scholarly journals Why Bilateral Damage Is Worse than Unilateral Damage to the Brain

2013 ◽  
Vol 25 (12) ◽  
pp. 2107-2123 ◽  
Author(s):  
Anna C. Schapiro ◽  
James L. McClelland ◽  
Stephen R. Welbourne ◽  
Timothy T. Rogers ◽  
Matthew A. Lambon Ralph

Human and animal lesion studies have shown that behavior can be catastrophically impaired after bilateral lesions but that unilateral damage often produces little or no effect, even controlling for lesion extent. This pattern is found across many different sensory, motor, and memory domains. Despite these findings, there has been no systematic, computational explanation. We found that the same striking difference between unilateral and bilateral damage emerged in a distributed, recurrent attractor neural network. The difference persists in simple feedforward networks, where it can be understood in explicit quantitative terms. In essence, damage both distorts and reduces the magnitude of relevant activity in each hemisphere. Unilateral damage reduces the relative magnitude of the contribution to performance of the damaged side, allowing the intact side to dominate performance. In contrast, balanced bilateral damage distorts representations on both sides, which contribute equally, resulting in degraded performance. The model's ability to account for relevant patient data suggests that mechanisms similar to those in the model may operate in the brain.

1976 ◽  
Vol 82 (4) ◽  
pp. 785-791 ◽  
Author(s):  
Shaul Feldman ◽  
Nissim Conforti

ABSTRACT In order to elucidate the mechanisms and the sites of action of the negative feedback of corticoids in the regulation of ACTH secretion, the effects of systemically administered dexamethasone on adrenocortical responses to ether stress were studied in intact rats and in 11 experimental groups. These included animals with partial anterior, anterolateral, posterolateral, posterior and small posterior deafferentations as well as bilateral lesions in the medial forebrain bundle (MFB), fasciculus longitudinalis dorsalis (FLD), medial and lateral midbrain reticular formation (MRF) and in the ventrolateral pons. In rats with posterior hypothalamic deafferentation the degree of the inhibitory effect of dexamethasone was much smaller than that in intact animals. In animals with lesions in the FLD and MRF, dexamethasone also produced a reduction in the suppression of the response, though the difference was not significant. Bilateral lesions in the MFB and MP have on the other hand very significantly enhanced the effect of the negative feedback of dexamethasone when compared to intact rats. These data would indicate that hypothalamic deafferentations and brain lesions may change the sensitivity of the hypothalamus for the feedback control of corticoids and that there exist two antagonistic systems, an inhibitory and a facilitatory, in the brain which mediate this effect.


2016 ◽  
Vol 1 (2) ◽  
pp. 1-41
Author(s):  
Pangeran Manurung

Eksegesa John 1 : 1-18 shows that the Jehovah's Witness teachings deviate from the truth of the Bible and dangerous for Christians . The danger Christology of Jehovah's Witnesses should be bringing us to the prudence and discretion to reject it . It can be said that Jehovah's Witnesses do not include Christianity in accordance with the search results against their teachings . first ; they do not recognize the Bible that has been issued by the Indonesian National Bible Institute and consider if the Bible has too much harm to use their own New Translation of the Holy Scriptures that have been proven not a translation , but just a collection of interpretations and teachings of their leader alone . second ; Jehovah's Witnesses do not acknowledge Jesus as Lord and Savior only . They simply believe that salvation is obtained through belief in Jehovah and his kingdom and perform service message and follow the trial associations .                Before errors interfere Christology Christology of Jehovah's Witnesses Bible , please note that the topic of Christology is the difference between Christianity and other religions . This discussion has also become one of the topics that face many attacks from the outside or from within Christianity , either in the form of religion , philosophy , and ideology . The debate on this topic appeared since the beginning of Christianity , and give rise to a long and complex debate for nearly three centuries ( 300 years ) !! . Such debates will continue to exist throughout the period and just a rehash issues that had once appeared . And Christians should study the various debates and views of the ever emerging that are not easily fooled by the views back to this era .Eksegesa John 1 : 1-18 has been done and produce a biblical Christology and biblical correct . The truth is not in doubt because of the analysis conducted in accordance with the procedures and rules that apply in general . Now if Christology Christology of John compared with Jehovah's Witnesses, it will show a striking difference . Once observed , Christology Witnesses builds upon the interpretation of individuals who previously have had a negative Christological doctrine .                Conclusion those who think that Jesus is the firstborn of Creation ; Jesus was a human being ; Jesus is God in creating a peer ; Jesus lower than God , Jesus is the Angel Gabriel , and other Christological doctrine which basically degrading nature of Christ is a form of insult to the majesty of Christ . The Bible clearly and emphatically teaches that Christ is God incarnate , private alpha and omega , the creator of all that exists , and the equivalent of God the Father . Summing Christ as superior human or clear eldest creation is false teachings . The followers of Jehovah's Witnesses must repent. Amen


