scholarly journals Decoding the neural mechanisms of human tool use

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Jason P Gallivan ◽  
D Adam McLean ◽  
Kenneth F Valyear ◽  
Jody C Culham
Keyword(s):  
Tool Use ◽  
Neural Mechanisms ◽  
Primate Species ◽  
Classification Methods ◽  
Body Perception ◽  
Sensorimotor Processing ◽  
Neural Representations ◽  
Frontoparietal Cortex ◽  
Hierarchical Nature ◽  
The Brain

Sophisticated tool use is a defining characteristic of the primate species but how is it supported by the brain, particularly the human brain? Here we show, using functional MRI and pattern classification methods, that tool use is subserved by multiple distributed action-centred neural representations that are both shared with and distinct from those of the hand. In areas of frontoparietal cortex we found a common representation for planned hand- and tool-related actions. In contrast, in parietal and occipitotemporal regions implicated in hand actions and body perception we found that coding remained selectively linked to upcoming actions of the hand whereas in parietal and occipitotemporal regions implicated in tool-related processing the coding remained selectively linked to upcoming actions of the tool. The highly specialized and hierarchical nature of this coding suggests that hand- and tool-related actions are represented separately at earlier levels of sensorimotor processing before becoming integrated in frontoparietal cortex.

scholarly journals Hand before foot? Cortical somatotopy suggests manual dexterity is primitive and evolved independently of bipedalism

2013 ◽  
Vol 368 (1630) ◽  
pp. 20120417 ◽  
Author(s):  
Teruo Hashimoto ◽  
Kenichi Ueno ◽  
Akitoshi Ogawa ◽  
Takeshi Asamizuya ◽  
Chisato Suzuki ◽  
...  
Keyword(s):  
Tool Use ◽  
Sensorimotor Cortex ◽  
Manual Dexterity ◽  
The Other ◽  
Bipedal Locomotion ◽  
Neural Representations ◽  
Brain Circuits ◽  
Primary Sensorimotor Cortex ◽  
Neural Mapping ◽  
The Brain

People have long speculated whether the evolution of bipedalism in early hominins triggered tool use (by freeing their hands) or whether the necessity of making and using tools encouraged the shift to upright gait. Either way, it is commonly thought that one led to the other. In this study, we sought to shed new light on the origins of manual dexterity and bipedalism by mapping the neural representations in the brain of the fingers and toes of living people and monkeys. Contrary to the ‘hand-in-glove’ notion outlined above, our results suggest that adaptations underlying tool use evolved independently of those required for human bipedality. In both humans and monkeys, we found that each finger was represented separately in the primary sensorimotor cortex just as they are physically separated in the hand. This reflects the ability to use each digit independently, as required for the complex manipulation involved in tool use. The neural mapping of the subjects’ toes differed, however. In the monkeys, the somatotopic representation of the toes was fused, showing that the digits function predominantly as a unit in general grasping. Humans, by contrast, had an independent neurological representation of the big toe (hallux), suggesting association with bipedal locomotion. These observations suggest that the brain circuits for the hand had advanced beyond simple grasping, whereas our primate ancestors were still general arboreal quadrupeds. This early adaptation laid the foundation for the evolution of manual dexterity, which was preserved and enhanced in hominins. In hominins, a separate adaptation, involving the neural separation of the big toe, apparently occurred with bipedality. This accords with the known fossil evidence, including the recently reported hominin fossils which have been dated to 4.4 million years ago.

scholarly journals Hand-selective visual regions represent how to grasp 3D tools for use: brain decoding during real actions

2020 ◽  
Author(s):  
Ethan Knights ◽  
Courtney Mansfield ◽  
Diana Tonin ◽  
Janak Saada ◽  
Fraser W. Smith ◽  
...  
Keyword(s):  
Tool Use ◽  
Pattern Analysis ◽  
Human Hand ◽  
Brain Areas ◽  
Sensorimotor Processing ◽  
The World ◽  
Parietal Cortices ◽  
The Brain ◽  
Real Action ◽  
2D Images

ABSTRACTMost neuroimaging experiments that investigate how tools and their associated actions are represented in the brain use visual paradigms where tools or hands are displayed as 2D images and no real movements are performed. These studies have discovered selective responses in occipito-temporal and parietal cortices for viewing pictures of hands or tools which are assumed to reflect action-related processing, but this claim has never been directly investigated. To address this, we examined the responses of independently visually defined category-selective brain areas when participants directly manipulated 3D tools with their hands. Using real action fMRI and multi-voxel pattern analysis, we found that representations about whether a 3D tool is being grasped appropriately for use (e.g., grasp knife by the handle rather than its serrated edge) were decodable from hand-selective areas in occipito-temporal and parietal cortices, but not from tool-, object-, or body-selective areas, even if partially overlapping. These representations were automatically evoked even when there was no requirement for tool use and participants were naïve to object category (tool vs non-tools). We further show that these effects were exclusive for actions with tools, but not for biomechanically matched actions with control non-tools. The lack of effects in tool-selective cortex challenges the long-standing assumption that brain activation for viewing tool images reflects tool manipulation sensorimotor processing. Instead our results show that representations of how to grasp tools for use are automatically evoked in visual regions specialised for representing the human hand, the brain’s primary tool for interacting with the world.

