Damage to the frontal and parietal lobes of the brain and conditioned reflexes in unconstrained subjects

1964 ◽  
Vol 55 (4) ◽  
pp. 378-380
Author(s):  
A. N. Sovetov
2020 ◽  
Vol 10 (3-4) ◽  
pp. 158-165
Author(s):  
Yalini Thivaharan ◽  
Indira Deepthi Gamage Kitulwatte

Introduction: Investigation into explosions is one of the major areas in forensic medicine and pathology. Medico legal issues associated with these deaths are diverse and forensic experts are often expected to make clarifications. Assistance of a methodical scientific investigation of such a death in evaluation of unanswered medico legal issues, of an autopsy of one of the victims of Easter Sunday explosions is discussed. Case history: The deceased was a 15-year-old girl who was participating in the Easter mass at St. Sebastian’s Church - Kattuwapaitya, Negombo, Sri Lanka when a suicide bomber blew himself up. The mother of the deceased noticed the deceased being rushed to the hospital. However, she was pronounced dead on admission. Pre-autopsy radiology revealed spherical shrapnel in the temporal region. At autopsy, the fatal injury was found on the head and a detailed study revealed skull fractures associated with penetration by 3 shrapnels. There was a keyhole lesion among the penetrations. Internal examination revealed an extensive dural tear underlying the compound fracture. The brain was grossly edematous with lacerations on the frontal and parietal lobes associated with localized subarachnoid hemorrhage. There were multiple underlying contusions on bilateral frontal white matter. Small subarachnoid haemorrhage was noted on the basal aspect of the brain. Discussion: Careful evaluation of the autopsy findings assisted in formulating the opinion scientifically on event reconstruction including the proximity of the victim to the epicenter of explosion and nature of explosive device, period of survival, mechanism of causation of skull fractures and the mechanism of death in addition to the cause of death. Conclusion: A forensic pathologist following a meticulous autopsy examination, along with a team of ballistic experts and specially trained police personnel play a pivotal task in analyzing a scene of explosion and an autopsy of a victim, in concluding the case and in bringing justice to all the victims and survivors of the catastrophe.


1994 ◽  
Vol 10 (4-5) ◽  
pp. 561-571
Author(s):  
Gunnar Heuser ◽  
Ismael Mena ◽  
Francisca Alamos

Exposures to neurotoxic chemicals such as pesticides, glues, solvents, etc. are known to induce neurologic and psychiatric symptomatology. We report on 41 patients 16 young patients (6 males, 10 females, age 34 8 yrs.) and 25 elderly patients (9 males, 16 females, age 55 7 yrs). Fifteen of them were exposed to pesticides, and 29 to solvents. They were studied with quantitative and qualitative analysis of regional cerebral bood flow (rCBF), performed with 30 mCi of Xe-133 by inhalation, followed by 30 mCi of Tc-HMPAO given intravenously. Imaging was performed with a brain dedicated system, distribution of rCBF was assessed with automatic ROI definition, and HMPAO was normalized to maximal pixel activity in the brain. Results of Xe rCBF are expressed as mean and S.D. in ml/min/100g, and HMPAO as mean and S.D. uptake per ROI, and compared with age-matched controls 10 young and 20 elderly individuals. Neurotoxics HMPAO Uptake Young Elderly R. Orbital frontal R. Dorsal frontal .70 .66 p < 0.05 R. Temporal .64 p < 0.001 R. Parietal .66 .66 We conclude that patients exposed to chemicals present with diminished CBF, worse in the right hemisphere, with random presentation of areas of hypoperfusion, more prevalent in the dorsal frontal and parietal lobes. These findings are significantly different from observations in patients with chronic fatigue and depression, suggesting primary cortical effect, possibly due to a vasculitis process.


Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 826
Author(s):  
Chi-Wen Jao ◽  
Jiann-Horng Yeh ◽  
Yu-Te Wu ◽  
Li-Ming Lien ◽  
Yuh-Feng Tsai ◽  
...  

The morphological changes in cortical parcellated regions during aging and whether these atrophies may cause brain structural network intra- and inter-lobe connectivity alterations are subjects that have been minimally explored. In this study, a novel fractal dimension-based structural network was proposed to measure atrophy of 68 parcellated cortical regions. Alterations of structural network parameters, including intra- and inter-lobe connectivity, were detected in a middle-aged group (30–45 years old) and an elderly group (50–65 years old). The elderly group exhibited significant lateralized atrophy in the left hemisphere, and most of these fractal dimension atrophied regions were included in the regions of the “last-in, first-out” model. Globally, the elderly group had lower modularity values, smaller component size modules, and fewer bilateral association fibers. They had lower intra-lobe connectivity in the frontal and parietal lobes, but higher intra-lobe connectivity in the temporal and occipital lobes. Both groups exhibited similar inter-lobe connecting pattern. The elderly group revealed separations, sparser long association fibers, commissural fibers, and lateral inter-lobe connectivity lost effect, mainly in the right hemisphere. New wiring and reconfiguring modules may have occurred within the brain structural network to compensate for connectivity, decreasing and preventing functional loss in cerebral intra- and inter-lobe connectivity.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Hyeonseok Kim ◽  
Natsue Yoshimura ◽  
Yasuharu Koike

