The relationship between internalising symptom development and academic attainment in early adolescence

Evidence for the longitudinal associations between internalising symptom development and academic attainment is sparse and results from existing studies are largely inconclusive. The approaches that have been used in existing studies examining this relationship have in common the limitation of grouping together all individuals in the sample which makes the assumption that the relationship between time, symptoms and attainment across all individuals is the same. The current study aimed to use heterogeneous trajectories of symptom development to examine the longitudinal associations between internalising symptom development and change in academic attainment over a three years period in early adolescence, a key period for internalising symptom development. Internalising symptoms were assessed for 3 consecutive years in a cohort from age 11-14 years (n = 2647, mean age at T1 = 11.7 years). National standardised test scores prior to the first wave and subsequent to the last wave were used as measures of academic attainment. Heterogeneous symptom development trajectories were identified using latent class growth analysis and socio-demographic correlates, such as gender, SES and ethnicity, of the different trajectory groupings were investigated. Derived trajectory groupings were examined as predictors of subsequent academic attainment, controlling for prior attainment. Results demonstrate that symptom trajectories differentially predicted change in academic attainment with increasing trajectories associated with significantly worse academic outcomes when compared to pupils with low levels of symptoms in all waves. Hence, a trajectory based approach provides a more nuanced breakdown of complexities in symptom development and their differential relationships with academic outcomes and in doing so helps clarify the longitudinal relationship between these two key domains of functioning in early adolescence.

Global spectral deconvolution based on non-negative matrix factorization in GC × GC-HRTOFMS

A global spectral deconvolution, based on non-negative matrix factorization (NMF) in comprehensive two-dimensional gas chromatography high-resolution time-of-flight mass spectrometry, was developed. We evaluated the ability of various instrumental parameters and NMF settings to derive high-performance detection in nontarget screening using a sediment sample. To evaluate the performance of the process, a NIST library search was used to identify the deconvoluted spectra. Differences of the instrumental scan rates (25 and 50 Hz) in deconvolution were evaluated and results show that a high scan rate enhanced the number of compounds detected in the sediment sample. A higher mass resolution in the range of 1,000 to 10,000 and a higher m/z precision in the deconvolution were needed to obtain an accurate mass database. After removal of multiple duplicate hits, which occurred in batch processes of NIST library search on the deconvolution result, 62 unique assignable spectra with a match factor ≥900 were obtained in the deconvoluted chromatogram from the sediment sample, including 54 spectra that were refined by the deconvolution. This method will help to detect and build up well-resolved reference spectra from various complex mixtures and will accelerate nontarget screening.

Attentional trade-offs maintain the tracking of moving objects across saccades

In many situations like playing sports or driving a car, we keep track of moving objects, despite the frequent eye movements that drastically interrupt their retinal motion trajectory. Here we report evidence that transsaccadic tracking relies on trade-offs of attentional resources from a tracked object's motion path to its remapped location. While participants covertly tracked a moving object, we presented pulses of coherent motion at different locations to probe the allocation of spatial attention along the object's entire motion path. Changes in the sensitivity for these pulses showed that during fixation attention shifted smoothly in anticipation of the tracked object's displacement. However, just before a saccade, attentional resources were withdrawn from the object's current motion path and reflexively drawn to the retinal location the object would have after saccade. This finding demonstrates the predictive choice the visual system makes to maintain the tracking of moving objects across saccades.

Integration of retinal and extraretinal information across eye movements

Visual perception is burdened with a highly discontinuous input stream arising from saccadic eye movements. For successful integration into a coherent representation, the visuomotor system needs to deal with these self-induced perceptual changes and distinguish them from external motion. Forward models are one way to solve this problem where the brain uses internal monitoring signals associated with oculomotor commands to predict the visual consequences of corresponding eye movements during active exploration. Visual scenes typically contain a rich structure of spatial relational information, providing additional cues that may help disambiguate self-induced from external changes of perceptual input. We reasoned that a weighted integration of these two inherently noisy sources of information should lead to better perceptual estimates. Volunteer subjects performed a simple perceptual decision on the apparent displacement of a visual target, jumping unpredictably in sync with a saccadic eye movement. In a critical test condition, the target was presented together with a flanker object, where perceptual decisions could take into account the spatial distance between target and flanker object. Here, precision was better compared to control conditions in which target displacements could only be estimated from either extraretinal or visual relational information alone. Our findings suggest that under natural conditions, integration of visual space across eye movements is based upon close to optimal integration of both retinal and extraretinal pieces of information.

Developmental trends in the facilitation of multisensory objects with distractors

Sensory integration and the ability to discriminate target objects from distractors are critical to survival, yet the developmental trajectories of these abilities are unknown. This study investigated developmental changes in 9- (n = 18) and 11-year-old (n = 20) children, adolescents (n = 19) and adults (n = 22) using an audiovisual object discrimination task with uni- and multisensory distractors. Reaction times (RTs) were slower with visual/audiovisual distractors, and although all groups demonstrated facilitation of multisensory RTs in these conditions, children's and adolescents' responses corresponded to fewer race model violations than adults', suggesting protracted maturation of multisensory processes. Multisensory facilitation could not be explained by changes in RT variability, suggesting that tests of race model violations may still have theoretical value at least for familiar multisensory stimuli.

