Dominant Hemisphere Research Articles

Facial Identity And Facial Speech Processing In Developmental Prosopagnosia

Developmental prosopagnosia is the life-long impaired ability to recognize familiar faces. The neural basis of this condition remains a matter of investigation. Face processing networks are bilateral but have right hemisphere dominance, and the location of lesions in acquired prosopagnosia is in keeping with this. There may be a complementary contribution from left hemisphere regions to certain types of face processing, and prior reports suggest that this might involve processing faces depicted by line contours or facial speech patterns by lip reading. We performed two studies in seven subjects with developmental prosopagnosia. The first task tested participants’ ability to match faces across viewpoint changes, with either unaltered photographs or high contrast line-drawing-like images. The second task involved a series of lip-reading tests to examine ability to perceive facial speech patterns. Performance on these two tasks was compared to twenty-three age- and education-matched control subjects. Prosopagnosic subjects had normal performance with line-contour faces, but facial processing showed no improvement with the added information in unaltered photographs. In facial speech pattern tests developmental prosopagnosic subjects could detect, discriminate, and identify facial speech patterns, but compared to controls, there was reduced use of visual cues or anomalous audiovisual integration in the McGurk effect, with only one subject performing normally. We conclude that developmental prosopagnosia may have a broader range of face processing impairment beyond just identity recognition. There can be association with a subtle impairment in lip-reading, which has been associated more with left than right fusiform damage after acquired lesions.

Right-dominant contextual cueing for global configuration cues, but not local position cues

Contextual cueing can depend on global configuration or local item position. We investigated the role of these two kinds of cues in the lateralization of contextual cueing effects. Cueing by item position was tested by recombining two previously learned displays, keeping the individual item locations intact, but destroying the global configuration. In contrast, cueing by configuration was investigated by rotating learned displays, thereby keeping the configuration intact but changing all item positions. We observed faster search for targets in the left display half, both for repeated and new displays, along with more first fixation locations on the left. Both position and configuration cues led to faster search, but the search time reduction compared to new displays due to position cues was comparable in the left and right display half. In contrast, configural cues led to increased search time reduction for right half targets. We conclude that only configural cues enabled memory-guided search for targets across the whole search display, whereas position cueing guided search only to targets in the vicinity of the fixation. The right-biased configural cueing effect is a consequence of the initial leftward search bias and does not indicate hemispheric dominance for configural cueing.

Personalized surgery of brain tumors in language areas: the role of preoperative brain mapping in patients not eligible for awake surgery.

Awake surgery represents the gold standard for resection of brain tumors close to the language network. However, in some cases patients may be considered not eligible for awake craniotomy. In these cases, a personalized brain mapping of the language network may be achieved by navigated transcranial magnetic stimulation (nTMS), which can guide resection in patients under general anesthesia. Here the authors describe their tailored nTMS-based strategy and analyze its impact on the extent of tumor resection (EOR) and language outcome in a series of patients not eligible for awake surgery. The authors reviewed data from all patients harboring a brain tumor in or close to the language network who were considered not eligible for awake surgery and were operated on during asleep surgery between January 2017 and July 2022, under the intraoperative guidance of nTMS data. The authors analyzed the effectiveness of nTMS-based mapping data in relation to 1) the ability of the nTMS-based mapping to stratify patients according to surgical risks, 2) the occurrence of postoperative language deficits, and 3) the EOR. A total of 176 patients underwent preoperative nTMS cortical language mapping and nTMS-based tractography of language fascicles. According to the nTMS-based mapping, tumors in 115 patients (65.3%) were identified as true-eloquent tumors because of a close spatial relationship with the language network. Conversely, tumors in 61 patients (34.7%) for which the nTMS mapping disclosed a location at a safer distance from the network were identified as false-eloquent tumors. At 3 months postsurgery, a permanent language deficit was present in 13 patients (7.3%). In particular, a permanent deficit was observed in 12 of 115 patients (10.4%) with true-eloquent tumors and in 1 of 61 patients (1.6%) with false-eloquent lesions. With nTMS-based mapping, neurosurgeons were able to distinguish true-eloquent from false-eloquent tumors in a significant number of cases based on the occurrence of deficits at discharge (p < 0.0008) and after 3 months from surgery (OR 6.99, p = 0.03). Gross-total resection was achieved in 80.1% of patients overall and in 69.5% of patients with true-eloquent lesions and 100% of patients with false-eloquent tumors. nTMS-based mapping allows for reliable preoperative mapping of the language network that may be used to stratify patients according to surgical risks. nTMS-guided asleep surgery should be considered a good alternative for personalized preoperative brain mapping of the language network that may increase the possibility of safe and effective resection of brain tumors in the dominant hemisphere whenever awake mapping is not feasible.

