFS application group in a manner similar to the extinction group. These results suggest that LFS-induced synaptic plasticity may be associated with the extinction processes that underlie context-dependent fear memory. This hypothesis was supported by the fact that synaptic potentiation induced by extinction training did not occur in a juvenile stress model that exhibited extinction deficits. Given the similarity between these electrophysiological and behavioral data, LFS-induced synaptic plasticity may be related to extinction learning, with some aspects of neuronal oscillations, during the acquisition and/or consolidation of extinction memory.     

An Eye‐Tracking Study of Exploitations of Spatial Constraints in Diagrammatic Reasoning

Semantic studies on diagrammatic notations (Barwise & Etchemendy, 1990 ; Shimojima, 1995 ; Stenning & Lemon, 2001 ) have revealed that the “non‐deductive,” “emergent,” or “perceptual” effects of diagrams (Chandrasekaran, Kurup, Banerjee, Josephson, & Winkler, 2004 ; Kulpa, 2003 ; Larkin & Simon, 1987 ; Lindsay, 1988 ) are all rooted in the exploitation of spatial constraints on graphical structures. Thus, theoretically, this process is a key factor in inference with diagrams, explaining the frequently observed reduction of inferential load. The purpose of this study was to examine the empirical basis for this theoretical suggestion, focusing on the reality of the constraint‐exploitation strategy in actual practices of diagrammatic reasoning. Eye movements were recorded while participants used simple position diagrams to solve three‐ or four‐term transitive inference problems. Our experiments revealed that the participants could exploit spatial constraints on graphical structures even when (a) they were not in the position of actually manipulating diagrams, (b) the semantic rule for the provided diagrams did not match their preferences, and (c) the constraint‐exploitation strategy invited a partly adverse effect. These findings indicate that the hypothesized process is in fact robust, with the potential to broadly account for the inferential advantage of diagrams.     

Effects of semantic context and event-related potentials: N400 correlates with inhibition effect

Two experiments investigated the modulation of event-related brain potentials (ERPs) by semantic context. A prime-target pair was visually presented in each trial of a lexical decision task. For word targets, three types of relatedness conditions were employed: (1) Related word condition (e.g., school-teacher); (2) Neutral word condition (e.g., [symbol: see text] - number); (3) Unrelated word c((e.g., hospital-potato). In Experiment 1, the reaction time for unrelated targets was longer than that for neutral targets (inhibition effect) which was longer than that for related targets (facilitation effect). The N400 amplitude in the unrelated targets was larger compared to those in the related and neutral targets, which did not differ. In Experiment 2, where only the facilitation effect was obtained, the N400 amplitude did not differ among conditions.     

How do Children Evaluate the Gossiper of Negative Gossip?

In this study, we investigated how children evaluate gossipers. There are two conflicting ways in which children evaluate the gossiper of negative gossip about another person. One is that they perceive the gossiper of negative gossip as bad because saying something negative about another person can be seen as indirect aggression. The other is that they perceive the gossiper of negative gossip as good because such gossip is beneficial to regulate their relationship with the gossip's target. To address the issue, we asked 7- and 8-year-olds to choose the gossiper of negative gossip or the gossiper of neutral gossip as a cooperative partner and to distribute resources between the gossipers. We found that the children often did not choose the gossiper of negative gossip as a partner and did not distribute many resources to her, indicating a perception of the negative gossiper as bad. This suggests that children's evaluation of a gossiper is influenced by the valence of gossip rather than the value of gossip.     

Subjective and objective measures of quality of life have different predictors for people with schizophrenia

