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Abnormalities in the Awareness and Control of Action
- Philos Trans R Soc Lond B Biol Sci
, 2000
"... this paper is to consider the extent to which we are aware of the functioning of some ..."
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Cited by 111 (2 self)
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this paper is to consider the extent to which we are aware of the functioning of some
The objects of action and perception
- Cognition
, 1998
"... Two major functions of the visual system are discussed and contrasted. One function of vision is the creation of an internal model or percept of the external world. Most research in object perception has concentrated on this aspect of vision. Vision also guides the control of object-directed action. ..."
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Two major functions of the visual system are discussed and contrasted. One function of vision is the creation of an internal model or percept of the external world. Most research in object perception has concentrated on this aspect of vision. Vision also guides the control of object-directed action. In the latter case, vision directs our actions with respect to the world by transforming visual inputs into appropriate motor outputs. We argue that separate, but interactive, visual systems have evolved for the perception of objects on the one hand and the control of actions directed at those objects on the other. This ‘duplex ’ approach to high-level vision suggests that Marrian or ‘reconstructive ’ approaches and Gibsonian or ‘purposiveanimate-behaviorist’ approaches need not be seen as mutually exclusive, but rather as complementary in their emphases on different aspects of visual function. © 1998 Elsevier Science
Neural topography and content of movement representations
- Journal of Cognitive Neuroscience
, 2005
"... Abstract & We have used implicit motor imagery to investigate the neural correlates of motor planning independently from actual movements. Subjects were presented with drawings of left or right hands and asked to judge the hand laterality, regardless of the stimulus rotation from its upright or ..."
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Abstract & We have used implicit motor imagery to investigate the neural correlates of motor planning independently from actual movements. Subjects were presented with drawings of left or right hands and asked to judge the hand laterality, regardless of the stimulus rotation from its upright orientation. We paired this task with a visual imagery control task, in which subjects were presented with typographical characters and asked to report whether they saw a canonical letter or its mirror image, regardless of its rotation. We measured neurovascular activity with fast event-related fMRI, distinguishing responses parametrically related to motor imagery from responses evoked by visual imagery and other task-related phenomena. By quantifying behavioral and neurovascular correlates of imagery on a trial-by-trial basis, we could discriminate between stimulusrelated, mental rotation-related, and response-related neural activity. We found that specific portions of the posterior parietal and precentral cortex increased their activity as a function of mental rotation only during the motor imagery task. Within these regions, the parietal cortex was visually responsive, whereas the dorsal precentral cortex was not. Response-but not rotation-related activity was found around the left central sulcus (putative primary motor cortex) during both imagery tasks. Our study provides novel evidence on the topography and content of movement representations in the human brain. During intended action, the posterior parietal cortex combines somatosensory and visuomotor information, whereas the dorsal premotor cortex generates the actual motor plan, and the primary motor cortex deals with movement execution. We discuss the relevance of these results in the context of current models of action planning. &
1998: ‘Frames of Reference for Perception and Action in the Human Visual System
- Neuroscience and Biobehavioral Reviews
"... GOODALE, M. A., A. HAFFENDEN. Frames of reference for perception and action in the human visual system. NEUROSCI BIOBEHAV REV 22(2), 161–172, 1998.—A growing body of evidence demonstrates that vision for perception and vision for action are mediated by separate neural mechanisms. After briefly revie ..."
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GOODALE, M. A., A. HAFFENDEN. Frames of reference for perception and action in the human visual system. NEUROSCI BIOBEHAV REV 22(2), 161–172, 1998.—A growing body of evidence demonstrates that vision for perception and vision for action are mediated by separate neural mechanisms. After briefly reviewing the neuropsychological evidence for this division of labor in the human visual system, we explore the evidence for a dissociation between perception and action in neurologically intact individuals. A number of studies have shown that unseen visual events can sometimes elicit movements of the hand and limb, despite the fact that subjects have no visual phenomenology of those events. Other work has shown that perceptual judgements about the location and size of objects can be quite different from the scaling of skilled actions directed at those objects. For example, size-contrast illusions, such as the Ebbinghaus illusion, have been shown to have little effect on the scaling of the grasp. Similar dissociations have been demonstrated in other studies in which psychophysical judgements about the dimensions of objects in the far peripheral field bear little relation to the calibration of grasping movements directed at those objects. Together with the neuropsychological work (and neurophysiological studies in the monkey), these findings provide compelling evidence for the operation of separate visual mechanisms in everyday life. In
Multiple movement representations in the human brain: an event-related fMRI study
- J. Cogn. Neurosci
, 2002
"... & Neurovascular correlates of response preparation have been investigated in human neuroimaging studies. However, conventional neuroimaging cannot distinguish, within the same trial, between areas involved in response selection and/ or response execution and areas specifically involved in respon ..."
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Cited by 21 (5 self)
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& Neurovascular correlates of response preparation have been investigated in human neuroimaging studies. However, conventional neuroimaging cannot distinguish, within the same trial, between areas involved in response selection and/ or response execution and areas specifically involved in response preparation. The specific contribution of parietal and frontal areas to motor preparation has been explored in electrophysiological studies in monkey. However, the asso-ciative nature of sensorimotor tasks calls for the additional contributions of other cortical regions. In this article, we have investigated the functional anatomy of movement represen-tations in the context of an associative visuomotor task with instructed delays. Neural correlates of movement representa-tions have been assessed by isolating preparatory activity that
Grasping visual illusions: Consistent data and no dissociation
- Cognitive Neuropsychology
, 2008
"... The finding that the Ebbinghaus/Titchener illusion deceives perception but not grasping is usually seen as strong evidence for Goodale and Milner’s (1992) notion of two parallel visual systems, one being conscious and deceived by the illusion (vision-for-perception) and the other being unconscious a ..."
