Aggression Among Children with ADHD,Anxiety, or Co-occurring Symptoms: Competing Exacerbation and Attenuation Hypotheses

Competing hypotheses for explaining the role of anxiety in the relation between attention-deficit/hyperactivity disorder (ADHD) symptoms and childhood aggression were evaluated. Two studies tested whether anxiety exacerbated, attenuated, or had no effect on the relation between ADHD and aggression subtypes among psychiatrically hospitalized children. In Study 1 (N = 99), children who scored above clinical cut-off levels for anxiety only, ADHD only, and co-occurring ADHD and anxiety were compared on aggression subtypes (i.e., reactive, proactive, overt, and relational aggression). In Study 2, the moderating role of anxiety on the relation between ADHD and aggression subtypes was examined with a larger sample (N = 265) and with continuous variables. No support was found for either the attenuation or exacerbation hypothesis, and results remained consistent when separately examining hyperactivity/impulsivity and inattention symptoms of ADHD. Although ADHD symptoms were significantly associated with all aggression subtypes, this association did not remain when including symptoms of oppositional defiant disorder.     

Individual differences in the mixture ratio of rotation and nonrotation trials during rotated mirror/normal letter discriminations

Mental rotation is thought to underlie the increase in response times (RTs) for deciding whether rotated letters are normal or mirrored versions. However, mental rotation predicts a linear increase in RTs, whereas the mirror/normal letter discrimination task typically produces a curved function. Recently, Kung and Hamm suggested that this curved function results from a mixture of trials in which mental rotation is employed and trials in which it is not. The mixture ratio may vary between individuals, with some individuals relying more on mental rotation than others. There is no factor in the Kung and Hamm model that reflects such individual differences. In the present study, we suggest that a possible exponent parameter could be added to the Kung and Hamm model to capture individual differences in the mixture ratio. This exponent parameter appears to capture an individual characteristic since the value obtained correlates between the mirror/normal letter task and a left/right object facing task. The development of a quantity that represents the mixture ratio will aid further testing of processes involved in the visual imagery system.     

Centre–surround inhibition is a general aspect of famous-person recognition: Evidence from negative semantic priming from clearly visible primes

A centre–surround attentional mechanism was proposed by Carr and Dagenbach (Journal of Experimental Psychology: Learning, Memory, and Cognition 16: 341–350, 1990) to account for their observations of negative semantic priming from hard-to-perceive primes. Their mechanism cannot account for the observation of negative semantic priming when primes are clearly visible. Three experiments (Ns = 30, 46, and 30) used a familiarity decision with names of famous people, preceded by a prime name with the same occupation as the target or with a different occupation. Negative semantic priming was observed at a 150- or 200-ms SOA, with positive priming at shorter (50-ms) and longer (1,000-ms) SOAs. In Experiment 3, we verified that the primes were easily recognisable in the priming task at an SOA that yielded negative semantic priming, which cannot be predicted by the original centre–surround mechanism. A modified version is proposed that explains transiently negative semantic priming by proposing that centre–surround inhibition is a normal, automatically invoked aspect of the semantic processing of visually presented famous names.     

The origin of the interaction between learning method and delay in the testing effect: The roles of processing and conceptual retrieval organization

Recent research has demonstrated a relationship between retrieval organization and the efficacy of prior repeated retrieval on delayed tests. The present study asked why repeated study engenders higher recall at a short delay despite lower retrieval organization but produces a decline at a long delay, and why repeated retrieval engenders lower recall at a short delay despite higher retrieval organization but produces stable recall over time. This relationship was examined through the inclusion of two successive recall tests—one immediately after learning method and one a week later. Results replicated the interaction in recall between learning method and delay characterizing the testing effect and, critically, revealed the qualitative differences inherent in the retrieval organization of each method. Specifically, stable recall in repeated retrieval was accompanied by strong and sustained conceptual organization, whereas organization for repeated study was tenuous and weakened across tests. These differences quantitatively were assessed through the use of five targeted analyses: specifically, the examination of cumulative recall curves, the accumulation of organization across time (a curve akin to cumulative recall), item gains and losses across time, changes in the size of categories across time, and the fate of specific clusters of recalled items across time. These differences are discussed within the context of differential processes occurring during learning method.     

Racial and Ethnic Differences in Direct-to-Consumer Genetic Tests Awareness in HINTS 2007: Sociodemographic and Numeracy Correlates

To examine the association of 1) race/ethnicity and 2) numeracy with awareness of DTC genetic tests. Secondary analysis of 6,754 Hispanic, black, and white adult respondents to the National Cancer Institute’s 2007 Health Information National Trends Survey (HINTS). Logistic regression was used to examine sociodemographic predictors of DTC genetic tests awareness including race/ethnicity, income, education, and gender. Next, two numeracy variables were added to the model. After controlling for sociodemographic variables, black respondents were significantly less likely to have heard of DTC genetic tests compared to white respondents (OR = 0.79; CI: 0.65–0.97). When numeracy variables were added to the model, the effect of black race was no longer significant (OR = 0.84; CI: 0.69–1.04). Hispanic respondents did not significantly differ from white respondents in awareness of DTC genetic tests. Other significant correlates of DTC genetic tests awareness in the full model included education, income, age, and numeracy variables including degree to which people use medical statistics and numbers to make health decisions, and preference for words or numbers when discussing “the chance of something happening.” Although black respondents were generally less aware of DTC genetic tests than white respondents, this relationship appears to be partially mediated by numeracy.     