Challenging emotional prejudice by changing self-concept: priming independent self-construal reduces racial in-group bias in neural responses to other's pain

Humans show stronger empathy for in-group compared with out-group members' suffering and help in-group members more than out-group members. Moreover, the in-group bias in empathy and parochial altruism tend to be more salient in collectivistic than individualistic cultures. This work tested the hypothesis that modifying self-construals, which differentiate between collectivistic and individualistic cultural orientations, affects in-group bias in empathy for perceived own-race vs other-race pain. By scanning adults using functional magnetic resonance imaging, we found stronger neural activities in the mid-cingulate, left insula and supplementary motor area (SMA) in response to racial in-group compared with out-group members' pain after participants had been primed with interdependent self-construals. However, the racial in-group bias in neural responses to others' pain in the left SMA, mid-cingulate cortex and insula was significantly reduced by priming independent self-construals. Our findings suggest that shifting an individual's self-construal leads to changes of his/her racial in-group bias in neural responses to others' suffering.

On the efficacy of procedures to normalize Ex-Gaussian distributions

Reaction time (RT) is one of the most common types of measure used in experimental psychology. Its distribution is not normal (Gaussian) but resembles a convolution of normal and exponential distributions (Ex-Gaussian). One of the major assumptions in parametric tests (such as ANOVAs) is that variables are normally distributed. Hence, it is acknowledged by many that the normality assumption is not met. This paper presents different procedures to normalize data sampled from an Ex-Gaussian distribution in such a way that they are suitable for parametric tests based on the normality assumption. Using simulation studies, various outlier elimination and transformation procedures were tested against the level of normality they provide. The results suggest that the transformation methods are better than elimination methods in normalizing positively skewed data and the more skewed the distribution then the transformation methods are more effective in normalizing such data. Specifically, transformation with parameter lambda -1 leads to the best results.

Combat high or traumatic stress: violent offending is associated with appetitive aggression but not with symptoms of traumatic stress

Former members of armed groups in eastern DR Congo had typically witnessed, experienced, and perpetrated extreme forms of violence. Enhanced trauma-related symptoms had been shown in prior research. But also lashing out in self-defense is a familiar response to threat defined as reactive aggression. Another potential response is appetitive aggression, in which the perpetration of excessive violence is perceived as pleasurable (combat high). What roles do these forms of aggressive behavior play in modern warfare and how are they related to posttraumatic stress symptoms? To answer the question, we sought to determine predictors for appetitive aggressive and trauma-related mental illness, and investigated the frequency of psychopathological symptoms for high- and low-intensity conflict demobilization settings. To this end, we interviewed 213 former members of (para)military groups in the eastern Democratic Republic of Congo in regard to their combat exposure, posttraumatic stress, appetitive aggression, depression, suicidality, and drug dependence. Random forest regression embedded in a conditional inference framework revealed that perpetrated violent acts are not necessarily stressful. In fact, the experience of violent acts that typically implicated salient cues of hunting (e.g., blood, suffering of the victim, etc.) had the strongest association with an appetite for aggression. Furthermore, the number of lifetime perpetrated violent acts was the most important predictor of appetitive aggression. However, the number of perpetrated violent acts did not significantly affect the posttraumatic stress. Greater intensity of conflict was associated with more severe posttraumatic stress symptoms and depression. Psychotherapeutic interventions that address appetitive aggression in addition to trauma-related mental illness, including drug dependence, therefore seem indispensible for a successful reintegration of those who fought in the current civil wars.

Reliability and validity of the Timed Floor To Stand Test-Natural in school-aged children

PURPOSE

To establish reliability for the Timed Floor to Stand-Natural (TFTS-N) test as a stand-alone measure for schoolchildren with typical development (TD) in preparation for normative data collection.

METHODS

Five physical therapists working in schools standardized testing procedures for a "natural" pace version of the TFTS. Time data were collected using a repeated-measures design.

RESULTS

Twenty-two students with TD (8 years 7 months to 12 years 7 months; (Equation is included in full-text article.)= 10 years, SD = 1.13) completed the TFTS-N in 6.27 (SD = 0.30) to 8.45 (SD = 0.68) seconds. Intraclass correlation coefficients (ICCs) (3,1) ranged from 0.713 to 0.800 for intrarater reliability and was 0.988 for interrater reliability. The ICC (3,3) was 0.871 for test-retest reliability.

CONCLUSION

The TFTS-N has high intra-, inter-, and test-retest reliability. TFTS-N has face validity as the task frequently occurs in school settings. The test procedures are reliable for trained physical therapists to establish individual baseline measures of schoolchildren with TD.

Serious games for elderly continuous monitoring

Information technology (IT) and serious games allow older population to remain independent for longer. Hence, when designing technology for this population, developmental changes, such as attention and/or perception, should be considered. For instance, a crucial developmental change has been related to cognitive speed in terms of reaction time (RT). However, this variable presents a skewed distribution that difficult data analysis. An alternative strategy is to characterize the data to an ex-Gaussian function. Furthermore, this procedure provides different parameters that have been related to underlying cognitive processes in the literature. Another issue to be considered is the optimal data recording, storing and processing. For that purpose mobile devices (smart phones and tablets) are a good option for targeting serious games where valuable information can be stored (time spent in the application, reaction time, frequency of use, and a long etcetera). The data stored inside the smartphones and tablets can be sent to a central computer (cloud storage) in order to store the data collected to not only fill the distribution of reaction times to mathematical functions, but also to estimate parameters which may reflect cognitive processes underlying language, aging, and decisional process.

Sentence repetition: what does the task measure?

BACKGROUND

Sentence repetition is gaining increasing attention as a source of information about children's sentence-level abilities in clinical assessment, and as a clinical marker of specific language impairment. However, it is widely debated what the task is testing and therefore how informative it is.

