Building tasks from verbal instructions: An EEG study on practice trial exposure and task structure complexity during novel sequences of behavior

Configuring the mind to perform a novel task is an effortful process and one that is related to differences in general intelligence. Previous research has suggested that when participants are given instructions for a future task, representations of the rules contained in the instructions can influence subsequent behavior, even when the rules are not necessary to perform the upcoming task. One hypothesis for the continued activation of rule representations suggests that the practice trials participants perform before the experimental trials may instantiate the unnecessary task rules into participants’ mental model of the task (i.e., the task space). To test this hypothesis, EEGs were recorded as participants (N = 66) completed a multirule task designed to contrast the effects of increasing task structure complexity and practice trial exposure. The results showed that, as was predicted, performance is significantly poorer when more task rules are specified in the task instructions. Practice trials with the extra rule did not affect task performance, indicating that an unacted verbal instruction is sufficient to incorporate the rule into participants’ mental model of the task. The EEG results showed that instruction complexity was linked to a phasic increase in frontal theta synchronization but reduced posterior alpha and beta desynchronization. These changes in synchronization occurred during a time period of low intertrial phase coherence and suggest that participants were “checking the task rules” amidst a trial. This transient neural activity may reflect compensatory mechanisms for dealing with increased mind-wandering that is more likely to occur in complex tasks.     

Teacher-child relationship quality and academic achievement of Chinese American children in immigrant families

This study examined the cross-sectional relations between teacher-child relationship quality (TCRQ) and math and reading achievement in a socio-economically diverse sample of Chinese American first- and second-grade children in immigrant families (N=207). Teachers completed a questionnaire measuring TCRQ dimensions including closeness, conflict, and intimacy, and children completed a questionnaire measuring overall TCRQ. Standardized tests were used to assess children's math and reading skills. Analyses were conducted to (a) test the factor structure of measures assessing TCRQ among Chinese American children, (b) examine the associations between teacher- and child-rated TCRQ and children's academic achievement, controlling for demographic characteristics, and (c) examine the potential role of child gender as a moderator in the relations between TCRQ and achievement. Results indicated that teacher-rated TCRQ Warmth was positively associated with Chinese American children's reading achievement. Two child gender-by-TCRQ interactions were found: (a) teacher-rated TCRQ Conflict was negatively associated with girls' (but not boys') math achievement, and (b) child-rated Overall TCRQ was positively associated with boys' (but not girls') reading achievement. These findings highlight the valuable role of TCRQ in the academic success of school-aged children in immigrant families.     

Recognition memory for social and non-social odors: differential effects of neurotoxic lesions to the hippocampus and perirhinal cortex

The contributions of the hippocampus (HC) and perirhinal cortex (PER) to recognition memory are currently topics of debate in neuroscience. Here we used a rapidly-learned (seconds) spontaneous novel odor recognition paradigm to assess the effects of pre-training N-methyl-D-aspartate lesions to the HC or PER on odor recognition memory. We tested memory for both social and non-social odor stimuli. Social odors were acquired from conspecifics, while non-social odors were household spices. Conspecific odor stimuli are ethologically-relevant and have a high degree of overlapping features compared to non-social household spices. Various retention intervals (5 min, 20 min, 1h, 24h, or 48 h) were used between study and test phases, each with a unique odor pair, to assess changes in novelty preference over time. Consistent with findings in other paradigms, modalities, and species, we found that HC lesions yielded no significant recognition memory deficits. In contrast, PER lesions caused significant deficits for social odor recognition memory at long retention intervals, demonstrating a critical role for PER in long-term memory for social odors. PER lesions had no effect on memory for non-social odors. The results are consistent with a general role for PER in long-term recognition memory for stimuli that have a high degree of overlapping features, which must be distinguished by conjunctive representations.     

