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.
Functional magnetic resonance imaging (fMRI) was used to localize brain areas active during manipulation of complex objects. In one experiment subjects were required to manipulate complex objects for exploring their macrogeometric features as compared to manipulation of a simple smooth object (a sphere). In a second experiment subjects were asked to manipulate complex objects and to silently name them upon recognition as compared to manipulation of complex not recognizable objects without covert naming. Manipulation of complex objects resulted in an activation of ventral premotor cortex [Brodmann's area (BA) 44], of a region in the intraparietal sulcus (most probably corresponding to the anterior intraparietal area in the monkey), of area SII and of a sector of the superior parietal lobule. When the objects were covertly named additional activations were found in the opercular part of BA 44 and in the pars triangularis of the inferior frontal gyrus (BA 45). We suggest that a fronto-parietal circuit for manipulation of objects exists in humans and involves basically the same areas as in the monkey. It is proposed that area SII analyses the intrinsic object characteristics whilst the superior parietal lobule is related to kinaesthesia.
concepts ("freedom") differ from concrete ones ("cat"), as they do not have a bounded, identifiable, and clearly perceivable referent. The way in which abstract concepts are represented has recently become a topic of intense debate, especially because of the spread of the embodied approach to cognition. Within this framework concepts derive their meaning from the same perception, motor, and emotional systems that are involved in online interaction with the world. Most of the evidence in favor of this view, however, has been gathered with regard to concrete concepts. Given the relevance of abstract concepts for higher-order cognition, we argue that being able to explain how they are represented is a crucial challenge that any theory of cognition needs to address. The aim of this article is to offer a critical review of the latest theories on abstract concepts, focusing on embodied ones. Starting with theories that question the distinction between abstract and concrete concepts, we review theories claiming that abstract concepts are grounded in metaphors, in situations and introspection, and in emotion. We then introduce multiple representation theories, according to which abstract concepts evoke both sensorimotor and linguistic information. We argue that the most promising approach is given by multiple representation views that combine an embodied perspective with the recognition of the importance of linguistic and social experience. We conclude by discussing whether or not a single theoretical framework might be able to explain all different varieties of abstract concepts. (PsycINFO Database Record
It has been shown in nonhuman primates that the posterior parietal cortex is involved in coordination of arm and eye movements in space, whereas the anterior intraparietal area in the anterior lateral bank of the intraparietal sulcus plays a crucial role in fine finger movements, such as grasping. In this study we show by optoelectronic movement recordings that patients with cortical lesions involving the anterior lateral bank of the intraparietal sulcus have selective deficits in the coordination of finger movements required for object grasping, whereas reaching is much less disturbed. Patients with parietal lesions sparing the cortex lining the anterior intraparietal sulcus showed intact grasping behavior. Complementary evidence was obtained from functional MRI in normal control subjects showing a specific activation of the anterior lateral bank of the intraparietal sulcus during grasping. In conclusion, this combined lesion and activation study suggests that the anterior lateral bank of the intraparietal sulcus, possibly including the human homologue of the anterior intraparietal area, mediates the processing of sensorimotor integration of precisely tuned finger movements in humans.
The distinction between dorsal and ventral visual processing streams, first proposed by Ungerleider and Mishkin (1982) and later refined by Milner and Goodale (1995) has been elaborated substantially in recent years, spurred by two developments. The first was proposed in large part by Rizzolatti and Matelli (2003) and is a more detailed description of the multiple neural circuits connecting the frontal, temporal, and parietal cortices. Secondly, there are a number of behavioral observations that the classic “two visual systems” hypothesis is unable to accommodate without additional assumptions. The notion that the Dorsal stream is specialized for “where” or “how” actions and the Ventral stream for “What” knowledge cannot account for two prominent disorders of action, limb apraxia and optic ataxia, that represent a double dissociation in terms of the types of actions that are preserved and impaired. A growing body of evidence, instead, suggests that there are at least two distinct Dorsal routes in the human brain, referred to as the “Grasp” and “Use” systems. Both of these may be differentiated from the Ventral route in terms of neuroanatomic localization, representational specificity, and time course of information processing.
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.
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