Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Language
Publication year range
1.
Neuroscience ; 166(2): 491-500, 2010 Mar 17.
Article in English | MEDLINE | ID: mdl-20038441

ABSTRACT

Cortical efferences to the heart are important for cardiovascular health, psychopathology, emotion regulation and other dimensions of human functioning. Although researchers have already begun to outline the underlying neuroanatomy, the timing of neurovisceral communication in humans is difficult to study non-invasively. A possible coupling between the brain and the heart can be observed following feedback stimuli, which have been shown to evoke both, early (i.e. <500 ms) signatures in the electroencephalogram (EEG) and changes in the chronotropy of subsequent heart beats. Because standard approaches may be insufficient to study how these responses are related, we suggest a method termed "Cardio-Electroencephalographic Covariance Tracing" (CECT), which is based on time-lagged P-correlations (i.e., correlations within individuals) between single-trial EEG magnitudes and heart period changes. When CECT was applied to data from n=31 individuals who performed a gambling task, central midline EEG magnitudes from 280 to 340 ms after feedback reliably P-correlated with cardiac acceleration 2 to 5 s thereafter. In addition positive vs. negative feedback lead to enhanced event related potential amplitudes from 200 to 280 ms and to relative cardiac acceleration from 1 to 3.5 s after feedback presentation. The results imply that neurogenic cardiac modulations begin to be affected 200 to 400 ms after stimulus presentation and demonstrate the utility of CECTs for future investigations.


Subject(s)
Biofeedback, Psychology/physiology , Evoked Potentials/physiology , Heart Rate/physiology , Heart/physiology , Adult , Brain Mapping , Cerebral Cortex/physiology , Efferent Pathways/physiology , Electrocardiography , Electroencephalography , Female , Humans , Image Processing, Computer-Assisted , Male , Neuropsychological Tests , Personality Inventory , Photic Stimulation , Signal Processing, Computer-Assisted , Surveys and Questionnaires
2.
Psychol Med ; 39(7): 1141-52, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19079826

ABSTRACT

BACKGROUND: Previous studies investigating attentional biases in social anxiety disorder (SAD) have yielded mixed results. Recent event-related potential (ERP) studies using the dot-probe paradigm in non-anxious participants have shown that the P1 component is sensitive to visuospatial attention towards emotional faces. We used a dot-probe task in conjunction with high-density ERPs and source localization to investigate attentional biases in SAD. METHOD: Twelve SAD and 15 control participants performed a modified dot-probe task using angry-neutral and happy-neutral face pairs. The P1 component elicited by face pairs was analyzed to test the hypothesis that SAD participants would display early hypervigilance to threat-related cues. The P1 component to probes replacing angry, happy or neutral faces was used to evaluate whether SAD participants show either sustained hypervigilance or decreased visual processing of threat-related cues at later processing stages. RESULTS: Compared to controls, SAD participants showed relatively (a) potentiated P1 amplitudes and fusiform gyrus (FG) activation to angry-neutral versus happy-neutral face pairs; (b) decreased P1 amplitudes to probes replacing emotional (angry and happy) versus neutral faces; and (c) higher sensitivity (d') to probes following angry-neutral versus happy-neutral face pairs. SAD participants also showed significantly shorter reaction times (RTs) to probes replacing angry versus happy faces, but no group differences emerged for RT. CONCLUSIONS: The results provide electrophysiological support for early hypervigilance to angry faces in SAD with involvement of the FG, and reduced visual processing of emotionally salient locations at later stages of information processing, which might be a manifestation of attentional avoidance.


Subject(s)
Arousal/physiology , Attention/physiology , Electroencephalography , Emotions/physiology , Evoked Potentials/physiology , Facial Expression , Pattern Recognition, Visual/physiology , Phobic Disorders/physiopathology , Adult , Anger/physiology , Cues , Dominance, Cerebral/physiology , Female , Humans , Male , Phobic Disorders/diagnosis , Phobic Disorders/psychology , Reaction Time/physiology , Reference Values , Sensory Thresholds/physiology , Signal Processing, Computer-Assisted , Temporal Lobe/physiopathology , Young Adult
3.
Rev. biol. trop ; 53(supl.1): 117-125, maio 2005. tab, mapas
Article in English | LILACS | ID: lil-456502

