Passivity experiences are hallmark symptoms of schizophrenia that can be characterized by the belief that one's thoughts or actions are controlled by an external agent. It has recently been suggested that these psychotic experiences result from defective monitoring of one's own actions, i.e. disturbed comparison of actions and perceived outcomes. In this study, we examined the function of the p...

BACKGROUND:“Contextual interference” (CI) describes a counterintuitive phenomenon related to practice organization when learning multiple tasks that are presented in non-repetitive order. In CI, the lack of repetitiveness introduces high level interference within context such task performance during initial skill acquisition is frequently poorer than if practiced repetitive fashion. However, th...

To understand the contribution of the human pre-supplementary motor area (pre-SMA) in sequential motor behavior, we performed a series of finger key-press experiments. Experiment 1 revealed that each subject had a spontaneous tendency to organize or “chunk” a long sequence into shorter components. We hypothesized that the pre-SMA might have a special role in initiating each chunk but not at oth...

A rhesus monkey and five human subjects used a hand-held joystick to track unpredictable continuously moving targets. Both monkey and human respond by making discrete ("step-and-hold") corrections of positional error, at an average frequency of 1.33 and 2.26 movements/second, respectively. By delaying visual feedback of joystick position, we could reduce these frequencies in a predictable manne...

In the interest of promoting interaction among the laboratories of the world which have directed attention to the visually guided behavior of frogs and toads, a Workshop was held at the State University of New York, Downstate Medical Center in Brooklyn from August 22 to 24, 1972. The gathering was sponsored by the Graduate Program in Biological Psychology at Downstate and supported by the Alfre...

We investigated whether dopamine influences the rate of adaptation to a visuomotor distortion and the transfer of this learning from the right to the left limb in human subjects. We thus studied patients with Parkinson disease as a putative in vivo model of dopaminergic denervation. Despite normal adaptation rates, patients showed a reduced transfer compared with age-matched healthy controls. T...

The primate cortex represents the external world in a distributed way, which requires for a mechanism that integrates the features of a processed event. Animal and patients studies suggest that feature binding in the visual cortex is under muscarinic-cholinergic control, whereas visuomotor integration is driven by the dopaminergic system. Consistent with this picture, we present evidence that t...

Repetitive transcranial magnetic stimulation (rTMS) induces plasticity in normal and abnormal neural circuitries, an effect that may be influenced by intrinsic brain activity during treatment. Here, we study potential synergistic effects between low-intensity rTMS (LI-rTMS) and concurrent neural activity in promoting circuit reorganization and enhancing visual behavior. We used ephrin-A2A5-/- m...

Visuomotor priming occurs when our actions are influenced by observing a compatible or incompatible action. Here we ask whether visuomotor priming is specific to human, biological actions or generalises to non-biological movements, such as abstract shapes or robots. Reviewing the evidence indicates that priming occurs for both types of stimuli and emphasises the contributions of both bottom-up ...

Handwriting is an integral part of every child's school experience. In order to provide the best program to children both with and without handwriting problems, elementary educators need to understand the factors underlying the skill of handwriting. This study investigated the relationship between the cognitive understanding of locatives (e.g., words used for spatial and temporal concepts, such...