The development of reading tests for use in a regularly spelled language.

Data are presented on the development of tests of reading skill in rural Tanzanian primary school pupils. Instruction in these schools is in Kiswahili, a regularly spelt language. Using a translation of a standard reading test, children could read aloud all words once they had learnt sound-letter correspondences, regardless of comprehension. In addition, children can appear to pass traditional comprehension tasks by decoding only some of the words. Three graded tests were developed which allow testing of children who either have only some letter knowledge, can read single words, or are proficient readers. The tests require children to both decode and understand the reading material in order to achieve high scores. The tests correlated well with scores on other educational achievement tests, and showed age and school grade differences. It is suggested that these tests are useful measures of reading development in a regularly spelt language. Adaptation to English and validation against standardised instruments is planned

Shifting uncertainty intolerance: methylphenidate and attention-deficit hyperactivity disorder.

Risk evaluation is a critical component of decision making. Risk tolerance is relevant in both daily decisions and pathological disorders such as attention-deficit hyperactivity disorder (ADHD), where impulsivity is a cardinal symptom. Methylphenidate, a commonly prescribed drug in ADHD, improves attention but has mixed reports on risk-based decision making. Using a double-blinded placebo protocol, we studied the risk attitudes of ADHD patients and age-matched healthy volunteers while performing the 2-step sequential learning task and examined the effect of methylphenidate on their choices. We then applied a novel computational analysis using the hierarchical drift-diffusion model to extract parameters such as threshold ('a'-amount of evidence accumulated before making a decision), drift rate ('v'-information processing speed) and response bias ('z' apriori bias towards a specific choice) focusing specifically on risky choice preference. Critically, we show that ADHD patients on placebo have an apriori bias towards risky choices compared to controls. Furthermore, methylphenidate enhanced preference towards risky choices (higher apriori bias) in both groups but had a significantly greater effect in the patient population independent of clinical scores. Thus, methylphenidate appears to shift tolerance towards risky uncertain choices possibly mediated by prefrontal dopaminergic and noradrenergic modulation. We emphasise the utility of computational models in detecting underlying processes. Our findings have implications for subtle yet differential effects of methylphenidate on ADHD compared to healthy population.Wellcome Trust Intermediate Fellowship (093881/Z/10/Z) to Dr. Harrison, Brighton and Sussex Medical School and the Dr. Mortimer and Dame Theresa Sackler Foundation. Dr. Voon is supported by a Medical Research Council Senior Clinical Fellowship (MR/P008747/1)

Shifting uncertainty intolerance: methylphenidate and attention-deficit hyperactivity disorder

Abstract: Risk evaluation is a critical component of decision making. Risk tolerance is relevant in both daily decisions and pathological disorders such as attention-deficit hyperactivity disorder (ADHD), where impulsivity is a cardinal symptom. Methylphenidate, a commonly prescribed drug in ADHD, improves attention but has mixed reports on risk-based decision making. Using a double-blinded placebo protocol, we studied the risk attitudes of ADHD patients and age-matched healthy volunteers while performing the 2-step sequential learning task and examined the effect of methylphenidate on their choices. We then applied a novel computational analysis using the hierarchical drift–diffusion model to extract parameters such as threshold (‘a’—amount of evidence accumulated before making a decision), drift rate (‘v’—information processing speed) and response bias (‘z’ apriori bias towards a specific choice) focusing specifically on risky choice preference. Critically, we show that ADHD patients on placebo have an apriori bias towards risky choices compared to controls. Furthermore, methylphenidate enhanced preference towards risky choices (higher apriori bias) in both groups but had a significantly greater effect in the patient population independent of clinical scores. Thus, methylphenidate appears to shift tolerance towards risky uncertain choices possibly mediated by prefrontal dopaminergic and noradrenergic modulation. We emphasise the utility of computational models in detecting underlying processes. Our findings have implications for subtle yet differential effects of methylphenidate on ADHD compared to healthy population

Tuning the brakes – Modulatory role of transcranial random noise stimulation on inhibition