Hemispheric asymmetry and atypical lobar progression of Alzheimer‐type tauopathy

AbstractBackgroundNeurofibrillary tau pathology spread in Alzheimer’s disease (AD) mostly shows a stereotypical pattern of topographical progression. Atypical patterns have also been described and associated with interhemispheric asymmetry. As histopathological studies that used bilateral sampling are limited, this study aimed to assess interhemispheric tau pathology differences and the presence of topographically atypical cortical spreading patterns.MethodImmunohistochemical staining for detection of tau pathology was performed in 23 regions of interest of 57 autopsy cases and compared between cortical regions and hemispheres.ResultFrequent mild (82% of cases) and occasional moderate (32%) interhemispheric density discrepancies were observed while marked discrepancies were uncommon (7%) and restricted to occipital regions. Left and right hemispheric tau pathology dominance was observed with similar frequencies, except in Braak stage VI that favored a left dominance. Interhemispheric Braak stage differences were observed in 16% of cases and was more frequent in advanced (IV‐VI) than early stages (I‐III). One atypical lobar topographical pattern, where occipital tau pathology density exceeded frontal lobe scores, was identified in 4 cases, favoring a left dominant asymmetry.ConclusionWe speculate that asymmetry and atypical topographical progression patterns may be associated with described atypical AD clinical presentations and progression characteristics, which should be tested by comprehensive clinicopathological correlations.

Intact speech perception after resection of dominant hemisphere primary auditory cortex for the treatment of medically refractory epilepsy: illustrative case.

In classic speech network models, the primary auditory cortex is the source of auditory input to Wernicke's area in the posterior superior temporal gyrus (pSTG). Because resection of the primary auditory cortex in the dominant hemisphere removes inputs to the pSTG, there is a risk of speech impairment. However, recent research has shown the existence of other, nonprimary auditory cortex inputs to the pSTG, potentially reducing the risk of primary auditory cortex resection in the dominant hemisphere. Here, the authors present a clinical case of a woman with severe medically refractory epilepsy with a lesional epileptic focus in the left (dominant) Heschl's gyrus. Analysis of neural responses to speech stimuli was consistent with primary auditory cortex localization to Heschl's gyrus. Although the primary auditory cortex was within the proposed resection margins, she underwent lesionectomy with total resection of Heschl's gyrus. Postoperatively, she had no speech deficits and her seizures were fully controlled. While resection of the dominant hemisphere Heschl's gyrus/primary auditory cortex warrants caution, this case illustrates the ability to resect the primary auditory cortex without speech impairment and supports recent models of multiple parallel inputs to the pSTG.

Cognitive outcome after left functional hemispherectomy on dominant hemisphere in patients with Rasmussen encephalitis: beyond the myth of aphasia. Patient series.

