TMs Conditions Research Articles

0063 Slow-wave Sleep Onset Latency Mediates Improvements in Attention and Processing Speed Following Continuous Theta-Burst (cTBS) TMS

Abstract Introduction Insomnia causes substantial health-care cost burden and is a risk factor for neurocognitive impairment. Increased DMN activity has been implicated in the hyperarousal theory of insomnia. In this pilot clinical trial, DMN was targeted via the left inferior parietal lobe using a brief 40 second cTBS Transcranial Magnetic Stimulation (rTMS). We hypothesized that neurocognitive improvements due to cTBS would be mediated by polysomnographic (PSG) parameters of slow wave sleep. Methods Twenty participants (12 female; age=26.9, SD=6.6 years) meeting criteria for insomnia completed a counterbalanced sham-controlled crossover design in which they served as their own controls on two separate nights of in-laboratory assessments. Sessions for both conditions included neurocognitive assessments at baseline, after stimulation (cTBS/sham) before bed, and the following morning. After stimulation, participants were allowed an 8-hour sleep opportunity from 2300 to 0700 monitored with PSG. The symbol coding and digit span subtests of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) exam are the main assessments in the current investigation. Results Improvements in attention and processing speed were observed after a night of sleep following both active TMS (cTBS; B = 11.05, p < .001) and sham TMS conditions (B = 8.10, p = .002) the prior day. In the cTBS condition only, these improvements in attention were mediated by latency to slow wave sleep (N3), such that shorter latencies were related to greater improvements on a simple attention task (RBANS digit span; B = -0.75, p < .001). This effect of night to morning improvement in attention and processing speed was also found in the sham condition for the coding task (B = 60.81, p < .001), but not for digit span. No effects of slow wave sleep duration on RBANS coding or digit span were observed in either condition. Conclusion Improvements in simple attention performance in response to cTBS may be, in part, due to slow wave sleep parameters. Moreover, results suggest that simple attention may have been more sensitive to the effects of cTBS, whereas processing speed may have been a factor of lower slow wave sleep onset latency. Support (if any) DoD PRMRPD W81XWH2010173

Saying goodbye to an unwelcome guest: Towards robust methods for controlling multi-sensory confounds in TMS-EEG research.

Saying goodbye to an unwelcome guest: Towards robust methods for controlling multi-sensory confounds in TMS-EEG research.

Temporal dynamics of TMS interference over preparatory alpha activity during semantic decisions

The mean amplitude of the EEG alpha (8–12 Hz) power de-synchronization (ERD) is a robust electrophysiological correlate of task anticipation. Furthermore, in paradigms using a fixed period between warning and target stimuli, such alpha de-synchronization tends to increase and to peak just before target presentation. Previous studies from our group showed that the anticipatory alpha ERD can be modulated when magnetic stimulation is delivered over specific cortical regions during a variety of cognitive tasks. In this study we investigate the temporal dynamics of the anticipatory alpha ERD and test whether the magnetic stimulation produces either a general attenuation or an interruption of the typical development of alpha ERD. We report that, during a semantic decision task, rTMS over left AG, a region previously associated to semantic memory retrieval, shortened the peak latency and decreased the peak amplitude of the anticipatory alpha de-synchronization as compared to both active (left IPS) and non-active (Sham) TMS conditions. These results, while supporting the causal role of the left AG in the anticipation of a semantic decision task, suggest that magnetic interference not simply reduces the mean amplitude of anticipatory alpha ERD but also interrupts its typical temporal evolution in paradigms employing fixed cue-target intervals.

TRAUMA DALAM NOVEL YU ZHEN

a€S a½™eœ‡ a€‹ Yu Zhen or After Shock (2006) is a novel written by Zhang Ling, a Chinese woman writer who lives in Canada now. After Shock is a story about the great earthquake happened at Tangshan city, Hebei province, P.R.C in 1976. One interesting point to discuss from this novel is about Wan Xiaodeng’s emotional states and conditions as a main character, as well as an earthquake victim in this novel. Wan Xiaodeng not only suffers from physical trauma, but also suffers from acute psychological trauma.This psychological trauma existed from her childhood to adulthood. By psychological point of view, this writing is going to discuss Wan Xiaodeng’s symptoms of post traumatic stress disorder, and impacts or responses to the surroundings. Keywords: a€Sa½™eœ‡a€‹ Yu Zhen , After Shock , Zhang Ling, trauma Â