Author(s):  
F. Riva ◽  
T. Fracasso ◽  
A. Guerra ◽  
P. Genet

AbstractIn shooting crimes, ballistics tests are often recommended in order to reproduce the wound characteristics of the involved persons. For this purpose, several “simulants” can be used. However, despite the efforts in the research of “surrogates” in the field of forensic ballistic, the development of synthetic models needs still to be improved through a validation process based on specific real caseworks. This study has been triggered by the findings observed during the autopsy performed on two victims killed in the same shooting incident, with similar wounding characteristics; namely two retained head shots with ricochet against the interior wall of the skull; both projectiles have been recovered during the autopsies after migration in the brain parenchyma. The thickness of the different tissues and structures along the bullets trajectories as well as the incident angles between the bullets paths and the skull walls have been measured and reproduced during the assemblage of the synthetic head models. Two different types of models (“open shape” and “spherical”) have been assembled using leather, polyurethane and gelatine to simulate respectively skin, bone and soft tissues. Six shots have been performed in total. The results of the models have been compared to the findings of post-mortem computed tomography (PMCT) and the autopsy findings.Out of the six shots, two perforated the models and four were retained. When the projectile was retained, the use of both models allowed reproducing the wounds characteristics observed on both victims in terms of penetration and ricochet behaviour. However, the projectiles recovered from the models showed less deformation than the bullets collected during the autopsies. The “open shape” model allowed a better controlling on the shooting parameters than the “spherical” model. Finally, the difference in bullet deformation could be caused by the choice of the bone simulant, which might under-represent either the strength or the density of the human bone. In our opinion, it would be worth to develop a new, more representative material for ballistic which simulates the human bone.


2008 ◽  
Vol 10 (2) ◽  
pp. 96-108 ◽  
Author(s):  
Fred A. Baughman

All physicians attend medical school and learn of (a) all things physically normal; anatomy, physiology, and chemistry, (b) all things physically abnormal; pathology, disease, and (c) how to tell the difference. Diagnosis is the first obligation of every physician to every patient, and must precede treatment. Diagnosis first asks, “Is there a physical abnormality (physical abnormality = disorder = disease), yes or no?” Patients with no abnormality (no physical abnormality = no disorder = no disease = normal) are referred to as having “no evidence or disease” (NED) or “no organic disease” (NOD). Their problems may be psychological or psychiatric, but they are not medical or surgical. In patients found to have an abnormality, diagnosis now asks, “Which disease?” Psychiatrists are the only physicians who do not perform physical diagnosis. The absence of disease is determined for them by other physicians, usually referring physicians. In 1948 the previously conjoint specialty of neuropsychiatry was divided into neurology—responsible for the diagnosis and treatment or physical/organic disease of the nervous system—and psychiatry—responsible for the treatment of emotional and psychological problems, none of them due to organic diseases. Nor did psychiatry object to this scientific division of labor at the time. However, in the 1950s, with the advent of psychotropic drugs, psychiatry, increasingly in league with the pharmaceutical industry, began referring to psychological diagnoses as disorders/diseases/chemical imbalances of the brain, albeit with no proof or science. In a congressional hearing in 1970, psychiatrists and federal officials, including the Food and Drug Administration and the Department of Health, Education, and Welfare, represented hyperkinetic disorder (HKD) to be a disorder/disease of the brain leading to the appropriation of millions of dollars for research, diagnosis and treatment into the drug treatment of school children said to have the new disease HKD. HKD became ADD, then ADHD, a disorder/disease/chemical imbalance always in need of a “chemical balancer”—a pill. Without proof of an abnormality/disorder/disease, the ADHD epidemic grew from 150,000 in 1970 to 6 million to 7 million today, the most common childhood diagnosis in the United States, a multi-billion dollar industry, and a model for all 374 DSM–IV psychological/psychiatric diagnoses—none of them actual diseases. As such, psychiatry is not a legitimate branch of medicine deserving scientific-fiscal parity; rather, collectively, it is the greatest health care fraud in history. Every time a so-called chemical imbalance is diagnosed, a patient’s right to informed consent has been abrogated. Every time a medically normal person is treated with a psychotropic chemical balancer—a pill—their first and only abnormality is the iatrogenic intoxication: poisoning.