AIMS

(1) To evaluate the effects of different types of long-term linguistic knowledge on immediate recall, (2) to assess age sensitivity of repetition tasks designed to evaluate these effects, and (3) to establish if the effects are similar across typologically different languages. The study also considers the implications of the findings for the use of sentence repetition as a research and clinical assessment tool.

METHODS & PROCEDURES

Participants were 50 English-speaking and 50 Czech-speaking typically developing 4-5-year-olds. Children's ability to recall sequences of items was compared in seven linguistic conditions ranging from fully well-formed sentences to sequences of non-words. In each condition, children repeated blocks of successively longer stimuli to establish their span.

OUTCOMES & RESULTS

Results showed significant but differential effects of all linguistic factors in both languages. While syntactic violations and presence of non-words dramatically reduced children's span, semantic implausibility and the removal of sentence prosody played a significant but much smaller role. Familiarity of function words was more important than familiarity of content words. The effects of different linguistic factors on spans were the same for both languages and did not change between 4 and 5 years, although average spans increased over this age range.

CONCLUSIONS & IMPLICATIONS

Children's ability to repeat sentences is more dependent on their familiarity with morphosyntax and lexical phonology than semantics or prosody, with function words of particular importance. Findings have implications for the use of recall in clinical assessment and as a research tool.

Parenting and independent problem-solving in preschool children with food allergy

OBJECTIVE

To examine autonomy-promoting parenting and independent problem-solving in children with food allergy.

METHODS

66 children with food allergy, aged 3-6 years, and 67 age-matched healthy peers and their mothers were videotaped while completing easy and difficult puzzles. Coders recorded time to puzzle completion, children's direct and indirect requests for help, and maternal help-giving behaviors.

RESULTS

Compared with healthy peers, younger (3- to 4-year-old) children with food allergy made more indirect requests for help during the easy puzzle, and their mothers were more likely to provide unnecessary help (i.e., explain where to place a puzzle piece). Differences were not found for older children.

CONCLUSIONS

The results suggest that highly involved parenting practices that are medically necessary to manage food allergy may spill over into settings where high levels of involvement are not needed, and that young children with food allergy may be at increased risk for difficulties in autonomy development.

Does Rare Error Count in Impulsivity?

High impulsive individuals have problems with self-monitoring and learning from their mistakes. The aim of this study was to investigate whether error processing is impaired in high trait impulsivity, and how it is modulated by the task difficulty. Adults were classified as high (n = 10) and low (n = 10) impulsive participants based on the Barratt Impulsiveness Scale, and they participated in a modified flanker task. The flanker trials had three levels of task difficulty manipulated by visual degradation of the stimuli. We measured RTs and ERP components (Ne, Pe) related to erroneous responses. Low impulsive participants responded significantly faster than high impulsive participants. The two groups did not differ in accuracy. The Ne amplitude was smaller in high than in low impulsivity in case of medium and high difficulty levels, but not at low difficulty level. However, the groups did not differ either in the amplitude or in the latency of Pe. We suggest that trait impulsivity is characterized by impaired error detection.

Partner distress in the context of adult anorexia nervosa: the role of patients' perceived negative consequences of AN and partner behaviors

OBJECTIVE

Romantic partners can play an important role in the recovery from anorexia nervosa (AN). It is important to understand partners' behaviors and variables associated with their own distress. The aim was to examine associations of patients' perceived negative consequences of AN, behavioral strategies employed by partners, and partner distress.

METHOD

We used a cross-sectional design to assess associations between self-reports of patients' perceived negative consequences of AN, partners' caregiver distress, negative affect, relationship satisfaction, and observational coding measures of partners' behavioral strategies of change promotion and acceptance/validation. Sixteen adult patient-partner dyads in committed relationships were assessed at baseline of a couple-based intervention for AN.

RESULTS

Partners' change promotion moderated the association between patients' perceived negative consequences of AN and partners' caregiver distress. Partners' acceptance/validation was associated with partners' negative affect.

DISCUSSION

This report represents the first description of specific partner behaviors in the context of AN. Partners who reported the least distress were those who were trying to promote changes in AN behaviors in patients who reported high negative consequences of AN, and partners who were trying to show understanding of the patients' experience. Future studies should examine the impact of partner behaviors on AN treatment outcome.

Social influences on adaptive criterion learning

People adaptively shift decision criteria when given biased feedback encouraging specific types of errors. Given that work on this topic has been conducted in nonsocial contexts, we extended the literature by examining adaptive criterion learning in both social and nonsocial contexts. Specifically, we compared potential differences in criterion shifting given performance feedback from social sources varying in reliability and from a nonsocial source. Participants became lax when given false positive feedback for false alarms, and became conservative when given false positive feedback for misses, replicating prior work. In terms of a social influence on adaptive criterion learning, people became more lax in response style over time if feedback was provided by a nonsocial source or by a social source meant to be perceived as unreliable and low-achieving. In contrast, people adopted a more conservative response style over time if performance feedback came from a high-achieving and reliable source. Awareness that a reliable and high-achieving person had not provided their feedback reduced the tendency to become more conservative, relative to those unaware of the source manipulation. Because teaching and learning often occur in a social context, these findings may have important implications for many scenarios in which people fine-tune their behaviors, given cues from others.

