6,240 research outputs found

    Site Characterization Using Integrated Imaging Analysis Methods on Satellite Data of the Islamabad, Pakistan, Region

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    We develop an integrated digital imaging analysis approach to produce a first-approximation site characterization map for Islamabad, Pakistan, based on remote-sensing data. We apply both pixel-based and object-oriented digital imaging analysis methods to characterize detailed (1:50,000) geomorphology and geology from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery. We use stereo-correlated relative digital elevation models (rDEMs) derived from ASTER data, as well as spectra in the visible near-infrared (VNIR) to thermal infrared (TIR) domains. The resulting geomorphic units in the study area are classified as mountain (including the Margala Hills and the Khairi Murat Ridge), piedmont, and basin terrain units. The local geologic units are classified as limestone in the Margala Hills and the Khairi Murat Ridge and sandstone rock types for the piedmonts and basins. Shear-wave velocities for these units are assigned in ranges based on established correlations in California. These ranges include Vs30-values to be greater than 500 m/sec for mountain units, 200–600 m/sec for piedmont units, and less than 300 m/sec for basin units. While the resulting map provides the basis for incorporating site response in an assessment of seismic hazard for Islamabad, it also demonstrates the potential use of remote-sensing data for site characterization in regions where only limited conventional mapping has been done

    An EEG study on emotional intelligence and advertising message effectiveness

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    Some electroencephalography (EEG) studies have investigated emotional intelligence (EI), but none have examined the relationships between EI and commercial advertising messages and related consumer behaviors. This study combines brain (EEG) techniques with an EI psychometric to explore the brain responses associated with a range of advertisements. A group of 45 participants (23females, 22males) had their EEG recorded while watching a series of advertisements selected from various marketing categories such as community interests, celebrities, food/drink, and social issues. Participants were also categorized as high or low in emotional intelligence (n = 34). The EEG data analysis was centered on rating decision-making in order to measure brain responses associated with advertising information processing for both groups. The ïŹndings suggest that participants with high and low emotional intelligence (EI) were attentive to diïŹ€erent types of advertising messages. The two EI groups demonstrated preferences for “people” or “object,” related advertising information. This suggests that diïŹ€erences in consumer perception and emotions may suggest why certain advertising material or marketing strategies are eïŹ€ective or not

    Reversed cortical over-activity during movement imagination following neurofeedback treatment for central neuropathic pain

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    Objective: One of the brain signatures of the central neuropathic pain (CNP) is the theta band over-activity of wider cortical structures, during imagination of movement. The objective of the study was to investigate whether this over-activity is reversible following the neurofeedback treatment of CNP. Methods: Five paraplegic patients with pain in their legs underwent from twenty to forty neurofeedback sessions that significantly reduced their pain. In order to assess their dynamic cortical activity they were asked to imagine movements of all limbs a week before the first and a week after the last neurofeedback session. Using time–frequency analysis we compared EEG activity during imagination of movement before and after the therapy and further compared it with EEG signals of ten paraplegic patients with no pain and a control group of ten able-bodied people. Results: Neurofeedback treatment resulted in reduced CNP and a wide spread reduction of cortical activity during imagination of movement. The reduction was significant in the alpha and beta band but was largest in the theta band. As a result cortical activity became similar to the activity of other two groups with no pain. Conclusions: Reduction of CNP is accompanied by reduced cortical over-activity during movement imagination. Significance: Understanding causes and consequences mechanism through which CNP affects cortical activity

    Restriction of task processing time affects cortical activity during processing of a cognitive task: an event-related slow cortical potential study

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    As is known from psychometrics, restriction of task processing time by the instruction to respond as quickly and accurately as possible leads to task-unspecific cognitive processing. Since this task processing mode is used in most functional neuroimaging studies of human cognition, this may evoke cortical activity that is functionally not essential for the particular task under investigation. Using topographic recordings of event-related slow cortical potentials, two experiments have been performed to investigate whether cortical activity during processing of a visuo-spatial imagery task is substantially influenced by the time provided to process the task. Furthermore, it was investigated whether this effect is additionally modulated by a subject’s task-specific ability. The instruction to respond as quickly and accurately as possible led to increased negative slow cortical potential amplitudes over parietal and frontal regions and significantly interacted with task-specific ability. While cortical activity recorded over parietal and frontal regions was different between subjects with low and high spatial ability when processing time was unrestricted, no such differences were found between ability groups when subjects were instructed to answer both quickly and accurately. These results suggest that restricting processing time has considerable effects on the amount and the pattern of brain activity during cognitive processing and should be taken into account more explicitly in the experimental design and interpretation of neuroimaging studies of cognition