This study investigated the relationship between subjective and objective quality of life and assessed predictors in people with schizophrenia. The study population consisted of 99 stabilized outpatients with schizophrenia (DSM-IV) who had been regularly receiving outpatient treatment at the Department of Psychiatry, The Tokushima University Hospital. Subjective and objective quality of life were estimated using the Schizophrenia Quality of Life Scale and the Quality of Life Scale, respectively. Psychiatric symptoms were also measured with the Brief Psychiatric Rating Scale and the Calgary Depression Scale for Schizophrenia. Scores on the Schizophrenia Quality of Life Scale Motivation and Energy scales significantly correlated with the Quality of Life Scale total scores -.40 (p <.001), and with the scores on Interpersonal Relations subscale -.42 (p <.001), Instrumental Role subscale -.28 (p = .005), Intrapsychic Foundations subscale -.39 (p<.001), and Common Objects and Activities subscale -.25 (p =.014). The Schizophrenia Quality of Life Scale Psychosocial scale significantly correlated with only the Quality of Life Scale total score -.20 (p =.05), and there was no significant correlation between the scores on the Schizophrenia Quality of Life Scale Symptoms and Side-effects scales and the Quality of Life Scale. Stepwise regression analyses showed that the Calgary Depression Scale for Schizophrenia score was the most important predictor of each scale of the Schizophrenia Quality of Life Scale, and the Brief Psychiatric Rating Scale Negative Symptoms score was the most important predictor of the Quality of Life Scale total score and each subscale. These results suggest that subjective and objective quality of life have different predictors and should be considered as separate and complementary outcome variables.     

Self‐criticism and self‐reassurance as mediators between mental health attitudes and symptoms: Attitudes toward mental health problems in Japanese workers

Japanese workers suffer high rates of mental health symptoms, recognised recently by the Japanese government, which has enacted workplace well‐being initiatives. One reason for poor mental health concerns negative attitudes about mental health problems such as shame, which may be mediated by self‐reassurance and self‐criticism. This study aimed to evaluate shame‐based attitudes toward mental health problems and explore the relationship between mental health attitudes, self‐criticism, self‐reassurance, and mental health symptoms. Japanese workers (n = 131) completed three measures: attitudes toward mental health problems, mental health symptoms, and self‐criticism/reassurance. A high proportion of workers reported negative attitudes about mental health problems. There were strong relationships between mental health attitudes, mental health symptoms, self‐criticism, and self‐reassurance. Path analyses revealed that the total and indirect effects (through self‐criticism and self‐reassurance) of mental health attitudes on mental health were larger than the direct effect alone. Hated‐self and family reflected shame were identified as predictors for mental health symptoms. The findings suggest the importance of self‐criticism and self‐reassurance in mental health and mental health attitudes. Implications for help‐seeking behaviours also are discussed. Interventions aimed at reducing self‐criticism and enhancing self‐reassurance are recommended to improve mental health attitudes and increase help‐seeking in Japanese workers.     

Perception of the end position of a limb loaded with a weight

We examined the effect of loading a weight on the perception of the end position of the limb. The participants haptically perceived where the end of their limb was located while they swung the limb or statically held it. The results showed that the loading of a weight influenced participants' perception only when they swung the limb; when the weight was attached to a participant's hand, the position was perceived to be farther from the body than when the weight was attached to the forearm or no weight was attached. We also found that the end position was generally underestimated when the participants swung their limb. On the other hand, when the participants statically held their limb, the perceived position was not affected by the loading of the weight and was rather precise. These results suggest that the perceptual system for limb end position is sensitive to changes in the surrounding haptic information caused by moving the limb.     

Observing inefficient action can induce infant preference and learning

‘Motionese’ can be defined as an exaggerated and repetitive action. It induces preference and learning in infants. However, which action component of motionese promotes infants’ preference and learning remains largely unknown. In this study, we focused on inefficiency and toward-ness of action. Our study demonstrates that observing an inefficient holding out action can induce a visual preference in 4-month-old infants and learning in 10-month-old infants through eight experiments (N = 192). We found that when infants observe inefficient holding out action, the action attracts their attention and facilitates learning about the identity of the toy object accompanying it, especially when people direct inefficient actions towards them. Our findings indicate that both action efficiency and toward-ness may be key factors in infant learning.     

Where’s the difficulty in standardized reading tests: The passage or the question?

The purpose of this investigation was to examine the extent to which item and text characteristics predict item difficulty on the comprehension portion of the Gates-MacGinitie Reading Tests for the 7th–9th and 10th–12th grade levels. Detailed item-based analyses were performed on 192 comprehension questions on the basis of the cognitive processing model framework proposed by Embretson and colleagues (Embretson & Wetzel, 1987). Item difficulty was analyzed in terms of various passage features (e.g., word frequency and number of propositions) and individual-question characteristics (e.g., abstractness and degree of inferential processing), using hierarchical linear modeling. The results indicated that the difficulty of the items in the test for the 7th–9th grade level is primarily influenced by text features—in particular, vocabulary difficulty—whereas the difficulty of the items in the test for the 10th–12th grade level is less systematically influenced by text features.