P156 Ongoing EEG oscillations modulate MEP amplitudes: A possible mechanism of MEP variability

Objective Although the resting motor threshold (RMT) is relatively stable, the variability of MEPs produced by TMS over the primary motor cortex (M1) is well known, and its precise mechanism is still unclear. We hypothesized that EEG oscillations just before TMS could modulate the MEP amplitudes that underlie the MEP variability. Thus, we evaluated the relationship between EEG oscillations and MEP amplitudes. Methods Two experiments were conducted in this study. EEGs were obtained at 19 locations (international 10–20 system) and MEPs were recorded from right FDI in Exp. 1 (n = 12). Left M1 hotspot was stimulated by TMS with the intensity to obtain about 1 mV MEP amplitudes (S-1 mV). MEPs and EEGs were recorded for 200 times in total for each subject under the eyes-open (EO) and eyes-close (EC) conditions. EEGs were segmented between −500 and 0 ms of the TMS onset, and the power values (8–30 Hz) were calculated by wavelet analysis. EEG powers were compared between the epochs of higher and lower amplitude MEPs. In Exp. 2 (n = 9), the effect of low TMS intensity was evaluated under the EO condition. EEG oscillations were compared between the high (S-1 mV) and low intensity (RMT) TMS conditions. Results EEG powers of α and β range were significantly increased (synchronization) at C3 when MEP amplitudes were larger in both EO and EC conditions. When the EEG power difference of higher/lower MEPs was compared between the EO and EC conditions, these differences under EO were more pronounced than that of EC at frontal and parietal leads. In contrast, EEG powers were reduced (desynchronization) at C3 when MEP amplitudes were larger in the low TMS condition (Exp. 2). Discussion We found that EEG synchronization of α / β bands prior to TMS was a determinant factor for the MEP amplitudes at S-1 mV (Exp. 1). Distributed networks over the frontal areas may modulate MEPs differently under EO and EC conditions. However, desynchronization of α / β bands produced MEPs at RMT (Exp. 2). From this complex interaction between EEG synchronization/desynchronization and TMS intensity, we assume that ongoing EEG oscillations of α / β bands performs the dual functions of gateway and gatekeeper. Like a push–pull system, that depends on the ongoing EEG state and TMS intensity, the dual system may allow the TMS impulses to M1 by which the MEP variability occurs.

Pre-stimulus Alpha Oscillations and Inter-subject Variability of Motor Evoked Potentials in Single- and Paired-Pulse TMS Paradigms.

Inter- and intra-subject variability of the motor evoked potentials (MEPs) to TMS is a well-known phenomenon. Although a possible link between this variability and ongoing brain oscillations was demonstrated, the results of the studies are not consistent with each other. Exploring this topic further is important since the modulation of MEPs provides unique possibility to relate oscillatory cortical phenomena to the state of the motor cortex probed with TMS. Given that alpha oscillations were shown to reflect cortical excitability, we hypothesized that their power and variability might explain the modulation of subject-specific MEPs to single- and paired-pulse TMS (spTMS, ppTMS, respectively). Neuronal activity was recorded with multichannel electroencephalogram. We used spTMS and two ppTMS conditions: intracortical facilitation (ICF) and short-interval intracortical inhibition (SICI). Spearman correlations were calculated within and across subjects between MEPs and the pre-stimulus power of alpha oscillations in low (8–10 Hz) and high (10–12 Hz) frequency bands. Coefficient of quartile variation was used to measure variability. Across-subject analysis revealed no difference in the pre-stimulus alpha power among the TMS conditions. However, the variability of high-alpha power in spTMS condition was larger than in the SICI condition. In ICF condition pre-stimulus high-alpha power variability correlated positively with MEP amplitude variability. No correlation has been observed between the pre-stimulus alpha power and MEP responses in any of the conditions. Our results show that the variability of the alpha oscillations can be more predictive of TMS effects than the commonly used power of oscillations and we provide further support for the dissociation of high and low-alpha bands in predicting responses produced by the stimulation of the motor cortex.