scholarly journals Antagonism between brain regions relevant for cognitive control and emotional memory facilitates the generation of humorous ideas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Florian Bitsch ◽  
Philipp Berger ◽  
Andreas Fink ◽  
Arne Nagels ◽  
Benjamin Straube ◽  
...  
Keyword(s):  
Cognitive Control ◽  
Positive Emotions ◽  
Emotional Memory ◽  
Brain Regions ◽  
Neural Mechanisms ◽  
Functional Magnetic Resonance ◽  
Frontal Brain ◽  
Successful Resolution ◽  
Neural Underpinnings ◽  
The Brain

AbstractThe ability to generate humor gives rise to positive emotions and thus facilitate the successful resolution of adversity. Although there is consensus that inhibitory processes might be related to broaden the way of thinking, the neural underpinnings of these mechanisms are largely unknown. Here, we use functional Magnetic Resonance Imaging, a humorous alternative uses task and a stroop task, to investigate the brain mechanisms underlying the emergence of humorous ideas in 24 subjects. Neuroimaging results indicate that greater cognitive control abilities are associated with increased activation in the amygdala, the hippocampus and the superior and medial frontal gyrus during the generation of humorous ideas. Examining the neural mechanisms more closely shows that the hypoactivation of frontal brain regions is associated with an hyperactivation in the amygdala and vice versa. This antagonistic connectivity is concurrently linked with an increased number of humorous ideas and enhanced amygdala responses during the task. Our data therefore suggests that a neural antagonism previously related to the emergence and regulation of negative affective responses, is linked with the generation of emotionally positive ideas and may represent an important neural pathway supporting mental health.

scholarly journals Molecular evolutionary analysis of human primary microcephaly genes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nashaiman Pervaiz ◽  
Hongen Kang ◽  
Yiming Bao ◽  
Amir Ali Abbasi
Keyword(s):  
Evolutionary History ◽  
Genetic Basis ◽  
Brain Size ◽  
Primate Species ◽  
Evolutionary Analysis ◽  
Australopithecus Afarensis ◽  
Primary Microcephaly ◽  
Modern Humans ◽  
History Of ◽  
The Brain

Abstract Background There has been a rapid increase in the brain size relative to body size during mammalian evolutionary history. In particular, the enlarged and globular brain is the most distinctive anatomical feature of modern humans that set us apart from other extinct and extant primate species. Genetic basis of large brain size in modern humans has largely remained enigmatic. Genes associated with the pathological reduction of brain size (primary microcephaly-MCPH) have the characteristics and functions to be considered ideal candidates to unravel the genetic basis of evolutionary enlargement of human brain size. For instance, the brain size of microcephaly patients is similar to the brain size of Pan troglodyte and the very early hominids like the Sahelanthropus tchadensis and Australopithecus afarensis. Results The present study investigates the molecular evolutionary history of subset of autosomal recessive primary microcephaly (MCPH) genes; CEP135, ZNF335, PHC1, SASS6, CDK6, MFSD2A, CIT, and KIF14 across 48 mammalian species. Codon based substitutions site analysis indicated that ZNF335, SASS6, CIT, and KIF14 have experienced positive selection in eutherian evolutionary history. Estimation of divergent selection pressure revealed that almost all of the MCPH genes analyzed in the present study have maintained their functions throughout the history of placental mammals. Contrary to our expectations, human-specific adoptive evolution was not detected for any of the MCPH genes analyzed in the present study. Conclusion Based on these data it can be inferred that protein-coding sequence of MCPH genes might not be the sole determinant of increase in relative brain size during primate evolutionary history.

Neural Mechanisms of Negative Symptoms

1989 ◽  
Vol 155 (S7) ◽  
pp. 93-98 ◽  
Author(s):  
Nancy C. Andreasen
Keyword(s):  
Frontal Cortex ◽  
Negative Symptoms ◽  
Neural Mechanism ◽  
Brain Regions ◽  
Brain Dysfunction ◽  
Neural Mechanisms ◽  
Dementia Praecox ◽  
Intellectual Abilities ◽  
The Brain ◽  
Psychic Mechanisms

When Kraepelin originally defined and described dementia praecox, he assumed that it was due to some type of neural mechanism. He hypothesised that abnormalities could occur in a variety of brain regions, including the prefrontal, auditory, and language regions of the cortex. Many members of his department, including Alzheimer and Nissl, were actively involved in the search for the neuropathological lesions that would characterise schizophrenia. Although Kraepelin did not use the term ‘negative symptoms', he describes them comprehensively and states explicitly that he believes the symptoms of schizophrenia can be explained in terms of brain dysfunction:“If it should be confirmed that the disease attacks by preference the frontal areas of the brain, the central convolutions and central lobes, this distribution would in a certain measure agree with our present views about the site of the psychic mechanisms which are principally injured by the disease. On various grounds, it is easy to believe that the frontal cortex, which is specially well developed in man, stands in closer relation to his higher intellectual abilities, and these are the faculties which in our patients invariably suffer profound loss in contrast to memory and acquired ability.” Kraepelin (1919, p. 219)

scholarly journals Representation of Grammatical Categories of Words in the Brain

