Rapid naming deficits in dyslexia: a stumbling block for the perceptual anchor theory of dyslexia

According to a recent theory of dyslexia, the perceptual anchor theory, children with dyslexia show deficits in classic auditory and phonological tasks not because they have auditory or phonological impairments but because they are unable to form a ‘perceptual anchor’ in tasks that rely on a small set of repeated stimuli. The theory makes the strong prediction that rapid naming deficits should only be present in small sets of repeated items, not in large sets of unrepeated items. The present research tested this prediction by comparing rapid naming performance of a small set of repeated items with that of a large set of unrepeated items. The results were unequivocal. Deficits were found both for small and large sets of objects and numbers. The deficit was actually bigger for large sets than for small sets, which is the opposite of the prediction made by the anchor theory. In conclusion, the perceptual anchor theory does not provide a satisfactory account of some of the major hallmark effects of developmental dyslexia.     

Kooperatives Lernen mit Videokonferenzen: Gemeinsame Wissenskonstruktion und individueller Lernerfolg

Summary. Desktop video conferencing enables learners to cooperate while being spatially apart, and to communicate synchronously while working on a collaborative task. Yet, little is known about both the collaborative knowledge construction in these technological settings and the adequate methods of supporting this activity. Therefore, we conducted an empirical study with the following research questions: (1) To what extent does the mode of dyadic collaboration (net-based vs. face-to-face) and the kind of structural support (content-specific vs. content-unspecific) influence the collaborative knowledge construction? (2) To what extent do these factors influence both the individual learning outcomes and the dyadic divergence of learning partners' individual outcomes? Analyzing mean values of collaborative knowledge construction and learning outcome variables, we did not find differences between face-to-face and videoconferencing groups. However, the dyadic divergence of learning partners' individual transfer knowledge was influenced by the learning conditions. The results of this exploratory study are discussed in their relevance for future research on cooperative learning and videoconferencing. Zusammenfassung. Videokonferenzsysteme ermöglichen es, dass sich Lernpartner an verschiedenen Orten aufhalten und bei der Bearbeitung einer gemeinsamen Aufgabe zeitgleich über eine audiovisuelle Verbindung miteinander kommunizieren. Bislang ist kaum untersucht, wie Lernende in videokonferenzbasierten Lernumgebungen gemeinsam Wissen konstruieren und welche Formen instruktionaler Unterstützung dafür angemessen sind. In einer empirischen Untersuchung sind wir deshalb u. a. folgenden Fragestellungen nachgegangen: (1) Inwieweit beeinflussen der Kooperationsmodus (Netz vs. Face-to-face) und die Art des Struktu (inhaltsspezifisch vs. inhaltsunspezifisch) die gemeinsame Wissenskonstruktion? (2) Inwieweit beeinflussen der Kooperationsmodus (Netz vs. Face-to-face) und die Art des Strukturangebots (inhaltsspezifisch vs. inhaltsunspezifisch) den individuellen Lernerfolg und die Divergenz des individuellen Lernerfolgs zwischen den Lernpartnern? Im Mittel fanden sich weder Unterschiede im Hinblick auf die Merkmale der gemeinsamen Wissenskonstruktion noch hinsichtlich des individuellen Lernerfolgs zwischen Face-to-face- und Videokonferenz-Bedingungen. Es zeigte sich jedoch, dass sich die Divergenz des Lernerfolges in den verschiedenen Treatmentgruppen unterschied: Lernende, die in der Videokonferenz-Bedingung in derselben Dyade zusammengearbeitet hatten und dabei von dem inhaltsunspezifischen Strukturangebot unterstützt worden waren, waren sich im Lernerfolg weitaus ähnlicher als Lernende derselben Dyaden in den anderen experimentellen Gruppen. Die Befunde dieser explorativen Studie werden in ihrer Bedeutung für weitere Studien des Lernens mit Videokonferenzen und des kooperativen Lernens diskutiert.     

Fractional designs: A simulation study of usefulness in the social sciences

Fractional designs can be extremely useful in social science research, especially when a large number of factors is involved. Reluctance for the use of fractional designs seems to be warranted for two reasons: (1) In the social sciences, the amount of measurement error is often large, which may decrease the power, and (2) higher order interactions are assumed to be nonsignificant, which is difficult to guarantee without sufficient research. This simulation study shows the effects of measurement error and assumption violations under various conditions. It is concluded that fractional designs handle measurement error gracefully and that they are as powerful as a full design when equal degrees of freedom are available. Significant interaction effects can cause serious problems, especially in situations with low or intermediate measurement error, and can lead to erroneous conclusions. Only when estimated confounded effects are clearly not significant, the chance of a wrong decision is reasonably small. Therefore, fractional designs are especially warranted for the exclusion of irrelevant factors. However, we note pitfalls in the use of Version 1.0 of the program Trail Run from SPSS, Inc., to implement the procedures.     