2005 ◽  
Vol 17 (10) ◽  
pp. 2139-2175 ◽  
Author(s):  
Naoki Masuda ◽  
Brent Doiron ◽  
André Longtin ◽  
Kazuyuki Aihara

Oscillatory and synchronized neural activities are commonly found in the brain, and evidence suggests that many of them are caused by global feedback. Their mechanisms and roles in information processing have been discussed often using purely feedforward networks or recurrent networks with constant inputs. On the other hand, real recurrent neural networks are abundant and continually receive information-rich inputs from the outside environment or other parts of the brain. We examine how feedforward networks of spiking neurons with delayed global feedback process information about temporally changing inputs. We show that the network behavior is more synchronous as well as more correlated with and phase-locked to the stimulus when the stimulus frequency is resonant with the inherent frequency of the neuron or that of the network oscillation generated by the feedback architecture. The two eigenmodes have distinct dynamical characteristics, which are supported by numerical simulations and by analytical arguments based on frequency response and bifurcation theory. This distinction is similar to the class I versus class II classification of single neurons according to the bifurcation from quiescence to periodic firing, and the two modes depend differently on system parameters. These two mechanisms may be associated with different types of information processing.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Helen Kathryn Cyrus

Purpose Overview of coaching for recovery. The paper aims to show an overview of work that was carried out over 11 years with groups of mental health and physical staff. As the facilitator who had run this course for the duration in Nottingham, this was an excellent opportunity to be at the forefront of a brand new project. Design/methodology/approach The introduction of the skills are taught over two consecutive days followed by a further day a month later. The idea of coaching is to be enabled to find the answers in themselves by the use of powerful questions and using the technique of the grow model, combined with practice enables the brain to come up with its own answers. Using rapport and enabling effective communication to deliver the outcome. Findings Evidence from staff/clients and the purpose of the paper shows that when you step back it allows the individual patients/staff to allow the brain to process to create to come up with their solutions, which then helps them to buy into the process and creates ownership. Research limitations/implications The evidence suggests that the approach that was there prior to the course was very much a clinical approach to working with clients and treating the person, administering medication and not focussing on the inner person or personal recovery. The staff review has shown that in the clinical context change is happening from the inside out. Practical implications “Helps change culture”; “change of work practice”; “it changed staff focus – not so prescriptive”; “powerful questions let clients come to their own conclusions”; “coaching gives the ability to find half full. Helps to offer reassurance and to find one spark of hope”. Social implications This has shown that the approach is now person-centred/holistic. This has been the “difference that has made the difference”. When this paper looks at the issues from a different angle in this case a coaching approach, applying technique, knowledge and powerful questions the results have changed. The same clients, same staff and same problems but with the use of a different approach, there is the evidence of a different outcome, which speaks for itself. The coaching method is more facilitative, therefore it illicit’s a different response, and therefore, result. Originality/value The results/evidence starts with the individual attending and their commitment to the process over the two-day course. Then going away for the four weeks/six for managers and a commitment again to practice. Returning to share the impact if any with the group. This, in turn, helps to inspire and gain motivation from the feedback to go back to work invigorated to keep going.


1993 ◽  
Vol 265 (3) ◽  
pp. R481-R486 ◽  
Author(s):  
Y. Hirosue ◽  
A. Inui ◽  
A. Teranishi ◽  
M. Miura ◽  
M. Nakajima ◽  
...  

To examine the mechanism of the satiety-producing effect of cholecystokinin (CCK) in the central nervous system, we compared the potency of intraperitoneally (ip) or intracerebroventricularly (icv) administered CCK-8 and its analogues on food intake in fasted mice. The icv administration of a small dose of CCK-8 (0.03 nmol/brain) or of Suc-(Thr28, Leu29, MePhe33)-CCK-7 (0.001 nmol/brain) suppressed food intake for 20 min, whereas CCK-8 (1 nmol/kg, which is equivalent to 0.03 nmol/brain) or Suc-(Thr28, Leu29, MePhe33)-CCK-7 (1 nmol/kg) had satiety effect after ip administration. Dose-response studies indicated the following rank order of potency: Suc-CCK-7 > or = Suc-(Thr28, Leu29, MePhe33)-CCK-7 > or = CCK-8 > or = (Nle28,31)-CCK-8 >> desulfated CCK-8 = CCK-4 = 0 in the case of ip administration and Suc-(Thr28, Leu29, MePhe33)-CCK-7 >> Suc-CCK-7 > or = CCK-8 > or = (Nle28,31)-CCK-8 >> desulfated CCK-8 = CCK-4 = 0 in the case of icv administration. The selective CCK-A receptor antagonist MK-329 reversed the inhibitory effect of the centrally as well as peripherally administered CCK-8, or of Suc-(Thr28, Leu29, MePhe33)-CCK-7, whereas the selective CCK-B receptor antagonist L-365260 did not. The icv administered CCK-8 did not appear in the peripheral circulation. These findings suggest the participation of CCK-A receptors in the brain in mediating the satiety effect of CCK and the difference in CCK-A receptors in the brain and peripheral tissues.