Rasmussen encephalitis is a rare chronic neurological pathology frequently treated with functional hemispherectomy (or hemispherotomy). This surgical procedure frees patients of their severe epilepsy associated with the disease but may induce cognitive disorders and notably language alterations after disconnection of the left hemisphere. The authors describe longitudinally 3 cases of female patients with Rasmussen encephalitis who underwent left hemispherotomy in childhood and benefited from a favorable cognitive outcome. In the first patient, the hemispherotomy occurred at a young age, and the recovery of language and cognitive abilities was rapid and efficient. The second patient benefited from the surgery later in childhood. In addition, she presented a reorganization of language and memory functions that seem to have been at the expense of nonverbal ones. The third patient was a teenager during surgery. She benefited from a more partial cognitive recovery with persistent disorders several years after the surgery. Recovery of cognitive functions, including language, occurs after left hemispherotomy, even when performed late in childhood. Therefore, the surgery should be considered as early as possible to promote intercognitive reorganization.

The Lateralization of Spatial Cognition in Table Tennis Players: Neuroplasticity in the Dominant Hemisphere.

Spatial cognition facilitates the successful completion of specific cognitive tasks through lateral processing and neuroplasticity. Long-term training in table tennis induces neural processing efficiency in the visuospatial cognitive processing cortex of athletes. However, the lateralization characteristics and neural mechanisms of visual-spatial cognitive processing in table tennis players in non-sport domains are unclear. This study utilized event-related potentials to investigate differences in the spatial cognition abilities of regular college students (controls) and table tennis players. A total of 48 participants (28 controls; 20 s-level national table tennis players) completed spatial cognitive tasks while electroencephalography data were recorded. Task performance was better in the table tennis group than in the control group (reaction time: P &lt; 0.001; correct number/sec: P = 0.043), P3 amplitude was greater in the table tennis group (P = 0.040), spatial cognition showed obvious lateralization characteristics (P &lt; 0.001), table tennis players showed a more obvious right-hemisphere advantage, and the P3 amplitude in the right hemisphere was significantly greater in table tennis athletes than in the control group. (P = 0.044). Our findings demonstrate a right-hemisphere advantage in spatial cognition. Long-term training strengthened the visual-spatial processing ability of table tennis players, and this advantage effect was reflected in the neuroplasticity of the right hemisphere (the dominant hemisphere for spatial processing).

Left visual field bias during face perception aligns with individual differences in reading skills and is absent in dyslexia.

When looking at faces, we tend to attend more to the left visual field (corresponding to the right side of the person's face). This phenomenon is called the left visual field bias (LVF) and is presumed to reflect the brain's right-sided dominance for face processing. Whether alterations in hemispheric dominance are present in dyslexia, and are linked with individual differences in word reading development more generally, is still unclear, and no prior research has utilized gaze-based LVF bias to explore these topics. The aim of the study was to examine whether the LVF bias differs in dyslexia and to examine the association with word-reading skills assessed dimensionally. Forty-six 9-13 year-old children with dyslexia and community control children, matched on age and listening comprehension. Participants were presented with a recorded face on a screen while their gaze patterns were collected with an eye tracker. Fixations to the left versus the right side of the face stimuli were compared. Results showed a clear LVF bias in community controls, while no such bias was seen in the dyslexic group. Moreover, the strength of the LVF bias was correlated with better word reading in the controls. Our results suggest a link between weakened hemispheric dominance for face processing in dyslexia and in poor word reading, at least to the extent that the LVF bias actually mirrors underlying physiology. We discuss the implications of these novel findings, highlighting the need for future research to determine the specificity and developmental sources of LVF bias alterations.

Neuroanatomical correlates of screening for aphasia in NeuroDegeneration (SAND) battery in non-fluent/agrammatic variant of primary progressive aphasia.

