Is a single graphemic buffer used in reading and spelling?

Background: The graphemic buffer was originally conceived as a component dedicated to the temporary storage of abstract orthographic representations prior to their format-specific expression in spelling (Caramazza, Miceli, Villa, & Romani, 1987). Since then, it has been argued that the graphemic buffer is also involved in reading (Caramazza, Capasso, & Miceli, 1996). Aims: The goal of this study was to test the hypothesis that a single graphemic buffer is used in reading and spelling. In addition, we examined the hypothesis that, under normal reading circumstances, words and pseudowords place different demands on the graphemic buffer because of differences in the degree to which they can be processed globally. Methods & Procedures: We performed detailed analyses of the reading and spelling performance of MC who presented with dyslexia (restricted to pseudowords) and dysgraphia following resection of a left parietal lobe tumour. Additionally, we compared the effect of presentation format (standard print, mirror reversed, and orally spelled stimuli) on word and pseudoword naming. Outcomes & Results: First, MC's spelling impairment showed all the characteristics of a graphemic buffer deficit. Second, MC's spelling of words and pseudowords as well as his reading of pseudowords were remarkably similar, both quantitatively and qualitatively (quasi-identical distribution of errors, length effect, and error position curves). Third, MC's reading of words (but not pseudowords) was disrupted under conditions that interfered with global (i.e., whole-word) processing. Conclusions: This study supports the claim that a single graphemic buffer is used in reading and spelling. It also suggests that reading nonwords places greater demands on the graphemic buffer than reading words.     

Cortical processing of complex sound: a way forward?

The organization of the cortical auditory system remains controversial. In particular, the extent to which there is regional specialization in the cortical processing of complex sound is unclear. Here, we ask whether we are currently asking the right questions of auditory cortex, or using the appropriate techniques to do so. A key factor that will promote such understanding in the future will be increasing dialogue between workers using electrophysiological recording methods to assess the response properties of single neurons and those using imaging techniques to map regional organization. In the future, further insights will be obtained by efforts to test hypotheses developed on the basis of one approach by the use of the other. Imaging can tell the neurophysiologists where to look, and work on single neurons can constrain network models based on imaging. There is a crucial need for better understanding of the anatomy of the auditory cortex in different species and for comparative studies that will underpin both approaches.     

Do dual-route models accurately predict reading and spelling performance in individuals with acquired alexia and agraphia?

Coltheart and co-workers [Castles, A., Bates, T. C., & Coltheart, M. (2006). John Marshall and the developmental dyslexias. Aphasiology, 20, 871-892; Coltheart, M., Rastle, K., Perry, C., Langdon, R., & Ziegler, J. (2001). DRC: A dual route cascaded model of visual word recognition and reading aloud. Psychological Review, 108, 204-256] have demonstrated that an equation derived from dual-route theory accurately predicts reading performance in young normal readers and in children with reading impairment due to developmental dyslexia or stroke. In this paper, we present evidence that the dual-route equation and a related multiple regression model also accurately predict both reading and spelling performance in adult neurological patients with acquired alexia and agraphia. These findings provide empirical support for dual-route theories of written language processing.     

Does preterm birth affect global and configural processing differently?

Aim We investigated whether preterm birth affects later visuocognitive function and, in particular, whether it affects global and configural perceptual processing differently. Method We compared the performance of 21 healthy preterm children (8 females, 13 males; mean age 7y 8mo, SD 8mo; mean gestational age 29.3wks, SD 1.9; mean birthweight 1186.5g, SD 377.2) with that of a matched term comparison group (8 females, 13 males; mean age 7y 11mo, SD 1y 1mo; mean gestational age >37wks; mean birthweight >2500g) in two perceptual tasks pinpointing differences between local and global and between local and configural processing. Results There was no difference between preterm and term children’s global processing, as both groups showed a bias towards global information (preterm: t[1,20]=2.6, p=0.01; comparison group: t[1,20]=3.0, p=0.01). By contrast, no such typical pattern of performance was found for configural processing as, unlike the comparison group (t[1,20]=7.1, p<0.001), preterm children preferentially relied on local rather than on configural information (t[1,20]=?15.4, p<0.001). Interpretation These findings suggest that preterm birth may have a greater influence on the development of later perceptual skills than originally envisaged. We discuss the results according to the current and dominant view of the visual system.     

