Developmental stability and leadership effectiveness

Developmental stability is the degree to which we can withstand environmental or genetic stressors during development. Fluctuating asymmetry (FA), concerns the extent to which the right and left side of the body is asymmetrical and is one way to measure developmental stability. Two studies were carried out that examined both the predictive value of leader FA with leadership behaviors and its role in facilitating group performance. The first study examined the hypothesis that a leader's FA is correlated with scores on the Multifactor Leadership Questionnaire (MLQ). The results revealed individuals with a more asymmetrical morphology scored higher on the transformational, but not transactional, dimensions of leadership behavior. A second study examined the hypothesis that asymmetrical morphology and leadership effectiveness would share a positive relationship. In this study participants who led a business game exercise, revealed a positive relationship between FA and self-reported well-being and task satisfaction. Importantly, there was also a positive correlation between the leader's FA score and group performance. The role that developmental stability may play in leadership effectiveness is discussed in the wider context of evolutionary psychology.

Investigation of dyslexia and SLI risk variants in reading- and language-impaired subjects

Dyslexia (or reading disability) and specific language impairment (or SLI) are common childhood disorders that show considerable co-morbidity and diagnostic overlaps and have been suggested to share some genetic aetiology. Recently, genetic risk variants have been identified for SLI and dyslexia enabling the direct evaluation of possible shared genetic influences between these disorders. In this study we investigate the role of variants in these genes (namely MRPL19/C20RF3, ROBO1, DCDC2, KIAA0319, DYX1C1, CNTNAP2, ATP2C2 and CMIP) in the aetiology of SLI and dyslexia. We perform case–control and quantitative association analyses using measures of oral and written language skills in samples of SLI and dyslexic families and cases. We replicate association between KIAA0319 and DCDC2 and dyslexia and provide evidence to support a role for KIAA0319 in oral language ability. In addition, we find association between reading-related measures and variants in CNTNAP2 and CMIP in the SLI families.

PCSK6 is associated with handedness in individuals with dyslexia

Approximately 90% of humans are right-handed. Handedness is a heritable trait, yet the genetic basis is not well understood. Here we report a genome-wide association study for a quantitative measure of relative hand skill in individuals with dyslexia [reading disability (RD)]. The most highly associated marker, rs11855415 (P = 4.7 × 10-7), is located within PCSK6. Two independent cohorts with RD show the same trend, with the minor allele conferring greater relative right-hand skill. Meta-analysis of all three RD samples is genome-wide significant (n = 744, P = 2.0 × 10-8). Conversely, in the general population (n = 2666), we observe a trend towards reduced laterality of hand skill for the minor allele (P = 0.0020). These results provide molecular evidence that cerebral asymmetry and dyslexia are linked. Furthermore, PCSK6 is a protease that cleaves the left–right axis determining protein NODAL. Functional studies of PCSK6 promise insights into mechanisms underlying cerebral lateralization and dyslexia.

Are poor mathematics skills associated with visual deficits in temporal processing?

Developmental learning disabilities such as dyslexia and dyscalculia have a high rate of co-occurrence in pediatric populations, suggesting that they share underlying cognitive and neurophysiological mechanisms. Dyslexia and other developmental disorders with a strong heritable component have been associated with reduced sensitivity to coherent motion stimuli, an index of visual temporal processing on a millisecond time-scale. Here we examined whether deficits in sensitivity to visual motion are evident in children who have poor mathematics skills relative to other children of the same age. We obtained psychophysical thresholds for visual coherent motion and a control task from two groups of children who differed in their performance on a test of mathematics achievement. Children with math skills in the lowest 10% in their cohort were less sensitive than age-matched controls to coherent motion, but they had statistically equivalent thresholds to controls on a coherent form control measure. Children with mathematics difficulties therefore tend to present a similar pattern of visual processing deficit to those that have been reported previously in other developmental disorders. We speculate that reduced sensitivity to temporally defined stimuli such as coherent motion represents a common processing deficit apparent across a range of commonly co-occurring developmental disorders.

Deficits in dyslexia:Barking up the wrong tree?

Reviews of the dyslexia literature often seem to suggest that children with dyslexia perform at a lower level on almost any task. Richards et al. (Dyslexia 2002; 8: 1-8) note the importance of being able to demonstrate dissociations between tasks. However, increasingly elegant experiments, in which dissociations are found, almost inevitably find that the performance of children with dyslexia is lower as tasks become more difficult! By looking for deficits in dyslexia, could we be barking up the wrong tree? A methodological approach for circumventing this potential problem is discussed. Copyright © 2004 John Wiley & Sons, Ltd.