Non-fluent/agrammatic variant of Primary Progressive Aphasia (avPPA) is primarily characterized by language impairment due to atrophy of the inferior frontal gyrus and the insula cortex in the dominant hemisphere. The Screening for Aphasia in NeuroDegeneration (SAND) battery has been recently proposed as a screening tool for PPA, with several tasks designed to be specific for different language features. Applying multivariate approaches to neuroimaging data and verbal fluency tasks, Aachener Aphasie Test (AAT) naming subtest and SAND data may help in elucidating the neuroanatomical correlates of language deficits in avPPA. To investigate the neuroanatomical correlates of language deficits in avPPA using verbal fluency tasks, AAT naming subtest and SAND scores as proxies of brain structural imaging abnormalities. Thirty-one avPPA patients were consecutively enrolled and underwent extensive neuropsychological assessment and MRI scan. Raw scores of verbal fluency tasks, AAT naming subtest, and SAND subtests, namely living and non-living picture naming, auditory sentence comprehension, single-word comprehension, words and non-words repetition and sentence repetition, were used as proxies to explore structural (gray matter volume) neuroanatomical correlates. We assessed univariate (voxel-based morphometry, VBM) as well as multivariate (source-based morphometry, SBM) approaches. Age, gender, educational level, and disease severity were considered nuisance variables. SAND picture naming (total, living and non-living scores) and AAT naming scores showed a direct correlation with the left temporal network derived from SBM. At univariate analysis, the left middle temporal gyrus was directly correlated with SAND picture naming (total and non-living scores) and AAT naming score. When words and non-words repetition (total score) was considered, a direct correlation with the left temporal network (SBM) and with the left fusiform gyrus (VBM) was also evident. Naming impairments that characterize avPPA are related to specific network-based involvement of the left temporal network, potentially expanding our knowledge on the neuroanatomical basis of this neurodegenerative condition.

Cortical Reorganization of Early Somatosensory Processing in Hemiparetic Stroke.

The cortical motor system can be reorganized following a stroke, with increased recruitment of the contralesional hemisphere. However, it is unknown whether a similar hemispheric shift occurs in the somatosensory system to adapt to this motor change, and whether this is related to movement impairments. This proof-of-concept study assessed somatosensory evoked potentials (SEPs), P50 and N100, in hemiparetic stroke participants and age-matched controls using high-density electroencephalograph (EEG) recordings during tactile finger stimulation. The laterality index was calculated to determine the hemispheric dominance of the SEP and re-confirmed with source localization. The study found that latencies of P50 and N100 were significantly delayed in stroke brains when stimulating the paretic hand. The amplitude of P50 in the contralateral (to stimulated hand) hemisphere was negatively correlated with the Fügl-Meyer upper extremity motor score in stroke. Bilateral cortical responses were detected in stroke, while only contralateral cortical responses were shown in controls, resulting in a significant difference in the laterality index. These results suggested that somatosensory reorganization after stroke involves increased recruitment of ipsilateral cortical regions, especially for the N100 SEP component. This reorganization delays the latency of somatosensory processing after a stroke. This research provided new insights related to the somatosensory reorganization after stroke, which could enrich future hypothesis-driven therapeutic rehabilitation strategies from a sensory or sensory-motor perspective.

Aphasic Syndromes in Cerebral Venous and Dural Sinuses Thrombosis—A Review of the Literature

Aphasia is an acquired central disorder of language that affects a person's ability to understand and/or produce spoken and written language, caused by lesions situated usually in the dominant (left) cerebral hemisphere. On one hand aphasia has a prevalence of 25-30% in acute ischemic stroke, especially in arterial infarcts. On the other hand, cerebral venous and dural sinuses thrombosis (CVT) remains a less common and underdiagnosed cause of ischemic stroke (0.5-1% of all strokes). Aphasia has been observed in almost 20% of patients who suffered CVT. The presence of aphasia is considered a negative predictive factor in patients with stroke, severe language disorders corresponding to arduous recovery. Taking into consideration data from the literature, aphasia is also considered a predictive factor for patients with CVT; its absences, together with the absence of worsening after admission, are determinants of complete recovery after CVT. This review has as the principal role of gathering current information from the literature (PubMed database 2012-2022) regarding the clinical features of aphasic syndromes and its incidence in patients with CVT. The main conclusion of this review was that aphasic syndromes are not usually the consequence of isolated thrombosis of dural sinuses or cerebral veins thrombosis. The most frequent form of CVT that determines aphasia is represented by the left transverse sinus thrombosis associated with a posterior left temporal lesion (due to left temporal cortical veins thrombosis), followed by the superior sagittal sinus thrombosis associated with a left frontal lesion (due to left frontal cortical veins thrombosis). Only a few cases are presenting isolated cortical veins thrombosis and left thalamus lesions due to deep cerebral vein thrombosis. We also concluded that the most important demographic factor was the gender of the patients, women being more affected than men, due to their postpartum condition.

