Unilateral spatial neglect frequently involves a lateralised reading disorder, neglect dyslexia (ND). Reading of single words in ND is characterised by left-sided omissions and substitutions of letters. However, it is unclear whether the distribution of error types and positions within a word shows a unique pattern of ND when directly compared to…

When skilled readers read briefly-presented word pairs, they produce between-word errors, in which letters migrate between neighboring words (e.g., "mild wind" can be misread as "wild mind"). Such errors are also produced by individuals with attentional dyslexia, even without time limitation. In this study, we tested several aspects of skilled…

Human motor behaviour is continually modified on the basis of errors between desired and actual movement outcomes. It is emerging that the role played by the primary motor cortex (M1) in this process is contingent upon a variety of factors, including the nature of the task being performed, and the stage of learning. Here we used repetitive TMS to…

Patients with right hemisphere lesions often omit or misread words on the left side of a text or the initial letters of single words, a phenomenon termed neglect dyslexia (ND). Omissions of words on the contralesional side of the page are considered as egocentric or space-based errors, whereas misread words can be viewed as a type of…

Errors generate typical brain responses, characterized by two successive event-related potentials (ERP) following incorrect action: the error-related negativity (ERN) and the positivity error (Pe). However, it is unclear whether these error-related responses are sensitive to the magnitude of the error, or instead show all-or-none effects. We…

Neglect dyslexia--a peripheral reading disorder generally associated with left spatial neglect--is characterized by omissions or substitutions of the initial letters of words. Several observations suggest that neglect dyslexia errors are independent of viewer-centered coordinates; the disorder is therefore thought to reflect impairment at the…

Learning to select optimal behavior in new and uncertain situations is a crucial aspect of living and requires the ability to quickly associate stimuli with actions that lead to rewarding outcomes. Mathematical models of reinforcement-based learning to select rewarding actions distinguish between (1) the formation of stimulus-action-reward…

This study evaluates spelling errors in the three subtypes of primary progressive aphasia (PPA): agrammatic (PPA-G), logopenic (PPA-L), and semantic (PPA-S). Forty-one PPA patients and 36 age-matched healthy controls were administered a test of spelling. The total number of errors and types of errors in spelling to dictation of regular words,…

Crawford and Howell (1998) have pointed out that the common practice of z-score inference on cognitive disability is inappropriate if a patient's performance on a task is compared with relatively few typical control individuals. Appropriate univariate and multivariate statistical tests have been proposed for these studies, but these are only valid…

When subjects are given the balls-and-boxes problem-solving task (Kotovsky & Simon, 1990), they move rapidly towards the goal after an extended exploratory phase, despite having no awareness of how to solve the task. We investigated possible non-conscious learning mechanisms by giving subjects three runs of the task while recording ERPs. Subjects…

The Sustained Attention to Response Task (SART) is a widely used tool in cognitive neuroscience increasingly employed to identify brain regions associated with failures of sustained attention. An important claim of the SART is that it is significantly related to real-world problems of sustained attention such as those experienced by TBI and ADHD…

Patients with semantic dementia show a specific pattern of impairment on both verbal and non-verbal "pre-semantic" tasks, e.g., reading aloud, past tense generation, spelling to dictation, lexical decision, object decision, colour decision and delayed picture copying. All seven tasks are characterised by poorer performance for items that are…

Sustained attention is modulated by the neurotransmitter noradrenaline. The balance of dopamine and noradrenaline in the cortex is controlled by the DBH gene. The principal variant in this gene is a C/T change at position-1021, and the T allele at this locus is hypothesised to result in a slower rate of dopamine to noradrenaline conversion than…

The influence of multiple mild traumatic brain injuries (mTBIs) on neuroelectric and task performance indices of the cognitive control of action monitoring was assessed in individuals with and without a history of concussion. Participants completed a standard clinical neurocognitive assessment and the error-related negativity of the…

Patients with right hemisphere lesions often omit or misread words on the left side of a text or the beginning letters of single words which is termed neglect dyslexia (ND). Two types of reading errors are typically observed in ND: omissions and word-based reading errors. The prior are considered as space-based omission errors on the…