1,153 research outputs found
Boundary completion is automatic and dissociable from shape discrimination
Normal visual perception readily overcomes suboptimal or degraded viewing conditions through perceptual filling-in processes, enhancing object recognition and discrimination abilities. This study used visual evoked potential (VEP) recordings in conjunction with electrical neuroimaging analyses to determine the spatiotemporal brain dynamics of boundary completion and shape discrimination processes in healthy humans performing the so-called "thin/fat" discrimination task (Ringach and Shapley, 1996) with stimuli producing illusory contours. First, results suggest that boundary completion processes occur independent of subjects' accuracy on the discrimination task. Modulation of the VEP to the presence versus absence of illusory contours [the IC effect (Murray et al., 2002)] was indistinguishable in terms of response magnitude and scalp topography over the 124-186 ms poststimulus period, regardless of whether task performance was correct. This suggests that failure on this discrimination task is not primarily a consequence of failed boundary completion. Second, the electrophysiological correlates of thin/fat shape discrimination processes are temporally dissociable from those of boundary completion, occurring during a substantially later phase of processing (approximately 330-406 ms). The earlier IC effect was unaffected by whether the perceived contour produced a thin or fat shape. In contrast, later time periods of the VEP modulated according to perceived shape only in the case of stimuli producing illusory contours, but not for control stimuli for which performance was at near-chance levels. Collectively, these data provide further support for a multistage model of object processing under degraded viewing conditions
âIt's Not What You Say, But How You Say itâ: A Reciprocal Temporo-frontal Network for Affective Prosody
Humans communicate emotion vocally by modulating acoustic cues such as pitch, intensity and voice quality. Research has documented how the relative presence or absence of such cues alters the likelihood of perceiving an emotion, but the neural underpinnings of acoustic cue-dependent emotion perception remain obscure. Using functional magnetic resonance imaging in 20 subjects we examined a reciprocal circuit consisting of superior temporal cortex, amygdala and inferior frontal gyrus that may underlie affective prosodic comprehension. Results showed that increased saliency of emotion-specific acoustic cues was associated with increased activation in superior temporal cortex [planum temporale (PT), posterior superior temporal gyrus (pSTG), and posterior superior middle gyrus (pMTG)] and amygdala, whereas decreased saliency of acoustic cues was associated with increased inferior frontal activity and temporo-frontal connectivity. These results suggest that sensory-integrative processing is facilitated when the acoustic signal is rich in affective information, yielding increased activation in temporal cortex and amygdala. Conversely, when the acoustic signal is ambiguous, greater evaluative processes are recruited, increasing activation in inferior frontal gyrus (IFG) and IFG STG connectivity. Auditory regions may thus integrate acoustic information with amygdala input to form emotion-specific representations, which are evaluated within inferior frontal regions
Reproductive Genetic Testing: Issues and Options for Policymakers
Reproductive genetic testing offers prospective parents information about their risk of having a child with a genetic disease or characteristic. This information can be used to help prospective parents make reproductive decisions both before and during a pregnancy. Before pregnancy, prospective parents who know they have a risk of bearing a child with a genetic disease may choose to avoid pregnancy; use donated eggs, sperm or embryos; adopt, use in vitro fertilization followed by preimplantation genetic diagnosis to select those embryos free of a particular genetic mutation or pursue pregnancy better informed and prepared for the possibility of bearing an affected child. After pregnancy has begun, genetic testing can provide reassurance if tests are negative. Positive prenatal genetic test results can give parents time to prepare for the birth of a child with a particular disorder, or be used as the basis for a decision to terminate the pregnancy.
Reproductive genetic testing raises a variety of concerns. Some care most that the tests are accurate and reliable. Yet, unlike drugs and medical devices, genetic tests - including those to test embryos and fetuses - are not required to meet standards of accuracy and reliability before they are marketed. Some agencies within the federal government regulate certain limited aspects of genetic testing, but there are gaps in the regulatory process.
A genetic test can only identify the presence of a particular mutation or characteristics. It cannot ascribe social significance to that finding. Some worry about the potential uses of genetic tests. For example, they fear a world in which parents choose their child's height, eye color, intelligence level or other non-health-related trait. While these possibilities are all hypothetical, it is currently possible to choose the sex of one's child, and some believe this use of testing is inappropriate. Some also fear that as testing becomes increasingly available, people will face increased pressure to test, both to have the "very best baby" possible and to avoid the birth of an "unhealthy" child. Some people feel there should be limits on reproductive genetic testing. But what should those limits be? Who should set them? These questions raise ethical, social and legal issues that cannot be resolved by science and technology alone. Finally, concerns have been raised that access to genetic tests is not equitable, and that tests are not being delivered at the right time and with the appropriate context and counseling.
To help inform public discussion and facilitate policymaking around these issues, the Genetics and Public Policy Center - funded by The Pew Charitable Trusts - has produced a report, Reproductive Genetic Testing: Issues and Options for Policymakers. This report presents a range of policy options that address genetic testing; it is supported by expert analysis that considers the potential effects, positive and negative, of a variety of different policy directions. The report develops policy options around four key areas of concern: (1) use of tests, (2) safety and accuracy, (3) access and (4) delivery.
