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Sarah-J. Blakemore

Bio: Sarah-J. Blakemore is an academic researcher from University College London. The author has contributed to research in topics: Stimulus (physiology) & Sensory system. The author has an hindex of 5, co-authored 5 publications receiving 2416 citations. Previous affiliations of Sarah-J. Blakemore include French Institute of Health and Medical Research.

Papers
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Journal ArticleDOI
TL;DR: FMRI examination of neural responses when subjects experienced a tactile stimulus that was either self-produced or externally produced suggests that the cerebellum is involved in predicting the specific sensory consequences of movements, providing the signal used to cancel the sensory response to self-generated stimulation.
Abstract: A self-produced tactile stimulus is perceived as less ticklish than the same stimulus generated externally. We used fMRI to examine neural responses when subjects experienced a tactile stimulus that was either self-produced or externally produced. More activity was found in somatosensory cortex when the stimulus was externally produced. In the cerebellum, less activity was associated with a movement that generated a tactile stimulus than with a movement that did not. This difference suggests that the cerebellum is involved in predicting the specific sensory consequences of movements, providing the signal that is used to cancel the sensory response to self-generated stimulation.

1,169 citations

Journal ArticleDOI
TL;DR: It is proposed that the extent to which self-produced tactile sensation is attenuated is proportional to the error between the sensory feedback predicted by an internal forward model of the motor system and the actual sensory feedback produced by the movement.
Abstract: We investigated why self-produced tactile stimulation is perceived as less intense than the same stimulus produced externally.A tactile stimulus on the palm of the right hand was either externally produced, by a robot or self-produced by the subject. In the conditions in which the tactile stimulus was self-produced, subjects moved the arm of a robot with their left hand to produce the tactile stimulus on their right hand via a second robot. Subjects were asked to rate intensity of the tactile sensation and consistently rated self-produced tactile stimuli as less tickly, intense, and pleasant than externally produced tactile stimuli. Using this robotic setup we were able to manipulate the correspondence between the action of the subjects' left hand and the tactile stimulus on their right hand. First, we parametrically varied the delay between the movement of the left hand and the resultant movement of the tactile stimulus on the right hand. Second, we implemented varying degrees of trajectory perturbation and varied the direction of the tactile stimulus movement as a function of the direction of left-hand movement. The tickliness rating increased significantly with increasing delay and trajectory perturbation. This suggests that self-produced movements attenuate the resultant tactile sensation and that a necessary requirement of this attenuation is that the tactile stimulus and its causal motor command correspond in time and space. We propose that the extent to which self-produced tactile sensation is attenuated (i.e., its tickliness) is proportional to the error between the sensory feedback predicted by an internal forward model of the motor system and the actual sensory feedback produced by the movement.

746 citations

Journal ArticleDOI
TL;DR: In this article, the authors used H2(15)O PET to examine neural responses to parametrically varied degrees of discrepancy between the predicted and actual sensory consequences of movement.
Abstract: We used H2(15)O PET to examine neural responses to parametrically varied degrees of discrepancy between the predicted and actual sensory consequences of movement. Subjects used their right hand to move a robotic arm. The motion of this robotic arm determined the position of a second foam-tipped robotic arm, which made contact with the subject's left palm. Using this robotic interface, computer controlled delays were introduced between the movement of the right hand and the tactile stimulation on the left. Activity in the right lateral cerebellar cortex showed a positive correlation with delay. These results suggest the cerebellum is involved in signalling the sensory discrepancy between the predicted and actual sensory consequences of movements.

517 citations

Journal ArticleDOI
TL;DR: This prediction is accurate when tactile stimuli are self-produced relative to when they are externally produced, and is therefore used to attenuate the somatosensory response to the former type of tactile stimulation but not the former, and supports the proposal that the cerebellum is involved in predicting the sensory consequences of movements.