Error-related brain activation has been investigated for advanced brain-machine interfaces (BMI). However, how a delayed response of cursor control in BMI systems should be handled is not clear. Therefore, the purpose of this study was to investigate how participants responded to delayed cursor control. Six subjects participated in the experiment and performed a wrist-bending task. For three distinct delay intervals (an interval where participants could not perceive the delay, an interval where participants could not be sure whether there was a delay or not, and an interval where participants could perceive the delay), we assessed two types of binary classifications (“Yes + No” vs. “I don’t know” and “Yes” vs. “No”) based on participants’ responses and applied delay times (thus, four types of classification, overall). For most participants, the “Yes vs. No” classification had higher accuracy than “Yes + No” vs. “I don’t know” classification. For the “Yes + No” vs. “I don’t know” classification, most participants displayed higher accuracy based on response classification than delay classification. Our results demonstrate that a class only for “I don’t know” largely contributed to these differences. Many independent components (ICs) that exhibited high accuracy in “Yes + No” vs. “I don’t know” response classification were associated with activation of areas from the frontal to parietal lobes, while many ICs that showed high accuracy in the “Yes vs. No” classification were associated with activation of an area ranging from the parietal to the occipital lobes and were more broadly localized in cortical regions than was seen for the “Yes + No” vs. “I don’t know” classification. Our results suggest that small and large delays in real-time cursor control differ not only in the magnitude of the delay but should be handled as distinct information in different ways and might involve differential processing in the brain.


1995 ◽  
Vol 40 (2) ◽  
pp. 89-102 ◽  
Author(s):  
George Windholz

In the 1920s, as I. P. Pavlov was growing old, he began to show interest in the general process of aging. In order to study senescence, Pavlov and his disciples experimented in the laboratory on old dogs by the method of salivary conditioning and also observed aged psychotic patients in the psychiatric clinic. Pavlov never formulated a theory of aging per se, but incorporated his findings on aging into his theory of higher nervous activity, which dealt with the function of the brain in higher organisms' adaptation to the environment. Some of the major findings showed that salivary conditioning and stimulus differentiation were difficult to establish in old dogs. Conditioned reflexes established earlier in dogs' lives, however, persisted into old age. Pavlov explained these findings in terms of hypothesized neural processes in the brain; with age, neural processes deteriorate and their reactivity to the environment wanes. In light of more recent research, Pavlov's views on senescence, with the exception of the relation of conditioning to aging, are mainly of historical interest.


Neurology ◽  
2019 ◽  
Vol 92 (12) ◽  
pp. 575-578 ◽  
Author(s):  
Richard Leblanc

Wilder Penfield's contributions to the structure–function relationships of the brain are well-known. Less well-known is the influence that Ivan Pavlov and the conditioned reflex had on Penfield's understanding of epileptogenesis, and on his concept of the acquisition of memories, language, and perception—what Penfield referred to as the physiology of the mind. Penfield invoked conditioned reflexes to explain responses to electrocortical stimulation of the temporal lobes that encompass memory, perception, and affect. Penfield referred to these responses as experiential phenomena since he considered that they constituted a record of past experiences. Penfield also invoked the conditioned reflex to explain the acquisition of the interpretive aspects of written and spoken language in the dominant temporal cortex. This article describes and discusses these neglected aspects of Penfield's work, and how they contributed to a broader understanding of the functional integration of the temporal cortex and the limbic system.


2019 ◽  
Vol 11 (2) ◽  
pp. 98
Author(s):  
Artur Jaschke

Music activates a wide array of brain areas involved in different functions such as   perception, processing and execution of music. Understanding musical processes in the brain has multiple implications in the neuro- and health sciences.  Challenging the brain with a multisensory stimulus such as music activates responses beyond the auditory cortex of the temporal lobe. Other areas that are involved include the frontal lobes, parietal lobes, areas of the limbic system such as the amygdala, hippocampus and thalamus, the cerebellum and the brainstem. Nonetheless, there has been no attempt to summarize all involved brain areas in music into one overall encompassing map. This may well be, as there has been no thorough theory introduced, which would allow an initial point of departure in creating such a mapTherefore, a thorough systematic review has been conducted to identify all mentioned neural connections involved in the perception, processing and execution of music.  Communication between the thalamic nuclei is the initial step in multisensory integration, which lies at the base of the neural networks as proposed in this paper. Against this background, this manuscript introduces the to our knowledge first map of all brain regions involved in the perception, processing and execution of music.Consequently, placing thalamic multisensory integration at the core of this atlas allowed us to create a preliminary theory to explain the complexity of music induced brain activation.


