Twice random,once mixed: Applying mixed models to simultaneously analyze random effects of language and participants

Psychologists, psycholinguists, and other researchers using language stimuli have been struggling for more than 30 years with the problem of how to analyze experimental data that contain two crossed random effects (items and participants). The classical analysis of variance does not apply; alternatives have been proposed but have failed to catch on, and a statistically unsatisfactory procedure of using two approximations (known as F ₁ and F ₂) has become the standard. A simple and elegant solution using mixed model analysis has been available for 15 years, and recent improvements in statistical software have made mixed models analysis widely available. The aim of this article is to increase the use of mixed models by giving a concise practical introduction and by giving clear directions for undertaking the analysis in the most popular statistical packages. The article also introduces the djmixed add-on package for SPSS, which makes entering the models and reporting their results as straightforward as possible.     

Learning and development of embodied numerosity

Recent empirical evidence indicates that seemingly abstract numerical cognitions are rooted in sensory and bodily experiences. In particular in finger counting finger-based representations reflect a specific case of embodied cognition, we termed embodied numerosity. Furthermore, we suggest that finger-based representations should be considered a distinct representation of number (magnitude) and argue that this representation is activated automatically whenever we encounter a number. We discuss in what way such a theoretical framework can account for the associations of fingers and numbers observed so far. In the final part, we evaluate whether the concept of embodied numerosity should be generalized beyond finger-based representations with particular focus on whether bodily-sensory experiences (such as moving the whole body along the mental number line) may corroborate numerical capabilities. In a series of intervention studies, we consistently observed more pronounced training effects for our embodied numerosity trainings for different age groups, different digital media, different number ranges, and different control conditions. Taken together, we conclude that embodied representations of number (magnitude) exist, are not limited to finger-based representations, and influence number processing in a systematic and functional way that can be used to foster the efficiency of numerical trainings.     

Factor Structure and Psychometric Properties of the Modified Childhood Anxiety Sensitivity Index in a Sample of Croatian Children and Adolescents

Anxiety sensitivity (AS) refers to a person’s tendency to fear anxiety-related symptoms due to the belief that they have harmful consequences. The Childhood Anxiety Sensitivity Index (CASI) is a well accepted operationalization of the AS construct in children and adolescents. This study evaluated the factor structure, gender stability and psychometric properties of the CASI, modified to a 5-point scale, in a sample of Croatian children and adolescents (N = 1,679). Exploratory and confirmatory analysis and a Schmid-Leiman solution confirmed the multidimensional and hierarchical structure of the CASI, which consisted of three lower-order factors and a single higher-order factor. Further, the modification of the CASI to a 5-point scale resulted in higher reliability, while maintaining acceptable levels of factor stability and validity.     

Psychoedukation bei Personen mit erh?htem Psychoserisiko

Background

So far only few studies are available which have evaluated the effectiveness of psychoeducation for individuals at risk of psychosis in the early initial prodromal state (EIPS) whereas the benefit of psychoeducation in psychotic patients has been repeatedly confirmed. Thus the aim of this study was to investigate the effect of psychoeducation in individuals with increased risk of psychosis in the EIPS.

Method

A total of 128 help-seeking outpatients in the EIPS participated in a randomized controlled multicentre trial of 12 months of either psychoeducation as part of an integrated psychological intervention (IPI) or supportive counseling (SC). The time to transition to psychosis at 12-month and 24-month follow-up as well as the social adjustment at baseline, time of transition or post-treatment by means of the social adjustment scale (SAS?II) were assessed.

Results

The IPI was superior to SC in preventing progression to psychosis at 12-month (3.2% versus 16.9%, p?=0.008) and 24-month follow-up (6.3% versus 20.0%, p?=0.019). Both treatments resulted in significant pre-post improvements in SAS?II with no significant differences between the two groups.

Conclusions

Psychoeducation as part of an integrated intervention is effective for preventing the onset of psychosis over a 24-month time period in people in an EIPS. Moreover patients at risk of developing first episode psychosis seem to benefit from a specific psychoeducational intervention in the context of other treatments as well as from SC.     

Factor structure and psychometric properties of the Anxiety Sensitivity Index in a sample of Croatian adults

Anxiety sensitivity (AS) refers to a person's tendency to fear anxiety-related symptoms due to the belief that these symptoms may have harmful consequences. The most widely used operationalization of AS in adults is the Anxiety Sensitivity Index (ASI). The factor structure, gender stability, and psychometric properties of the ASI in a sample of Croatian adults (N = 984) were evaluated. Results confirm the multidimensional and hierarchical structure of the ASI, which consisted of three lower-order factors (Physical Concerns, Psychological Concerns, and Social Concerns) and a single higher-order factor, AS. Furthermore, the achievement of normative scores for the ASI in a Croatian adult sample demonstrates the cross-national stability of the ASI. Reliability coefficients for the ASI, Physical Concerns, and Psychological Concerns are high and satisfactory in the total sample and for both genders. Overall, the results confirmed the cross-national stability, gender stability, reliability, and validity of the ASI in a sample of Croatian adults.     

Multi-target visual search organisation across the lifespan: cancellation task performance in a large and demographically stratified sample of healthy adults

Accurate tests of cognition are vital in (neuro)psychology. Cancellation tasks are popular tests of attention and executive function, in which participants find and ‘cancel’ targets among distractors. Despite extensive use in neurological patients, it remains unclear whether demographic variables (that vary among patients) affect cancellation performance. Here, we describe performance in 523 healthy participants of a web-based cancellation task. Age, sex, and level of education did not affect cancellation performance in this sample. We provide norm scores for indices of spatial bias, perseverations, revisits, processing speed, and search organisation. Furthermore, a cluster analysis identified four cognitive profiles among participants, characterised by many omissions (N=18), many revisits (N=18), relatively poor search organisation (N=125), and relatively good search organisation (N=362). Thus, patient scores pertaining to search organisation should be interpreted cautiously: Given the large proportion of healthy individuals with poor search organisation, disorganised search in patients might be pre-existing rather than disorder-related.