Attention deficits in dyslexia:Evidence for an automatisation deficit?

Both attentional difficulties and rapid processing deficits have recently been linked with dyslexia. We report two studies comparing the performance of dyslexic and control teenagers on attentional tasks. The two studies were based on two different conceptions of attention. Study 1 employed a design that allowed three key components of attention - focusing, switching, and sustaining - to be investigated separately. One hypothesis under investigation was that rapid processing problems - in particular impaired ability to switch attention rapidly - might be associated with dyslexia. However, although dyslexic participants were significantly less accurate than their controls in a condition where they had to switch attention between two target types, the nature of the deficit suggested that the problem was not in switching attention per se. Thus, in Study 2, we explored an alternative interpretation of the Study 1 results in terms of the classic capacity-limited models of "central" attention. We contrasted two hypotheses: (1) that dyslexic teenagers have reduced cognitive resources versus (2) that they suffer from a general impairment in the ability to automatise basic skills. To investigate the automaticity of the shape recognition component of the task a similar attention paradigm to that used in Study 1 was employed, but using degraded, as well as intact, stimuli. It was found that stimulus degradation led to relatively less impairment for dyslexic than for matched control groups. The results support the hypothesis that dyslexic people suffer from a general impairment in the ability to automatise skills - in this case the skill of automatic shape recognition.

A developmental dissociation of view-dependent and view-invariant object recognition in adolescence

Spatial generalization skills in school children aged 8-16 were studied with regard to unfamiliar objects that had been previously learned in a cross-modal priming and learning paradigm. We observed a developmental dissociation with younger children recognizing objects only from previously learnt perspectives whereas older children generalized acquired object knowledge to new viewpoints as well. Haptic and - to a lesser extent - visual priming improved spatial generalization in all but the youngest children. The data supports the idea of dissociable, view-dependent and view-invariant object representations with different developmental trajectories that are subject to modulatory effects of priming. Late-developing areas in the parietal or the prefrontal cortex may account for the retarded onset of view-invariant object recognition. © 2006 Elsevier B.V. All rights reserved.

Phonology as Cause, Symptom and Treatment? Early Reading Development and Dyslexia, by Valerie Muter, London: Whurr, 2003, 232 pages + viii, ISBN 1 86156 327 2

Book review

Developmental anomalies of the eye: the genetic link

As in other areas of the body, developmental anomalies of the eye arise as a result of the disturbance of events during embryology and in a proportion of cases these anomalies are genetically inherited. Developmental anomalies that occur early in embryonic life may be so severe that the embryo may not survive but others result in the birth of healthy babies but with developmental eye defects of varying severity. The most dramatic developmental defects of the eye include anophthalmos (complete absence of an eye), microphthalmos (a general failure of the eye to develop resulting in a small, undeveloped eye), coloboma (caused by failure of the optic vesicle to invaginate), and aniridia (complete or partial loss of the iris). The present article does not provide an exhaustive review of the topic but considers the major types of developmental anomaly to affect the eye and will discuss how recent progress in genetics has increased our understanding of these disorders. The major genes linked to the developmental anomalies are discussed as well as how defects in these genes might lead to specific problems.

Leadership development: the role of developmental readiness, personality dispositions, and individual values

Increased awareness of the crucial role of leadership as a competitive advantage for organisations (McCall, 1998; Petrick, Scherer, Brodzinski, Quinn, & Ainina, 1999) has led to billions spent on leadership development programmes and training (Avolio & Hannah, 2008). However, research reports confusing and contradictory evidence regarding return on investment and developmental outcomes, and a lot of variance has been observed across studies (Avolio, Reichard, Hannah, Walumbwa, & Chan, 2009). The purpose of this thesis is to understand the mechanisms underlying this variability in leadership development. Of the many factors at play in the process, such as programme design and delivery, organisational support, and perceptions of relevance (Mabey, 2002; Day, Harrison, & Halpin, 2009), individual differences and characteristics stand out. One way in which individuals differ is in their Developmental Readiness (DR), a concept recently introduced in the literature that may well explain this variance and which has been proposed to accelerate development (Avolio & Hannah, 2008, 2009). Building on previous work, DR is introduced and conceptualised somewhat differently. In this study, DR is construed of self-awareness, self-regulation, and self-motivation, proposed by Day (2000) to be the backbones of leadership development. DR is suggested to moderate the developmental process. Furthermore, personality dispositions and individual values are proposed to be precursors of DR. The empirical research conducted uses a pre-test post-test quasi-experimental design. Before conducting the study, though, both a measure of Developmental Readiness and a competency profiling measure are tested in two pilot studies. Results do not find evidence of a direct effect of leadership development programmes on development, but do support an interactive effect between DR and leadership development programmes. Personality dispositions Agreeableness, Conscientiousness, and Openness to Experience and value orientations Conservation, Open, and Closed Orientation are found to significantly predict DR. Finally, the theoretical and practical implications of findings are discussed.