Exploration of RCBF and Metabolic Changes in the Brain Functional Areas of Patients with Hypothyroidism by ASL and MRS Techniques.

Objective To study the regional cerebral blood flow (rCBF) in important brain functional areas and the metabolic levels of these brain functional areas in patients with primary hypothyroidism by using arterial spin labeling (ASL) and magnetic resonance spectroscopy (MRS) techniques to explain the possible causes of brain dysfunction in patients with primary hypothyroidism. Methods Twenty-five patients with primary hypothyroidism (newly diagnosed and not treated) who were treated in the endocrinology department of our hospital were selected as the research group, and 25 healthy patients with normal thyroid function who came to our hospital during the same period with matched gender and age were selected as the control group. ASL and MRS techniques were used to detect and calculate regional cerebral blood flow (rCBF) in the frontal lobe, hippocampus, and posterior cingulate gyrus, as well as N-acetylaspartate/creatine (NAA/Cr), choline/creatine (Cho) in the brain/Cr, and inositol/creatine (mI/Cr) ratio. The correlations between metabolite ratios measured by rCBF, MRS, and serum TSH, FT3, and FT4 levels were analyzed. Results Compared with the control group, the rCBF in the frontal lobe, hippocampus, and posterior cingulate gyrus of the dominant hemisphere of the hypothyroid patients in the study group decreased significantly (P < 0.05). The comparison of metabolite ratios showed that compared with the control group, the NAA/Cr ratio of the frontal lobe and posterior cingulate gyrus of the study group was significantly decreased, and the Cho/Cr ratio of the posterior cingulate gyrus of the study group was significantly increased. The MI/Cr ratio of the hippocampus was significantly decreased (all P values < 0.05). Correlation analysis showed that rCBF and NAA/Cr in posterior cingulate gyrus were significantly negatively correlated with serum TSH levels (P < 0.05). Conclusion The changes of rCBF and metabolite ratios in the frontal lobe, hippocampus, and posterior cingulate gyrus of patients with primary hypothyroidism can be detected using ASL and MRS techniques. The changes of rCBF and metabolite ratio and their negative correlation with serum TSH level are helpful to explain the causes of brain dysfunction in patients with primary hypothyroidism.

