The profile of spatial ability is of interest across autism spectrum disorders (ASD) because of reported spatial strengths in ASD and due to the recent association of Asperger's syndrome with Nonverbal Learning Disability. Spatial functions were examined in relation to two cognitive theories in autism: the central coherence and executive function…

The effect of two linguistic factors in Broca's and Wernicke's aphasia was examined using Dutch and English subjects. Three tasks were used to test (1) the comprehension and (2) the construction of sentences, where verbs (in Dutch) and verb arguments (in Dutch and English) are in canonical versus non-canonical position; (3) the production of…

This study tested the hypothesis that memory is a major source of variance in temporal processing. Participants categorized intervals as short or long. The number of base durations and interval types mixed within blocks of trials varied from 1 session to another. Results revealed that mixing 2 base durations within blocks increased categorization…

The research into perceptual organization in schizophrenia spectrum disorders has found evidence for and against a perceptual organization deficit and has interpreted the data from within several different theoretical frameworks. A synthesis of this evidence, however, reveals that this body of work has produced reliable evidence for deficits in…

This study examined the factors that constrain the working memory span performance and reading ability of individuals with generalized learning difficulties. In the study, 50 individuals with learning difficulties (LD) and 50 typically developing children (TD) matched for reading age completed two working memory span tasks. Participants also…

Neuropsychological and neuroimaging studies implicate attentional difficulties in obsessive-compulsive disorder (OCD), but results are inconsistent due possibly to sample heterogeneity and lack of control of comorbid disorders, such as Tourette's syndrome (TS). Nevertheless, it has been suggested that OCD symptomatology may be a result of…

Posttraining rapid eye movement (REM) sleep has been reported to be important for efficient memory consolidation. The present results demonstrate increases in the intensity of REM sleep during the night of sleep following cognitive procedural/implicit task acquisition. These REM increases manifest as increases in total number of rapid eye…

We tested the hypothesis that rapid eye movement (REM) sleep is important for complex associative learning by restricting rats from entering REM sleep for 4 h either immediately after training on an eight-box spatial task (0-4 REMr) or 4 h following training (4-8 REMr). Both groups of REM-restricted rats eventually reached the same overall…

These experiments examined the release of acetylcholine in the hippocampus and striatum when rats were trained, within single sessions, on place or response versions of food-rewarded mazes. Microdialysis samples of extra-cellular fluid were collected from the hippocampus and striatum at 5-min increments before, during, and after training. These…

Absolute auditory thresholds, frequency resolution and temporal resolution develop with age. It is still discussed whether low-level auditory performance is of clinical significance--specifically, for delayed maturation of central auditory processing. Recently, five new auditory tasks were used to study the development of low-level auditory…

A variety of studies have reported that learners of English as a second language find subject relative clauses easier to produce and comprehend than direct object relatives, but it is unclear whether this preference should be attributed to structural factors or to a linear distance effect. This paper seeks to resolve this issue and to extend our…

Two experiments examined the role of perceptual complexity, object familiarity and form class cues on how children interpret novel adjectives and count nouns. Four-year-old children participated in a forced-choice match-to-target task in which an exemplar was named with a novel word and children were asked to choose another one that matched the…

Objective: The present study investigates whether there is an association between trait impulsivity in the normal population and inhibitory motor control as assessed by the stop task. Method: Low- and high-impulsive participants (as assessed by the I[subscript 7] questionnaire; both groups n = 31) performed the stop task. Differences in…

Seven-year-olds completed a Posner cued attention task, under both neutral and affectively charged conditions. Compared to the traditional (affect-neutral) Posner task, performance in the affective Posner task was marked by dramatic decreases in reaction times (RTs), an increase in errors, an increased validity effect (difference in RTs to the…

This experiment tested whether children's insight into a difficult symbolic relation could be increased by explicitly emphasizing the intentionality surrounding the artifact's creation and use. Specifically, I explicitly emphasized (a) the adult's intent to communicate information via the artifact and (b) the artifact's intentional origins and…