Characteristics of visual function in Asperger’s syndrome and the autism spectrum

Autism is a pervasive developmental disorder and Asperger’s syndrome is part of the spectrum of autism disorders. This thesis aims to: • Review and investigate current theories concerning visual function in individuals with Asperger’s syndrome and high functioning autism spectrum disorder and to translate the findings into clinical practice by developing a specific protocol for the eye examination of individuals of this population. • Investigate whether those with Asperger’s syndrome are more likely to suffer from Meares-Irlen syndrome and/or dyslexia. • Assess the integrity of the M-cell pathway in Asperger’s syndrome using perimetric tests available in optometric practice to investigate and also to describe the nature of any defects. • Evaluate eye movement strategies in Asperger’s whilst viewing both text and images. Also to evaluate the most appropriate methodology for investigating eye movements; namely optical digital eye tracking and electrophysiology methodologies. Findings of the investigations include • Eye examinations for individuals with Asperger’s syndrome should contain the same testing methods as for the general population, with special consideration for clear communication. • There is a depression of M-pathway visual field sensitivity in 57% (8/14) of people with Asperger’s syndrome, supporting previous evidence for an M-cell deficit in some individuals. • There is a raised prevalence of dyslexia in Asperger’s syndrome (26% of a sample of 31) but not necessarily of Meares-Irlen syndrome. • Gaze strategies are abnormal in Asperger’s syndrome, for both reading and viewing of images. With increased saccadic movement and decreased viewing of faces in comparison to background detail.

Varieties of acquired phonological dyslexia

The existence of different varieties of the acquired reading disorder termed "phonological dyslexia" is demonstrated in this thesis. The data are interpreted in terms of an information-processing model of normal reading which postulates autonomous routes for pronouncing lexical and non-lexical items and identifies a number of separable sub-processes within both lexical and non-lexical routes. A case study approach is used and case reports on ten patients who have particular difficulty in processing non-lexical stimuli following cerebral insult are presented, Chapters 1 and 2 describe the theoretical background to the investigation. Cognitive models of reading are examined in Chapter 1 and the theoretical status of the current taxonomy of the acquired dyslexias discussed in relation to the models. In Chapter 2 the symptoms associated with phonological dyslexia are discussed both in terms of the theoretical models and in terms of the cosistency with which they are reported to occur in clinical studies. Published cases of phonological dyslexia are reviewed. Chapter 3 describes the tests administered and the analysis of error responses. The majority of tests require reading aloud of single lexical or non-lexical items and investigate the effect of different variables on reading performance. Chapter 4 contains the case reports. The final chapter summarises the different patterns of reading behaviour observed. The theoretical model predicts the selective impairment of subsystems within the phonological route. The data provide evidence of such selective impairment. It is concluded that there are different varieties of phonological dyslexia corresponding to the different loci of impairment within the phonological route. It is also concluded that the data support the hypothesis that there are two lexical routes. A further subdivision of phonological dyslexia is made on the basis of selective impairment of the direct or lexical-semantic routes.

Individual differences in occupational perceptions: a developmental study

This thesis presents an investigation of the structure of people's occupational perceptions. The questionnaires used In this study collected both descriptive information about people's perceptions of occupations and also pair comparison similarities data. The data were collected both in the United States of America and England from samples of subjects who differed in terms of age and sex. This provided, therefore, both cross-cultural and developmental dimensions to the study. A cognitive orientation to the study of vocational behaviour is developed and multidimensional scaling procedures are used to analyze the data. A prime concern of the thesis is to examine the appropriateness of this approach and these techniques to this subject area. The results of this study show that a considerable range of individuaI differences exist in occupational perceptions.0lder subjects have a more complex structure to their perceptions and showed greater consensus as to how they perceived occupations to relate to each other. Younger subjects exhibited a greater range of individual differences in occupational perceptions but had, on average, a simpler subjective occupational structure. The multidimensional scaling procedures used in this study were able to reveal how occupational perceptions were structured, to relate these occupational perceptions to occupational preferences and other evaluative data, and to show that the groupings and structure of occupational perceptions ore similar to the dimensions used in occupational classification schemes. ImpIications of these resultts to vocationaI guidance theory and practice are discussed. The resuIts reported here strongly support both the use of the cognitive approach adopted here and demonstrate the potential of multidimensional scaling techniques for further:research in the field of vocational psychology.