Dispositional Anxiety and Frontal‐Midline Theta: On the Modulatory Influence of Sex and Situational Threat

In their adaptive control hypothesis, Cavanagh and Shackman (2015) recently claimed that dispositional anxiety is correlated with frontal‐midline theta (FMθ) as a generic “need for control” signal of the anterior midcingulate cortex. Here, we tested this assumption, also considering potential modulatory influences of anticipatory threat and individuals’ sex. In a nonclinical sample of 168 participants (84 women), electroencephalogram was recorded while individuals performed a simple two‐choice task. Half of the participants were assigned to a threat anticipation condition (anticipation of public speaking), whereas the other half was assigned to a control condition. State anxiety was monitored across the experiment. Dispositional anxiety was assessed by self‐report scales, which were completed before individuals came to the laboratory. Target stimuli in the two‐choice task induced a transient increase in FMθ power that was subject to an interaction of dispositional anxiety, sex, and experimental group. Only in women who anticipated public speaking did we observe a substantial positive relation between dispositional anxiety and general FMθ power. Our results indicate that the link between dispositional anxiety and FMθ is not universal but rather depends on complex interactions of individuals’ sex and situational threat.     

The cycle of violence as a function of PTSD and appetitive aggression: A longitudinal study with Burundian soldiers

During deployment, soldiers face situations in which they are not only exposed to violence but also have to perpetrate it themselves. This study investigates the role of soldiers' levels of posttraumatic stress disorder (PTSD) symptoms and appetitive aggression, that is, a lust for violence, for their engaging in violence during deployment. Furthermore, factors during deployment influencing the level of PTSD symptoms and appetitive aggression after deployment were examined for a better comprehension of the maintenance of violence. Semi-structured interviews were conducted with 468 Burundian soldiers before and after a 1-year deployment to Somalia. To predict violent acts during deployment (perideployment) as well as appetitive aggression and PTSD symptom severity after deployment (postdeployment), structural equation modeling was utilized. Results showed that the number of violent acts perideployment was predicted by the level of appetitive aggression and by the severity of PTSD hyperarousal symptoms predeployment. In addition to its association with the predeployment level, appetitive aggression postdeployment was predicted by violent acts and trauma exposure perideployment as well as positively associated with unit support. PTSD symptom severity postdeployment was predicted by the severity of PTSD avoidance symptoms predeployment and trauma exposure perideployment, and negatively associated with unit support. This prospective study reveals the importance of appetitive aggression and PTSD hyperarousal symptoms for the engagement in violent acts during deployment, while simultaneously demonstrating how these phenomena may develop in mutually reinforcing cycles in a war setting.     

Levels-of-processing effects in subject-performed tasks

In memory for subject-performed tasks (SPTs), subjects encode a list of simple action phrases (e.g., thumb through a book, knock at the door) by performing these actions during learning. In three experiments, we investigated the size of the levels-of-processing effects in SPTs as compared with those in standard verbal learning tasks (VTs). Subjects under SPT and VT conditions learned lists of action phrases in a surface or a conceptual orienting task. Under both encoding conditions, the subjects recalled fewer items with surface orienting tasks than with conceptual orienting tasks, but the levels-of-processing effects were strongly reduced in the SPT condition. In the SPT condition, items that were encoded in a surface orienting task were still substantially recalled. The items were recalled almost as well as the conceptually encoded items in the VT condition. The distinct reduction of the levels-of-processing effect is caused by the fact that, in SPT encoding even with a verbal surface orienting task, subjects process conceptual information in order to perform the denoted action. We attribute the small conceptual advantage, which remains with SPT despite the conceptual processing for performing, to the fact that items are not as well integrated into memory as they are when conceptual processing is focused on the action component, rather than on the semantic contexts. This lower integration reduces the accessibility of items in the verbal surface task, even with SPT encoding.     

Bizarreness effects in verbal tasks and subject-performed tasks

Abstract

Recognition and cued recall of ordinary action phrases (e.g. “open the book”) and bizarre ones (e.g. “plant the hammer”) were compared under two encoding conditions: in verbal tasks (VTs), subjects learned the phrases by simply listening to them; in subject-performed tasks (SPTs), subjects learned the phrases by performing the denoted actions (without real objects). Memory performance was better after SPTs than after VTs in recognition and cued recall. In addition to this already established finding, it was observed that recognition was better for bizarre phrases than for ordinary ones after VTs and that bizarreness was unrelated to recognition after SPTs. Cued recall, on the other hand, depended on bizarreness after VTs as well as after SPTs and, in contrast to the recognition findings, ordinary phrases were recalled better than bizarre phrases. This pattern of findings was explained by the assumptions that lexical and conceptual information is encoded after VTs and motor information is additionally encoded after SPTs, and that different kinds of information are used in recognition and cued recall, and after VTs and SPTs.