Lexical prediction in the aging brain: The effects of predictiveness and congruency on the N400 ERP component

Although the N400 ERP component has been extensively studied in younger adults, the underlying mechanisms are still unclear. In older adults, N400 ERP studies have shown less efficient use of context compared to younger adults. Here, we asked whether the mechanisms underlying the N400 effect are the same in terms of predictiveness and congruency in younger and older adults. We used a simple picture-word matching task in which we crossed predictiveness and congruency. Our results indicate a three-way interaction between predictiveness, congruency, and age, in that, younger adults showed an N400 effect only in strongly constrained conditions; whereas, older adults showed an effect in both strongly- and weakly constrained conditions. This interaction was not modulated by language experience or cognitive decline. Our results support either two separate mechanisms (lexical access and integration) that run in parallel and are modulated by age or a common prediction error mechanism that changes with age.     

Positive post‐disaster images: A daydream machine?

This study explores the impact of post‐earthquake images inserted in a vigilance task, in terms of performance, self‐reports of task‐focus, and cerebral activity using functional near‐infrared spectroscopy (fNIRS). Vigilance tasks present a sequence of stimuli in which only a few are pre‐designated critical or target stimuli requiring an overt response from the participant. Seventy‐one residents participated (51 women, 20 men) by taking part in a vigilance task with task‐irrelevant images inserted in the sequence. There were three conditions consisting positive (emotive inducing), negative (emotive inducing), and control (devoid of meaning) images embedded in the vigilance task to assess possible impacts on vigilance performance. The images were obtained through crowdsourcing and represented parts of the city 3–4 years post‐earthquake. Task performance was assessed with signal detection theory metrics of sensitivity A’ and bias β’’. This enables the separation of an individual's ability to accurately discriminate critical signals from non‐critical stimuli (sensitivity) and shifts in their willingness to respond to any stimuli whether critical or not (bias). Individuals viewing the positive images, relating to progress, rebuild, or aesthetic aspects within the city, had a more conservative response bias (they responded less to both rare critical and distractor stimuli) than those in the other conditions. These individuals also reported lower task‐focus, as would be expected. However, contrary to expectations, indicators of cerebral activity (fNIRS) did not differ significantly between the experimental groups. These results, when combined, suggest that mind wandering events may be being generated when exposed to positive post‐earthquake images.     

An improved method for counting stressful life events (SLEs) when predicting mental health and wellness

Objective: Checklists for registering stressful life events (SLEs) generally correlate negatively, but weakly, with mental health outcome measures. Thus, the present study examined various methodological approaches for improving these relationships.

Design: A total of 1679 participants (women?=?943, men?=?736, M age-39.8) were randomly drawn from the general Norwegian population (response rate 34%). This prospective cohort study included two follow-ups at 10 (n?=?1181) and 23 months (n?=?942).

Main outcome measures: Satisfaction with life and absence of psychological distress (i.e. anxiety and depression) represented a joint measure for indexing ‘mental wellness’ (MW).

Results: A simple count of SLEs weakly predicted MW, as expected, whereas the addition of a moderator (i.e. manageability of the event) substantially improved predictive power. Four additional moderators were examined: duration, impact, help-seeking and time since onset, but these were non-significant after inserting manageability into the model. This SLE counting method also retained its predictive power after including multiple criterion-related variables that substantially adjusted the longitudinal statistical model.

Conclusion: This new SLE counting method exhibited a considerable improvement to predicting mental health and well-being. It is well suited for use in epidemiological research requiring a short SLE checklist format with high predictive power.     

汶川地震8.5年后青少年的社会支持与创伤后成长的关系:自我效能感和自尊的中介作用

为考察汶川地震8.5年后青少年的社会支持、自我效能感、自尊与创伤后成长（PTG）之间的关系，利用社会支持问卷、自我效能感问卷、自尊量表和创伤后成长问卷对地震灾区的1185名中学生进行了调查。结果发现，创伤暴露程度对社会支持、自我效能感和自尊均不具有显著影响，但对PTG具有显著的预测作用；而在控制创伤暴露后，社会支持不仅可以直接促进PTG，也可以分别通过自我效能感和自尊促进PTG，还可以通过自我效能感经自尊的多重中介作用来促进PTG，表明自我效能感和自尊在社会支持与PTG的关系中发挥着显著的中介效应。这些结果说明社会支持对PTG影响的一个重要机制是通过提升个体的自我效能感、增加其自尊来实现的。