800,997 research outputs found

    Frontal Lobe and Psychopathy

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    This research paper presents an analysis of the functions of the frontal lobe and how damage to the frontal lobe correlates to psychopathy. Initially, it will look at how damage to the frontal lobe obstructs frontal lobe functions. The decrease in executive function, due to a reduction of blood flow to the frontal lobe following a subarachnoid hemorrhage, is explored. The correlation between cortical thickness and impulsiveness in adolescence is examined. Subsequently, the issue is then examined through the observation of groups with psychopathy and how the diagnosis relates to their frontal lobes. One study compares individuals with psychopathy to individuals who suffered lesions to their frontal cortex. Another study discusses the correlation between cortical thickness and frontal information processing; it also compares the location of where the information processing occurs for individuals with psychopathy versus non-psychopathic individuals. Lastly, the functions of the frontal lobe are compared with the characteristics of psychopathy to further understand their correlation

    Complications of frontal defects

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    A case where the severe course of an orbital phlegmon led to a functionally and cosmetically poor condition is presented. Thirty-five years later, it was possible to achieve a satisfactory result through several operations performed with interdisciplinary cooperation. The orbit and forehead were reconstructed with porous polyethylene, thus ensuring a cosmetically good result. In two operations, the left eye was freed from its upward fixation through cicatrectomy and mobilization of the mucles, so that the eyes were straight again in the primary position. There is a limited binocular visual field. Binocular vision could be restored again after an interruption of 35 years

    fMRI of Healthy Older Adults During Stroop Interference

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    The Stroop interference effect, caused by difficulty inhibiting overlearned word reading, is often more pronounced in older adults. This has been proposed to be due to declines in inhibitory control and frontal lobe functions with aging. Initial neuroimaging studies of inhibitory control show that older adults have enhanced activation in multiple frontal areas, particularly in inferior frontal gyrus, indicative of recruitment to aid with performance of the task. The current study compared 13 younger and 13 older adults, all healthy and well educated, who completed a Stroop test during functional magnetic resonance imaging. Younger adults were more accurate across conditions, and both groups were slower and less accurate during the interference condition. The groups exhibited comparable activation regions, but older adults exhibited greater activation in numerous frontal areas, including the left inferior frontal gyrus. The results support the recruitment construct and suggest, along with previous research, that the inferior frontal gyrus is important for successful inhibition

    Comparison of different FFT-based methods for computing the mechanical response of heteregoneous materials

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    International audienceThe last decade has witnessed a growing interest for the so-called " FFT-based methods " for computing the overall and local properties of heterogeneous materials submitted to mechanical solicita-tions. Since the original method was introduced by Moulinec and Suquet [1], several authors have proposed different algorithms to better deal with non-linear materials or with materials with highly contrasted mechanical properties between their constituents. The study concerns a linear elastic material-although the methods involved can be extended into the case of non-linear behavior-submitted to a prescribed overall strain E. The stiffness tensor c(x) of the material varies with the position x. The numerical method proposed by Moulinec & Suquet lies on the iterative resolution of the Lippmann-Schwinger equation and can be summarized by the following relation between two successive iterates ε i and ε i+1 of the strain field: ε i+1 (x) = −Γ 0 * (c(x) − c 0) : ε i (x) + E , where c 0 is the stiffness tensor of a reference medium supposed to be linear elastic, where Γ 0 is a Green operator associated to c 0 and where * denotes the convolution operator. Eyre & Milton [2], Michel et al. [3] and Monchiet & Bonnet [4] proposed different schemes to accelerate the convergence of the initial scheme. It has been recently demonstrated in [5] that the two first schemes are particular cases of the last one. On the other hand, Zeman et al. [6] proposed to use a conjugate gradient method for solving the Lippmann-Schwinger equation. The present paper aims to compare these different methods with a special attention paid to their relative efficiency and their rates of convergence

    Use of balloon catheter dilation vs. traditional endoscopic sinus surgery in management of light and severe chronic rhinosinusitis of the frontal sinus: a multicenter prospective randomized study

