24,863 research outputs found

    A randomized controlled trial to examine the posttreatment efficacy of neurofeedback, behavior therapy, and pharmacology on ADHD measures

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    Objective: To examine the efficacy of neurofeedback (NF), behavior therapy (BT), and pharmacology (PH) on the improvement of ADHD-related symptoms. Method: Fifty-nine children with ADHD (M = 8.80 years, SD = 1.92 years) were randomly assigned to one of the three treatments in a pre/post assessment design. Mother- and teacher-rated ADHD scales and children were assessed using The Integrated Visual and Auditory Continuous Performance Test (IVA/CPT). Results: The three treatments were effective on the IVA/CPT, but with different trends. BT and especially NF achieved improvement on response control and attention, and PH mainly in visual attention. On the rating scales, BT improved all measures, and NF and PH had a minor but interesting influence. Conclusion: From a global perspective, behavior therapy had the most extensive results, but PH had the greatest capacity to improve overall attention. NF was able to improve both control response and inattention. Clinical implications are discussed.Plan Nacional i+d+i PSI2008–06008-C02–0

    Unitization during Category Learning

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    Five experiments explored the question of whether new perceptual units can be developed if they are diagnostic for a category learning task, and if so, what are the constraints on this unitization process? During category learning, participants were required to attend either a single component or a conjunction of five components in order to correctly categorize an object. In Experiments 1-4, some evidence for unitization was found in that the conjunctive task becomes much easier with practice, and this improvement was not found for the single component task, or for conjunctive tasks where the components cannot be unitized. Influences of component order (Experiment 1), component contiguity (Experiment 2), component proximity (Experiment 3), and number of components (Experiment 4) on practice effects were found. Using a Fourier Transformation method for deconvolving response times (Experiment 5), prolonged practice effects yielded responses that were faster than expected by analytic model that integrate evidence from independently perceived components

    A Randomized Controlled Trial Comparing two Cognitive-Behavioral Programs for Adolescent Girls with Subclinical Depression: A School-Based Program (Op Volle Kracht) and a Computerized Program (SPARX)

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    Limited research has indicated the effectiveness of the school-based Cognitive Behavioral Therapy (CBT) prevention program ‘Op Volle Kracht (OVK)’ and the computerized CBT program ‘SPARX’ in decreasing depressive symptoms. Therefore, a randomized controlled trial of the effectiveness of OVK and SPARX was conducted among Dutch female adolescents (n = 208, mean age = 13.35) with elevated depressive symptoms. Participants were randomly assigned to one of four conditions: OVK only (n = 50), SPARX only (n = 51), OVK and SPARX combined (n = 56) and a monitoring control condition (n = 51). Participants in the first three conditions received OVK lessons and/or the SPARX game. Depressive symptoms were assessed before interventions started, weekly during the interventions, and immediately after the interventions ended, with follow-up assessments at 3, 6 and 12 months. Intention to treat results showed that depressive symptoms decreased in all conditions (F(12, 1853.03) = 14.62, p < .001), with no difference in depressive symptoms between conditions. Thus, all conditions, including the monitoring control condition, were equally effective in reducing depressive symptoms. Possible explanations for the decrease of depressive symptoms in all conditions are discussed and suggestions for future research are provided. Dutch Trial Register: NTR3737

    What do we perceive in a glance of a real-world scene?

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    What do we see when we glance at a natural scene and how does it change as the glance becomes longer? We asked naive subjects to report in a free-form format what they saw when looking at briefly presented real-life photographs. Our subjects received no specific information as to the content of each stimulus. Thus, our paradigm differs from previous studies where subjects were cued before a picture was presented and/or were probed with multiple-choice questions. In the first stage, 90 novel grayscale photographs were foveally shown to a group of 22 native-English-speaking subjects. The presentation time was chosen at random from a set of seven possible times (from 27 to 500 ms). A perceptual mask followed each photograph immediately. After each presentation, subjects reported what they had just seen as completely and truthfully as possible. In the second stage, another group of naive individuals was instructed to score each of the descriptions produced by the subjects in the first stage. Individual scores were assigned to more than a hundred different attributes. We show that within a single glance, much object- and scene-level information is perceived by human subjects. The richness of our perception, though, seems asymmetrical. Subjects tend to have a propensity toward perceiving natural scenes as being outdoor rather than indoor. The reporting of sensory- or feature-level information of a scene (such as shading and shape) consistently precedes the reporting of the semantic-level information. But once subjects recognize more semantic-level components of a scene, there is little evidence suggesting any bias toward either scene-level or object-level recognition

    Role of lateral and feedback connections in primary visual cortex in the processing of spatiotemporal regularity: a TMS study

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    Our human visual system exploits spatiotemporal regularity to interpret incoming visual signals. With a dynamic stimulus sequence of four collinear bars (predictors) appearing consecutively toward the fovea, followed by a target bar with varying contrasts, we have previously found that this predictable spatiotemporal stimulus structure enhances target detection performance and its underlying neural process starts in the primary visual cortex (area V1). However, the relative contribution of V1 lateral and feedback connections in the processing of spatiotemporal regularity remains unclear. In this study we measured human contrast detection of a briefly presented foveal target that was embedded in a dynamic collinear predictor-target sequence. Transcranial magnetic stimulation (TMS) was used to selectively disrupt V1 horizontal and feedback connections in the processing of predictors. The coil was positioned over a cortical location corresponding to the location of the last predictor prior to target onset. Single-pulse TMS at an intensity of 10% below phosphene threshold was delivered at 20 or 90ms after the predictor onset. Our analysis revealed that the delivery of TMS at both time windows equally reduced, but did not abolish, the facilitation effect of the predictors on target detection. Furthermore, if the predictors’ ordination was randomized to suppress V1 lateral connections, the TMS disruption was significantly more evident at 20ms than at 90ms time window. We suggest that both lateral and feedback connections contribute to the encoding of spatiotemporal regularity in V1. These findings develop understanding of how our visual system exploits spatiotemporal regularity to facilitate the efficiency of visual perception
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