190 citations

Book ChapterDOI
01 Jan 2000
TL;DR: Schizophrenia is a complex mental illness characterized by acute phases of delusions, hallucinations and thought disorder and chronically, by apathy, flat affect and social withdrawal as discussed by the authors, and it is currently widely accepted that schizophrenia has a biological etiology.
Abstract: This chapter focuses on schizophrenia. Schizophrenia is a complex mental illness characterized by acute phases of delusions, hallucinations and thought disorder and chronically, by apathy, flat affect and social withdrawal. The IQ of schizophrenic patients is significantly lower than that of controls. Schizophrenic patients experience specific cognitive impairments. Findings demonstrating that intellectual impairment is more marked in some domains than others support the notion that circumscribed brain abnormalities may be associated with schizophrenia. Schizophrenic patients have difficulty in initiating and completing everyday tasks, being easily distracted and tending to give up when confronted by any obstacles. It is currently widely accepted that schizophrenia has a biological etiology. However, the shift toward this agreement is recent and the etiology of schizophrenia has been the subject of lengthy and intense debate. The diversity of symptoms in schizophrenia makes it unlikely that the pathophysiology can be accounted for by a single localized brain dysfunction. Instead, the strategy of attempting to localize specific symptoms to specific brain regions or connections between regions is encouraging. Schizophrenia is a heterogeneous illness, comprising a variety of different symptoms. Using groups of patients defined by diagnosis may explain the inconsistent and equivocal results of functional imaging studies.

15 citations


Cited by
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Journal ArticleDOI
TL;DR: The Perception-Action Model (PAM), together with an understanding of how representations change with experience, can explain the major empirical effects in the literature and can also predict a variety of empathy disorders.
Abstract: There is disagreement in the literature about the exact nature of the phenomenon of empathy. There are emotional, cogni- tive, and conditioning views, applying in varying degrees across species. An adequate description of the ultimate and proximate mecha- nism can integrate these views. Proximately, the perception of an object's state activates the subject's corresponding representations, which in turn activate somatic and autonomic responses. This mechanism supports basic behaviors (e.g., alarm, social facilitation, vicar- iousness of emotions, mother-infant responsiveness, and the modeling of competitors and predators) that are crucial for the reproduc- tive success of animals living in groups. The Perception-Action Model (PAM), together with an understanding of how representations change with experience, can explain the major empirical effects in the literature (similarity, familiarity, past experience, explicit teach- ing, and salience). It can also predict a variety of empathy disorders. The interaction between the PAM and prefrontal functioning can also explain different levels of empathy across species and age groups. This view can advance our evolutionary understanding of empa- thy beyond inclusive fitness and reciprocal altruism and can explain different levels of empathy across individuals, species, stages of de- velopment, and situations.

3,350 citations

Journal ArticleDOI
TL;DR: The 'minimum variance model' is another major recent advance in the computational theory of motor control, strongly suggesting that both kinematic and dynamic internal models are utilized in movement planning and control.

2,469 citations

Journal ArticleDOI
01 Jan 1966
TL;DR: Koestler as mentioned in this paper examines the idea that we are at our most creative when rational thought is suspended, for example, in dreams and trancelike states, and concludes that "the act of creation is the most creative act in human history".
Abstract: While the study of psychology has offered little in the way of explaining the creative process, Koestler examines the idea that we are at our most creative when rational thought is suspended--for example, in dreams and trancelike states. All who read The Act of Creation will find it a compelling and illuminating book.

2,201 citations

Journal ArticleDOI
TL;DR: The mentalizing (theory of mind) system of the brain is probably in operation from 18 months of age, allowing implicit attribution of intentions and other mental states, and from this age children are able to explain the misleading reasons that have given rise to a false belief.
Abstract: The mentalizing (theory of mind) system of the brain is probably in operation from ca. 18 months of age, allowing implicit attribution of intentions and other mental states. Between the ages of 4 and 6 years explicit mentalizing becomes possible, and from this age children are able to explain the misleading reasons that have given rise to a false belief. Neuroimaging studies of mentalizing have so far only been carried out in adults. They reveal a system with three components consistently activated during both implicit and explicit mentalizing tasks: medial prefrontal cortex (MPFC), temporal poles and posterior superior temporal sulcus (STS). The functions of these components can be elucidated, to some extent, from their role in other tasks used in neuroimaging studies. Thus, the MPFC region is probably the basis of the decoupling mechanism that distinguishes mental state representations from physical state representations; the STS region is probably the basis of the detection of agency, and the temporal poles might be involved in access to social knowledge in the form of scripts. The activation of these components in concert appears to be critical to mentalizing.

2,110 citations