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The finding that the Ebbinghaus/Titchener illusion deceives perception but not grasping is usually seen as strong evidence for Goodale and Milner’s (1992) notion of two parallel visual systems, one being conscious and deceived by the illusion (vision-for-perception) and the other being unconscious and not deceived (vision-for-action). However, this finding is controversial and led to studies with seemingly contradictory results. We argue that these results are not as contradictory as it might seem. Instead, studies consistently show similar effects of the illusion on grasping. The perceptual effects are strongly dependent on the specific perceptual measure employed. If, however, some methodological precautions are used, then these diverse perceptual results can be reconciled and point to a single internal size esti-mate that is used for perception and for grasping. This suggests that the Ebbinghaus illusion deceives a common representation of object size that is used by perception and action.
Toward a dynamic theory of intentions
- In
"... In this paper, I shall offer a sketch of a dynamic theory of intentions. I shall argue that several categories or forms of intentions should be distinguished based on their different (and complementary) functional roles and on the different contents or types of contents they involve. I ..."
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Cited by 17 (6 self)
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In this paper, I shall offer a sketch of a dynamic theory of intentions. I shall argue that several categories or forms of intentions should be distinguished based on their different (and complementary) functional roles and on the different contents or types of contents they involve. I
PERCEPTION-ACTION DISSOCIATIONS OF A WALKABLE MÜLLER-LYER CONFIGURATION
, 2000
"... These studies examined the role of spatial encoding in inducing perception-action dissociations in visual illusions. Participants were shown a large-scale Müller-Lyer configuration with hoops as its tails. In Experiment 1, participants either made verbal estimates of the extent of the Müller-Lyer s ..."
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Cited by 12 (0 self)
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These studies examined the role of spatial encoding in inducing perception-action dissociations in visual illusions. Participants were shown a large-scale Müller-Lyer configuration with hoops as its tails. In Experiment 1, participants either made verbal estimates of the extent of the Müller-Lyer shaft (verbal task) or walked the extent without vision, in an offset path (blind-walking task). For both tasks, participants stood a small distance away from the configuration, to elicit object-relative encoding of the shaft with respect to its hoops. A similar illusion bias was found in the verbal and motoric tasks. In Experiment 2, participants stood at one endpoint of the shaft in order to elicit egocentric encoding of extent. Verbal judgments continued to exhibit the illusion bias, whereas blind-walking judgments did not. These findings underscore the importance of egocentric encoding in motor tasks for producing perception-action dissociations. A growing body of empirical evidence suggests that the human visual system comprises two separate but interacting processing
Implicit Perception in Action -- Short-lived motor representations of space
, 1998
"... Perception is often conscious, which allows one to report about the object of perception, and to elaborate deliberate actions in the environment. But there is a considerable body of evidence that action does not always result primarily from such elaborated perceptual processes. These two statements ..."
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Cited by 11 (0 self)
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Perception is often conscious, which allows one to report about the object of perception, and to elaborate deliberate actions in the environment. But there is a considerable body of evidence that action does not always result primarily from such elaborated perceptual processes. These two statements are illustrated on Figure 6.1. The experimental data reported in this chapter represent an attempt to summarize several instances of implicit (or non-conscious) use of sensory information during action. These data make it clear that the idea of a pure serial processing of sensory information from mental representation to action (see Figure 6.1: upper panel) is out of date. Examples of such implicit sensory representation will be obtained from various experimental fields ranging from psychology to neurophysiology and neuropsychology. These empirical data not only make the case for a dissociation between conscious awareness and motor representations of sensory targets, but also provide a basis for understanding how these two representations can interact (see Figure 6.1). Current theoretical and experimental work about consciousness seems to make the assumption that implicit processing may be an intermediate level between brain mechanisms and consciousness (e.g. Rossetti 1992, Bock and
Selective reaching: Evidence for multiple frames of reference
- Journal of Experimental Psychology: Human Perception & Performance
, 2002
"... Students participated in 3 experiments investigating the use of environment- and action-centered reference frames in selective reaching. They pointed to a green target appearing either with or without a red distractor. Target–distractor distance was manipulated, and distractor interference (differen ..."
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Cited by 8 (1 self)
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Students participated in 3 experiments investigating the use of environment- and action-centered reference frames in selective reaching. They pointed to a green target appearing either with or without a red distractor. Target–distractor distance was manipulated, and distractor interference (difference between distractor trials and no-distractor trials) was measured in reaction time, movement time, and movement endpoint. Target–distractor distance determined the dominant frame of reference. Small distances evoked an environment-centered framework that encoded targets within an external context. Large distances evoked an action-centered framework that encoded targets relative to the start position of the hand. Results support the hypothesis that the brain represents spatial information in multiple frames of reference, with the dominant frame of reference being dependent on the task demands. A well-known example used to highlight the concept of selec-tive attention is picking a ripe apple from a branch when an unripe apple is nearby on the same branch (e.g., Meegan & Tipper, 1999). This example shows that selective attention mediates goal-directed action through selection of appropriate actions and inhibition of inappropriate actions (i.e., picking the unripe apple). These selec-