Does robotic gait training improve balance in Parkinson's disease? A randomized controlled trial

BackgroundTreadmill training (with or without robotic assistance) has been reported to improve balance skills in patients with Parkinson's disease (PD). However, its effectiveness on postural instability has been evaluated mainly in patients with mild to moderate PD (Hoehn &; Yahr stage ≤3). Patients with more severe disease may benefit from robot-assisted gait training performed by the Gait-Trainer GT1, as a harness supports them with their feet placed on motor-driven footplates. The aim of this study was to determine whether robot-assisted gait training could have a positive influence on postural stability in patients with PD at Hoehn &; Yahr stage 3–4.MethodsThirty-four patients with PD at Hoehn &; Yahr stage 3–4 were randomly assigned into two groups. All patients received twelve, 40-min treatment sessions, three days/week, for four consecutive weeks. The Robotic Training group (n = 17) underwent robot-assisted gait training, while the Physical Therapy group (n = 17) underwent a training program not specifically aimed at improving postural stability. Patients were evaluated before, immediately after and 1-month post-treatment. Primary outcomes were: Berg Balance scale; Nutt's rating.ResultsA significant improvement was found after treatment on the Berg Balance Scale and the Nutt's rating in favor of the Robotic Training group (Berg: 43.44 ± 2.73; Nutt: 1.38 ± 0.50) compared to the Physical Therapy group (Berg: 37.27 ± 5.68; Nutt: 2.07 ± 0.59). All improvements were maintained at the 1-month follow-up evaluation.ConclusionsRobot-assisted gait training may improve postural instability in patients with PD at Hoehn &; Yahr stage 3–4.     

Does familiarity facilitate the cortical processing of music sounds?

Automatic cortical sound discrimination, as indexed by the mismatch negativity (MMN) component of the auditory evoked potential, is facilitated for familiar speech sounds (phonemes). In musicians as compared to non-musicians, an enhanced MMN has been observed for complex non-speech sounds. Here, musically trained subjects were presented with sequences of either familiar (tonal) or structurally matched unfamiliar (atonal) triad chords, both with either fixed or randomly transposed chord root pitch. The MMN elicited by deviant chords did not differ for familiar and unfamiliar triad sequences, and was undiminished even to unfamiliar deviant sounds which were consciously undetectable. Only subsequent attention-related components indicated facilitated cognitive processing of familiar sounds, corresponding to higher behavioral detection scores.     

The recognition potential: semantic processing or the detection of differences between stimuli?

The recognition potential is traditionally described as an electrical index elicited when subjects view a recognizable stimulus. Recent studies further show that it may be influenced by semantic processing. In this study, we investigated whether this observed influence is really produced by differences in semantic processing or whether it might be caused by the detection of differences between sequentially presented stimuli. In two different experiments, we systematically altered the type of background images presented while keeping the recognizable word constant. Analyses revealed that the same recognizable words elicited an RP with different amplitudes and latencies when viewed under different background conditions. Control stimuli, which were identical to background stimuli, did not elicit the RP. Hence, we postulate that when using the rapid stream stimulation paradigm, RP might also be influenced by the detection of differences between sequentially input stimuli. It is necessary to clarify whether RP changes are caused by the processing of the stimuli or by the detection of difference between successively input stimuli before any conclusion could be made.     

Does multimodality therapy of arteriovenous malformations improve patient outcome?

The strategy for treating arteriovenous malformations (AVMs) has undergone changes and long-term follow-up results remain unclear. To compare the outcomes of different treatment strategies, we divided 112 patients with 113 AVMs into groups with hemorrhagic (n = 71, 62.8%) and nonhemorrhagic (n = 42, 37.2%) AVMs and subdivided these according to the period in which they were treated (before/after 1990). In the more recent period, treatment more frequently involved the use of the gamma-knife and microembolization to the AVM as well as combination therapy. Long-term follow-up showed that the complication rate was lower and the Rankin scale better, in the more recently treated group. Based on our findings we suggest that AVMs should be treated aggressively using a multimodality strategy.     

Does imprint cytology of brain tumours improve intraoperative diagnoses?

OBJECTIVES: To evaluate the diagnostic accuracy using frozen sections only and a combination of imprint cytology and frozen sections. MATERIAL AND METHODS: After introduction of imprint cytology as a supplement to frozen sections in 1999, 153 patients with brain tumours underwent stereotactic or open surgery. An equal number of cases prior to 1999 were chosen for comparison. Intraoperative diagnoses were compared with final diagnoses based on paraffin sections of the same tissue samples. The number of delayed intraoperative diagnoses was noted in each patient group. RESULTS: The combined use of the two techniques improved intraoperative diagnostic accuracy from 87 to 91% while the delayed intraoperative diagnoses were significantly reduced from 30 to 8. The choice of surgical procedure did not affect the outcome of the pathological investigations. CONCLUSION: A combination of frozen sections and imprints significantly reduced the number of delayed intraoperative diagnoses. Intraoperative diagnostic accuracy was improved, although not to a statistically significant level. Choice of surgical procedure did not affect the diagnostic outcome.     