Memory Without Consolidation: Temporal Distinctiveness Explains Retroactive Interference

Is consolidation needed to account for retroactive interference in free recall? Interfering mental activity during the retention interval of a memory task impairs performance, in particular if the interference occurs in temporal proximity to the encoding of the to-be-remembered (TBR) information. There are at least two rival theoretical accounts of this temporal gradient of retroactive interference. The cognitive neuroscience literature has suggested neural consolidation is a pivotal factor determining item recall. According to this account, interfering activity interrupts consolidation processes that would otherwise stabilize the memory representations of TBR items post-encoding. Temporal distinctiveness theory, by contrast, proposes that the retrievability of items depends on their isolation in psychological time. According to this theory, information processed after the encoding of TBR material will reduce the temporal distinctiveness of the TBR information. To test between these accounts, implementations of consolidation were added to the SIMPLE model of memory and learning. We report data from two experiments utilizing a two-list free recall paradigm. Modeling results imply that SIMPLE was able to model the data and did not benefit from the addition of consolidation. It is concluded that the temporal gradient of retroactive interference cannot be taken as evidence for memory consolidation.

Refreshing memory traces: thinking of an item improves retrieval from visual working memory

This article provides evidence that refreshing, a hypothetical attention-based process operating in working memory (WM), improves the accessibility of visual representations for recall. "Thinking of", one of several concurrently active representations, is assumed to refresh its trace in WM, protecting the representation from being forgotten. The link between refreshing and WM performance, however, has only been tenuously supported by empirical evidence. Here, we controlled which and how often individual items were refreshed in a color reconstruction task by presenting cues prompting participants to think of specific WM items during the retention interval. We show that the frequency with which an item is refreshed improves recall of this item from visual WM. Our study establishes a role of refreshing in recall from visual WM and provides a new method for studying the impact of refreshing on the amount of information we can keep accessible for ongoing cognition.

Diurnal rhythms of plasma GLP-1 levels in normal and overweight/obese subjects: lack of effect of weight loss

Food intake is regulated by not only neurohormonal, but also social, educational, and even cultural factors. Within the former, there is a complex interaction between orexigenic (ghrelin) and anorexigenic (glucagon-like peptide-1 (GLP-1)) factors in order to adjust the food intake to caloric expenditure; however, the number of subjects that are unable to properly balance appetite and body weight is increasing continuously. A loss of circadian or diurnal coordination of any of these factors may be implied in this situation. Special attention has retrieved GLP-1 due to its usefulness as a therapeutic agent against obesity and related alterations. Thus, the objective of the present study was to compare GLP-1 diurnal synthesis between normal weight and overweight/obese subjects, and to evaluate whether weight loss can restore the synthesis rhythms of GLP-1. Three groups of 25 subjects were divided attending to their body mass index (BMI) in normal weight, overweight, or obese subjects. Diurnal (5 points) GLP-1 levels were analyzed. Secondly, an intervention (behavioral-dietary treatment) study was conducted to analyze the effect of weight loss on plasma GLP-1 concentrations. Our results showed that baseline GLP-1 level was significantly lower in normal weight subjects (p = 0.003); furthermore, our cosinor analysis revealed a higher amplitude (p = 0.040) and daily GLP-1 variation (47%) in these subjects. In fact, our ANOVA data showed a lack of rhythmicity in overweight/obese patients. Weight loss was not able to restore a diurnal rhythm of plasma GLP-1 levels. In summary, the present work shows a disruption of diurnal GLP-1 levels in overweight/obese subjects, which worsen as body fat progresses. The attenuation of the GLP-1 synthesis rhythms may be important to understand the impairment of food intake regulation in overweight/obese subjects.

Learning to tie well with others: bimanual versus intermanual performance of a highly practised skill

Studies indicate that novices are faster in manual tasks when performing with a partner ('intermanual') than with their own two hands ('bimanual'). The generality of this 'mode effect' was examined using a highly practised bimanual task, shoe tying, at which participants were experts. Speed-variability correlations confirmed participants were bimanually skilled but not intermanually skilled. Contrary to results using novices, intermanual was slower, such that prior skill reverses the effect. Analyses incorporating the similarity of shoe-tying strategies across dyads implicated a perceptual rather than shared knowledge/representation basis for intermanual performance. Practice effects indicated that intermanual performance built upon prior bimanual skill, such that novel relative timings between dyads' hands must be acquired. Motor transfer effects provided support for this conclusion. During shoe tying, hands were tightly coupled in the intermanual mode due to the perceptual coupling constraints of intermanual performance. Increased coupling was correlated with slower performance. Implications for real-world tasks (e.g. surgical knot tying) are described.

The perception of naturalness correlates with low-level visual features of environmental scenes

Previous research has shown that interacting with natural environments vs. more urban or built environments can have salubrious psychological effects, such as improvements in attention and memory. Even viewing pictures of nature vs. pictures of built environments can produce similar effects. A major question is: What is it about natural environments that produces these benefits? Problematically, there are many differing qualities between natural and urban environments, making it difficult to narrow down the dimensions of nature that may lead to these benefits. In this study, we set out to uncover visual features that related to individuals' perceptions of naturalness in images. We quantified naturalness in two ways: first, implicitly using a multidimensional scaling analysis and second, explicitly with direct naturalness ratings. Features that seemed most related to perceptions of naturalness were related to the density of contrast changes in the scene, the density of straight lines in the scene, the average color saturation in the scene and the average hue diversity in the scene. We then trained a machine-learning algorithm to predict whether a scene was perceived as being natural or not based on these low-level visual features and we could do so with 81% accuracy. As such we were able to reliably predict subjective perceptions of naturalness with objective low-level visual features. Our results can be used in future studies to determine if these features, which are related to naturalness, may also lead to the benefits attained from interacting with nature.

