Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
J Am Heart Assoc ; 12(19): e031221, 2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37750574

RESUMO

Background COVID-19 stressed hospitals and may have disproportionately affected the stroke outcomes and treatment of Black and Hispanic individuals. Methods and Results This retrospective study used 100% Medicare Provider Analysis and Review file data from between 2016 and 2020. We used interrupted time series analyses to examine whether the COVID-19 pandemic exacerbated disparities in stroke outcomes and reperfusion therapy. Among 1 142 560 hospitalizations for acute ischemic strokes, 90 912 (8.0%) were Hispanic individuals; 162 752 (14.2%) were non-Hispanic Black individuals; and 888 896 (77.8%) were non-Hispanic White individuals. The adjusted odds of mortality increased by 51% (adjusted odds ratio [aOR], 1.51 [95% CI, 1.34-1.69]; P<0.001), whereas the rates of nonhome discharges decreased by 11% (aOR, 0.89 [95% CI, 0.82-0.96]; P=0.003) for patients hospitalized during weeks when the hospital's proportion of patients with COVID-19 was >30%. The overall rates of motor deficits (P=0.25) did not increase, and the rates of reperfusion therapy did not decrease as the weekly COVID-19 burden increased. Black patients had lower 30-day mortality (aOR, 0.70 [95% CI, 0.69-0.72]; P<0.001) but higher rates of motor deficits (aOR, 1.14 [95% CI, 1.12-1.16]; P<0.001) than White individuals. Hispanic patients had lower 30-day mortality and similar rates of motor deficits compared with White individuals. There was no differential increase in adverse outcomes or reduction in reperfusion therapy among Black and Hispanic individuals compared with White individuals as the weekly COVID-19 burden increased. Conclusions This national study of Medicare patients found no evidence that the hospital COVID-19 burden exacerbated disparities in treatment and outcomes for Black and Hispanic individuals admitted with an acute ischemic stroke.


Assuntos
COVID-19 , AVC Isquêmico , Acidente Vascular Cerebral , Idoso , Humanos , Negro ou Afro-Americano , COVID-19/terapia , Medicare , Pandemias , Estudos Retrospectivos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/terapia , Resultado do Tratamento , Estados Unidos/epidemiologia , Hispânico ou Latino , Brancos
2.
Obstet Gynecol ; 142(2): 403-423, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37411038

RESUMO

The Society of Anesthesia and Sleep Medicine and the Society for Obstetric Anesthesia and Perinatology tasked an expert group to review existing evidence and to generate recommendations on the screening, diagnosis, and treatment of patients with obstructive sleep apnea during pregnancy. These recommendations are based on a systematic review of the available scientific evidence and expert opinion when scientific evidence is lacking. This guideline may not be appropriate for all clinical situations and patients, and physicians must decide whether these recommendations are appropriate for their patients on an individual basis. We recognize that not all pregnant people may identify as women. However, data on non-cisgendered pregnant patients are lacking, and many published studies use gender-binary terms; therefore, depending on the study referenced, we may refer to pregnant individuals as women. This guideline may inform the creation of clinical protocols by individual institutions that consider the unique considerations of their patient populations and the available resources.


Assuntos
Anestesia Obstétrica , Médicos , Apneia Obstrutiva do Sono , Feminino , Humanos , Gravidez , Perinatologia , Sono , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/terapia
3.
Artigo em Inglês | MEDLINE | ID: mdl-37192477

