Neuropsychology of Early-treated Phenylketonuria: Specific Executive Function Deficits

This study explored the hypothesis that children with early-treated phenylketonuria (PKU) are selectively impaired on executive function measures, even when still on diet. The rationale for this hypothesis is that even mild elevations in phenylalanine (Phe) can lead to lower central levels of biogenic amines, including dopamine (DA). We hypothesize that this mild DA depletion causes subtle prefrontal dysfunction, which in turn affects executive functions such as set maintenance, planning, and organized search. 11 preschool early-treated PKU children (M age = 4.64) and a sample of age- and IQ-matched unaffected peers (n = 11) were evaluated on a battery of executive function (EF) measures. In addition, a "non-executive function" task, recognition memory, was administered to all subjects. Group comparisons demonstrated that PKU children were significantly impaired on an executive function composite score; there were no group differences, however, in recognition memory. These results supported the hypothesized specific deficit in executive function. Furthermore, within the PKU group the executive function composite score was significantly negatively correlated with concurrent phenylalanine levels, even after controlling for the correlation between IQ and executive function skills. This second finding provides support for the proposed biochemical mechanism underlying the specific cognitive deficits.     

Differential genetic etiology of reading disability as a function of mathematics performance

In order to assess the etiology of reading disability as a function of mathematics performance, data from 168 monozygotic (MZ) and 127 same-sex dizygotic (DZ) twin pairs in which at least one member of each pair was reading-disabled were subjected to quantitative genetic analyses. MZ and DZ concordance rates for reading disability were computed for different levels of mathematics performance, and reading performance data were fitted to an extension of the basic multiple regression model for the analysis of selected twin data. Results of these analyses suggest that genetic factors may be especially salient as a cause of reading disability in children with borderline deficits in mathematics performance: thus, mathematics performance may be a valid dimension for diagnosing subtypes of reading disability.     

Differential risk for developmental reading disorders in the offspring of compensated versus noncompensated parents

When one or both parents have a history of developmental reading disorder (RD) in childhood, the risk to their offspring for developing reading problems is substantially increased. However, risk research has usually assumed a stability of reading problems across the lifespan (i.e., if a parent was affected in childhood, he or she remains affected in adulthood). Yet, some individuals with RD in childhood compensate for the disorder as they grow older. Both an environmental and genetic hypothesis would predict that the risk for RD in offspring will vary as a function of parental compensation. This study examined whether risk to offspring was dependent on the parents' successful or unsuccessful compensation for their childhood reading problems. Two large family data sets were analyzed (N=907). Diagnoses with either an age discrepant or IQ discrepant criteria essentially showed that having at least one still affected parent (i.e., RD both as a child and as an adult) put the offspring at a higher risk for RD than having at least one compensated parent (i.e., RD as a child but not as an adult). The lowest risk to an offspring occurred when both parents were never affected (i.e., not RD as a child or as an adult). The implications of these findings are discussed with regard to counseling and early diagnosis of reading problems.     

Comorbidity of reading disability and attention-deficit/hyperactivity disorder: differences by gender and subtype

This study used a community sample of 494 twins with a reading disability (223 girls, 271 boys) and 373 twins without a reading disability (189 girls, 184 boys) to assess the relation between reading disability (RD) and attention-deficit/hyperactivity disorder (ADHD). Symptoms of DSM-III and DSM-IV ADHD were classified into symptoms of inattention and symptoms of hyperactivity-impulsivity (H/I). Results indicated that individuals with RD were more likely than individuals without RD to meet criteria for ADHD and that the association between RD and ADHD was stronger for symptoms of inattention than for symptoms of H/I. Parents and teachers reported similar rates of ADHD, suggesting that ADHD symptoms were pervasive across settings and were not solely attributable to academic frustration. Analyses of possible gender differences revealed that RD was significantly associated with inattention in both girls and boys but associated with H/I only in boys. This difference may provide a partial explanation for the discrepancy between the gender ratio obtained in referred (approximately 4 boys to 1 girl) and nonreferred (1.2 to 1.5 boys to 1 girl) samples of individuals with RD. Specifically, the hyperactive and impulsive behaviors exhibited by boys with RD may be more disruptive than the inattentive behaviors exhibited by girls and may therefore precipitate more frequent referrals for clinical attention.     