Spectral analyses of systolic blood pressure and heart rate variability and their association with cognitive performance in elderly hypertensive subjects

Systolic hypertension is associated with cognitive decline in the elderly. Altered blood pressure (BP) variability is a possible mechanism of reduced cognitive performance in elderly hypertensives. We hypothesized that altered beat-to-beat systolic BP variability is associated with reduced global cognitive performance in elderly hypertensive subjects. In exploratory analyses, we also studied the correlation between diverse discrete cognitive domains and indices of systolic BP and heart rate variability. Disproving our initial hypothesis, we have shown that hypertension and low education, but not indices of systolic BP and heart rate variability, were independent predictors of lower global cognitive performance. However, exploratory analyses showed that the systolic BP variability in semi-upright position was an independent predictor of matrix reasoning (B = 0.08 ± .03, P-value = 0.005), whereas heart rate variability in semi-upright position was an independent predictor of the executive function score (B = -6.36 ± 2.55, P-value = 0.02). We conclude that myogenic vascular and sympathetic modulation of systolic BP do not contribute to reduced global cognitive performance in treated hypertensive subjects. Nevertheless, our results suggest that both systolic BP and heart rate variability might be associated with modulation of frontal lobe cognitive domains, such as executive function and matrix reasoning.

The allocation of attention and working memory in visual crowding

When the distance between a visual target and nearby flankers falls below a critical distance, target discrimination declines precipitously. This is called "crowding." Many researchers have proposed that selective attention plays a role in crowding. However, although some research has examined the effects of directing attention toward versus away from the targets, no previous research has assessed how attentional allocation varies as a function of target-flanker distance in crowding. Here, we used ERPs to assess the operation of attention during crowding, focusing on the attention-related N2pc component. We used a typical crowding task in which participants were asked to report the category (vowel/consonant) of a lateralized target letter flanked by distractor letters at different distances. We tested the hypothesis that attention fails when the target-flanker distance becomes too small for attention to operate effectively. Consistent with this hypothesis, we found that N2pc amplitude was maximal at intermediate target-flanker distances and decreased substantially when crowding became severe. In addition, we examined the sustained posterior contralateral negativity (SPCN), which reflects the amount of information being maintained in working memory. Unlike the N2pc component, the SPCN increased in amplitude at small target-flanker distances, suggesting that observers stored information about the target and flankers in working memory when attention failed to select the target. Together, the N2pc and SPCN results suggest that attention and working memory play distinctive roles in crowding: Attention operates to minimize interference from the flankers at intermediate target-flanker distances, whereas working memory may be recruited when attention fails to select the target at small target-flanker distances.

Interhemispheric inhibition of corticospinal projections to forearm muscles

OBJECTIVE

Interhemispheric inhibition (IHI) is typically examined via responses elicited in intrinsic hand muscles. As the cortical representations of proximal and distal muscles in the upper limb are distinguished in terms of their inter-hemispheric projections, we sought to determine whether the IHI parameters established for the hand apply more generally.

METHODS

We investigated IHI at 5 different conditioning stimulus (CS) intensities and a range of short-latency inter-stimulus intervals (ISIs) in healthy participants. Conditioning and test stimuli were delivered over the M1 representation of the right and left flexor carpi radialis respectively.

RESULTS

IHI increased as a function of CS intensity, and was present for ISIs between 7 and 15ms. Inhibition was most pronounced for the 10ms ISI at all CS intensities.

CONCLUSIONS

The range of parameters for which IHI is elicited in projections to the forearm is similar to that reported for the hand. The specific utility lies in delineation of stimulus parameters that permit both potentiation and attenuation of IHI to be assessed.

SIGNIFICANCE

In light of evidence that there is a greater density of callosal projections between cortical areas that represent proximal muscles than between those corresponding to distal limb muscles, and in view of the assumption that variations in functional connectivity to which such differences give rise may have important implications for motor behavior, it is critical to determine whether processes mediating the expression of IHI depend on the effector that is studied. This issue is of further broad significance given the practical utility of movements generated by muscles proximal to the wrist in the context of upper limb rehabilitation.

What Is Typical Is Good

The role of face typicality in face recognition is well established, but it is unclear whether face typicality is important for face evaluation. Prior studies have focused mainly on typicality’s influence on attractiveness, although recent studies have cast doubt on its importance for attractiveness judgments. Here, we argue that face typicality is an important factor for social perception because it affects trustworthiness judgments, which approximate the basic evaluation of faces. This effect has been overlooked because trustworthiness and attractiveness judgments have a high level of shared variance for most face samples. We show that for a continuum of faces that vary on a typicality-attractiveness dimension, trustworthiness judgments peak around the typical face. In contrast, perceived attractiveness increases monotonically past the typical face, as faces become more like the most attractive face. These findings suggest that face typicality is an important determinant of face evaluation.

Subject-Motion Correction in HARDI Acquisitions: Choices and Consequences

Diffusion-weighted imaging (DWI) is known to be prone to artifacts related to motion originating from subject movement, cardiac pulsation, and breathing, but also to mechanical issues such as table vibrations. Given the necessity for rigorous quality control and motion correction, users are often left to use simple heuristics to select correction schemes, which involves simple qualitative viewing of the set of DWI data, or the selection of transformation parameter thresholds for detection of motion outliers. The scientific community offers strong theoretical and experimental work on noise reduction and orientation distribution function (ODF) reconstruction techniques for HARDI data, where post-acquisition motion correction is widely performed, e.g., using the open-source DTIprep software (1), FSL (the FMRIB Software Library) (2), or TORTOISE (3). Nonetheless, effects and consequences of the selection of motion correction schemes on the final analysis, and the eventual risk of introducing confounding factors when comparing populations, are much less known and far beyond simple intuitive guessing. Hence, standard users lack clear guidelines and recommendations in practical settings. This paper reports a comprehensive evaluation framework to systematically assess the outcome of different motion correction choices commonly used by the scientific community on different DWI-derived measures. We make use of human brain HARDI data from a well-controlled motion experiment to simulate various degrees of motion corruption and noise contamination. Choices for correction include exclusion/scrubbing or registration of motion corrupted directions with different choices of interpolation, as well as the option of interpolation of all directions. The comparative evaluation is based on a study of the impact of motion correction using four metrics that quantify (1) similarity of fiber orientation distribution functions (fODFs), (2) deviation of local fiber orientations, (3) global brain connectivity via graph diffusion distance (GDD), and (4) the reproducibility of prominent and anatomically defined fiber tracts. Effects of various motion correction choices are systematically explored and illustrated, leading to a general conclusion of discouraging users from setting ad hoc thresholds on the estimated motion parameters beyond which volumes are claimed to be corrupted.