Surgical treatment of tumors of the supplementary motor area

Background. The supplementary motor area is a part of the medial frontal cortex, that is located just anterior to the primary motor cortex entirely within the interhemispheric fissure. This area belongs traditionally to the secondary motor cortex and perhaps it is the least studied motor region of the brain. While functions and symptoms of a damage to the primary motor and the premotor cortex areas have been well known and described for a long time, study of the supplementary motor area has been limited to fundamental neuroimaging and electrophysiological researches, and a practical side of the issue and clinical significance of this region remained outside the interest of researchers.Aim. To present the anatomical and functional features of the supplementary motor area, the clinical symptoms of its lesion, to analyze all the data available today and aspects of surgical treatment of tumors in this region.Materials and methods. A search in scientific databases (PubMed, etc.) led to the selection and analysis of sixty-two literary sources. The review is mainly devoted to the aspects and risk factors of surgical treatment of pathologies localized in this region.Results. According to its anatomical and functional characteristics, the supplementary motor area is a heterogeneous region - it has two separate subregions in it. In addition to the motor function of the supplementary motor area, its role has also been reliably established in the implementation of working memory processes, language, perceptual, cognitive and other functions. Such a number of functions performed by the supplementary motor area is associated with numerous neural connections of this area. For example, the frontal aslant tract has been described recently, and it connects medial part of the superior frontal gyrus with the pars opercularis of the inferior frontal gyrus. This tract, apparently, is associated with the implementation of language function in the dominant hemisphere and function of working memory in the non-dominant hemisphere.When the supplementary motor area is affected, various neurological motor and speech symptoms can occur, in particular, the supplementary motor area syndrome, which is characterized by the development of akinetic mutism in patients and, in most cases, is completely reversible within a few days or months. Among all pathologies in this area, tumors are most common, especially gliomas, which can also manifest themselves with various clinical symptoms both in the preoperative and postoperative periods.Conclusion. Critically important preoperative planning, informing the patient about the spatio-temporal picture of the predicted postoperative clinical disorders and the timing of rehabilitation are critically important. It is recommended to use methods of intraoperative neuronavigation, as well as intraoperative neurophysiological monitoring. It is necessary to further study the supplementary motor area and the peculiarities of its surgery in order to standardize approaches to the treatment of pathologies.

Effects of Cerebellar Transcranial Alternating Current Stimulation on Gait and Balance in Healthy Subjects

Transcranial Alternating Current Stimulation (tACS) is a non-invasive brain stimulation technique [1] able to modulate neural oscillatory activities, including those linked to the cortico-cerebello-thalamo- cortical network [2,3]. In this double-blind sham-controlled study, we aimed to investigate the effects of cerebellar tACS delivered at theta and gamma frequencies on gait and balance in healthy subjects, as assessed by kinematic techniques. In a group of young healthy subjects, we applied tACS over the dominant cerebellar hemisphere during the execution of three different motor tasks: 1) standing (both with eyes open and closed); 2) gait initiation (assessed both for the dominant and non-dominant lower limb); 3) 5-meter walk test (5MWT) (Fig. 1). tACS was delivered in a random order at the theta (5 Hz, theta-tACS) and gamma (50 Hz, gamma-tACS) frequencies, and sham-tACS was used as a control condition. The stimulation intensity was set at 1,5 mA and the stimulation duration lasted as long as the motor task was accomplished. Kinematic data were obtained using a force platform and an optoelectronic system. The data analysis was conducted using a dedicated software. Theta-tACS induced a significant reduction of the Centre Of Pressure (COP) displacement during standing with eyes closed compared to sham- and gamma-tACS (mean radius displacement: theta- tACS 4.65±0.74 mm, gamma-tACS 5.58±1.26 mm, sham-tACS 5.99±2.12 mm). A similar, though weaker, trend was present in the eyes open condition. Furthermore, stride width during 5MWT resulted tighter during theta-tACS compared to sham- and gamma tACS. Boosting theta oscillations in the cerebellum through tACS improves balance during standing and gait in healthy subjects. This effect may rely on the modulation of the activity of cerebellar neurons resonant to the theta rhythm. This non-invasive neuromodulation approach could be applied in neurological conditions characterized by ataxia to possibly ameliorate the imbalance and reduce the risk of falling.

Evaluating syntactic comprehension during awake intraoperative cortical stimulation mapping.

Electrocortical stimulation mapping (ECS) is widely used to identify essential language areas, but sentence-level processing has rarely been investigated. While undergoing awake surgery in the dominant left hemisphere, 6 subjects were asked to comprehend sentences varying in their demands on syntactic processing. In all 6 subjects, stimulation of the inferior frontal gyrus disrupted comprehension of passive sentences, which critically depend on syntactic processing to correctly assign grammatical roles, without disrupting comprehension of simpler tasks. In 4 of the 6 subjects, these sites were localized to the pars opercularis. Sentence comprehension was also disrupted by stimulation of other perisylvian sites, but in a more variable manner. These findings suggest that there may be language regions that differentially contribute to sentence processing and which therefore are best identified using sentence-level tasks. The functional consequences of resecting these sites remain to be investigated.