RESUMO

BACKGROUND: The aim of this survey was to understand institutional spine surgery practices and their concordance with published best practices/recommendations. METHODS: Using a global internet-based survey examining perioperative spine surgery practice, reported institutional spine pathway elements (n=139) were compared with the level of evidence published in guideline recommendations. The concordance of clinical practice with guidelines was categorized as poor (≤20%), fair (21%-40%), moderate (41%-60%), good (61%-80%), or very good (81%-100%). RESULTS: Seventy-two of 409 (17.6%) institutional contacts started the survey, of which 31 (7.6%) completed the survey. Six (19.4%) of the completed surveys were from respondents in low/middle-income countries, and 25 (80.6%) were from respondents in high-income countries. Forty-one incomplete surveys were not included in the final analysis, as most were less than 40% complete. Five of 139 (3.6%) reported elements had very good concordance for the entire cohort; hospitals with spine surgery pathways reported 18 elements with very good concordance, whereas institutions without spine surgery pathways reported only 1 element with very good concordance. Reported spine pathways included between 7 and 47 separate pathway elements. There were 87 unique elements in the reviewed pathways. Only 3 of 87 (3.4%) elements with high-quality evidence demonstrated very good practice concordance. CONCLUSIONS: This global survey-based study identified practice variation and low adoption rates of high-quality evidence in the care of patients undergoing complex spine surgery.

5.
Perioper Med (Lond) ; 12(1): 2, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36631831

RESUMO

BACKGROUND: Studies indicate that patients can be "seeded" with their own cancer cells during oncologic surgery and that the immune response to these circulating cancer cells might influence the risk of cancer recurrence. Preliminary data from animal studies and some retrospective analyses suggest that anesthetic technique might affect the immune response during surgery and hence the risk of cancer recurrence. In 2015, experts called for prospective scientific inquiry into whether anesthetic technique used in cancer resection surgeries affects cancer-related outcomes such as recurrence and mortality. Therefore, we designed a pragmatic phase 3 multicenter randomized controlled trial (RCT) called General Anesthetics in Cancer Resection (GA-CARES). METHODS: After clinical trial registration and institutional review board approval, patients providing written informed consent were enrolled at five sites in New York (NY) State. Eligible patients were adults with known or suspected cancer undergoing one of eight oncologic surgeries having a high risk of cancer recurrence. Exclusion criteria included known or suspected history of malignant hyperthermia or hypersensitivity to either propofol or volatile anesthetic agents. Patients were randomized (1:1) stratified by center and surgery type using REDCap to receive either propofol or volatile agent for maintenance of general anesthesia (GA). This pragmatic trial, which seeks to assess the potential impact of anesthetic type in "real world practice", did not standardize any aspect of patient care. However, potential confounders, e.g., use of neuroaxial anesthesia, were recorded to confirm the balance between study arms. Assuming a 5% absolute difference in 2-year overall survival rates (85% vs 90%) between study arms (primary endpoint, minimum 2-year follow-up), power using a two-sided log-rank test with type I error of 0.05 (no planned interim analyses) was calculated to be 97.4% based on a target enrollment of 1800 subjects. Data sources include the National Death Index (gold standard for vital status in the USA), NY Cancer Registry, and electronic harvesting of data from electronic medical records (EMR), with minimal manual data abstraction/data entry. DISCUSSION: Enrollment has been completed (n = 1804) and the study is in the follow-up phase. This unfunded, pragmatic trial, uses a novel approach for data collection focusing on electronic sources. TRIAL REGISTRATION: Registered (NCT03034096) on January 27, 2017, prior to consent of the first patient on January 31, 2017.