Intraindividual variability in inhibitory function in adults with ADHD--an ex-Gaussian approach

OBJECTIVE

Attention deficit disorder (ADHD) is commonly associated with inhibitory dysfunction contributing to typical behavioral symptoms like impulsivity or hyperactivity. However, some studies analyzing intraindividual variability (IIV) of reaction times in children with ADHD (cADHD) question a predominance of inhibitory deficits. IIV is a measure of the stability of information processing and provides evidence that longer reaction times (RT) in inhibitory tasks in cADHD are due to only a few prolonged responses which may indicate deficits in sustained attention rather than inhibitory dysfunction. We wanted to find out, whether a slowing in inhibitory functioning in adults with ADHD (aADHD) is due to isolated slow responses.

METHODS

Computing classical RT measures (mean RT, SD), ex-Gaussian parameters of IIV (which allow a better separation of reaction time (mu), variability (sigma) and abnormally slow responses (tau) than classical measures) as well as errors of omission and commission, we examined response inhibition in a well-established GoNogo task in a sample of aADHD subjects without medication and healthy controls matched for age, gender and education.

RESULTS

We did not find higher numbers of commission errors in aADHD, while the number of omissions was significantly increased compared with controls. In contrast to increased mean RT, the distributional parameter mu did not document a significant slowing in aADHD. However, subjects with aADHD were characterized by increased IIV throughout the entire RT distribution as indicated by the parameters sigma and tau as well as the SD of reaction time. Moreover, we found a significant correlation between tau and the number of omission errors.

CONCLUSIONS

Our findings question a primacy of inhibitory deficits in aADHD and provide evidence for attentional dysfunction. The present findings may have theoretical implications for etiological models of ADHD as well as more practical implications for neuropsychological testing in aADHD.

Reinforcement of perceptual inference: reward and punishment alter conscious visual perception during binocular rivalry

Perception is an inferential process, which becomes immediately evident when sensory information is conflicting or ambiguous and thus allows for more than one perceptual interpretation. Thinking the idea of perception as inference through to the end results in a blurring of boundaries between perception and action selection, as perceptual inference implies the construction of a percept as an active process. Here we therefore wondered whether perception shares a key characteristic of action selection, namely that it is shaped by reinforcement learning. In two behavioral experiments, we used binocular rivalry to examine whether perceptual inference can be influenced by the association of perceptual outcomes with reward or punishment, respectively, in analogy to instrumental conditioning. Binocular rivalry was evoked by two orthogonal grating stimuli presented to the two eyes, resulting in perceptual alternations between the two gratings. Perception was tracked indirectly and objectively through a target detection task, which allowed us to preclude potential reporting biases. Monetary reward or punishments were given repeatedly during perception of only one of the two rivaling stimuli. We found an increase in dominance durations for the percept associated with reward, relative to the non-rewarded percept. In contrast, punishment led to an increase of the non-punished compared to a relative decrease of the punished percept. Our results show that perception shares key characteristics with action selection, in that it is influenced by reward and punishment in opposite directions, thus narrowing the gap between the conceptually separated domains of perception and action selection. We conclude that perceptual inference is an adaptive process that is shaped by its consequences.

Is off-frequency overshoot caused by adaptation of suppression?

This study is concerned with the mechanism of off-frequency overshoot. Overshoot refers to the phenomenon whereby a brief signal presented at the onset of a masker is easier to detect when the masker is preceded by a “precursor” sound (which is often the same as the masker). Overshoot is most prominent when the masker and precursor have a different frequency than the signal (henceforth referred to as “off-frequency overshoot”). It has been suggested that off-frequency overshoot is based on a similar mechanism as “enhancement,” which refers to the perceptual pop-out of a signal after presentation of a precursor that contains a spectral notch at the signal frequency; both have been proposed to be caused by a reduction in the suppressive masking of the signal as a result of the adaptive effect of the precursor (“adaptation of suppression”). In this study, we measured overshoot, suppression, and adaptation of suppression for a 4-kHz sinusoidal signal and a 4.75-kHz sinusoidal masker and precursor, using the same set of participants. We show that, while the precursor yielded strong overshoot and the masker produced strong suppression, the precursor did not appear to cause any reduction (adaptation) of suppression. Predictions based on an established model of the cochlear input–output function indicate that our failure to obtain any adaptation of suppression is unlikely to represent a false negative outcome. Our results indicate that off-frequency overshoot and enhancement are likely caused by different mechanisms. We argue that overshoot may be due to higher-order perceptual factors such as transient masking or attentional diversion, whereas enhancement may be based on mechanisms similar to those that generate the Zwicker tone.

