scholarly journals Invariant representations of mass in the human brain

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Sarah Schwettmann ◽  
Joshua B Tenenbaum ◽  
Nancy Kanwisher

An intuitive understanding of physical objects and events is critical for successfully interacting with the world. Does the brain achieve this understanding by running simulations in a mental physics engine, which represents variables such as force and mass, or by analyzing patterns of motion without encoding underlying physical quantities? To investigate, we scanned participants with fMRI while they viewed videos of objects interacting in scenarios indicating their mass. Decoding analyses in brain regions previously implicated in intuitive physical inference revealed mass representations that generalized across variations in scenario, material, friction, and motion energy. These invariant representations were found during tasks without action planning, and tasks focusing on an orthogonal dimension (object color). Our results support an account of physical reasoning where abstract physical variables serve as inputs to a forward model of dynamics, akin to a physics engine, in parietal and frontal cortex.

2018 ◽  
Vol 29 (8) ◽  
pp. 3380-3389
Author(s):  
Timothy J Andrews ◽  
Ryan K Smith ◽  
Richard L Hoggart ◽  
Philip I N Ulrich ◽  
Andre D Gouws

Abstract Individuals from different social groups interpret the world in different ways. This study explores the neural basis of these group differences using a paradigm that simulates natural viewing conditions. Our aim was to determine if group differences could be found in sensory regions involved in the perception of the world or were evident in higher-level regions that are important for the interpretation of sensory information. We measured brain responses from 2 groups of football supporters, while they watched a video of matches between their teams. The time-course of response was then compared between individuals supporting the same (within-group) or the different (between-group) team. We found high intersubject correlations in low-level and high-level regions of the visual brain. However, these regions of the brain did not show any group differences. Regions that showed higher correlations for individuals from the same group were found in a network of frontal and subcortical brain regions. The interplay between these regions suggests a range of cognitive processes from motor control to social cognition and reward are important in the establishment of social groups. These results suggest that group differences are primarily reflected in regions involved in the evaluation and interpretation of the sensory input.


2015 ◽  
Vol 113 (10) ◽  
pp. 1539-1549 ◽  
Author(s):  
Stine Hasselholt ◽  
Pernille Tveden-Nyborg ◽  
Jens Lykkesfeldt

Vitamin C (VitC) deficiency is surprisingly common in humans even in developed parts of the world. The micronutrient has several established functions in the brain; however, the consequences of its deficiency are not well characterised. To elucidate the effects of VitC deficiency on the brain, increased knowledge about the distribution of VitC to the brain and within different brain regions after varying dietary concentrations is needed. In the present study, guinea pigs (like humans lacking the ability to synthesise VitC) were randomly divided into six groups (n 10) that received different concentrations of VitC ranging from 100 to 1500 mg/kg feed for 8 weeks, after which VitC concentrations in biological fluids and tissues were measured using HPLC. The distribution of VitC was found to be dynamic and dependent on dietary availability. Brain saturation was region specific, occurred at low dietary doses, and the dose–concentration relationship could be approximated with a three-parameter Hill equation. The correlation between plasma and brain concentrations of VitC was moderate compared with other organs, and during non-scorbutic VitC deficiency, the brain was able to maintain concentrations from about one-quarter to half of sufficient levels depending on the region, whereas concentrations in other tissues decreased to one-sixth or less. The adrenal glands have similar characteristics to the brain. The observed distribution kinetics with a low dietary dose needed for saturation and exceptional retention ability suggest that the brain and adrenal glands are high priority tissues with regard to the distribution of VitC.


2016 ◽  
Vol 113 (34) ◽  
pp. E5072-E5081 ◽  
Author(s):  
Jason Fischer ◽  
John G. Mikhael ◽  
Joshua B. Tenenbaum ◽  
Nancy Kanwisher

To engage with the world—to understand the scene in front of us, plan actions, and predict what will happen next—we must have an intuitive grasp of the world’s physical structure and dynamics. How do the objects in front of us rest on and support each other, how much force would be required to move them, and how will they behave when they fall, roll, or collide? Despite the centrality of physical inferences in daily life, little is known about the brain mechanisms recruited to interpret the physical structure of a scene and predict how physical events will unfold. Here, in a series of fMRI experiments, we identified a set of cortical regions that are selectively engaged when people watch and predict the unfolding of physical events—a “physics engine” in the brain. These brain regions are selective to physical inferences relative to nonphysical but otherwise highly similar scenes and tasks. However, these regions are not exclusively engaged in physical inferences per se or, indeed, even in scene understanding; they overlap with the domain-general “multiple demand” system, especially the parts of that system involved in action planning and tool use, pointing to a close relationship between the cognitive and neural mechanisms involved in parsing the physical content of a scene and preparing an appropriate action.


2011 ◽  
Vol 366 (1564) ◽  
pp. 468-475 ◽  
Author(s):  
David Melcher

Our vision remains stable even though the movements of our eyes, head and bodies create a motion pattern on the retina. One of the most important, yet basic, feats of the visual system is to correctly determine whether this retinal motion is owing to real movement in the world or rather our own self-movement. This problem has occupied many great thinkers, such as Descartes and Helmholtz, at least since the time of Alhazen. This theme issue brings together leading researchers from animal neurophysiology, clinical neurology, psychophysics and cognitive neuroscience to summarize the state of the art in the study of visual stability. Recently, there has been significant progress in understanding the limits of visual stability in humans and in identifying many of the brain circuits involved in maintaining a stable percept of the world. Clinical studies and new experimental methods, such as transcranial magnetic stimulation, now make it possible to test the causal role of different brain regions in creating visual stability and also allow us to measure the consequences when the mechanisms of visual stability break down.