1995 ◽  
Vol 7 (3) ◽  
pp. 396-407 ◽  
Author(s):  
Argye E. Hillis ◽  
Alfonso Caramazza
Keyword(s):  
Neural Mechanisms ◽  
Single Patient ◽  
Grammatical Category ◽  
Lexical Knowledge ◽  
Double Dissociation ◽  
Category Information ◽  
Orthographic Representations ◽  
Organizational Principle ◽  
The Brain ◽  
Verbal Output

We report the performance of a patient who, as a consequence of left frontal and temporoparietal strokes, makes far more errors on nouns than on verbs in spoken output tasks, but makes far more errors on verbs than on nouns in written input tasks. This double dissociation within a single patient with respect to grammatical category provides evidence for the hypothesis that phonological and orthographic representations of nouns and verbs are processed by independent neural mechanisms. Furthermore, the opposite dissociation in the verbal output modality, an advantage for nouns over verbs in spoken tasks, by a different patient using the same stimuli has also been reported (Caramazza & Hillis, 1991). This double dissociation across patients on the same task indicates that results cannot be ascribed to "greater difficulty" with one type of stimulus, and provides further evidence for the view that grammatical category information is an important organizational principle of lexical knowledge in the brain.

scholarly journals Talent in the taxi: a model system for exploring expertise

2009 ◽  
Vol 364 (1522) ◽  
pp. 1407-1416 ◽  
Author(s):  
Katherine Woollett ◽  
Hugo J. Spiers ◽  
Eleanor A. Maguire
Keyword(s):  
Model System ◽  
Neural Mechanisms ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Taxi Drivers ◽  
The Brain ◽  
Use Of Expertise ◽  
Widespread Interest ◽  
Key Questions ◽  
Extensive Practice

While there is widespread interest in and admiration of individuals with exceptional talents, surprisingly little is known about the cognitive and neural mechanisms underpinning talent, and indeed how talent relates to expertise. Because many talents are first identified and nurtured in childhood, it can be difficult to determine whether talent is innate, can be acquired through extensive practice or can only be acquired in the presence of the developing brain. We sought to address some of these issues by studying healthy adults who acquired expertise in adulthood. We focused on the domain of memory and used licensed London taxi drivers as a model system. Taxi drivers have to learn the layout of 25 000 streets in London and the locations of thousands of places of interest, and pass stringent examinations in order to obtain an operating licence. Using neuropsychological assessment and structural and functional magnetic resonance imaging, we addressed a range of key questions: in the context of a fully developed brain and an average IQ, can people acquire expertise to an exceptional level; what are the neural signatures, both structural and functional, associated with the use of expertise; does expertise change the brain compared with unskilled control participants; does it confer any cognitive advantages, and similarly, does it come at a cost to other functions? By studying retired taxi drivers, we also consider what happens to their brains and behaviour when experts stop using their skill. Finally, we discuss how the expertise of taxi drivers might relate to the issue of talent and innate abilities. We suggest that exploring talent and expertise in this manner could have implications for education, rehabilitation of patients with cognitive impairments, understanding individual differences and possibly conditions such as autism where exceptional abilities can be a feature.

Domain-Specific Knowledge Systems in the Brain: The Animate-Inanimate Distinction

1998 ◽  
Vol 10 (1) ◽  
pp. 1-34 ◽  
Author(s):  
Alfonso Caramazza ◽  
Jennifer R. Shelton
Keyword(s):  
Knowledge Systems ◽  
Neural Mechanisms ◽  
Specific Knowledge ◽  
Knowledge Framework ◽  
Semantic Categories ◽  
Domain Specific ◽  
Domain Specific Knowledge ◽  
Cognitive Neuropsychological ◽  
The Brain ◽  
Selective Impairment

We claim that the animate and inanimate conceptual categories represent evolutionarily adapted domain-specific knowledge systems that are subserved by distinct neural mechanisms, thereby allowing for their selective impairment in conditions of brain damage. On this view, (some of) the category-specific deficits that have recently been reported in the cognitive neuropsychological literature—for example, the selective damage or sparing of knowledge about animals—are truly categorical effects. Here, we articulate and defend this thesis against the dominant, reductionist theory of category-specific deficits, which holds that the categorical nature of the deficits is the result of selective damage to noncategorically organized visual or functional semantic subsystems. On the latter view, the sensory/functional dimension provides the fundamental organizing principle of the semantic system. Since, according to the latter theory, sensory and functional properties are differentially important in determining the meaning of the members of different semantic categories, selective damage to the visual or the functional semantic subsystem will result in a category-like deficit. A review of the literature and the results of a new case of category-specific deficit will show that the domain-specific knowledge framework provides a better account of category-specific deficits than the sensory/functional dichotomy theory.

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