TMS reveals flexible use of form and motion cues in biological motion perception

The perception of human movement is a key component of daily social interactions. Although extrastriate area MT+/V5 is closely associated with motion processing, its role in the processing of sparse ‘biological motion’ displays is still unclear. We developed two closed matched psychophysical tasks to assess simple coherent motion perception and biological motion perception, and measured changes in performance caused by application of TMS over MT+/V5. Performance of the simple motion discrimination task was significantly depressed by TMS stimulation, and highly correlated within observers in TMS conditions, but there was no significant decrement in performance of the biological motion task, despite low intra-observer correlations across TMS conditions. We conclude that extrastriate area MT+/V5 is an obligatory waypoint in the neural processing of simple coherent motion, but is not obligatory for the processing of biological motion. Results are consistent with a dual neural processing route for biological motion processing.

Improvement in Paretic Arm Reach-to-Grasp following Low Frequency Repetitive Transcranial Magnetic Stimulation Depends on Object Size: A Pilot Study.

Introduction. Low frequency repetitive transcranial magnetic stimulation (LF-rTMS) delivered to the nonlesioned hemisphere has been shown to improve limited function of the paretic upper extremity (UE) following stroke. The outcome measures have largely included clinical assessments with little investigation on changes in kinematics and coordination. To date, there is no study investigating how the effects of LF-rTMS are modulated by the sizes of an object to be grasped. Objective. To investigate the effect of LF-rTMS on kinematics and coordination of the paretic hand reach-to-grasp (RTG) for two object sizes in chronic stroke. Methods. Nine participants received two TMS conditions: real rTMS and sham rTMS conditions. Before and after the rTMS conditions, cortico-motor excitability (CE) of the nonlesioned hemisphere, RTG kinematics, and coordination was evaluated. Object sizes were 1.2 and 7.2 cm in diameter. Results. Compared to sham rTMS, real rTMS significantly reduced CE of the non-lesioned M1. While rTMS had no effect on RTG action for the larger object, real rTMS significantly improved movement time, aperture opening, and RTG coordination for the smaller object. Conclusions. LF-rTMS improves RTG action for only the smaller object in chronic stroke. The findings suggest a dissociation between effects of rTMS on M1 and task difficulty for this complex skill.

Solutions and techniques for conservative and effective use of arable lands in the Somesan Plateau

The results presented in this paper were obtained in the experimental fields of agrotechnics discipline from the Jucu region in Cluj, on an argic - stagnic Phaoezem soil, with a humus content of 3.8% and a pH of 6.5. The soil tillage system made using plow, chisel, paraplow and direct sowing affects the quality of soil's structure by modifying the structure of macroagregate fractions and the percentage of microaggregates, identifiable on a 0-10 cm depth. In the first 30 cm the best degree of loosening was recorded on soils which had been plowed, where bulk density did not exceed 1.28 g/cm3, and the lowest loosening on soils sown directly where the values ​​ranged arownd 1.43 g/cm3. In variants tilled with chisel and paraplow the bulk density values ​​are practically equal 1.27-1.28 g/cm3. Soil resistance to penetration is significantly influenced on all depths. The highest value of the three cultures determined on the depth of 0-10 cm is recorded for direct seeding with values ​​of 980 kPa, followed by the unconventional variants tilled with paraplow and chisel of 767-877 kPa. Wheat production in the experimenal yers was influenced by the tillage system and rainfall so that in Somes Plateau’s conditions, productions ranged from 3887 kg/ha in the variant worked with plow and 3465 kg/ha for the direct sown variant. In the case of unconventional tillage variants, using chisel and paraplow, the productions were similar. The tillage system for the variants made using plow respectively chisel, paraplow and direct sow ensures soybean’s productions between 2310 kg/ha for the plowing variant, 2142 kg/ha for direct sowing variant and variants worked with chisel and paraplow ensure production of 2176-2234 kg/ha. Tillage systems with chisel and paraplow registered on maize production of 94.4-97.2% from the control variant tilled with plow. The difference in minus for the variants with chisel and paraplow is primarily attributed to the higher degree of weeds at the two ways of soil tillage. In the variant of direct sowing is only carried out 89.3% of the production of the control variant with plow, which calls into question the economic efficiency of this mode of tillage for maize crops in the conditions of Somesan Plateau. After the economic analysis of the three variants it can be found that in the case of wheat crops is achieved a profit of 2-8% and one of 4-12% for soybean, this profit made per unit area is motivated since energy consumptions is more reduced to three modes of tillage. For the maize crops the profits are lower in all three variants up to 8% as the number of plants per unit area is lower due to the uneven emergence.