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    OBJECTIVE: Chronic rhinosinusitis (CRS) of the frontal sinus is a complex pathological condition and many surgical techniques were described to treat this area endoscopically, like traditional endoscopic sinus surgery (ESS) and balloon catheter dilation (BCD). PATIENTS AND METHODS: We designed a multicenter prospective randomized study to assess the validity and safety of BCD vs. ESS in symptomatological chronic rhinosinusitis of the frontal sinus enrolling a population of 102 adult patients (64 men and 38 women; overall 148 frontal sinuses studied) with non-polypoid CRS. For a better evaluation of the disease, in our study we decided to analyze both radiological (Lund-McKay CT scoring modified by Zinreich) and symptomatological results (SNOT-20 questionnaire). We divided the population affected in two groups, one with light/mild frontal CRS and the other with moderate/severe frontal CRS, basing on radiological findings at Lund-MacKay modified by Zinreich score. Every group was divided in two subgroups, in one we used BCD and in the other we used traditional ESS. RESULTS: The current literature does not support the suggestion that indications for BCD and ESS are identical, and additional research is needed to determine the role for BCD in specific patient populations. The results showed a not statistically significative difference between BCD and conventional ESS of the frontal sinus in patients with light/mild CRS and in patients with moderate/severe CRS at Lund-Mackay modified by Zinreich score. The same not statistically significative difference was observed comparing the results of SNOT-20 questionnaire in the group of light/mild frontal chronic rhinosinusitis. However, we noticed a statistically significant better outcome of SNOT-20 score in patients with moderate/severe chronic rhinosinusitis that underwent BCD of frontal sinus compared to ESS. CONCLUSIONS: BCD and ESS are two alternative weapons in the baggage of every endoscopic surgeon, even because they present similar outcomes, safeness and effectiveness both in light/mild and moderate/severe chronic rhinosinusitis of the frontal sinus. An interesting result of our study was the statistically significant better outcome of SNOT-20 score in patients that underwent BCD of frontal sinus for a moderate/severe CRS, compared to those that underwent a traditional ESS

    The role of precuneus and left inferior frontal cortex during source memory episodic retrieval

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    The posterior medial parietal cortex and left prefrontal cortex (PFC) have both been implicated in the recollection of past episodes. In a previous study, we found the posterior precuneus and left lateral inferior frontal cortex to be activated during episodic source memory retrieval. This study further examines the role of posterior precuneal and left prefrontal activation during episodic source memory retrieval using a similar source memory paradigm but with longer latency between encoding and retrieval. Our results suggest that both the precuneus and the left inferior PFC are important for regeneration of rich episodic contextual associations and that the precuneus activates in tandem with the left inferior PFC during correct source retrieval. Further, results suggest that the left ventro-lateral frontal region/ frontal operculum is involved in searching for task-relevant information (BA 47) and subsequent monitoring or scrutiny (BA 44/45) while regions in the dorsal inferior frontal cortex are important for information selection (BA 45/46). (C) 2005 Elsevier Inc. All rights reserved.NIGMS NIH HHS [2 T32 GM 07266]info:eu-repo/semantics/publishedVersio

    Non-frontal model based approach to forensic face recognition

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    In this paper, we propose a non-frontal model based approach which ensures that a face recognition system always gets to compare images having similar view (or pose). This requires a virtual suspect reference set that consists of non-frontal suspect images having pose similar to the surveillance view trace image. We apply the 3D model reconstruction followed by image synthesis approach to the frontal view mug shot images in the suspect reference set in order to create such a virtual suspect reference set. This strategy not only ensures a stable 3D face model reconstruction because of the relatively good quality mug shot suspect images but also provides a practical solution for forensic cases where the trace is often of very low quality. For most face recognition algorithms, the relative pose difference between the test and reference image is one of the major causes of severe degradation in recognition performance. Moreover, given appropriate training, comparing a pair of non-frontal images is no more difficult that comparing frontal view images

    The statistical neuroanatomy of frontal networks in the macaque

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    We were interested in gaining insight into the functional properties of frontal networks based upon their anatomical inputs. We took a neuroinformatics approach, carrying out maximum likelihood hierarchical cluster analysis on 25 frontal cortical areas based upon their anatomical connections, with 68 input areas representing exterosensory, chemosensory, motor, limbic, and other frontal inputs. The analysis revealed a set of statistically robust clusters. We used these clusters to divide the frontal areas into 5 groups, including ventral-lateral, ventral-medial, dorsal-medial, dorsal-lateral, and caudal-orbital groups. Each of these groups was defined by a unique set of inputs. This organization provides insight into the differential roles of each group of areas and suggests a gradient by which orbital and ventral-medial areas may be responsible for decision-making processes based on emotion and primary reinforcers, and lateral frontal areas are more involved in integrating affective and rational information into a common framework

    Wearing a bike helmet leads to less cognitive control, revealed by lower frontal midline theta power and risk indifference

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    A recent study claims that participants wearing a bike helmet behave riskier in a computer-based risk task compared to control participants without a bike helmet. We hypothesized that wearing a bike helmet reduces cognitive control over risky behavior. To test our hypothesis, we recorded participants' EEG brain responses while they played a risk game developed in our laboratory. Previously, we found that, in this risk game, anxious participants showed greater levels of cognitive control as revealed by greater frontal midline theta power, which was associated with less risky decisions. Here, we predicted that cognitive control would be reduced in the helmet group, indicated by reduced frontal midline theta power, and that this group would prefer riskier options in the risk game. In line with our hypothesis, we found that participants in the helmet group showed significantly lower frontal midline theta power than participants in the control group, indicating less cognitive control. We did not replicate the finding of generally riskier behavior in the helmet group. Instead, we found that participants chose the riskier option in about half of trials, no matter how risky the other option was. Our results suggest that wearing a bike helmet reduces cognitive control, as revealed by reduced frontal midline theta power, leading to risk indifference when evaluating potential behaviors
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