    Effects of visuospatial tasks on desensitization to emotive memories

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    Objectives: Vivid and intrusive memories of extreme trauma can disrupt a stepwise approach to imaginal exposure. Concurrent tasks that load the visuo-spatial sketchpad (VSSP) of working memory reduce memory vividness during imaginal exposure. Such tasks may help maintain a progressive exposure protocol while minimizing distress during treatment. The current study tested whether relief of distress from a competing VSSP load during emotive imagery is at the cost of impaired desensitization. Design: This study examined repeated exposure to emotive memories using 18 unselected undergraduates, using a within-subjects design. Method: Participants recalled three positive and three negative self-related memories, and rated the vividness and emotiveness of the image. Participants then received all three conditions (Eye Movements; Visual Noise; Control) in a counterbalanced order. One positive and one negative recollection were used for each condition. They then rated the vividness of the image and their emotional response before proceeding to the next trial. There were 8 trials for each image. At a noninterference session one week later, participants recalled each image, rating its vividness and their emotional response. Results: Consistent with previous research, vividness and distress during imaging were lower during eye movements than in exposure alone, with passive visual interference giving intermediate results. A small reduction in emotional responses a week later was of similar size for the three conditions

    Effect of visual feedback on the occipital-parietal-motor network in Parkinson's disease with freezing of gait.

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    Freezing of gait (FOG) is an elusive phenomenon that debilitates a large number of Parkinson's disease (PD) patients regardless of stage of disease, medication status, or deep brain stimulation implantation. Sensory feedback cues, especially visual feedback cues, have been shown to alleviate FOG episodes or even prevent episodes from occurring. Here, we examine cortical information flow between occipital, parietal, and motor areas during the pre-movement stage of gait in a PD-with-FOG patient that had a strong positive behavioral response to visual cues, one PD-with-FOG patient without any behavioral response to visual cues, and age-matched healthy controls, before and after training with visual feedback. Results for this case study show differences in cortical information flow between the responding PD-with-FOG patient and the other two subject types, notably, an increased information flow in the beta range. Tentatively suggesting the formation of an alternative cortical sensory-motor pathway during training with visual feedback, these results are proposed as subject for further verification employing larger cohorts of patients

    Central neuropathic pain in paraplegia alters movement related potentials

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    Objectives: Spinal Cord Injured (SCI) persons with and without Central Neuropathic Pain (CNP) show different oscillatory brain activities during imagination of movement. This study investigates whether they also show differences in movement related cortical potentials (MRCP). Methods: SCI paraplegic patients with no CNP (n = 8), with CNP in their lower limbs (n = 8), and healthy control subjects (n = 10) took part in the study. EEG clustering involved independent component analysis, equivalent current dipole fitting, and Measure Projection to define cortical domains that have functional modularity during the motor imagery task. Results: Three domains were identified: limbic system, sensory-motor cortex and visual cortex. The MRCP difference between the groups of SCI with and without CNP was reflected in a domain located in the limbic system, while the difference between SCI patients and control subjects was in the sensorimotor domain. Differences in MRCP morphology between patients and healthy controls were visible for both paralysed and non paralysed limbs. Conclusion: SCI but not CNP affects the movement preparation, and both SCI and CNP affect sensory processes. Significance: Rehabilitation strategies of SCI patients based on MRCP should take into account the presence of CNP

    Reasoning and Reading in Adults. A New Reasoning Task for Detecting the Visual Impendance Effect

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    The visual impedance hypothesis states that at the time of reasoning, the reading context provokes visual images, which may add irrelevant details to an inference and thus could hamper reasoning. This study aims to create a new visual version of a reasoning task, similar to the traditional propositional task of relational syllogisms, but based on visuospatial components. Using such a task, it would be possible to investigate the deductive ability of relational inferences in tests without the need for reading. Two reasoning tasks were used and measures of working memory, visuospatial memory, intelligence, and reading comprehension were taken. The participants were 61 university students without reading difficulties. Results show that both versions of the reasoning task work similarly in finding the main reasoning effects expected. Findings support the visual impedance effect, that is, fewer correct responses in problems with imaginable contents than with neutral ones. They indicate that this new visual task could be used to explore reasoning skills without reading being involved, and this would be useful for testing reasoning in people both with and without reading difficulties.The research reported in this work is partially funded by the Junta de AndalucĂ­a research group HUM 820 “LEE. Lectura y Escritura en Español,” FEDER Fundings, and the MINECO Project PSI2015- 63505-P

    Multi-frequency fine resolution imaging radar instrumentation and data acquisition

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    Development of a dual polarized L-band radar imaging system to be used in conjunction with the present dual polarized X-band radar is described. The technique used called for heterodyning the transmitted frequency from X-band to L-band and again heterodyning the received L-band signals back to X-band for amplification, detection, and recording
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