Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

Meta-analyzing left hemisphere language areas: Phonology, semantics, and sentence processing

https://www.cell.com/neuron/pdf/S0896-6273(07)00460-6.pdf

Transcranial Magnetic Stimulation: A Primer

A brain-computer interface (BCI) is a hardware and software communications system that permits cerebral activity alone to control computers or external devices. The immediate goal of BCI research is to provide communications capabilities to severely disabled people who are totally paralyzed or 'locked in' by neurological neuromuscular disorders, such as amyotrophic lateral sclerosis, brain stem stroke, or spinal cord injury. Here, we review the state-of-the-art of BCIs, looking at the different steps that form a standard BCI: signal acquisition, preprocessing or signal enhancement, feature extraction, classification and the control interface. We discuss their advantages, drawbacks, and latest advances, and we survey the numerous technologies reported in the scientific literature to design each step of a BCI. First, the review examines the neuroimaging modalities used in the signal acquisition step, each of which monitors a different functional brain activity such as electrical, magnetic or metabolic activity. Second, the review discusses different electrophysiological control signals that determine user intentions, which can be detected in brain activity. Third, the review includes some techniques used in the signal enhancement step to deal with the artifacts in the control signals and improve the performance. Fourth, the review studies some mathematic algorithms used in the feature extraction and classification steps which translate the information in the control signals into commands that operate a computer or other device. Finally, the review provides an overview of various BCI applications that control a range of devices.

/pdf/brain-computer-interfaces-a-review-2z42gnpdfy.pdf

Brain Computer Interfaces, a Review

From an early age, musicians learn complex motor and auditory skills (e.g., the translation of visually perceived musical symbols into motor commands with simultaneous auditory monitoring of output), which they practice extensively from childhood throughout their entire careers. Using a voxel-by-voxel morphometric technique, we found gray matter volume differences in motor, auditory, and visual-spatial brain regions when comparing professional musicians (keyboard players) with a matched group of amateur musicians and non-musicians. Although some of these multiregional differences could be attributable to innate predisposition, we believe they may represent structural adaptations in response to long-term skill acquisition and the repetitive rehearsal of those skills. This hypothesis is supported by the strong association we found between structural differences, musician status, and practice intensity, as well as the wealth of supporting animal data showing structural changes in response to long-term motor training. However, only future experiments can determine the relative contribution of predisposition and practice.

https://www.jneurosci.org/content/jneuro/23/27/9240.full.pdf

Brain Structures Differ between Musicians and Non-Musicians

Little is known about the neural correlates of tics and associated urges. In the present study, we aimed to explore the neural basis of tics in patients with Tourette syndrome by using event-related functional MRI (fMRI). Ten patients (6 women, 4 men; age: mean +/- SD = 31 +/- 11.2) were studied while spontaneously exhibiting a variety of motor and vocal tics. On the basis of synchronized video/audio recordings, fMRI activities were analysed 2 s before and at tic onset irrespective of the clinical phenomenology. We identified a brain network of paralimbic areas such as anterior cingulate and insular cortex, supplementary motor area (SMA) and parietal operculum (PO) predominantly activated before tic onset (P < 0.05, corrected for multiple comparisons). In contrast, at the beginning of tic action, significant fMRI activities were found in sensorimotor areas including superior parietal lobule bilaterally and cerebellum. The results of this study indicate that paralimbic and sensory association areas are critically implicated in tic generation, similar to movements triggered internally by unpleasant sensations, as has been shown for pain or itching.

Neural correlates of tic generation in Tourette syndrome: an event-related functional MRI study.

It has been hypothesized that language functions are more strongly lateralized to the left hemisphere in males than in females. Previous anatomical data and patient studies have suggested that the posterior language areas should exhibit sex differences. However, neuroimaging studies to date have only provided support for differences in the anterior language areas. To look for differences in the posterior language areas, functional magnetic resonance imaging scans were obtained while male and female subjects listened attentively to a story read aloud and to the same story replayed in reverse. Comparing activation in the superior and the middle temporal gyri during a story to activation during reverse replay of the story showed lateralization to the left in males but not in females. There was no lateralization in either sex when comparing activation during random fragmentation of the story to reverse replay. In the angular and the supramarginal gyri, however, activation was lateralized to the left hemisphere in both sexes, unlike the sex-dependent activation of the posterior temporal lobes. We infer that females use the posterior temporal lobes more bilaterally during linguistic processing of global structures in a narrative than males do.

http://zielinskifam.com/lit/gumc_nsci_papers/sexdiff_lang.pdf

Sex Differences in Lateralization Revealed in the Posterior Language Areas

We used functional magnetic resonance imaging (fMRI) and dual tasks to investigate the physiology of how movements become automatic. Normal subjects were asked to practice some self-initiated, self-paced, memorized sequential finger movements with different complexity until they could perform the tasks automatically. Automaticity was evaluated by having subjects perform a secondary task simultaneously with the sequential movements. Our secondary task was a letter-counting task where subjects were asked to identify the number of times a target letter from the letter sequences was seen. Only the performances that achieved high accuracy in both single and dual tasks were considered automatic. The fMRI results before and after automaticity was achieved were compared. Our data showed that for both conditions, sequential movements activated similar brain regions. No additional activity was observed in the automatic condition. There was less activity in bilateral cerebellum, presupplementary motor area, cingulate cortex, left caudate nucleus, premotor cortex, parietal cortex, and prefrontal cortex during the automatic stage. These findings suggest that most of the motor network participates in executing automatic movements and that it becomes more efficient as movements become more automatic. Our results do not provide evidence for any area to become more activated for automatic movements.

https://www.physiology.org/doi/pdf/10.1152/jn.01052.2003

How self-initiated memorized movements become automatic: a functional MRI study.

Little is known about how the brain binds together signals from multiple sensory modalities to produce unified percepts of objects and events in the external world. Using event-related functional magnetic resonance imaging (fMRI) in humans, we measured transient brain responses to auditory/visual binding, as evidenced by a sound-induced change in visual motion perception. Identical auditory and visual stimuli were presented in all trials, but in some trials they were perceived to be bound together and in others they were perceived as unbound unimodal events. Cross-modal binding was associated with higher activity in multimodal areas, but lower activity in predominantly unimodal areas. This activation pattern suggests that a reciprocal and 'competitive' interaction between multimodal and unimodal areas underlies the perceptual interpretation of simultaneous signals from multiple sensory modalities.

Neural correlates of cross-modal binding.

No consistent cerebral anatomical abnormality has ever been reported in primary focal hand dystonia (FHD). The present voxel-based morphometry study showed a significant bilateral increase in gray matter in the hand representation area of primary somatosensory and, to a lesser extent, primary motor cortices in 36 patients with unilateral FHD compared with 36 controls. The presence of anatomical changes in the perirolandic cortex for the unaffected hand as well as that for the affected hand suggests that these disturbances may be, at least in part, primary.

Kenji Kansaku

Papers

Neural correlates of tic generation in Tourette syndrome: an event-related functional MRI study.

Sex Differences in Lateralization Revealed in the Posterior Language Areas

How self-initiated memorized movements become automatic: a functional MRI study.

Neural correlates of cross-modal binding.

Changes in brain anatomy in focal hand dystonia.