Attention Skills and Risk of Developing Learning Difficulties

Attention is a heterogeneous function, composed of different components involved in acquiring and developing all cognitive and behavioural skills. Attentive difficulties, such as insufficient or inadequate control of the stream of occurring stimuli, have been linked to impairment in executive functions, impulsive behavioral style, academic failure, and difficulties in basic scholastic skills, such as reading and writing. Moreover, specific Learning Disabilities often occur along with and/or complicated by problems in attention. Considering that prerequisites of school learning evolve early in childhood, the overall goal of this study is to investigate the relationships between attention skills and the risk of developing learning difficulties. Specifically, this study attempts to contribute to better identification of the role of the attention measures in the early detection of risk signs of developing learning difficulties. Research has been conducted through a computerized battery to assess attention and an observational questionnaire aimed at identifying the risk of developing learning difficulties. The study examined a sample of preschoolers. The results showed that different components of attention, such as visual selectivity and reaction times, are diversely involved in the risk of developing learning difficulties and in the prerequisite of school learning.     

Physico-mathematics and the search for causes in Descartes’ optics—1619–1637

One of the chief concerns of the young Descartes was with what he, and others, termed “physico-mathematics”. This signalled a questioning of the Scholastic Aristotelian view of the mixed mathematical sciences as subordinate to natural philosophy, non explanatory, and merely instrumental. Somehow, the mixed mathematical disciplines were now to become intimately related to natural philosophical issues of matter and cause. That is, they were to become more ’physicalised’, more closely intertwined with natural philosophising, regardless of which species of natural philosophy one advocated. A curious, short-lived yet portentous epistemological conceit lay at the core of Descartes’ physico-mathematics—the belief that solid geometrical results in the mixed mathematical sciences literally offered windows into the realm of natural philosophical causation—that in such cases one could literally “see the causes”. Optics took pride of place within Descartes’ physico-mathematics project, because he believed it offered unique possibilities for the successful vision of causes. This paper traces Descartes’ early physico-mathematical program in optics, its origins, pitfalls and its successes, which were crucial in providing Descartes resources for his later work in systematic natural philosophy. It explores how Descartes exploited his discovery of the law of refraction of light—an achievement well within the bounds of traditional mixed mathematical optics—in order to derive—in the manner of physico-mathematics—causal knowledge about light, and indeed insight about the principles of a “dynamics” that would provide the laws of corpuscular motion and tendency to motion in his natural philosophical system.     

Bridging a yawning chasm: EEG investigations into the debate concerning the role of the human mirror neuron system in contagious yawning

Ongoing debate in the literature concerns whether there is a link between contagious yawning and the human mirror neuron system (hMNS). One way of examining this issue is with the use of the electroencephalogram (EEG) to measure changes in mu activation during the observation of yawns. Mu oscillations are seen in the alpha bandwidth of the EEG (8–12 Hz) over sensorimotor areas. Previous work has shown that mu suppression is a useful index of hMNS activation and is sensitive to individual differences in empathy. In two experiments, we presented participants with videos of either people yawning or control stimuli. We found greater mu suppression for yawns than for controls over right motor and premotor areas, particularly for those scoring higher on traits of empathy. In a third experiment, auditory recordings of yawns were compared against electronically scrambled versions of the same yawns. We observed greater mu suppression for yawns than for the controls over right lateral premotor areas. Again, these findings were driven by those scoring highly on empathy. The results from these experiments support the notion that the hMNS is involved in contagious yawning, emphasise the link between contagious yawning and empathy, and stress the importance of good control stimuli.     

Effects of cage mesh on pointing: hand shapes in chimpanzees (<Emphasis Type="Italic">Pan troglodytes</Emphasis>)

It has been speculated that cage mesh exerts a shaping influence on reaching behavior by captive apes, which is then misconstrued as pointing by human observers. Although this notion is clearly falsified by the pointing of captive language-trained apes—who point in the absence of intervening cage mesh—nevertheless, the degree to which cage mesh might influence pointing hand shapes by captive great apes in other housing environments remains relatively unexplored. We examined 259 pointing gestures displayed in archival footage from over 18 h of observation by three nonlanguage-trained chimpanzees housed at a biomedical research center. We coded points in relation to how close to the boundaries of the diamond-shaped cage mesh their points were displayed. We found that points with the whole hand were significantly more likely to be displayed away from the mesh boundaries, relative to points with the index finger or other single-digit points. However, points of each hand shape were displayed at each location, demonstrating that these physical parameters do not fully account for the number of fingers extended while pointing by chimpanzees.