A single optimum degree of hemispheric specialisation in two tasks, in two UK national birth cohorts

How differences between the two sides of the brain (or 'laterality') relate to level of function are important components of theories of the origin and purpose of hemispheric asymmetry, although different measures show different relationships, and this heterogeneity makes discerning any underlying relationships a difficult task. There are some exceptions, for example it has been concluded that increasing lateralization (eg of hand skill or planum temporale area) occurs at the expense of the non-dominant hemisphere. However, we have previously demonstrated this latter relationship to be an artefact: a consequence of plotting two variables against each other, that are not independent of each other [Leask, S. J., & Crow, T. J. (1997) How far does the brain lateralize? An unbiased method for determining the optimum degree of hemispheric specialisation. Neuropsychologia, 36, 1275-1282; Mazoyer, B. M., & Tzourio-Mazoyer, N. G. (2004). Title Planum temporale asymmetry and models of dominance for language: a reappraisal. Neuroreport, 15, 1057-1059]. Two approaches to discerning any underlying relationships are presented in data from over 20,000 10- and 11-year olds from the 1958 and 1970 UK national cohort studies. These demonstrate that maximal performance, both cognitive and hand function, is found in association with one particular degree of functional lateralization.     

Quality of phonological representations, verbal learning, and phoneme awareness in dyslexic and normal readers

This study of dyslexia was concerned with the quality of phonological representations of lexical items. It extended the studies of verbal learning in dyslexia from learning new vocabulary items (pseudo-names) to the learning of more well-specified variants of known words. The participants were 19 dyslexic adolescents in grades 4 to 6 and 19 younger normal readers in grade 2 matched on single word decoding. The dyslexics were significantly outperformed by the reading-age controls in non-word reading and in phoneme awareness. The dyslexics also took longer time to learn to associate a set of pseudo-names with pictures of persons although the dyslexics learned to associate familiar names with pictures as quickly as the controls did. The acquisition of new phonological representations of words was studied in an imitation task with maximally distinct pronunciations of long, familiar words. The dyslexics gained less than the controls in this task. They also gained less on one measure taken from a phoneme substitution task with the same words as in the distinctness task. The results are interpreted in the light of the hypothesis that poorly specified phonological representations may be an underlying problem in dyslexia.     

Modulation of brain activity during phonological familiarization

We measured brain activity in 12 adults for the repetition of auditorily presented words and nonwords, before and after repeated exposure to their phonological form. The nonword phoneme combinations were either of high (HF) or low (LF) phonotactic frequency. After familiarization, we observed, for both word and nonword conditions, decreased activation in the left posterior superior temporal gyrus, in the bilateral temporal pole and middle temporal gyri. At the same time, interaction analysis showed that the magnitude of decrease of activity in bilateral posterior temporal lobe was significantly smaller for LF nonwords, relative to words and HF nonwords. Decrease of activity in this area also correlated with the size of behavioral familiarization effects for LF nonwords. The results show that the posterior superior temporal gyrus plays a fundamental role during phonological learning. Its relationship to sublexical and lexical phonological processing as well as to phonological short-term memory is discussed.     

Symbol-string sensitivity and adult performance in lexical decision

In this study of adult readers, we used a symbol-string task to assess participants' sensitivity to the position of briefly presented, non-alphabetic but letter-like symbols. We found that sensitivity in this task explained a significant proportion of sample variance in visual lexical decision. Based on a number of controls, we show that this relationship cannot be explained by other factors including: chronological age, intelligence, speed of processing and/or concentration, short term memory consolidation, or fixation stability. This approach represents a new way to elucidate how, and to what extent, individual variation in pre-orthographic visual and cognitive processes impinge on reading skills, and the results suggest that limitations set by visuo-spatial processes constrain visual word recognition.     

Phonological recoding and rapid orthographic learning in third-graders' silent reading: a critical test of the self-teaching hypothesis

This study examined rapid orthographic learning following silent reading in third-grade children as a function of number of target nonword repetitions and test delay. In each of two test sessions at least 6 days apart, children read a series of short stories, with each story containing a different nonword repeated either four or eight times. In the second session, after the stories had been read, children were asked to read short lists of target nonwords or homophonic alternatives. Children read target nonwords faster than homophones, indicating that they had formed functional orthographic representations of the target nonwords through phonologically recoding them during silent story reading. They also preferred target nonwords to homophones in an orthographic choice task in which the alternatives included the target, the homophone, and a visually similar foil, although here orthographic learning was stronger for items encountered eight times within stories and stronger for items tested immediately. These findings provide critical evidence in support of Share's self-teaching through phonological recoding hypothesis.     