2018 ◽  
Vol 29 (9) ◽  
pp. 3922-3931 ◽  
Author(s):  
Qinggang Yu ◽  
Nobuhito Abe ◽  
Anthony King ◽  
Carolyn Yoon ◽  
Israel Liberzon ◽  
...  

Abstract Recent evidence suggests a systematic cultural difference in the volume/thickness of prefrontal regions of the brain. However, origins of this difference remain unclear. Here, we addressed this gap by adopting a unique genetic approach. People who carry the 7- or 2-repeat (7/2-R) allele of the dopamine D4 receptor gene (DRD4) are more sensitive to environmental influences, including cultural influences. Therefore, if the difference in brain structure is due to cultural influences, it should be moderated by DRD4. We recruited 132 young adults (both European Americans and Asian-born East Asians). Voxel-based morphometry showed that gray matter (GM) volume of the medial prefrontal cortex and the orbitofrontal cortex was significantly greater among European Americans than among East Asians. Moreover, the difference in GM volume was significantly more pronounced among carriers of the 7/2-R allele of DRD4 than among non-carriers. This pattern was robust in an alternative measure assessing cortical thickness. A further exploratory analysis showed that among East Asian carriers, the number of years spent in the U.S. predicted increased GM volume in the orbitofrontal cortex. The present evidence is consistent with a view that culture shapes the brain by mobilizing epigenetic pathways that are gradually established through socialization and enculturation.


1997 ◽  
Vol 78 (2) ◽  
pp. 960-976 ◽  
Author(s):  
Fredrik Ullén ◽  
Tatiana G. Deliagina ◽  
Grigori N. Orlovsky ◽  
Sten Grillner

Ullén, Fredrik, Tatiana G. Deliagina, Grigori N. Orlovsky, and Sten Grillner. Visual pathways for postural control and negative phototaxis in lamprey. J. Neurophysiol. 78: 960–976, 1997. The functional roles of the major visuo-motor pathways were studied in lamprey. Responses to eye illumination were video-recorded in intact and chronically lesioned animals. Postural deficits during spontaneous swimming were analyzed to elucidate the roles of the lesioned structures for steering and postural control. Eye illumination in intact lampreys evoked the dorsal light response, that is, a roll tilt toward the light, and negative phototaxis, that is a lateral turn away from light, and locomotion. Complete tectum-ablation enhanced both responses. During swimming, a tendency for roll tilts and episodes of vertical upward swimming were seen. The neuronal circuitries for dorsal light response and negative phototaxis are thus essentially extratectal. Responses to eye illumination were abolished by contralateral pretectum-ablation but normal after the corresponding lesion on the ipsilateral side. Contralateral pretectum thus plays an important role for dorsal light response and negative phototaxis. To determine the roles of pretectal efferent pathways for the responses, animals with a midmesencephalichemisection were tested. Noncrossed pretecto-reticular fibers from the ipsilateral pretectum and crossed fibers from the contralateral side were transected. Eye illumination on the lesioned side evoked negative phototaxis but no dorsal light response. Eye illumination on the intact side evoked an enhanced dorsal light response, whereas negative phototaxis was replaced with straight locomotion or positive phototaxis. The crossed pretecto-reticular projection is thus most important for the dorsal light response, whereas the noncrossed projection presumably plays the major role for negative phototaxis. Transection of the ventral rhombencephalic commissure enhanced dorsal light response; negative phototaxis was retained with smaller turning angles than normal. Spontaneous locomotion showed episodes of backward swimming and deficient roll control (tilting tendency). Transections of different spinal pathways were performed immediately caudal to the brain stem. All spinal lesions left dorsal light response in attached state unaffected; this response presumably is mediated by the brain stem. Spinal hemisection impaired all ipsiversive yaw turns; the animals spontaneously rolled to the intact side. Bilateral transection of the lateral columns impaired all yaw turns, whereas roll control and dorsal light response were normal. After transection of the medial spinal cord, yaw turns still could be performed whereas dorsal light response was suppressed or abolished, and a roll tilting tendency during spontaneous locomotion was seen. We conclude that the contralateral optic nerve projection to the pretectal region is necessary and sufficient for negative phototaxis and dorsal light response. The crossed descending pretectal projection is most important for dorsal light response, whereas the noncrossed one is most important for negative phototaxis. In the most rostral spinal cord, fibers for lateral yaw turns travel mainly in the lateral columns, whereas fibers for roll turns travel mainly in the medial spinal cord.


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