6.
JAMA Surg ; 157(8): e222236, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35767247

RESUMO

Importance: Perioperative strokes are a major cause of death and disability. There is limited information on which to base decisions for how long to delay elective nonneurologic, noncardiac surgery in patients with a history of stroke. Objective: To examine whether an association exists between the time elapsed since an ischemic stroke and the risk of recurrent stroke in older patients undergoing elective nonneurologic, noncardiac surgery. Design, Setting, and Participants: This cohort study used data from the 100% Medicare Provider Analysis and Review files, including the Master Beneficiary Summary File, between 2011 and 2018 and included elective nonneurologic, noncardiac surgeries in patients 66 years or older. Patients were excluded if they had more than 1 procedure during a 30-day period, were transferred from another hospital or facility, were missing information on race and ethnicity, were admitted in December 2018, or had tracheostomies or gastrostomies. Data were analyzed May 7 to October 23, 2021. Exposures: Time interval between a previous hospital admission for acute ischemic stroke and surgery. Main Outcomes and Measures: Acute ischemic stroke during the index surgical admission or rehospitalization for stroke within 30 days of surgery, 30-day all-cause mortality, composite of stroke and mortality, and discharge to a nursing home or skilled nursing facility. Multivariable logistic regression models were used to estimate adjusted odds ratios (AORs) to quantify the association between outcome and time since ischemic stroke. Results: The final cohort included 5 841 539 patients who underwent elective nonneurologic, noncardiac surgeries (mean [SD] age, 74.1 [6.1] years; 3 371 329 [57.7%] women), of which 54 033 (0.9%) had a previous stroke. Patients with a stroke within 30 days before surgery had higher adjusted odds of perioperative stroke (AOR, 8.02; 95% CI, 6.37-10.10; P < .001) compared with patients without a previous stroke. The adjusted odds of stroke were not significantly different at an interval of 61 to 90 days between previous stroke and surgery (AOR, 5.01; 95% CI, 4.00-6.29; P < .001) compared with 181 to 360 days (AOR, 4.76; 95% CI, 4.26-5.32; P < .001). The adjusted odds of 30-day all-cause mortality were higher in patients who underwent surgery within 30 days of a previous stroke (AOR, 2.51; 95% CI, 1.99-3.16; P < .001) compared with those without a history of stroke, and the AOR decreased to 1.49 (95% CI, 1.15-1.92; P < .001) at 61 to 90 days from previous stroke to surgery but did not decline significantly, even after an interval of 360 or more days. Conclusions and Relevance: The findings of this cohort study suggest that, among patients undergoing nonneurologic, noncardiac surgery, the risk of stroke and death leveled off when more than 90 days elapsed between a previous stroke and elective surgery. These findings suggest that the recent scientific statement by the American Heart Association to delay elective nonneurologic, noncardiac surgery for at least 6 months after a recent stroke may be too conservative.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Medicare , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Estados Unidos/epidemiologia
7.
J Neurosurg Anesthesiol ; 34(3): 257-276, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34483301

RESUMO

Evidence-based standardization of the perioperative management of patients undergoing complex spine surgery can improve outcomes such as enhanced patient satisfaction, reduced intensive care and hospital length of stay, and reduced costs. The Society for Neuroscience in Anesthesiology and Critical Care (SNACC) tasked an expert group to review existing evidence and generate recommendations for the perioperative management of patients undergoing complex spine surgery, defined as surgery on 2 or more thoracic and/or lumbar spine levels. Institutional clinical management protocols can be constructed based on the elements included in these clinical practice guidelines, and the evidence presented.


Assuntos
Anestesiologia , Cuidados Críticos , Humanos , Vértebras Lombares , Procedimentos Neurocirúrgicos , Assistência Perioperatória
8.
Local Reg Anesth ; 13: 95-98, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32884335

RESUMO

Pain after lumbar spine fusion surgery is often difficult to control in the immediate postoperative period. Historically, opioids have been the mainstay of treatment, but are associated with many unwanted side effects as well as increased hospital length of stay. The ultrasound-guided erector spinae plane block (ESP) is a relatively safe and simple regional option for the management of acute postoperative pain after spine surgery without the technical difficulty or complications noted with paravertebral injection (eg, pneumothorax, hematoma). To date, there have been reports of preoperative placement of ESP block prior to spine surgery with some success. We present a report of two cases that highlight the efficacy of the ESP block as an early postoperative "rescue" regional anesthetic technique in lumbar spine surgery. These cases demonstrate the potential effectiveness of a "rescue" use of the ESP block in patients having uncontrolled or poorly controlled pain in the early postoperative period with no evidence of significant side effects.

10.
J Vis Exp ; (150)2019 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-31449264

RESUMO

The Translational Brain Mapping Program at the University of Rochester is an interdisciplinary effort that integrates cognitive science, neurophysiology, neuroanesthesia, and neurosurgery. Patients who have tumors or epileptogenic tissue in eloquent brain areas are studied preoperatively with functional and structural MRI, and intraoperatively with direct electrical stimulation mapping. Post-operative neural and cognitive outcome measures fuel basic science studies about the factors that mediate good versus poor outcome after surgery, and how brain mapping can be further optimized to ensure the best outcome for future patients. In this article, we describe the interdisciplinary workflow that allows our team to meet the synergistic goals of optimizing patient outcome and advancing scientific understanding of the human brain.