Phonological alexia with vowel-consonant dissociation in non-word reading

We present a patient with alexia secondary to cerebral lesion whose errors in the reading of non-words affect vowels more than consonants. The interest of the case resides in: (1) the documentation of a vowel-consonant dissociation selectively affecting the reading of non-words; and (2) the localization of the alteration in a specific stage of the perilexical reading pathway, that is, the blending of phonetic chains. The case contributes to the discussion on the nature of representations and the processing of vowels and consonants.     

Motor learning without physical practice: The effects of combined action observation and motor imagery practice on cup-stacking speed

In this study we explored training effects for combined action observation and motor imagery (AO + MI) instructions on a complex cup-stacking task, without physical practice. Using a Graeco-Latin Square design, we randomly assigned twenty-six participants into four groups. This counterbalanced the within-participant factor of practice condition (AO + MI, AO, MI, Control) across four cup-stacking tasks, which varied in their complexity. On each of the three consecutive practice days participants experienced twenty trials under each of the three mental practice conditions. On each trial, a first-person perspective video depicted bilateral cup-stacking performed by an experienced model. During AO, participants passively observed this action, responding only to occasional colour cues. For AO + MI, participants imagined performing the observed action and synchronised their concurrent MI with the display. For MI, a sequence of pictures cued imagery of each stage of the task. Analyses revealed a significant main effect of practice condition both at the ’surprise’ post-test (Day 3) and at the one-week retention test. At both time points movement execution times were significantly shorter for AO + MI compared with AO, MI and the Control. Execution times were also shorter overall at the retention compared with the post-test. These results demonstrate that a complex novel motor task can be acquired without physical training. Practitioners can therefore use AO + MI practice to supplement physical practice and optimise skill learning.     

Empirical indistinguishability: From the knowledge structure to the skills

Recent literature has pointed out that the basic local independence model (BLIM) when applied to some specific instances of knowledge structures presents identifiability issues. Furthermore, it has been shown that for such instances the model presents a stronger form of unidentifiability named empirical indistinguishability, which leads to the fact that the existence of certain knowledge states in such structures cannot be empirically tested. In this article the notion of indistinguishability is extended to skill maps and, more generally, to the competence-based knowledge space theory. Theoretical results are provided showing that skill maps can be empirically indistinguishable from one another. The most relevant consequence of this is that for some skills there is no empirical evidence to establish their existence. This result is strictly related to the type of probabilistic model investigated, which is essentially the BLIM. Alternative models may exist or can be developed in knowledge space theory for which this indistinguishability problem disappears.     

汉语儿童的语音意识特点及阅读能力高低读者的差异

选取小学３,４,５年级儿童各２０名作为被试,系统探讨了儿童汉语普通话的音节意识、首音韵脚意识和音位意识的特点及发展,根据老师的评价把被试分为好的读者和差的读者。研究结果表明,语音意识测验成绩随年级的增长而提高;音节意识与首音一韵脚意识先于音位意识而发展;好、差读者在语音意识测验成绩上差异显著,而且,年级差异与好、差读者差异的程度和趋势是一致的,好、差读者在语音意识发展的速度上是不同的。     

Pyramid training of elementary school teachers to use a classroom management "skill package"

Three regular elementary teachers were trained in the use of a classroom management "skill package". Subsequently, each of these three teachers (tier 1 of training) trained three more teachers to use the same skill package (tier 2 of training). Direct behavioral measures of student disruptiveness were taken in the three tier-1 classrooms and four tier-2 classrooms, and permanent product measures of student productivity in arithmetic were taken in the three tier-1 classrooms. Results indicated that student disruptiveness decreased at least as much in the tier-2 classrooms as in the tier-1 classrooms. Data also indicated that serving as trainers benefited two of the tier-1 teachers who profited least from the original training by producing further reductions in disruptiveness in their respective classrooms. Productivity data suggested that use of the "skill package" increased classroom academic output, especially for those students below the median in productivity during baseline. The investigators' time investment in training a tier-2 teacher was one-fourth that of training a tier-1 teacher.