ABSTRACT

This project was undertaken as the initial monitoring program to determine if mosquito adulticides applied along the Florida Keys cause adverse ecological effects in the Florida Keys National Marine Sanctuary (FKNMS). The study monitored the distribution and persistence of two mosquito adulticides, permethrin and dibrom (naled), during three separate routine applications by the Florida Keys Mosquito Control District. The approach was to determine if toxic concentrations of the pesticides entered the FKNMS by aerial drift or tidal transport. The amount of pesticide entering the FKNMS by way of aerial drift was monitored by collection on glass fiber filter pads, set on floats in a grid pattern on either side of the FKNMS. Permethrin was recovered from filter pads on the leeward side for each of the three applications, ranging from 0.5 to 50.1 microg/m(2) throughout the study. Tidal current transport was monitored by collection of surface and subsurface water samples at each grid site. Tidal transport of naled and dichlorvos (naled degradation product) was apparent in the adjacent waters of the FKNMS. These compounds were detected in subsurface, offshore water at 0.1 to 0.6 microg/1, 14 hr after application. Permethrin was not detected in offshore water samples; however, concentrations ranging from 5.1 to 9.4 microg/l were found in surface water from the canal system adjacent to the application route. Comparison of the observed environmental concentrations with toxicity data (permethrin LC-50, 96 hr for Mysidopsis bahia = 0.02 microg/l) indicated a potential hazard to marine invertebrates in the canals with possible tidal transport to other areas


Subject(s)
Animals , Air Movements , Insecticides/analysis , Naled/analysis , Permethrin/analysis , Seawater/chemistry , Water Movements , Dichlorvos/adverse effects , Dichlorvos/analysis , Dichlorvos/toxicity , Environmental Monitoring , Gas Chromatography-Mass Spectrometry , Insecticides/adverse effects , Insecticides/toxicity , Naled/adverse effects , Naled/toxicity , Permethrin/adverse effects , Permethrin/toxicity
4.
Clin Radiol ; 60(4): 425-38, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15767100

ABSTRACT

Regional migratory osteoporosis is an uncommon self-limiting disease characterized by an arthralgia which migrates between the weight-bearing joints of the lower limb. The radiological features of the disease obtained by conventional radiography, CT, MRI and radionuclide scintigraphy are illustrated by means of five case reports. These range from the most common presentation of sequential, proximal to distal spread in the lower limb to the rare intra-articular form, and disease involving the axial skeleton is also recognized. Clinical and radiographical features often overlap with those of diseases such as transient osteoporosis of the hip and transient bone marrow oedema syndrome, which is reflected in confusing terminology. Histological sampling is usually unnecessary; the radiological features are characteristic and the histological findings are not specific. Regional migratory osteoporosis is associated with systemic osteoporosis. This association is probably under-recognized, and has implications for the pathophysiology of the disease and for treatment.


Subject(s)
Osteoporosis/diagnosis , Adult , Ankle , Bone Marrow/diagnostic imaging , Bone Marrow Diseases/diagnostic imaging , Bone and Bones/diagnostic imaging , Edema , Female , Femur/diagnostic imaging , Humans , Leg , Magnetic Resonance Imaging/methods , Male , Middle Aged , Osteoporosis/diagnostic imaging , Pelvis , Radionuclide Imaging , Tomography, X-Ray Computed/methods
5.
Rev Biol Trop ; 53 Suppl 1: 117-25, 2005 May.
Article in English | MEDLINE | ID: mdl-17465151

ABSTRACT

This project was undertaken as the initial monitoring program to determine if mosquito adulticides applied along the Florida Keys cause adverse ecological effects in the Florida Keys National Marine Sanctuary (FKNMS). The study monitored the distribution and persistence of two mosquito adulticides, permethrin and dibrom (naled), during three separate routine applications by the Florida Keys Mosquito Control District. The approach was to determine if toxic concentrations of the pesticides entered the FKNMS by aerial drift or tidal transport. The amount of pesticide entering the FKNMS by way of aerial drift was monitored by collection on glass fiber filter pads, set on floats in a grid pattern on either side of the FKNMS. Permethrin was recovered from filter pads on the leeward side for each of the three applications, ranging from 0.5 to 50.1 microg/m(2) throughout the study. Tidal current transport was monitored by collection of surface and subsurface water samples at each grid site. Tidal transport of naled and dichlorvos (naled degradation product) was apparent in the adjacent waters of the FKNMS. These compounds were detected in subsurface, offshore water at 0.1 to 0.6 microg/1, 14 hr after application. Permethrin was not detected in offshore water samples; however, concentrations ranging from 5.1 to 9.4 microg/l were found in surface water from the canal system adjacent to the application route. Comparison of the observed environmental concentrations with toxicity data (permethrin LC-50, 96 hr for Mysidopsis bahia = 0.02 microg/l) indicated a potential hazard to marine invertebrates in the canals with possible tidal transport to other areas.


Subject(s)
Air Movements , Insecticides/analysis , Naled/analysis , Permethrin/analysis , Seawater/chemistry , Water Movements , Animals , Dichlorvos/analysis , Dichlorvos/toxicity , Environmental Monitoring , Gas Chromatography-Mass Spectrometry , Insecticides/toxicity , Lethal Dose 50 , Naled/toxicity , Permethrin/toxicity
SELECTION OF CITATIONS
SEARCH DETAIL
...