Assuntos
Centros Médicos Acadêmicos/métodos , Mapeamento Encefálico/métodos , Encéfalo/diagnóstico por imagem , Monitorização Neurofisiológica Intraoperatória/métodos , Medicina de Precisão/métodos , Pesquisa Translacional Biomédica/métodos , Encéfalo/cirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Procedimentos Neurocirúrgicos/métodos
12.
Front Immunol ; 8: 1528, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29181002

RESUMO

INTRODUCTION: Aside from direct effects on neurotransmission, inhaled and intravenous anesthetics have immunomodulatory properties. In vitro and mouse model studies suggest that propofol inhibits, while isoflurane increases, neuroinflammation. If these findings translate to humans, they could be clinically important since neuroinflammation has detrimental effects on neurocognitive function in numerous disease states. MATERIALS AND METHODS: To examine whether propofol and isoflurane differentially modulate neuroinflammation in humans, cytokines were measured in a secondary analysis of cerebrospinal fluid (CSF) samples from patients prospectively randomized to receive anesthetic maintenance with propofol vs. isoflurane (registered with http://www.clinicaltrials.gov, identifier NCT01640275). We measured CSF levels of EGF, eotaxin, G-CSF, GM-CSF, IFN-α2, IL-1RA, IL-6, IL-7, IL-8, IL-10, IP-10, MCP-1, MIP-1α, MIP-1ß, and TNF-α before and 24 h after intracranial surgery in these study patients. RESULTS: After Bonferroni correction for multiple comparisons, we found significant increases from before to 24 h after surgery in G-CSF, IL-10, IL-1RA, IL-6, IL-8, IP-10, MCP-1, MIP-1α, MIP-1ß, and TNF-α. However, we found no difference in cytokine levels at baseline or 24 h after surgery between propofol- (n = 19) and isoflurane-treated (n = 21) patients (p > 0.05 for all comparisons). Increases in CSF IL-6, IL-8, IP-10, and MCP-1 levels directly correlated with each other and with postoperative CSF elevations in tau, a neural injury biomarker. We observed CSF cytokine increases up to 10-fold higher after intracranial surgery than previously reported after other types of surgery. DISCUSSION: These data clarify the magnitude of neuroinflammation after intracranial surgery, and raise the possibility that a coordinated neuroinflammatory response may play a role in neural injury after surgery.

13.
Clin Neurophysiol ; 128(8): 1421-1425, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28618293

RESUMO

OBJECTIVE: Delirium is a common post-operative complication associated with significant costs, morbidity, and mortality. We sought sleep/EEG predictors of delirium present prior to delirium symptoms to facilitate developing and targeting therapies. METHODS: Continuous EEG data were obtained in 12 patients post-orthopedic surgery from the day of surgery until delirium assessment on post-operative day 2 (POD2). RESULTS: Diminished total sleep time (r=-0.68; p<0.05) and longer latency to sleep onset (r=0.67; p<0.05) on the first night in the hospital were associated with greater POD2 delirium severity. Patients experiencing delirium slept 2.4h less and took 2h longer to fall asleep. Greater waking EEG delta power (r=0.84; p<0.05) on POD1 and less non-REM sleep EEG delta power (r=-0.72; p<0.05) on night 2 also predicted POD2 delirium severity. CONCLUSIONS: Loss of sleep on night1 post-surgery is an early predictor of subsequent delirium. EEG Delta Power alterations in waking and sleep appear to be later indicators of impending delirium. Further work is needed to evaluate reproducibility/generalizability and assess whether sleep loss contributes to causing delirium. SIGNIFICANCE: This first study to prospectively collect continuous EEG data for an extended period prior to delirium onset identified EEG-derived indices that predict subsequent delirium that could aid in developing and targeting therapies.