The Identity-Location Binding Problem

The binding problem is fundamental to visual perception. It is the problem of associating an object's visual properties with itself and not with some other object. The problem is made particular difficult because different properties of an object, such as its color, shape, size, and motion, are often processed independently, sometimes in different cortical areas. The results of these separate analyses have to be combined before the object can be seen as a single coherent entity as opposed to a collection of unconnected features. Visual bindings are typically initiated and updated in a serial fashion, one object at a time. Here, we show that one type of binding, location-identity bindings, can be updated in parallel. We do this by using two complementary techniques, the simultaneous-sequential paradigm and systems factorial technology. These techniques make different assumptions and rely on different behavioral measures, yet both came to the same conclusion.

Developmental pathways of social avoidance across adolescence: the role of social anxiety and negative cognition

It is argued that the adolescent onset of social anxiety disorder (SAD) may be partly attributable to an increase in avoidance of social situations across this period. The current cohort-sequential study investigated developmental pathways of social avoidance in adolescence and examined the explanatory role of social anxiety and negative cognitive processes. A community sample of youth (9-21 years, N=331) participated in a four-wave study. Trajectory analyses revealed two pathways: an increased avoidance pathway and a low avoidance pathway. The pathways were hardly distinguishable at age 9 and they steadily diverged across adolescence. Logistic regression analyses showed that social anxiety and post-event rumination were significantly related to the increased avoidance pathway; anticipatory processing and self-focused attention were not. The findings suggest that adolescence is a key developmental period for the progression of social avoidance among youth who show relatively high levels of social anxiety and post-event rumination.

Reliability of reagent strips for semi-quantitative measurement of glucosuria in a neonatal intensive care setting

BACKGROUND

Glucosuria in preterm infants is often measured using a visually readable reagent strip, e.g., when monitoring total parenteral nutrition or during sepsis or when treating with corticosteroids. However, the specific circumstances in a neonatal intensive care unit (NICU), such as the use of diapers and the high temperature in incubators, could affect its reliability.

OBJECTIVES

To evaluate the reliability of the semi-quantitative measurement of glucosuria under the specific circumstances of a NICU setting.

METHODS

Nine hundred assessments of artificially supplemented (contrived) urine samples, intended to simulate pathological specimens, were performed under the following varying conditions: environmental temperature (21°C and 34°C); different times of contact of the urine with the diaper; and using two different methods of collecting urine from the diaper. Each reagent strip was read independently by three observers. The test strips scores were categorized as 0, 1+, 2+, 3+, or 4+ in ascending degree of glucosuria.

RESULTS

Agreement was excellent under all the different conditions (temperature, weighted kappa (κ(w)) = 0.92; method of urine collection, κ(w) = 0.88; time, p = 0.266). Inter-observer reliability was very good (multi-rater κ = 0.81). The deviation between the different conditions was seldom larger than one category (2.9%). The reagent strip readings were concordant with the true urinary glucose concentrations in 79.0% of assessments. The discordance was never larger than one category.

CONCLUSION

The reliability of the semi-quantitative measurement of glucosuria in newborn infants using reagent strips is good, even under the conditions of a NICU. Changes in the rating of reagent strips of more than one category are most likely to be beyond measurement error.

Causal Influence of Articulatory Motor Cortex on Comprehending Single Spoken Words: TMS Evidence

Classic wisdom had been that motor and premotor cortex contribute to motor execution but not to higher cognition and language comprehension. In contrast, mounting evidence from neuroimaging, patient research, and transcranial magnetic stimulation (TMS) suggest sensorimotor interaction and, specifically, that the articulatory motor cortex is important for classifying meaningless speech sounds into phonemic categories. However, whether these findings speak to the comprehension issue is unclear, because language comprehension does not require explicit phonemic classification and previous results may therefore relate to factors alien to semantic understanding. We here used the standard psycholinguistic test of spoken word comprehension, the word-to-picture-matching task, and concordant TMS to articulatory motor cortex. TMS pulses were applied to primary motor cortex controlling either the lips or the tongue as subjects heard critical word stimuli starting with bilabial lip-related or alveolar tongue-related stop consonants (e.g., “pool” or “tool”). A significant cross-over interaction showed that articulatory motor cortex stimulation delayed comprehension responses for phonologically incongruent words relative to congruous ones (i.e., lip area TMS delayed “tool” relative to “pool” responses). As local TMS to articulatory motor areas differentially delays the comprehension of phonologically incongruous spoken words, we conclude that motor systems can take a causal role in semantic comprehension and, hence, higher cognition.

Sleep facilitates learning a new linguistic rule

Natural languages contain countless regularities. Extraction of these patterns is an essential component of language acquisition. Here we examined the hypothesis that memory processing during sleep contributes to this learning. We exposed participants to a hidden linguistic rule by presenting a large number of two-word phrases, each including a noun preceded by one of four novel words that functioned as an article (e.g., gi rhino). These novel words (ul, gi, ro and ne) were presented as obeying an explicit rule: two words signified that the noun referent was relatively near, and two that it was relatively far. Undisclosed to participants was the fact that the novel articles also predicted noun animacy, with two of the articles preceding animate referents and the other two preceding inanimate referents. Rule acquisition was tested implicitly using a task in which participants responded to each phrase according to whether the noun was animate or inanimate. Learning of the hidden rule was evident in slower responses to phrases that violated the rule. Responses were delayed regardless of whether rule-knowledge was consciously accessible. Brain potentials provided additional confirmation of implicit and explicit rule-knowledge. An afternoon nap was interposed between two 20-min learning sessions. Participants who obtained greater amounts of both slow-wave and rapid-eye-movement sleep showed increased sensitivity to the hidden linguistic rule in the second session. We conclude that during sleep, reactivation of linguistic information linked with the rule was instrumental for stabilizing learning. The combination of slow-wave and rapid-eye-movement sleep may synergistically facilitate the abstraction of complex patterns in linguistic input.