Cognitive and emotional processes during dreaming: a neuroimaging view

Dream is a state of consciousness characterized by internally-generated sensory, cognitive and emotional experiences occurring during sleep. Dream reports tend to be particularly abundant, with complex, emotional, and perceptually vivid experiences after awakenings from rapid eye movement (REM) sleep. This is why our current knowledge of the cerebral correlates of dreaming, mainly derives from studies of REM sleep. Neuroimaging results show that REM sleep is characterized by a specific pattern of regional brain activity. We demonstrate that this heterogeneous distribution of brain activity during sleep explains many typical features in dreams. Reciprocally, specific dream characteristics suggest the activation of selective brain regions during sleep. Such an integration of neuroimaging data of human sleep, mental imagery, and the content of dreams is critical for current models of dreaming; it also provides neurobiological support for an implication of sleep and dreaming in some important functions such as emotional regulation.     

Transitive inference in adults with autism spectrum disorders

Individuals with autism spectrum disorders (ASDs) exhibit intact rote learning with impaired generalization. A transitive inference paradigm, involving training on four sequentially presented stimulus pairs containing overlapping items, with subsequent testing on two novel pairs, was used to investigate this pattern of learning in 27 young adults with ASDs and 31 matched neurotypical individuals (TYPs). On the basis of findings about memory and neuropathology, we hypothesized that individuals with ASDs would use a relational flexibility/conjunctive strategy reliant on an intact hippocampus, versus an associative strength/value transfer strategy requiring intact interactions between the prefrontal cortex and the striatum. Hypotheses were largely confirmed. ASDs demonstrated reduced interference from intervening pairs in early training; only TYPs formed a serial position curve by test; and ASDs exhibited impairments on the novel test pair consisting of end items with intact performance on the inner test pair. However, comparable serial position curves formed for both groups by the end of the first block.     

Academic Integrity in Higher Education: The Case of Plagiarism of Graduation Reports by Undergraduate Seniors in Vietnam

Plagiarism in higher education has become widespread among students in Vietnam. This paper aims to examine the seriousness of the problem by comparing the severity of plagiarism in two universities, one of which uses Turnitin software to check its student reports. For that purpose, 977 samples have been drawn from 1434 required graduation reports written by senior undergraduates in the economics and management field from 2013 to 2015. Turnitin’s “Similarity Index” (SI) was used to check for alleged plagiarism, which was found to be more widespread at the university not using Turnitin. At that university, 91.7% of the graduation reports were defined as plagiarized, while 61.7% of the reports were plagiarized at the university using the software. The main source of this problem was the use of information from the internet without citing the original authors.     

The Psychological Cost of Racial Discrimination: What is the Role of Residential Segregation?

Racial discrimination is known to harm health, but to what extent the health burden of racial discrimination is contingent on residential contexts is understudied. This study examines the moderating role of racial residential segregation in the relationship between racial discrimination and psychological distress. Nationally representative data from the 2002–2003 National Latino and Asian American Study were merged with metropolitan-level data from the U.S. Census. Logistic regression models were used to test the independent and joint contributions of racial discrimination and residential segregation to psychological distress among Asians and Latinxs, stratified by nativity status. Higher residential segregation (measured by the interaction index) is associated with lower odds of distress among U.S.-born Asians but not among other groups. As for the moderating effect, residential segregation exacerbates the positive association between discrimination and distress among foreign-born Asians (measured by the dissimilarity index) and foreign-born Latinxs (measured by the interaction index), but not among their respective U.S.-born counterparts. Taken together, the present study highlights that strategies to mitigate the psychological burden of racial discrimination need to move beyond individual-level efforts to incorporate neighborhood-based approaches. In particular, results provide empirical support for efforts to reduce residential segregation, particularly among immigrants who are discriminated against.     

Feeding upon awakening in breastfeeding and bottlefeeding mothers does not affect the awakening cortisol response

An acute breastfeeding stimulus is generally followed by a transient decrease in cortisol levels in mothers. It is currently not clear whether breastfeeding upon waking up would affect the awakening cortisol response (ACR), a significant increase in salivary cortisol levels occurring within 30-45 min after awakening. In the present study, we measured the amplitude and stability of the ACR in response to infant feeding in women who were exclusively bottle-feeding (n = 16), or breastfeeding (n = 13) or feeding their child solid food (n = 12). The results show that the type of infant feeding did not affect the amplitude and stability of the ACR. Given that the ACR has been reported to reflect physical and psychological well-being, our finding that infant feeding upon waking up might not be a confounding factor in ACR studies on the postpartum population represents valuable methodological information.