The options present a range of possible roles that federal and state governments and private entities could play in overseeing the development and use of these technologies, and describe the strengths and weaknesses of each approach. The options were developed by the Center through expert analysis and consultation with a variety of experts representing a wide range of political and religious viewpoints; the options were also informed by the results of the Center's extensive public opinion research.
A companion report, Reproductive Genetic Testing: What America Thinks, reveals opinions about how regulation should be implemented and who should control regulation, ranging from no regulation at all to government regulation of both the safety and ethics surrounding the use of these tests
Predicting success: patterns of cortical activation and deactivation prior to response inhibition
The present study investigated the relationships between attention and other preparatory processes prior to a response inhibition task and the processes involved in the inhibition itself. To achieve this, a mixed fMRI design was employed to identify the functional areas activated during both inhibition decision events and the block of trials following a visual cue introduced 2 to 7 sec prior (cue period). Preparing for successful performance produced increases in activation for both the cue period and the inhibition itself in the frontoparietal cortical network. Furthermore, preparation produced activation decreases in midline areas (insula and medial prefrontal) argued to be responsible for monitoring internal emotional states, and these cue period deactivations alone predicted subsequent success or failure. The results suggest that when cues are provided to signify the imminent requirement for behavioral control, successful performance results from a coordinated pattern of preparatory activation in task-relevant areas and deactivation of task-irrelevant ones
Grabbing Your Ear: Rapid Auditory-Somatosensory Multisensory Interactions in Low-level Sensory Cortices Are Not Constrained by Stimulus Alignment
Multisensory interactions are observed in species from single-cell organisms to humans. Important early work was primarily carried out in the cat superior colliculus and a set of critical parameters for their occurrence were defined. Primary among these were temporal synchrony and spatial alignment of bisensory inputs. Here, we assessed whether spatial alignment was also a critical parameter for the temporally earliest multisensory interactions that are observed in lower-level sensory cortices of the human. While multisensory interactions in humans have been shown behaviorally for spatially disparate stimuli (e.g. the ventriloquist effect), it is not clear if such effects are due to early sensory level integration or later perceptual level processing. In the present study, we used psychophysical and electrophysiological indices to show that auditory-somatosensory interactions in humans occur via the same early sensory mechanism both when stimuli are in and out of spatial register. Subjects more rapidly detected multisensory than unisensory events. At just 50 ms post-stimulus, neural responses to the multisensory âwhole' were greater than the summed responses from the constituent unisensory âparts'. For all spatial configurations, this effect followed from a modulation of the strength of brain responses, rather than the activation of regions specifically responsive to multisensory pairs. Using the local auto-regressive average source estimation, we localized the initial auditory-somatosensory interactions to auditory association areas contralateral to the side of somatosensory stimulation. Thus, multisensory interactions can occur across wide peripersonal spatial separations remarkably early in sensory processing and in cortical regions traditionally considered unisensor
Contributions of early cortical processing and reading ability to functional status in individuals at clinical high risk for psychosis
Background: There is a growing recognition that individuals at clinical high risk need intervention for functional impairments, along with emerging psychosis, as the majority of clinical high risk (CHR) individuals show persistent deficits in social and role functioning regardless of transition to psychosis. Recent studies have demonstrated reduced reading ability as a potential cause of functional disability in schizophrenia, related to underlying deficits in generation of mismatch negativity (MMN). The present study extends these findings to subjects at CHR. Methods: The sample consisted of 34 CHR individuals and 33 healthy comparison subjects (CNTLs) from the Recognition and Prevention (RAP) Program at the Zucker Hillside Hospital in New York. At baseline, reading measures were collected, along with MMN to pitch, duration, and intensity deviants, and measures of neurocognition, and social and role (academic/work) functioning. Results: CHR subjects showed impairments in reading ability, neurocognition, and MMN generation, relative to CNTLs. Lower-amplitude MMN responses were correlated with worse reading ability, slower processing speed, and poorer social and role functioning. However, when entered into a simultaneous regression, only reduced responses to deviance in sound duration and volume predicted poor social and role functioning, respectively. Conclusions: Deficits in reading ability exist even prior to illness onset in schizophrenia and may represent a decline in performance from prior abilities. As in schizophrenia, deficits are related to impaired MMN generation, suggesting specific contributions of sensory-level impairment to neurocognitive processes related to social and role function. (C) 2015 Elsevier B.V. All rights reserved
Hospital Episode Statistics and trends in ophthalmic surgery 1998 â 2004