Touching Motion: rTMS on the Human Middle Temporal Complex Interferes with Tactile Speed Perception

Brain functional and psychophysical studies have clearly demonstrated that visual motion perception relies on the activity of the middle temporal complex (hMT+). However, recent studies have shown that hMT+ seems to be also activated during tactile motion perception, suggesting that this visual extrastriate area is involved in the processing and integration of motion, irrespective of the sensorial modality. In the present study, we used repetitive transcranial magnetic stimulation (rTMS) to assess whether hMT+ plays a causal role in tactile motion processing. Blindfolded participants detected changes in the speed of a grid of tactile moving points with their finger (i.e. tactile modality). The experiment included three different conditions: a control condition with no TMS and two TMS conditions, i.e. hMT+-rTMS and posterior parietal cortex (PPC)-rTMS. Accuracies were significantly impaired during hMT+-rTMS but not in the other two conditions (No-rTMS or PPC-rTMS), moreover, thresholds for detecting speed changes were significantly higher in the hMT+-rTMS with respect to the control TMS conditions. These findings provide stronger evidence that the activity of the hMT+ area is involved in tactile speed processing, which may be consistent with the hypothesis of a supramodal role for that cortical region in motion processing.

Influence of memory strategies on memory test performance: A study in healthy and pathological aging

ABSTRACT The ability to generate memory strategies is a key factor in the performance of episodic memory tasks. Whether the ability to generate memory strategies exerts an influence in the performance of memory tests in the elderly population is still a matter of debate. Here we present results from an experimental memory task (Test of Memory Strategies, TMS), comprised of five lists of words starting from an incidental learning task, and four more lists which progressively gain in their external organization of the material, reducing the necessity of mobilizing complex memory strategies. TMS has been applied to four groups of elderly patients (amnestic Mild Cognitive Impairment – aMCI, multidomain (mMCI), and Vascular Cognitive Impairment – VCI and Depression) and a healthy aging group. In conditions with low organization of the material, the mMCI and VCI groups (both showing a greater executive function impairment) have shown lower performance. However, as the material was progressively organized, they improved their performance. The aMCI group showed similar performance to the control group at the lower level of external organization but did not improve performance in conditions with a high level of external organization. The mMCI and VCI groups showed lower performance on all TMS conditions compared with controls. Discriminant analysis revealed 90% sensitivity and specificity to differentiate between groups based on TMS conditions. These results indicate how executive functions influence performance on memory tasks in elderly subjects with different neuropsychological profiles.

Results of a pilot study on the involvement of bilateral inferior frontal gyri in emotional prosody perception: an rTMS study

BackgroundThe right hemisphere may play an important role in paralinguistic features such as the emotional melody in speech. The extent of this involvement however is unclear. Imaging studies have shown involvement of both left and right inferior frontal gyri in emotional prosody perception. The present pilot study examined whether these brain areas are critically involved in the processing of emotional prosody and of semantics in 9 healthy subjects. Repetitive transcranial magnetic stimulation was used with a coil centred over left and right inferior frontal gyri, as localized by neuronavigation based on the subject's MRI. A sham condition was included. An online-TMS approach was applied; an emotional language task was completed during stimulation. This computerized task consisted of sentences pronounced by actors. In the semantics condition an emotion (fear, anger or neutral) was expressed in the content pronounced with a neutral intonation. In the prosody condition the emotion was expressed in the intonation, while the content was neutral.ResultsReaction times on the emotional prosody task condition were significantly longer after rTMS over both the right and the left inferior frontal gyrus as compared to sham stimulation and after controlling for learning effects associated with order of condition. When taking all emotions together, there was no difference in effect on reaction times between the right and left stimulation. For the emotion Fear, reaction times were significantly longer after stimulating the left inferior frontal gyrus as compared to the right inferior frontal gyrus. Reaction times in the semantics task condition were not significantly different between the three TMS conditions.ConclusionsThe data indicate a critical involvement of both the right and the left inferior frontal gyrus in emotional prosody perception. The findings of this pilot study need replication. Future studies should include more subjects and examine whether the left and right inferior frontal gyrus play a differential role and complement each other, e.g. in the integrated processing of linguistic and prosodic aspects of speech, respectively.