Assuntos
Delírio/fisiopatologia , Eletroencefalografia/tendências , Complicações Pós-Operatórias/fisiopatologia , Distúrbios do Início e da Manutenção do Sono/fisiopatologia , Fases do Sono/fisiologia , Idoso , Idoso de 80 Anos ou mais , Delírio/diagnóstico , Delírio/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos/efeitos adversos , Procedimentos Ortopédicos/tendências , Projetos Piloto , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Valor Preditivo dos Testes , Estudos Prospectivos , Distúrbios do Início e da Manutenção do Sono/diagnóstico , Distúrbios do Início e da Manutenção do Sono/epidemiologia
14.
J Alzheimers Dis ; 52(4): 1299-310, 2016 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-27079717

RESUMO

BACKGROUND: Preclinical studies have found differential effects of isoflurane and propofol on the Alzheimer's disease (AD)-associated markers tau, phosphorylated tau (p-tau) and amyloid-ß (Aß). OBJECTIVE: We asked whether isoflurane and propofol have differential effects on the tau/Aß ratio (the primary outcome), and individual AD biomarkers. We also examined whether genetic/intraoperative factors influenced perioperative changes in AD biomarkers. METHODS: Patients undergoing neurosurgical/otolaryngology procedures requiring lumbar cerebrospinal fluid (CSF) drain placement were prospectively randomized to receive isoflurane (n = 21) or propofol (n = 18) for anesthetic maintenance. We measured perioperative CSF sample AD markers, performed genotyping assays, and examined intraoperative data from the electronic anesthesia record. A repeated measures ANOVA was used to examine changes in AD markers by anesthetic type over time. RESULTS: The CSF tau/Aß ratio did not differ between isoflurane- versus propofol-treated patients (p = 1.000). CSF tau/Aß ratio and tau levels increased 10 and 24 h after drain placement (p = 2.002×10-6 and p = 1.985×10-6, respectively), mean CSF p-tau levels decreased (p = 0.005), and Aß levels did not change (p = 0.152). There was no interaction between anesthetic treatment and time for any of these biomarkers. None of the examined genetic polymorphisms, including ApoE4, were associated with tau increase (n = 9 polymorphisms, p > 0.05 for all associations). CONCLUSION: Neurosurgery/otolaryngology procedures are associated with an increase in the CSF tau/Aß ratio, and this increase was not influenced by anesthetic type. The increased CSF tau/Aß ratio was largely driven by increases in tau levels. Future work should determine the functional/prognostic significance of these perioperative CSF tau elevations.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Anestesia Intravenosa , Anestésicos Intravenosos/farmacologia , Isoflurano/farmacologia , Propofol/farmacologia , Proteínas tau/líquido cefalorraquidiano , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Anestesia Intravenosa/métodos , Biomarcadores/líquido cefalorraquidiano , Feminino , Variação Genética/genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas tau/genética
15.
Anesthesiol Clin ; 33(3): 517-50, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26315636

RESUMO

Postoperative cognitive dysfunction (POCD) is a common complication associated with significant morbidity and mortality in elderly patients. There is much interest in and controversy about POCD, reflected partly in the increasing number of articles published on POCD recently. Recent work suggests surgery may also be associated with cognitive improvement in some patients, termed postoperative cognitive improvement (POCI). As the number of surgeries performed worldwide approaches 250 million per year, optimizing postoperative cognitive function and preventing/treating POCD are major public health issues. In this article, we review the literature on POCD and POCI, and discuss current research challenges in this area.


Assuntos
Transtornos Cognitivos/etiologia , Complicações Pós-Operatórias/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Transtornos Cognitivos/psicologia , Delírio/etiologia , Delírio/psicologia , Humanos , Complicações Pós-Operatórias/psicologia , Qualidade de Vida , Resiliência Psicológica
16.
J Neurosci ; 33(35): 14061-74, 14074a, 2013 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-23986242