BACKGROUND: Hospital episode statistics (HES) is a UK national database for the National Health Service (NHS), now available online. The purpose of this study was to observe trends in ophthalmic operations performed during the period from 1998 to 2004, using this data. METHODS: From the 'Main Operation' codes within the 'Free data' section of the HES website we analysed data in regard to 28 specific ophthalmic operations. These represented each sub speciality within ophthalmology. RESULTS: The figures show a change in the total number and proportions of operations performed for many of the procedures. For example, there was an increase in numbers of orbital decompressions, but a decrease in numbers of glaucoma filtering operations. Changing trends could be seen in different surgical areas such as the change in operations used for corneal grafting and in retinal surgery. CONCLUSION: The HES database represents an important, potentially useful source of information. There are imitations in interpretation of and validity of such data related to coding inconsistencies. We suggest the benefit of the data comes from observing trends rather than exact numbers. As other studies using this data have suggested, it is important that clinicians are involved in improving the quality of this data
Regionally Distinct N -Methyl-D-Aspartate Receptors Distinguished by Quantitative Autoradiography of [ 3 H]MK-801 Binding in Rat Brain
Quantitative autoradiography of [ 3 H]MK-801 binding was used to characterize regional differences in N -methyl-d-aspartate (NMDA) receptor pharmacology in rat CNS. Regionally distinct populations of NMDA receptors were distinguished on the basis of regulation of [ 3 H]MK-801 binding by the NMDA antagonist 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP). CPP inhibited [ 3 H]MK-801 binding in outer cortex (OC) and medial cortex (MC) with apparent K i values of 0.32-0.48 Î M , whereas in the medial striatum (MS), lateral striatum (LS), CA1, and dentate gyrus (DG) of hippocampus, apparent K i values were 1.1-1.6 Î M . In medial thalamus (MT) and lateral thalamus (LT) the apparent K i values were 0.78 Î M . In the presence of added glutamate (3 Î M ), the relative differences in apparent K i values between regions maintained a similar relationship with the exception of the OC. Inhibition of [ 3 H]MK-801 binding by the glycine site antagonist 7-chlorokynurenic acid (7-ClKyn) distinguished at least two populations of NMDA receptors that differed from populations defined by CPP displacement. 7-ClKyn inhibited [ 3 H]MK-801 binding in OC, MC, MS, and LS with apparent K i values of 6.3-8.6 Î M , whereas in CA1, DG, LT, and MT, K i values were 11.4-13.6 Î M . In the presence of added glycine (1 Î M ), the relative differences in apparent K i values were maintained. Under conditions of differential receptor activation, regional differences in NMDA receptor pharmacology can be detected using [ 3 H]MK-801 binding.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65616/1/j.1471-4159.1993.tb03295.x.pd
DetecciĂłn de huevos de Toxocara sp. en suelos de las plazas y parques pĂșblicos de la zona centro de Barquisimeto, estado Lara
This work is the continuation of a research line started in 2012 and aimed to investigate the zoonotic potential of microorganisms found in public areas; results of soil analysis of public places are presented, this time from south-central area of Barquisimeto, Lara state, in search of Toxocara sp, a potentially zoonotic parasite. This new development was due to the need to know the reality of that area to make comparative inferences based on the previously obtained results, considering that the current socio-economic situation has affected the amount of dogs that are abandoned. As it was mentioned in the first investigation, the most vulnerable age group is children between two and six years old; so the existence of favorable conditions for the presentation of this disease is a public health problem. This time, it was sampled 6 of the existing 12 public places in city downtown's south area, where sampling elements of soil was taken to form a pool of samples in each site; each sampling element parasitologically analyzed showed the existence of Toxocara eggs, representing a 100% of parasitic contamination. These results demonstrate the wide spread of Toxocara, a parasite with zoonotic potential, in this city area; thus, it's justi-fied the continuation of this research in other city areas. Finally, there was a contribution of information materials about zoonotic diseases as much as aware-ness of good practices of pets' ownership to foment civic education that pro-mote quality of life for all
Community wide electronic distribution of summary health care utilization data
BACKGROUND: In recent years, the use of digital technology has supported widespread sharing of electronic health care data. Although this approach holds considerable promise, it promises to be a complicated and expensive undertaking. This study described the development and implementation of a community wide system for electronic sharing of summary health care utilization data. METHODS: The development of the community wide data system focused on the following objectives: ongoing monitoring of the health care system, evaluation of community wide individual provider initiatives, identification and development of new initiatives. The system focused on the sharing of data related to hospital acute care, emergency medical services, long term care, and mental health. It was based on the daily distribution of reports among all health care providers related to these services. RESULTS: The development of the summary reports concerning health care utilization produced a system wide view of health care in Syracuse, New York on a daily basis. It was not possible to isolate the results of these reports because of the impact of specific projects and other factors. At the same time, the reports were associated with reduction of hospital inpatient stays, improvement of access to hospital emergency departments, reductions in stays for patients discharged to nursing homes, and increased access of mental health patients to hospital inpatient units. CONCLUSION: The implementation of the system demonstrated that summary electronic utilization data could provide daily information that would support the improvement of health care outcomes and efficiency. This approach could be implemented in a simple, direct manner with minimal expenses
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