Optimizing Functional Accuracy of TMS in Cognitive Studies: A Comparison of Methods

Transcranial magnetic stimulation (TMS) is a tool for inducing transient disruptions of neural activity noninvasively in conscious human volunteers. In recent years, the investigative domain of TMS has expanded and now encompasses causal structure-function relationships across the whole gamut of cognitive functions and associated cortical brain regions. Consequently, the importance of how to determine the target stimulation site has increased and a number of alternative methods have emerged. Comparison across studies is precluded because different studies necessarily use different tasks, sites, TMS conditions, and have different goals. Here, therefore, we systematically compare four commonly used TMS coil positioning approaches by using them to induce behavioral change in a single cognitive study. Specifically, we investigated the behavioral impact of right parietal TMS during a number comparison task, while basing TMS localization either on (i) individual fMRI-guided TMS neuronavigation, (ii) individual MRI-guided TMS neuronavigation, (iii) group functional Talairach coordinates, or (iv) 10-20 EEG position P4. We quantified the exact behavioral effects induced by TMS using each approach, calculated the standardized experimental effect sizes, and conducted a statistical power analysis in order to calculate the optimal sample size required to reveal statistical significance. Our findings revealed a systematic difference between the four approaches, with the individual fMRI-guided TMS neuronavigation yielding the strongest and the P4 stimulation approach yielding the smallest behavioral effect size. Accordingly, power analyses revealed that although in the fMRI-guided neuronavigation approach five participants were sufficient to reveal a significant behavioral effect, the number of necessary participants increased to n = 9 when employing MRI-guided neuronavigation, to n = 13 in case of TMS based on group Talairach coordinates, and to n = 47 when applying TMS over P4. We discuss these graded effect size differences in light of the revealed interindividual variances in the actual target stimulation site within and between approaches.

Modulation of cortical oscillatory activities induced by varying single-pulse transcranial magnetic stimulation intensity over the left primary motor area: A combined EEG and TMS study

Combined transcranial magnetic stimulation/electroencephalography (TMS/EEG) was used to study the activation and interaction of cortical regions to a variety of focused sub- and suprathreshold magnetic pulses over the left primary motor cortex (M1) in ten healthy subjects. Five single-pulse TMS conditions were performed based on the individual resting motor threshold (RMT): (1) 80%; (2) 100%; (3) 120%; (4) 130%; and (5) sham. Simple self-paced movements of the right first finger were also executed. We evaluated the reactions to magnetic stimulation and movement conditions using event-related power and event-related coherence transformations of α and β rhythms. Event-related power reflected regional oscillatory activity of neural assemblies, while event-related coherence reflected the inter-regional functional coupling of oscillatory neural activity. The event-related power transformation revealed that the magnetic pulse modulated cortical oscillations within the first half second for both frequency ranges. For the α rhythm, threshold TMS induced a small decrease in the amplitude of EEG oscillations over the stimulation site, while for both rhythms, a progressive synchronization was observed as the intensity of TMS was increased in both hemispheres. Movement onset produced a greater bilateral decrease of power compared with the effects of a magnetic pulse. The event-related coherence revealed that TMS enhanced the electrode connectivity of both hemispheres. Additionally, it was more enhanced within the first 500 ms following stimulation and was seen only for the α frequency rhythm. The increase of functional connectivity between cortical areas was minor for magnetic stimulation conditions compared with that for finger movements. The single-pulse TMS over M1 partially modulated the motor cortex generators of oscillatory activity, while a simple active self-paced movement of the right first finger induced greater cortex activation and coupling between cortical regions. We propose that finger movements impose higher functional demands on the motor system compared to artificial magnetic stimulation. These findings are consistent with the possibility that the human motor system may be based on network-like oscillatory cortical activity and might be modulated by brief electromagnetic sub- and suprathreshold pulses applied to M1, suggesting a phenomenon of resetting.