Early reading development in children at family risk for dyslexia

In a 3-year longitudinal study, middle- to upper-middle-class preschool children at high family risk (HR group, N = 67) and low family risk (LR group, N = 57) for dyslexia (or reading disability, RD), were evaluated yearly from before kindergarten to the end of second grade. Both phonological processing and literacy skills were tested at each of four time points. Consistent with the well-known familiarity of RD, 34% of the HR group compared with 6% of the LR group became RD. Participants who became RD showed deficits in both implicit and explicit phonological processing skills at all four time points, clearly indicating a broader phonological deficit than is often found at older ages. The predictors of literacy skill did not vary by risk group. Both risk groups underwent a similar developmental shift from letter-name knowledge to phoneme awareness as the main predictor of later literacy skill. This shift, however, occurred 2 years later in the HR group. Familial risk was continuous rather than discrete because HR children who did not become RD performed worse than LR non-RD children on some phonological and literacy measures. Finally, later RD could be predicted with moderate accuracy at age 5 years, with the strongest predictor being letter-name knowledge.     

“What’s the Middle Ground? Am I Ever Going to be the Perfect Teacher?:” Self-Study of a Doctoral Student’s Acculturation Process

In higher education, doctoral training has been identified as a process of stewardship development whereby individuals learn the knowledge and skills required to advance their respective disciplines. Self-study of teacher education practices is one approach that has gained the interest of doctoral students to help them understand their own development whilst also forging recommendations for others in publications. In this self-study, we worked to understand the experiences of Shrehan, a teacher from England beginning doctoral study in the USA. Shrehan had no experience teaching at the college level prior to moving to the USA, and she saw self-study as an opportunity to understand her development and acculturation into an unfamiliar system of higher education. Data were collected through journaling, critical-friend discussions, and artefacts, as well as student data in the form of surveys, exit slips, and focus-group interviews. Qualitative data analysis of Shrehan’s experiences was guided by the four stages of acculturation theory – honeymoon, culture shock, adjustment, and recovery. Shrehan’s journey emphasizes the importance of getting to know undergraduate students and building rapport as key aspects of teaching at the college level. Self-study provided Shrehan with a heightened personal-identity awareness that increased her cultural sensitivity and broadened her worldview. Results are discussed with reference to acculturation theory and future directions for research are provided.     

Intercollegiate Athletics at the Community College

Each year, many community college leaders find themselves, either methodically or haphazardly, making decisions about intercollegiate athletics. There have, however, been few empirical studies on how and why community colleges initiate, expand, or terminate athletic programs. Two studies investigating leaders' perceptions of intercollegiate athletics provide data which may be helpful to community college officials considering the pros and cons of athletic programs. Recommendations are provided regarding the need for statewide guidelines on community college athletics and the importance of a campus-based Council on Athletics.     

Component reading skills in Down Syndrome

This study investigates word reading skill in Down Syndrome (DS). Two main questions are addressed: (1) Is reading an island of ability in DS? and (2) What are the cognitive correlates of word reading ability in DS? In particular, how do language versus visual-spatial skills relate to individual differences in reading ability in DS? Participants were 19 individuals with DS, ranging in age from 10 to 19 years, and 19 typically developing children (mean age = 4.9 years) matched with the DS individuals for mental age. Overall, reading ability in DS was very poor. There was no evidence that reading represents an “island of ability” in DS; instead, the average reading level of DS participants was even lower than would be predicted by their IQ. However, there were substantial individual differences in literacy among DS participants. DS word reading and spelling skill correlated strongly with the ability to read by phonological recoding. It also correlated with several language measures. As a matter of fact, the often reported language-mental age gap was found only among the poor readers with DS.     

Comparing the phonological and double deficit hypotheses for developmental dyslexia

This study tested the predictions of thephonological and double deficit hypotheses byexperimentally examining speech perception,phoneme awareness, lexical retrieval (serialand discrete), articulatory speed, and verbalSTM in school age child (N = 35) and adolescent(N = 36) dyslexics, and both chronological age(CA) and reading age (RA) controls. Theresults confirmed the findings of previousstudies of a deficit in phoneme awareness indevelopmental dyslexia. At both age levels,dyslexics performed significantly more poorlythan both their CA and RA controls. Althoughdeficits in the other processes investigated,particularly in rapid serial naming, were alsoapparent, they were not as clear-cut as thedeficit in phoneme awareness. In general,definite evidence of a deficit in rapid serialnaming was limited to the more severelyimpaired dyslexics. Furthermore, although rapidserial naming contributed independent variationto various literacy skills, its contributionwas modest relative to the contribution ofphoneme awareness, regardless of whether theliteracy skill relied more or less heavily onphonological or orthographic coding skills. Further analyses suggested that variation inrapid serial skill is particularly importantfor fluent reading of text, whereas phonemeawareness is particularly important for thedevelopment of the ability to read byphonologically recoding letters or groups ofletters in words into their phonological codes.This explains the relatively strongcontribution of phoneme awareness to readingand spelling ability in general. In sum, thephonological hypothesis offers a moreparsimonious account of the present resultsthan the double deficit hypothesis.