2021 ◽  
Vol 2071 (1) ◽  
pp. 012041
Author(s):  
I Amalina ◽  
A Saidatul ◽  
C Y Fook ◽  
R F Navea

Abstract The brain signals recorded by EEG devices are largely developed in for biometric authentication purposes. Those signals are very informative and reliable to be classified using signal processing. In this paper, the feature extraction and feature fusion are further studied to observe their performance towards the typing tasks. The signals are pre-processed to eliminate the unwanted noise present in the signals. The feature extraction method such as Welch’s method, Burg’s method and Yule Walk’s method are applied to extract the mean, median, standard deviation and variance in the data. Nonlinear feature such as fuzzy entropy is also been extracted. The extracted features are further classified by using k-Nearest Neighbour (k-NN), Random Forest (RF) and Ensemble Bagged Tree (EBT). The performance of feature extraction and feature fusion through concatenation are recorded and compared. For comparison, the feature fusion shows a better performance accuracy rather than feature extraction. The highest percentage accuracy was produced by Burg’s method for frontal-parietal lobes feature fusion which is 95.94% using Ensemble Bagged Tree (EBT).


2021 ◽  
Vol 118 (12) ◽  
pp. e2021474118
Author(s):  
Cameron T. Ellis ◽  
Lena J. Skalaban ◽  
Tristan S. Yates ◽  
Nicholas B. Turk-Browne

Young infants learn about the world by overtly shifting their attention to perceptually salient events. In adults, attention recruits several brain regions spanning the frontal and parietal lobes. However, it is unclear whether these regions are sufficiently mature in infancy to support attention and, more generally, how infant attention is supported by the brain. We used event-related functional magnetic resonance imaging (fMRI) in 24 sessions from 20 awake behaving infants 3 mo to 12 mo old while they performed a child-friendly attentional cuing task. A target was presented to either the left or right of the infant’s fixation, and offline gaze coding was used to measure the latency with which they saccaded to the target. To manipulate attention, a brief cue was presented before the target in three conditions: on the same side as the upcoming target (valid), on the other side (invalid), or on both sides (neutral). All infants were faster to look at the target on valid versus invalid trials, with valid faster than neutral and invalid slower than neutral, indicating that the cues effectively captured attention. We then compared the fMRI activity evoked by these trial types. Regions of adult attention networks activated more strongly for invalid than valid trials, particularly frontal regions. Neither behavioral nor neural effects varied by infant age within the first year, suggesting that these regions may function early in development to support the orienting of attention. Together, this furthers our mechanistic understanding of how the infant brain controls the allocation of attention.


2020 ◽  
Vol 4 (1) ◽  
pp. 23-30
Author(s):  
Shuhada J.M ◽  
Husbani M.A.R ◽  
A I A Hamid ◽  
Muhammad

The default mode network (DMN) is involved in conscious, resting state cognition and is thought to be affected in TLE where seizures cause impairment of consciousness. The study aimed to evaluate the brain activation of the DMN regions in both temporal lobe epilepsy (TLE) patients  and healthy subjects by using resting-state functional Magnetic Resonance Imaging (rsfMRI) technique. A same number of fourteen participants with age and gender matched for the healthy subjects and TLE patients were selected with the average age is 36.9 and 37.0 years old, respectively. The rsfMRI imaging protocol was executed using a 3-T Phillips Achieva MRI scanner at the Radiology Department, Hospital Universiti Sains Malaysia (HUSM). For healthy subjects, the brain activation cluster in bilateral superior parietal lobes (SPL),precuneus (PRE), supramarginal gyrus (SMG) and inferior parietal lobes (IPL) were found higher than TLE patients. While for TLE patients displays higher activation clusters in bilateral MFG, STG, and ANG. The result from  random effects (RFX) on  two-sample t-tests thresholded at p = 0.001 revealed that the TLE patients display significantly higher activations on the bilateral superior frontal gyrus (SFG), left SMG, left middle frontal gyrus (MFG) and right IPL. However for the core-region of DMN such as  bilateral precuneus, left MFG, bilateral STG and bilateral IPL were significantly activated but the number of voxels survives are substantially smaller than other regions such as bilateral SFG. The findings suggested that TLE patients may suffer from an impairment in some DMN region, which may cause certain neuropsychological and cognitive degradation.       Keywords: resting-state fMRI, temporal lobe epilepsy, brain activation, two-sample t-tests


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