Four-dimensional ultrasound current source density imaging of a dipole field.

Ultrasound current source density imaging (UCSDI) potentially transforms conventional electrical mapping of excitable organs, such as the brain and heart. For this study, we demonstrate volume imaging of a time-varying current field by scanning a focused ultrasound beam and detecting the acoustoelectric (AE) interaction signal. A pair of electrodes produced an alternating current distribution in a special imaging chamber filled with a 0.9% NaCl solution. A pulsed 1 MHz ultrasound beam was scanned near the source and sink, while the AE signal was detected on remote recording electrodes, resulting in time-lapsed volume movies of the alternating current distribution.

Do self-statements enhance the effectiveness of virtual reality exposure therapy? A comparative evaluation in acrophobia.

There is a clear need for more detailed analysis of the role of cognitive self-statements in virtual reality exposure therapy (VRET). To date, no research on this topic has been done. The primary aim of this study was to investigate whether coping self-statements would enhance the effectiveness of VRET. In a randomized crossover design, 26 patients with acrophobia (DSM-IV diagnosis of specific phobia) were randomly assigned to two sessions of VRET followed by two sessions of VRET plus coping self-statements, or the other way around: first two sessions of VRET plus coping self-statements followed by two sessions of VRET. Results showed that VRET, regardless of addition of coping self-statements, decreased anxiety of heights, decreased avoidance of height situations, and improved attitudes towards heights. However, at 6-month follow-up, most gains during treatment were not fully retained.

Virtual reality exposure therapy of anxiety disorders: a review.

Virtual reality exposure therapy (VRET) is an altered form of behavioral therapy and may be a possible alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse patients in a computer-generated virtual environment. Research on this type of treatment for anxiety disorders is discussed in this article, and the mediating and moderating variables that influence VR treatment effectiveness as well. Evidence is found that VRET is effective for participants with fear of heights and of flying. For other phobias, research to date is not conclusive. More randomized clinical trials in which VRET is compared with standard exposure are required. Furthermore, studies are needed in which VRET is not just a component of the treatment package evaluated, but in which VRET should be assessed as a stand-alone treatment.