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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
Visual-motor recalibration in geographical slant perception. Manuscript submitted for publication
, 1997
"... In 4 experiments, it was shown that hills appear steeper to people who are encumbered by wearing a heavy backpack (Experiment 1), are fatigued (Experiment 2), are of low physical fitness (Experiment 3), or are elderly and/or in declining health (Experiment 4). Visually guided actions are unaffected ..."
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Cited by 104 (12 self)
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In 4 experiments, it was shown that hills appear steeper to people who are encumbered by wearing a heavy backpack (Experiment 1), are fatigued (Experiment 2), are of low physical fitness (Experiment 3), or are elderly and/or in declining health (Experiment 4). Visually guided actions are unaffected by these manipulations of physiological potential. Although dissociable, the awareness and action systems were also shown to be interconnected. Recalibration of the transformation relating awareness and actions was found to occur over long-term changes in physiological potential (fitness level, age, and health) but not with transitory changes (fatigue and load). Findings are discussed in terms of a time-dependent coordination between the separate systems that control explicit visual awareness and visually guided action. In conscious awareness, the apparent slant of hills is greatly exaggerated. For example, 5 ° hills appear to be about 20°, and 10 ° ones look to be about 30 ° (Proffitt, Bhalla, Gossweiler, & Midgett, 1995). Be that as it may, people are not especially prone to stumble whenever the terrain over
Grasping objects by their handles: A necessary interaction between cognition and action
- Journal of Experimental Psychology: Human Perception and Performance
, 2001
"... Research has illustrated dissociations between "cognitive " and "action " systems, suggesting that different representations may underlie phenomenal experience and visuomotor behavior. However, these systems also interact. The present studies show a necessary interaction when sem ..."
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Cited by 54 (2 self)
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Research has illustrated dissociations between "cognitive " and "action " systems, suggesting that different representations may underlie phenomenal experience and visuomotor behavior. However, these systems also interact. The present studies show a necessary interaction when semantic processing of an object is required for an appropriate action. Experiment 1 demonstrated that a semantic task interfered with grasping objects appropriately by their handles, but a visuospatial task did not. Experiment 2 assessed performance on a visuomotor task that had no semantic component and showed a reversal of the effects of the concurrent tasks. In Experiment 3, variations on concurrent word tasks suggested that retrieval of semantic information was necessary for appropriate grasping. In all, without semantic processing, the visuomotor system can direct the effective grasp of an object, but not in a manner that is appropriate for its use. Dissociations between cognition and action have been proposed in several domains, including perception (Gibson, 1979), attention (Mack & Rock, 1998), and the neural substrate of the visual system (Jeannerod, 1997; Milner & Goodale, 1995). It has been repeatedly demonstrated that phenomenal experience and visuomotor
The Effect of Pictorial Illusion on Prehension and Perception’,
- Journal of Cognitive Neuroscience,
, 1998
"... Abstract The present study examined the effect of a size-contrast illusion (Ebbinghaus or Titchener Circles Illusion) on visual perception and the visual control of grasping movements. Seventeen right-handed participants picked up and, on other trials, estimated the size of "poker-chip" d ..."
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Cited by 51 (2 self)
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Abstract The present study examined the effect of a size-contrast illusion (Ebbinghaus or Titchener Circles Illusion) on visual perception and the visual control of grasping movements. Seventeen right-handed participants picked up and, on other trials, estimated the size of "poker-chip" disks, which functioned as the target circles in a three-dimensional version of the illusion. In the estimation condition, subjects indicated how big they thought the target was by separating their thumb and fore nger to match the target's size. After initial viewing, no visual feedback from the hand or the target was available. Scaling of grip aperture was found to be strongly correlated with the physical size of the disks, while manual estimations of disk size were biased in the direction of the illusion. Evidently, grip aperture is calibrated to the true size of an object, even when perception of object size is distorted by a pictorial illusion, a result that is consistent with recent suggestions that visually guided prehension and visual perception are mediated by separate visual pathways.
Effect of reversible inactivation of macaque lateral intraparietal area on visual and memory saccades
- J Neurophysiol
, 1999
"... sen. Effect of reversible inactivation of macaque lateral intraparietal area on visual and memory saccades. J. Neurophysiol. 81: 1827–1838, 1999. Previous studies from our laboratory identified a parietal eye field in the primate lateral intraparietal sulcus, the lateral intraparietal area (area LIP ..."