Effect of different attentional instructions on the acquisition of a serial movement task

Recent research in attentional focus of instruction has predominantly over-emphasized the investigation of discrete and continuous skills rather than serial skills. The purpose of this study was therefore to examine the effect of different attentional focus instructions on learning a serial skill task (i.e., taekwondo routine) in novice learners. It was predicted that the use of movement outcome instructions could enhance the learning of a serial skill as previously supported in studies examining the acquisition of discrete and continuous skills. Thirteen female participants were recruited for this study and were assigned to either movement form condition - control group (n = 7) or movement outcome condition - treatment group (n = 6). All participants underwent 12 practice sessions over an 8-week period with their respective instructional conditions with each session lasting 30 minutes. Video recording of the serial skill tasks (hand techniques, kicking techniques and 10-step routine) were captured at "the-twelfth-training session", "after 1-week", and "after 1-month". It was found that more participants in the treatment group obtained a higher score in all three serial skill tasks, especially in Mastery component of 'Kicking' techniques at 'after 1-week' (p < 0.05, r = 0.57). This study suggested that movement outcome instructions have positive medium effect on balance control for serial skill task, especially in kicking actions. Key PointsMovement outcome (MO) instructions have a positive impact on learning a serial task, especially in kicking actions.More functional coordination during movement executions for MO participants.Benefits for MO instructions may be individual specific.

Pain trajectory groups in persons with, or at high risk of, knee osteoarthritis: findings from the Knee Clinical Assessment Study and the Osteoarthritis Initiative

OBJECTIVE

The authors aimed to characterize distinct trajectories of knee pain in adults who had, or were at high risk of, knee osteoarthritis using data from two population-based cohorts.

METHOD

Latent class growth analysis was applied to measures of knee pain severity on activity obtained at 18-month intervals for up to 6 years between 2002 and 2009 from symptomatic participants aged over 50 years in the Knee Clinical Assessment Study (CAS-K) in the United Kingdom. The optimum latent class growth model from CAS-K was then tested for reproducibility in a matched sample of participants from the Osteoarthritis Initiative (OAI) in the United States.

RESULTS

A 5-class linear model produced interpretable trajectories in CAS-K with reasonable goodness of fit and which were labelled "Mild, non-progressive" (N = 201, 35%), "Progressive" (N = 162, 28%), "Moderate" (N = 124, 22%) "Improving" (N = 68, 12%), and "Severe, non-improving" (N = 15, 3%). We were able to reproduce "Mild, non-progressive", "Moderate", and "Severe, non-improving" classes in the matched sample of participants from the OAI, however, absence of a "Progressive" class and instability of the "Improving" classes in the OAI was observed.

CONCLUSIONS

Our findings strengthen the grounds for moving beyond a simple stereotype of osteoarthritis as "slowly progressive". Mild, non-progressive or improving symptom trajectories, although difficult to reproduce, can nevertheless represent a genuinely favourable prognosis for a sizeable minority.

Preliminary reliability and validity of a battery for assessing functional skills in children with Sturge-Weber syndrome

PURPOSE

The purpose of this study was to evaluate inter-rater reliability and validity of a proposed functional outcome battery for clinical trials in children with Sturge-Weber syndrome (SWS).

METHODS

Ten children were evaluated twice on the same day using a series of functional outcome measures selected for sensitivity to the range of age and function of children with SWS: Modified Rankin Scale, Pediatric Evaluation of Disability Index, Modified House Functional Classification, and a modified version of the Erhardt Developmental Prehension Assessment. Inter-rater reliability was calculated, and criterion validity was explored through correlations with the Sturge-Weber Syndrome-Neurological Rating Score (SWS-NRS).

RESULTS

Inter-rater reliability was high across all measures. Correlations were identified between the SWS-NRS and the study measures.

CONCLUSIONS

The proposed battery of functional outcome measures captures child's functioning at the levels of impairment, activity and participation and is robust to evaluation by different raters and across sessions on the same day. This battery is expected to be sensitive to treatment-related changes in qualitative patterns of hand use, functional skills, and/or change in independence in daily living.

Development and Initial Validation of the Self-Directed Learning Inventory With Korean College Students

This article describes the development and psychometric evaluation of the Self-Directed Learning Inventory (SDLI) tailored to Korean college students, based on study evidences of differences in learning behavior across culture and educational level. With a sample of 605 female college students in Korea, exploratory factor analysis (EFA) results suggested a 28-item, eight-factor solution: (a) Learning Needs, (b) Utilizing Skills, (c) Enduring Challenges, (d) Self-efficacy in Learning, (e) Planning Skills, (f) Evaluating Skills, (g) Completing Tasks, and (h) Internal Attribution; confirmatory factor analysis cross-validated the EFA solutions. The SDLI demonstrated adequate internal consistency, as well as evidences that support construct validity.

The effect of motoric fluency on metamemory

Prior research has demonstrated that certain types of fluency can influence memory predictions, with more fluent processing being associated with greater memory confidence. However, no study has systematically examined whether this pattern extends to the fluency of motoric output. The current study investigated the effect of a motoric-fluency manipulation of hand dominance on judgments of learning (JOLs) and memory performance. Participants predicted better memory for fluently written than nonfluently written stimuli despite no differences in actual recall. A questionnaire-based study suggested that the effect of motoric fluency on predictions was not due to peoples' a priori beliefs about memory. These findings are consistent with other fluency effects on JOLs.