May 07, 2007
A MEG-based brain-computer interface
A MEG-based brain-computer interface (BCI).
Neuroimage. 2007 Mar 27;
Authors: Mellinger J, Schalk G, Braun C, Preissl H, Rosenstiel W, Birbaumer N, Kübler A
Brain-computer interfaces (BCIs) allow for communicating intentions by mere brain activity, not involving muscles. Thus, BCIs may offer patients who have lost all voluntary muscle control the only possible way to communicate. Many recent studies have demonstrated that BCIs based on electroencephalography (EEG) can allow healthy and severely paralyzed individuals to communicate. While this approach is safe and inexpensive, communication is slow. Magnetoencephalography (MEG) provides signals with higher spatiotemporal resolution than EEG and could thus be used to explore whether these improved signal properties translate into increased BCI communication speed. In this study, we investigated the utility of an MEG-based BCI that uses voluntary amplitude modulation of sensorimotor mu and beta rhythms. To increase the signal-to-noise ratio, we present a simple spatial filtering method that takes the geometric properties of signal propagation in MEG into account, and we present methods that can process artifacts specifically encountered in an MEG-based BCI. Exemplarily, six participants were successfully trained to communicate binary decisions by imagery of limb movements using a feedback paradigm. Participants achieved significant mu rhythm self control within 32 min of feedback training. For a subgroup of three participants, we localized the origin of the amplitude modulated signal to the motor cortex. Our results suggest that an MEG-based BCI is feasible and efficient in terms of user training.
21:50 Posted in Brain-computer interface | Permalink | Comments (0) | Tags: brain-computer interface
Overt and imagined singing of an Italian aria
Overt and imagined singing of an Italian aria.
Neuroimage. 2007 Mar 24;
Authors: Kleber B, Birbaumer N, Veit R, Trevorrow T, Lotze M
Activation maps of 16 professional classical singers were evaluated during overt singing and imagined singing of an Italian aria utilizing a sparse sampling functional magnetic imaging (fMRI) technique. Overt singing involved bilateral primary and secondary sensorimotor and auditory cortices but also areas associated with speech and language production. Activation magnitude within the gyri of Heschl (A1) was comparable in both hemispheres. Subcortical motor areas (cerebellum, thalamus, medulla and basal ganglia) were active too. Areas associated with emotional processing showed slight (anterior cingulate cortex, anterior insula) activation. Cerebral activation sites during imagined singing were centered on fronto-parietal areas and involved primary and secondary sensorimotor areas in both hemispheres. Areas processing emotions showed intense activation (ACC and bilateral insula, hippocampus and anterior temporal poles, bilateral amygdala). Imagery showed no significant activation in A1. Overt minus imagined singing revealed increased activation in cortical (bilateral primary motor; M1) and subcortical (right cerebellar hemisphere, medulla) motor as well as in sensory areas (primary somatosensory cortex, bilateral A1). Imagined minus overt singing showed enhanced activity in the medial Brodmann's area 6, the ventrolateral and medial prefrontal cortex (PFC), the anterior cingulate cortex and the inferior parietal lobe. Additionally, Wernicke's area and Brocca's area and their homologues were increasingly active during imagery. We conclude that imagined and overt singing involves partly different brain systems in professional singers with more prefrontal and limbic activation and a larger network of higher order associative functions during imagery.
21:49 Posted in Mental practice & mental simulation | Permalink | Comments (0) | Tags: mental practice
Spirituality and addiction: a research and clinical perspective
Spirituality and addiction: a research and clinical perspective.
Am J Addict. 2006 Jul-Aug;15(4):286-92
Authors: Galanter M
Spirituality is a construct that has recently gained currency among clinicians because of its close association with twelve-step modalities and its perceived role in the promotion of meaningfulness in recovery from addiction. This article draws on studies from physiology, psychology, and cross-cultural sources to examine its nature and its relationship to substance use disorders. Illustrations of its potential and limitations as a component of treatment in spiritually oriented recovery movements like Alcoholics Anonymous, meditative practices, and treatment systems for the dually diagnosed are given.
21:47 Posted in Meditation & brain | Permalink | Comments (0) | Tags: spirituality