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Cited by 37 (1 self)
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sen. Effect of reversible inactivation of macaque lateral intraparietal area on visual and memory saccades. J. Neurophysiol. 81: 1827–1838, 1999. Previous studies from our laboratory identified a parietal eye field in the primate lateral intraparietal sulcus, the lateral intraparietal area (area LIP). Here we further explore the role of area LIP in processing saccadic eye movements by observing the effects of re-versible inactivation of this area. One to 2!l of muscimol (8 mg/ml) were injected at locations where saccade-related activities were re-corded for each lesion experiment. After the muscimol injection we observed in two macaque monkeys consistent effects on both the metrics and dynamics of saccadic eye movements at many injection sites. These effects usually took place within 10–30 min and disap-peared after 5–6 h in most cases and certainly when tested the next day. After muscimol injection memory saccades directed toward the contralesional and upper space became hypometric, and in one mon-
Functional anatomy of pointing and grasping in humans
- Cereb Cortex
, 1996
"... The functional anatomy of reaching and grasping simple objects was determined in nine healthy subjects with positron emission tomogra-phy imaging of regional cerebral blood flow (rCBF). In a prehension (grasping) task, subjects reached and grasped illuminated cylindrical objects with their right han ..."
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Cited by 34 (6 self)
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The functional anatomy of reaching and grasping simple objects was determined in nine healthy subjects with positron emission tomogra-phy imaging of regional cerebral blood flow (rCBF). In a prehension (grasping) task, subjects reached and grasped illuminated cylindrical objects with their right hand. In a pointing task, subjects reached and pointed over the same targets. In a control condition subjects looked at the targets. Both movement tasks increased activity in a distributed set of cortical and subcortical sites: contralateral motor, premotor, ventral supplementary motor area (SMA), cingulate, superior parietal, and dorsal occipital cortex. Cortical areas including cuneate and dor-sal occipital cortex were more extensively activated than ventral oc-cipital or temporal pathways. The left parietal operculum (putative Sll) was recruited during grasping but not pointing. Blood flow changes were individually localized with respect to local cortical anatomy us-ing sulcal landmarks. Consistent anatomic landmarks from MRI scans
Cortical Connections of the Macaque Anterior Intraparietal (AIP) Area
- CEREBRAL CORTEX
, 2007
"... We traced the cortical connections of the anterior intraparietal (AIP) area, which is known to play a crucial role in visuomotor transformations for grasping. AIP displayed major connections with 1) areas of the inferior parietal lobule convexity, the rostral part of the lateral intraparietal area a ..."
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Cited by 24 (6 self)
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We traced the cortical connections of the anterior intraparietal (AIP) area, which is known to play a crucial role in visuomotor transformations for grasping. AIP displayed major connections with 1) areas of the inferior parietal lobule convexity, the rostral part of the lateral intraparietal area and the SII region; 2) ventral visual stream areas of the lower bank of the superior temporal sulcus and the middle temporal gyrus; and 3) the premotor area F5 and prefrontal areas 46 and 12. Additional connections were observed with the caudal intraparietal area and the ventral part of the frontal eye field. This study suggests that visuomotor transformations for object-oriented actions, processed in AIP, rely not only on dorsal visual stream information related to the object’s physical properties but also on ventral visual stream information related to object identity. The identification of direct anatomical connections with the inferotemporal cortex suggests that AIP also has a unique role in linking the parietofrontal network of areas involved in sensorimotor transformations for grasping with areas involved in object recognition. Thus, AIP could represent a crucial node in a cortical circuit in which hand-related sensory and motor signals gain access to representations of object identity for tactile object recognition.
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
Hand path priming in manual obstacle avoidance: Rapid decay of dorsal stream information.
- Neuropsychologia,
, 2009
"... According to a prominent theory of human perception and performance (M. A. ..."
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Cited by 18 (1 self)
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According to a prominent theory of human perception and performance (M. A.
Visuomotor channels: their integration in goaldirected prehension
- Hum Mov Sci 1999;18:210 /8
, 1999
"... prehension ..."
