Results 1 - 10
of
743
Action observation activates premotor and parietal areas in a somatotopic manner: an fMRI study
, 2001
"... Functional magnetic resonance imaging (fMRI) was used to localize brain areas that were active during the observation of actions made by another individual. Object- and non-object-related actions made with different effectors (mouth, hand and foot) were presented. Observation of both object- and non ..."
Abstract
-
Cited by 364 (31 self)
- Add to MetaCart
Functional magnetic resonance imaging (fMRI) was used to localize brain areas that were active during the observation of actions made by another individual. Object- and non-object-related actions made with different effectors (mouth, hand and foot) were presented. Observation of both object- and non-object-related actions determined a somatotopically organized activation of premotor cortex. The somatotopic pattern was similar to that of the classical motor cortex homunculus. During the observation of object-related actions, an activation, also somatotopically organized, was additionally found in the posterior parietal lobe. Thus, when individuals observe an action, an internal replica of that action is automatically generated in their premotor cortex. In the case of object-related actions, a further object-related analysis is performed in the parietal lobe, as if the subjects were indeed using those objects. These results bring the previous concept of an action observation/execution matching system (mirror system) into a broader perspective: this system is not restricted to the ventral premotor cortex, but involves several somatotopically organized motor circuits.
Is Vision Continuous with Cognition? The Case for Cognitive Impenetrability of Visual Perception
, 1998
"... This article defends the claim that a significant part of visual perception (called "early vision") is impervious to the influence of beliefs, expectations or knowledge. We examine a wide range of empirical evidence that has been cited in support of the continuity of vision and cognition a ..."
Abstract
-
Cited by 165 (10 self)
- Add to MetaCart
This article defends the claim that a significant part of visual perception (called "early vision") is impervious to the influence of beliefs, expectations or knowledge. We examine a wide range of empirical evidence that has been cited in support of the continuity of vision and cognition and argue that the evidence either shows withinvision top-down effects, or else the extra-visual effects that are demonstrated occur before the operation of the autonomous early vision system (through the allocation of focal attention) or after the visual system has produced its 3D shape-description (through the intervention of post-visual decision processes).
The time course of visual processing : from early perception to decision making
- J. Cogn. Neuroscience,in
, 2001
"... & Experiments investigating the mechanisms involved in visual processing often fail to separate low-level encoding mechanisms from higher-level behaviorally relevant ones. Using an alternating dual-task event-related potential (ERP) experimental paradigm (animals or vehicles categorization) wher ..."
Abstract
-
Cited by 144 (15 self)
- Add to MetaCart
(Show Context)
& Experiments investigating the mechanisms involved in visual processing often fail to separate low-level encoding mechanisms from higher-level behaviorally relevant ones. Using an alternating dual-task event-related potential (ERP) experimental paradigm (animals or vehicles categorization) where targets of one task are intermixed among distractors of the other, we show that visual categorization of a natural scene involves different mechanisms with different time courses: a perceptual, task-independent mechanism, followed by a taskrelated, category-independent process. Although average ERP responses reflect the visual category of the stimulus shortly after visual processing has begun (e.g. 75±80 msec), this difference is not correlated with the subject's behavior until 150 msec poststimulus. &
Premotor cortex activation during observation and naming of familiar tools
- NeuroImage
, 1997
"... Positron emission tomography was used to investi-gate whether observation of real objects (tools of com-mon use) activates premotor areas in the absence of any overt motor demand. Silent naming of the pre-sented tools and silent naming of their use were also studied. Right-handed normal subjects wer ..."
Abstract
-
Cited by 131 (7 self)
- Add to MetaCart
(Show Context)
Positron emission tomography was used to investi-gate whether observation of real objects (tools of com-mon use) activates premotor areas in the absence of any overt motor demand. Silent naming of the pre-sented tools and silent naming of their use were also studied. Right-handed normal subjects were employed. Tool observation strongly activated the left dorsal premotor cortex. In contrast, silent tool naming acti-vated Broca’s area without additional activity in the dorsal premotor cortex. Silent tool-use naming, in addition to activating Broca’s area, increased the activ-ity in the left dorsal premotor cortex and recruited the left ventral premotor cortex and the left supplemen-tary motor area. These data indicate that, even in the absence of any subsequent movement, the left premo-tor cortex processes objects that, like tools, have a motor valence. This dorsal premotor activation, which further augments when the subject names the tool use, should reflect the neural activity related to motor schemata for object use. The presence of an activation of both dorsal premotor cortex and ventral premotor cortex during tool-use naming suggests a role for these two areas in understanding object semantics. r 1997 Academic Press Key Words: PET; motor control; premotor cortex; human; tool; planning.
Perceptual awareness and its loss in unilateral neglect and extinction
, 2001
"... ..."
(Show Context)
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 ..."
Abstract
-
Cited by 111 (2 self)
- Add to MetaCart
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 ..."
Abstract
-
Cited by 104 (12 self)
- Add to MetaCart
(Show Context)
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
Sensory-Motor Coordination: The Metaphor and Beyond
- Robotics and Autonomous Systems
"... Any agent in the real world has to be able to make distinctions between different types of objects, i.e. it must have the competence of categorization. In mobile agents, there is a large variation in proximal sensory stimulation originating from the same object. Therefore, categorization behavior is ..."
Abstract
-
Cited by 96 (9 self)
- Add to MetaCart
(Show Context)
Any agent in the real world has to be able to make distinctions between different types of objects, i.e. it must have the competence of categorization. In mobile agents, there is a large variation in proximal sensory stimulation originating from the same object. Therefore, categorization behavior is hard to achieve, and the successes in the past in solving this problem, have been limited. In this paper it is proposed that the problem of categorization in the real world is significantly simplified if it is viewed as one of sensory-motor coordination, rather than one of information processing happening "on the input side". A series of models is presented to illustrate the approach. It is concluded that we should consider replacing the metaphor of information processing for intelligent systems by the one of sensory-motor coordination. But the principle of sensory-motor coordination is more than a metaphor. It offers concrete mechanisms for putting agents to work in the real world. These i...
Becoming Syntactic
, 2006
"... Psycholinguistic research has shown that the influence of abstract syntactic knowledge on performance is shaped by particular sentences that have been experienced. To explore this idea, the authors applied a connectionist model of sentence production to the development and use of abstract syntax. Th ..."
Abstract
-
Cited by 96 (6 self)
- Add to MetaCart
(Show Context)
Psycholinguistic research has shown that the influence of abstract syntactic knowledge on performance is shaped by particular sentences that have been experienced. To explore this idea, the authors applied a connectionist model of sentence production to the development and use of abstract syntax. The model makes use of (a) error-based learning to acquire and adapt sequencing mechanisms and (b) meaning–form mappings to derive syntactic representations. The model is able to account for most of what is known about structural priming in adult speakers, as well as key findings in preferential looking and elicited production studies of language acquisition. The model suggests how abstract knowledge and concrete experience are balanced in the development and use of syntax.
