Negation and the Brain

Author(s):  
Yosef Grodzinsky ◽  
Virginia Jaichenco ◽  
Isabelle Deschamps ◽  
María Elina Sánchez ◽  
Martín Fuchs ◽  
...  

This chapter reports an investigation into possible brain bases for negation. It begins with a review of negation experiments that used behavioral studies (measuring Reaction Time—RT), and functional Magnetic Resonance Imaging (fMRI) experiments that sought to identify local activations that correlate with the presence of negation. The chapter dwells on a major methodological problem that permeates the experimental study of negation processing, and proposes a solution: instead of overt negation, we study expressions that contain a covert negation—expressions that are Downward Entailing (DE) as evinced by their ability to reverse inferences and license NPIs in their scope. DE operators are thus taken to contain a hidden, or covert, negation, and contrast with the Upward Entailing counterparts (few vs. many; less vs. more). The chapter reviews behavioral experiments in healthy adults that indicate that DE has a processing cost, and an fMRI study that finds a single brain location for this computation. These results serve as a basis for an experiment on individuals with Broca’s aphasia. Tests with DE and UE quantifiers with these patients resulted in a mixed picture, which is discussed and its implications are derived.

2002 ◽  
Vol 27 (6) ◽  
pp. 514-519 ◽  
Author(s):  
G. LUNDBORG ◽  
B. ROSÉN ◽  
L. KNUTSSON ◽  
S. HOLTÅS ◽  
F. STÅHLBERG ◽  
...  

Hand-held vibrating tools may result in neuromuscular dysfunction and vasospastic problems of the hand. Sensory and motor dysfunction can be explained by injury to peripheral structures, but could also be due to changes in cortical somatotopic mapping of the hand in the brain. The purpose of the present study was to use functional magnetic resonance imaging (fMRI) to assess the somatotopic cortical representation of the hands of workers subjected to occupational vibration. The study included six men with severe vibration exposures who were suffering from hand–arm-vibration syndrome (HAVS) and six controls. The analysis focused on the pattern and degree of activation of contra- and ipsilateral hemispheres of the brain with tactile stimulation and motor activation of the hand. These stimulations resulted in well-defined activation of the contralateral, and to a lesser extent the ipsilateral hemisphere. Statistical analysis of this limited patient material did not indicate any significant somatotopic cortical changes following long-term exposure to vibrating hand-held tools, although there was a tendency to a shift of activation towards the more cranial parts of the cortex in the patient group.


2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Susan Thomas ◽  
Shobini L. Rao

A mantra is a word or phrase repeated aloud or silently and used to focus attention. Meditation using mantras is widely practiced in India. However, research on the effects of mantra meditation on the brain is sparse. The aim was to study the effect of listening to Gayatri mantra on the brain using Elecroencephalograph (EEG) functional Magnetic Resonance Imaging (fMRI). Sample included 8 meditation naive subjects, who have not been practicing any form of meditation. There were 12 subjects for the EEG study and 8 subjects for the fMRI study. The results showed that the areas that had maximum activation were the bilateral superior temporal gyri, right temporal lobe, right insula, left inferior parietal lobule, lateral globuspallidus and culmen of the cerebellum. There were some EEG changes before and after listening to Gayatri mantra also, but reliable analysis could not be carried out due to the less number of samples. Results indicate that mantra meditation can result in changes in the brain.


Author(s):  
Mark A Thornton ◽  
Diana I Tamir

Abstract The social world buzzes with action. People constantly walk, talk, eat, work, play, snooze and so on. To interact with others successfully, we need to both understand their current actions and predict their future actions. Here we used functional neuroimaging to test the hypothesis that people do both at the same time: when the brain perceives an action, it simultaneously encodes likely future actions. Specifically, we hypothesized that the brain represents perceived actions using a map that encodes which actions will occur next: the six-dimensional Abstraction, Creation, Tradition, Food(-relevance), Animacy and Spiritualism Taxonomy (ACT-FAST) action space. Within this space, the closer two actions are, the more likely they are to precede or follow each other. To test this hypothesis, participants watched a video featuring naturalistic sequences of actions while undergoing functional magnetic resonance imaging (fMRI) scanning. We first use a decoding model to demonstrate that the brain uses ACT-FAST to represent current actions. We then successfully predicted as-yet unseen actions, up to three actions into the future, based on their proximity to the current action’s coordinates in ACT-FAST space. This finding suggests that the brain represents actions using a six-dimensional action space that gives people an automatic glimpse of future actions.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yunqi Bu ◽  
Johannes Lederer

Abstract Graphical models such as brain connectomes derived from functional magnetic resonance imaging (fMRI) data are considered a prime gateway to understanding network-type processes. We show, however, that standard methods for graphical modeling can fail to provide accurate graph recovery even with optimal tuning and large sample sizes. We attempt to solve this problem by leveraging information that is often readily available in practice but neglected, such as the spatial positions of the measurements. This information is incorporated into the tuning parameter of neighborhood selection, for example, in the form of pairwise distances. Our approach is computationally convenient and efficient, carries a clear Bayesian interpretation, and improves standard methods in terms of statistical stability. Applied to data about Alzheimer’s disease, our approach allows us to highlight the central role of lobes in the connectivity structure of the brain and to identify an increased connectivity within the cerebellum for Alzheimer’s patients compared to other subjects.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuka Inamochi ◽  
Kenji Fueki ◽  
Nobuo Usui ◽  
Masato Taira ◽  
Noriyuki Wakabayashi

AbstractSuccessful adaptation to wearing dentures with palatal coverage may be associated with cortical activity changes related to tongue motor control. The purpose was to investigate the brain activity changes during tongue movement in response to a new oral environment. Twenty-eight fully dentate subjects (mean age: 28.6-years-old) who had no experience with removable dentures wore experimental palatal plates for 7 days. We measured tongue motor dexterity, difficulty with tongue movement, and brain activity using functional magnetic resonance imaging during tongue movement at pre-insertion (Day 0), as well as immediately (Day 1), 3 days (Day 3), and 7 days (Day 7) post-insertion. Difficulty with tongue movement was significantly higher on Day 1 than on Days 0, 3, and 7. In the subtraction analysis of brain activity across each day, activations in the angular gyrus and right precuneus on Day 1 were significantly higher than on Day 7. Tongue motor impairment induced activation of the angular gyrus, which was associated with monitoring of the tongue’s spatial information, as well as the activation of the precuneus, which was associated with constructing the tongue motor imagery. As the tongue regained the smoothness in its motor functions, the activation of the angular gyrus and precuneus decreased.


2009 ◽  
Vol 364 (1522) ◽  
pp. 1407-1416 ◽  
Author(s):  
Katherine Woollett ◽  
Hugo J. Spiers ◽  
Eleanor A. Maguire

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.


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