Does a continuous measure of handedness predict reading processes and reading-related skills across the lifespan?

The purpose of this research was to investigate the relationship between handedness, reading skills, and reading-related cognitive processes. Although lateralised differences in brain functioning are well known, research regarding handedness, specific reading skills, and reading-related cognitive processes is ambiguous at best because handedness is often measured as a dichotomous variable rather than a continuous variable. This methodological difference contributes to the diverse research findings, therefore the present investigation addressed these methodological limitations. A large normative sample of up to 1383 participants who ranged in age from 4 to 80 completed the Woodcock Johnson Psycho-Educational Battery-Revised (Woodcock & Johnson, 1989a, 1989b) or the Woodcock Johnson Psycho-Educational Battery-Third Edition (Woodcock, McGrew, & Mather, 2001) in combination with the Dean Woodcock Sensory Motor Battery (Dean & Woodcock, 2003) lateral preference scale, a continuous measure of handedness. Polynomial multiple regression analyses indicated curvilinear relationships between handedness and reading skills, along with handedness and auditory working memory. Individuals towards the extremes of the handedness continuum performed less well on the reading-related tasks. Therefore, just knowing a general classification of right, left, or mixed handed will not provide significant knowledge regarding lateralisation or potential cognitive and academic consequences but rather knowledge of an individual's hand preference on a continuum may well be useful for evaluative purposes.     

Does a continuous measure of handedness predict reading processes and reading-related skills across the lifespan?

The purpose of this research was to investigate the relationship between handedness, reading skills, and reading-related cognitive processes. Although lateralised differences in brain functioning are well known, research regarding handedness, specific reading skills, and reading-related cognitive processes is ambiguous at best because handedness is often measured as a dichotomous variable rather than a continuous variable. This methodological difference contributes to the diverse research findings, therefore the present investigation addressed these methodological limitations. A large normative sample of up to 1383 participants who ranged in age from 4 to 80 completed the Woodcock Johnson Psycho-Educational Battery-Revised (Woodcock & Johnson, 1989a, 1989b) or the Woodcock Johnson Psycho-Educational Battery-Third Edition (Woodcock, McGrew, & Mather, 2001) in combination with the Dean Woodcock Sensory Motor Battery (Dean & Woodcock, 2003) lateral preference scale, a continuous measure of handedness. Polynomial multiple regression analyses indicated curvilinear relationships between handedness and reading skills, along with handedness and auditory working memory. Individuals towards the extremes of the handedness continuum performed less well on the reading-related tasks. Therefore, just knowing a general classification of right, left, or mixed handed will not provide significant knowledge regarding lateralisation or potential cognitive and academic consequences but rather knowledge of an individual's hand preference on a continuum may well be useful for evaluative purposes.     

Does Irish-dance training influence lower-limb asymmetry?

Irish-dance is a dance form where asymmetry is required. This study investigated the influence of Irish-dance training on four lower-limb asymmetries by comparing 100 Irish-dancers and 100 non-dancers. All four asymmetries showed significant differences between the dancers and the non-dancers: the rigidity of the dance training influencing those asymmetries.     

Does methylphenidate improve academic performance? A systematic review and meta-analysis

Academic improvement is amongst the most common treatment targets when prescribing stimulants to children with ADHD. Previous reviews on stimulant-related academic improvements are inconclusive and focus on task engagement. Recent literature suggests outcome-domain-specific medication effects that are larger for productivity than for accuracy. The aims of this study are quantifying methylphenidate effects on academic productivity and accuracy for math, reading, spelling; exploring the mediating or moderating effects of symptom improvements, demographic-, design- and disorder-related variables. PubMed, EMBASE, ERIC and PsycINFO were searched for articles reporting methylphenidate effects on academic productivity and accuracy. Thirty-four studies met entry criteria. Methylphenidate improved math productivity (7.8% increase, p < .001); math accuracy (3.0% increase, p = .001); increased reading speed (SMD .47, p < .001) but not reading accuracy. None of the mediators or moderators tested affected methylphenidate efficacy. Academic improvements were small compared to symptom improvements; qualitative changes limited to math. Clinicians should take this discrepancy into account when prescribing medication for ADHD.