Electroencephalogram (EEG) and behavioural data (joystick) was collected from 15 healthy participants who completed a modified version of a Go/No-go task. This dataset consists of raw data, pre-processed EEG and behavioural data, along with impulsivity scores in a .csv file. The pre-processed data is in MATLAB .mat format. Raw Data The EEG and behavioural data (Joystick) along with trigger data was collected using a TMSi Porti amplifier with a sampling rate of 2,048Hz and is in .een format. The raw EEG files contain brain activity recorded in the first 16 channels and last 2 channels (channels 17 and 18) correspond to Joystick and Trigger information (used to identify the type of event – Go/Conflict/NoGo) respectively. The Raw data is segregated into 2 folders- Active and Sham which is further divided into baseline and after stimulation conditions. The main behavioural outcome is the change in NoGo errors (pre-processed folder- Figure 1C in from the article ‘Tuning the brakes – Modulatory role of transcranial random noise stimulation on inhibition,’ Brain Stimulation, 2024), comparing baseline and after-stimulation in sham and active conditions. Metadata corresponding to impulsivity scores and the change in NoGo behaviour are provided in ‘UPPS_nogo.csv’ (used for Figure 1D). The EEG data was recorded while the participants completed the task during baseline and after stimulation, and was used to calculate the spectral power (Figure 1E). The study also presents intermittent bursts from the EEG data, comparing the average burst durations at baseline and after-stimulation (Figure 1F) in sham and active stimulation conditions. Code All data were analysed in MATLAB (2018b) using a combination of EEGLAB, ERP LAB and FieldTrip packages. Installation guides can be found on https://sccn.ucsd.edu/eeglab/index.php https://matlab.mathworks.com/ https://erpinfo.org/erplab  https://www.fieldtriptoolbox.org/download/ The behavioural data plots use the software IOSR toolbox : https://github.com/IoSR-Surrey/MatlabToolbox Code_figure_IC.m: This script plots the NoGo error rates in baseline and after stimulation in sham and active conditions. This script uses the mat file ‘Nogo_behav_pre_post.mat’ Code_figure_1E.m: This script plots the spectral power and grand average of the after-stimulation EEG data with clusters obtained from a non-parametric analysis. This script uses the mat file ‘data_psd_trns_pre_post.mat’. Code_figure_1F.m: This script plots the intermittent burst durations during sham and active conditions and uses the file ‘Nogo_bursts_pre_post.mat

Time-locked acute alpha-frequency stimulation of subthalamic nuclei during the evaluation of emotional stimuli and its effect on power modulation

Deep brain stimulation (DBS) studies in Parkinson's Disease (PD) targeting the subthalamic nucleus (STN) have characterized its spectral properties across cognitive processes. In emotional evaluation tasks, specific alpha frequency (8–12 Hz) event-related de-synchronization (ERD) (reduced power) has been demonstrated. The time-locked stimulation of STN relative to stimuli onset has shown subjective positive valence shifts with 10 Hz but not with 130 Hz. However, neurophysiological effects of stimulation on power modulation have not been investigated. We aim to investigate effects of acute stimulation of the right STN on concurrent power modulation in the contralateral STN and frontal scalp EEG. From our previous study, we had a strong a priori hypothesis that negative imagery without stimulation would be associated with alpha ERD; negative imagery with 130 Hz stimulation would be also associated with alpha ERD given the lack of its effect on subjective valence ratings; negative imagery with 10 Hz stimulation was to be associated with enhanced alpha power given the shift in behavioral valence ratings

Impulsivity and craving in subjects with opioid use disorder on methadone maintenance treatment

Background Methadone maintenance treatment (MMT) is effective in decreasing opioid use or facilitating abstinence. Previous studies using small opioid use disorder samples suggest that cognitive impairments including impulsivity and executive functions may partially improve on MMT, but a range of deficits may persist. However, systematic assessments with larger samples are needed to confirm the profile of cognitive functions on MMT. Methods We assessed four types of impulsivity (delay discounting, reflection impulsivity, risk taking and motoric impulsivity), executive functioning (spatial working memory, paired associative learning and strategic planning) and drug cue-induced craving in a relatively large population (115 MMT patients, 115 healthy controls). The relationships between impulsivity, drug cue-induced craving and addiction-related variables were also assessed. Results Delay discounting, as well as drug cue-induced craving was increased in patients, while motoric impulsivity was lower than in controls. Paired associative learning was additionally impaired, which was explained by increased depression and anxiety levels in patients. Within the MMT group, the delay discounting and drug-cue induced craving scores were positively correlated with self-reported urgency, but unrelated to methadone dosage, duration on methadone, withdrawal symptoms, or presence of nicotine dependence. Conclusions Our findings highlight increased delay discounting and cue-induced craving in MMT patients suggesting a potential role for trait effects in delay discounting. Although previous smaller studies have shown impaired executive function, in our large sample size on chronic MMT we only observed impaired associative learning related to depressive and anxiety symptoms highlighting a role for managing comorbid symptoms to further optimize cognitive function

Oral mucosal lesions and their association with sociodemographic, behavioral, and health status factors

The aim of this study was to evaluate the frequency of oral mucosal lesions and their associations with sociodemographic, health, and behavioral factors in a southern Brazilian population. Information was collected from participants (n = 801) using a structured questionnaire during an oral cancer screening campaign held at an agribusiness show in southern Brazil in 2009. Data were described using frequency distributions or means and standard deviations. Associations between independent variables and outcomes were assessed using the Chi-squared test. A total of 465 lesions were detected (actinic cheilitis: n = 204, 25.5%; candidiasis: n = 50, 6.2%; fibrous inflammatory hyperplasia: n = 42, 5.2%; ulceration, n = 33, 4.1%; hemangioma: n = 14, 1.7%; leukoplakia: n = 11, 1.4%). Candidiasis, actinic cheilitis, and fibrous inflammatory hyperplasia were associated significantly with literacy. Actinic cheilitis was also associated significantly with sun exposure and hat use, and leukoplakia was associated with smoking. The high frequency of oral mucosal lesions observed highlights the importance of education about risk factors. Additionally, training of health professionals, mainly those from public health services, in the use of preventive and community education strategies is needed