41,137 research outputs found

    Hypnotic induction is followed by state-like changes in the organization of EEG functional connectivity in the theta and beta frequency bands in high-hypnotically susceptible individuals

    Get PDF
    Altered state theories of hypnosis posit that a qualitatively distinct state of mental processing, which emerges in those with high hypnotic susceptibility following a hypnotic induction, enables the generation of anomalous experiences in response to specific hypnotic suggestions. If so then such a state should be observable as a discrete pattern of changes to functional connectivity (shared information) between brain regions following a hypnotic induction in high but not low hypnotically susceptible participants. Twenty-eight channel EEG was recorded from 12 high susceptible (highs) and 11 low susceptible (lows) participants with their eyes closed prior to and following a standard hypnotic induction. The EEG was used to provide a measure of functional connectivity using both coherence (COH) and the imaginary component of coherence (iCOH), which is insensitive to the effects of volume conduction. COH and iCOH were calculated between all electrode pairs for the frequency bands: delta (0.1-3.9 Hz), theta (4-7.9 Hz) alpha (8-12.9 Hz), beta1 (13-19.9 Hz), beta2 (20-29.9 Hz) and gamma (30-45 Hz). The results showed that there was an increase in theta iCOH from the pre-hypnosis to hypnosis condition in highs but not lows with a large proportion of significant links being focused on a central-parietal hub. There was also a decrease in beta1 iCOH from the pre-hypnosis to hypnosis condition with a focus on a fronto-central and an occipital hub that was greater in high compared to low susceptibles. There were no significant differences for COH or for spectral band amplitude in any frequency band. The results are interpreted as indicating that the hypnotic induction elicited a qualitative change in the organization of specific control systems within the brain for high as compared to low susceptible participants. This change in the functional organization of neural networks is a plausible indicator of the much theorized "hypnotic-state". © 2014 Jamieson and Burgess

    Mapping Coastal Wetland Change Based on Lake Level Fluctuation on Lake Ontario

    Get PDF
    Using an integrated digital elevation and bathymetry model of Lake Ontario and historic lake level data from 1860 to present, coastal areas of periodic inundation were identified to generate, by association, an estimate of coastal wetland change due to lake level control. Pre and post Robert Morris Dam models were constructed to help determine the reduction of lake surface area when the dam started to control the extreme highs and lows. The model creates annual high and low lake surface coverages. The goal of this study is to create a baseline analysis and methodology for future studies on wetland change on Lake Ontario. Results of this study indicate an average change in lake surface area of 123 square kilometers between pre and post dam periods, based on 148 annual calculations of the high and low water levels for each year. Lake levels are generally stabilized after the dam installation, with considerably less fluctuation at the lowest lake levels, compared to pre dam fluctuations. Spatial results were limited by the currently available 3-second (90m) per pixel resolution of the combined bathymetry and elevation data, which renders general results that mask shoreline details and seem to over estimate inundation. As higher resolution data become available in the next few years, such as LiDAR and SONAR, the methodology of the model should be adaptable, resulting in more accurate models for predicting areas of inundation, exposure, and potential wetland change due to alterations of historic lake level variability

    Evidence from Strandings for Geomagnetic Sensitivity in Cetaceans

    Get PDF
    We tested the hypothesis that cetaceans use weak anomalies in the geomagnetic field as cues for orientation, navigation and/or piloting. Using the positions of 212 stranding events of live animals in the Smith sonian compilation which fall within the boundaries of the USGS East-Coast Aeromagnetic Survey, we found that there are highly significant tendencies for cetaceans to beach themselves near coastal locations with local magnetic minima. Monte-Carlo simulations confirm the significance of these effects. These results suggest that cetaceans have a magnetic sensory systemcomparable to that in other migratory and homing animals, and predict that the magnetic topography and in particular the marine magnetic lineations may play an important role in guiding long-distance migration. The ‘map’ sense of migratoryanimals may therefore be largely based on a simple strategy of following paths of local magnetic minima and avoiding magnetic gradients

    Synthesis of regional crust and upper-mantle structure from seismic and gravity data

    Get PDF
    Analyses of regional gravity and magnetic patterns, LANDSAT images and geological information revealed two major lineaments crossing western Pennsylvania and parts of surrounding states. These lineaments are inferred to be expressions of fracture zones which penetrare deeply into the crust and possibly the upper mantle. The extensions of the Tyron-Mt. Union and the Pittsburgh-Washington lineaments bound a distinct crustal block (Lake Erie-Maryland block) over 100 km wide and probably more than 600 km in length. Evidence exists for the lateral displacement of this block at least 60 km northwestward during late Precambrian to Lower Ordovician time. Subsequent movements have been mainly vertical with respect to neighboring blocks. A possible crustal block that passes through eastern Kentucky, proposed by a TVA study on tectonics in the southern Appalachians, was also investigated. Finally, the use of regional gravity and magnetic data in identifying major crustal structures beneath western Pennsylvania is discussed
    • …
    corecore