RESUMO

Perception of depth is based on a variety of cues, with binocular disparity and motion parallax generally providing more precise depth information than pictorial cues. Much is known about how neurons in visual cortex represent depth from binocular disparity or motion parallax, but little is known about the joint neural representation of these depth cues. We recently described neurons in the middle temporal (MT) area that signal depth sign (near vs far) from motion parallax; here, we examine whether and how these neurons also signal depth from binocular disparity. We find that most MT neurons in rhesus monkeys (Macaca Mulatta) are selective for depth sign based on both disparity and motion parallax cues. However, the depth-sign preferences (near or far) are not always aligned: 56% of MT neurons have matched depth-sign preferences ("congruent" cells) whereas the remaining 44% of neurons prefer near depth from motion parallax and far depth from disparity, or vice versa ("opposite" cells). For congruent cells, depth-sign selectivity increases when disparity cues are added to motion parallax, but this enhancement does not occur for opposite cells. This suggests that congruent cells might contribute to perceptual integration of depth cues. We also found that neurons are clustered in MT according to their depth tuning based on motion parallax, similar to the known clustering of MT neurons for binocular disparity. Together, these findings suggest that area MT is involved in constructing a representation of 3D scene structure that takes advantage of multiple depth cues available to mobile observers.


Assuntos
Sinais (Psicologia) , Percepção de Movimento , Lobo Temporal/fisiologia , Disparidade Visual , Animais , Macaca mulatta , Masculino , Neurônios/fisiologia , Lobo Temporal/citologia , Córtex Visual/citologia , Córtex Visual/fisiologia
17.
Neuron ; 63(4): 523-32, 2009 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-19709633

RESUMO

The capacity to perceive depth is critical for an observer to interact with his or her surroundings. During observer movement, information about depth can be extracted from the resulting patterns of image motion on the retina (motion parallax). Without extraretinal signals related to observer movement, however, depth-sign (near versus far) from motion parallax can be ambiguous. We previously demonstrated that MT neurons combine visual motion with extraretinal signals to code depth-sign from motion parallax in the absence of other depth cues. In that study, head translations were always accompanied by compensatory tracking eye movements, allowing at least two potential sources of extraretinal input. We now show that smooth eye movement signals provide the critical extraretinal input to MT neurons for computing depth-sign from motion parallax. Our findings demonstrate a powerful modulation of MT activity by eye movements, as predicted by human studies of depth perception from motion parallax.


Assuntos
Percepção de Profundidade/fisiologia , Movimentos Oculares/fisiologia , Percepção de Movimento/fisiologia , Neurônios/fisiologia , Estimulação Luminosa/métodos , Córtex Visual/fisiologia , Animais , Macaca mulatta , Masculino , Retina/fisiologia , Lobo Temporal/citologia , Lobo Temporal/fisiologia , Córtex Visual/citologia
18.
Nature ; 452(7187): 642-5, 2008 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-18344979

RESUMO

Perception of depth is a fundamental challenge for the visual system, particularly for observers moving through their environment. The brain makes use of multiple visual cues to reconstruct the three-dimensional structure of a scene. One potent cue, motion parallax, frequently arises during translation of the observer because the images of objects at different distances move across the retina with different velocities. Human psychophysical studies have demonstrated that motion parallax can be a powerful depth cue, and motion parallax seems to be heavily exploited by animal species that lack highly developed binocular vision. However, little is known about the neural mechanisms that underlie this capacity. Here we show, by using a virtual-reality system to translate macaque monkeys (Macaca mulatta) while they viewed motion parallax displays that simulated objects at different depths, that many neurons in the middle temporal area (area MT) signal the sign of depth (near versus far) from motion parallax in the absence of other depth cues. To achieve this, neurons must combine visual motion with extra-retinal (non-visual) signals related to the animal's movement. Our findings suggest a new neural substrate for depth perception and demonstrate a robust interaction of visual and non-visual cues in area MT. Combined with previous studies that implicate area MT in depth perception based on binocular disparities, our results suggest that area MT contains a more general representation of three-dimensional space that makes use of multiple cues.


Assuntos
Percepção de Profundidade/fisiologia , Macaca/fisiologia , Percepção de Movimento/fisiologia , Neurônios/fisiologia , Córtex Visual/citologia , Córtex Visual/fisiologia , Animais , Sinais (Psicologia) , Masculino , Estimulação Luminosa , Retina/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...