Author(s):  
Martin Brüne

The human brain is the most complex organ that has ever evolved. It contains more neurons and synapses than any other primate brain. In relation to body weight, it is outstandingly large and distinctly convoluted. Several parts of the brain have enlarged disproportionally over evolutionary time. Those brain regions are mainly involved in emotion processing, understanding and reflecting upon one’s own and other minds, memory, social decision-making, and action planning, suggesting that the human brain is adapted to dealing with social matters. The human brain is also conspicuous with regard to its slow maturation, which is linked to the huge amount of social information that needs to be learned until adulthood. Cross-talk among neurons is maintained by the action of neuromodulators and neurotransmitters, many of which are ancient and have served multiple purposes in plants and animals. They help regulate defensive and agonistic behaviour, social attachment, and inhibitory control.


2019 ◽  
Vol 9 (4) ◽  
pp. 34 ◽  
Author(s):  
Daniel Yarosh

Human physical characteristics and their perception by the brain are under pressure by natural selection to optimize reproductive success. Men and women have different strategies to appear attractive and have different interests in identifying beauty in people. Nevertheless, men and women from all cultures agree on who is and who is not attractive, and throughout the world attractive people show greater acquisition of resources and greater reproductive success than others. The brain employs at least three modules, composed of interconnected brain regions, to judge facial attractiveness: one for identification, one for interpretation and one for valuing. Key elements that go into the judgment are age and health, as well as symmetry, averageness, face and body proportions, facial color and texture. These elements are all Costly Signals of reproductive fitness because they are difficult to fake. However, people deceive others using tricks such as coloring hair, cosmetics and clothing styles, while at the same time they also focus on detecting fakes. People may also deceive themselves, especially about their own attractiveness, and use self-signally actions to demonstrate to themselves their own true value. The neuroscience of beauty is best understood by considering the evolutionary pressures to maximize reproductive fitness.


2009 ◽  
Vol 364 (1521) ◽  
pp. 1223-1234 ◽  
Author(s):  
Stephen Grossberg

An intimate link exists between the predictive and learning processes in the brain. Perceptual/cognitive and spatial/motor processes use complementary predictive mechanisms to learn, recognize, attend and plan about objects in the world, determine their current value, and act upon them. Recent neural models clarify these mechanisms and how they interact in cortical and subcortical brain regions. The present paper reviews and synthesizes data and models of these processes, and outlines a unified theory of predictive brain processing.


2019 ◽  
Vol 7 ◽  
Author(s):  
Christoph Guger ◽  
Christoph Kapeller ◽  
Hiroshi Ogawa ◽  
Satoru Hiroshima ◽  
Kyousuke Kamada

How do different parts of the brain work together to help us see, move, understand, and do other things? For many years, we have known that different brain regions perform different tasks that are important for vision. Some brain regions are responsible for seeing faces, colors, lines, movement, or other parts of the world. But mapping different brain regions in detail is very challenging, especially because everyone’s brain is slightly different. Sometimes, brain surgeons must place electrodes inside a patient’s skull—on the surface of the brain—to get a more detailed map. This article describes a study done by a group of brain surgeons, scientists, and engineers. We studied the activity of a patient’s brain while he looked at different objects. We identified two brain regions that were active when the patient processed faces or colors. If we stimulated these areas, the patient reported seeing faces or colors, even if he was looking at something else! The results of this study help show how different parts of the brain perform different tasks, and could lead to safer, more precise brain surgery.


GYNECOLOGY ◽  
2020 ◽  
Vol 22 (5) ◽  
pp. 84-86
Author(s):  
Sergei P. Sinchikhin ◽  
Sarkis G. Magakyan ◽  
Oganes G. Magakyan

Relevance.A neoplasm originated from the myelonic sheath of the nerve trunk is called neurinoma or neurilemmoma, neurinoma, schwannoglioma, schwannoma. This tumor can cause compression and dysfunction of adjacent tissues and organs. The most common are the auditory nerve neurinomas (1 case per 100 000 population per year), the brain and spinal cord neurinomas are rare. In the world literature, there is no information on the occurrences of this tumor in the pelvic region. Description.Presented below is a clinical observation of a 30-year-old patient who was scheduled for myomectomy. During laparoscopy, an unusual tumor of the small pelvis was found and radically removed. A morphological study allowed to identify the remote neoplasm as a neuroma. Conclusion.The presented practical case shows that any tumor can hide under a clinical mask of another disease. The qualification of the doctor performing laparoscopic myomectomy should be sufficient to carry out, if necessary, another surgical volume.


2018 ◽  
Author(s):  
Xiaoyang Yu

Nomological determinism does not mean everything is predictable. It just means everything follows the law of nature. And the most important thing Is that the brain and consciousness follow the law of nature. In other words, there is no free will. Without life, brain and consciousness, the world follows law of nature, that is clear. The life and brain are also part of nature, and they follow the law of nature. This is due to scientific findings. There are not enough scientific findings for consciousness yet. But I think that the consciousness is a nature phenomenon, and it also follows the law of nature.


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