Diffusion Tensor Tractography Studies on Recovery Mechanisms of Aphasia in Stroke Patients: A Narrative Mini-Review.

Aphasia is a common and serious clinical feature of stroke. Various neural tracts are known to be involved in language processing. Diffusion tensor tractography (DTT) appears to be an appropriate imaging technique for the elucidation of the recovery mechanisms of aphasia in the language-related neural tracts in stroke patients. In this article, twelve previous DTT-based studies on the recovery mechanisms of aphasia in stroke were reviewed. We classified the twelve studies into the following three categories according to the recovery mechanisms: recovery via the neural tracts in the dominant hemisphere (eight studies), via transcallosal fibers (two studies), and via the neural tracts in the non-dominant hemisphere (two studies). Although there are various neural tracts for language processing, eight of the ten studies focused only on the role of the arcuate fasciculus (AF) in the recovery process. Consequently, it appears from the studies that only one recovery mechanism of aphasia via the restoration of the integrity of the injured AF in the dominant hemisphere was clearly demonstrated. However, because various neural tracts are involved in language processing, there could be other mechanisms that have not yet been elucidated. Therefore, further original studies involving a larger number of patients with aphasia in stroke should be encouraged forthwith. Further studies involving various lesion locations and severity levels of injuries to the language-related neural tracts are also necessary because the recovery mechanisms of aphasia in stroke could be dependent on these factors.

Characteristics of auditory steady-state responses to different click frequencies in awake intact macaques

BackgroundAuditory steady-state responses (ASSRs) are periodic evoked responses to constant periodic auditory stimuli, such as click trains, and are suggested to be associated with higher cognitive functions in humans. Since ASSRs are disturbed in human psychiatric disorders, recording ASSRs from awake intact macaques would be beneficial to translational research as well as an understanding of human brain function and its pathology. However, ASSR has not been reported in awake macaques.ResultsElectroencephalograms (EEGs) were recorded from awake intact macaques, while click trains at 20–83.3 Hz were binaurally presented. EEGs were quantified based on event-related spectral perturbation (ERSP) and inter-trial coherence (ITC), and ASSRs were significantly demonstrated in terms of ERSP and ITC in awake intact macaques. A comparison of ASSRs among different click train frequencies indicated that ASSRs were maximal at 83.3 Hz. Furthermore, analyses of laterality indices of ASSRs showed that no laterality dominance of ASSRs was observed.ConclusionsThe present results demonstrated ASSRs, comparable to those in humans, in awake intact macaques. However, there were some differences in ASSRs between macaques and humans: macaques showed maximal ASSR responses to click frequencies higher than 40 Hz that has been reported to elicit maximal responses in humans, and showed no dominant laterality of ASSRs under the electrode montage in this study compared with humans with right hemisphere dominance. The future ASSR studies using awake intact macaques should be aware of these differences, and possible factors, to which these differences were ascribed, are discussed.

Psychosocial and Neurological Predictors of Creative Imagination of Artists: The Mediating Role of Social Adaptation

The present study aimed to assess the role of hemispheric orientation, emotional sensitivity, cognitive imagination and their correlation with the well-being of fine artist students, as well as to evaluate the mediating role of social adaptation. A correlational research design was used, and a sample of 200 artists or people from art communities (100 males and 100 females aged 18 to 30) was selected using purposive sampling. The data collection was done through an open hemispheric brain dominance scale, the Creativity scale created by Kaufman (2012) (K-DOCS), an Emotional sensitivity self-assessment scale, the Mental Health Continuum-short form, and scales for Social adaptation. Data analysis was done through Pearson Product Moment Correlation, Independent Sample t-test, Multiple Regression Analysis, ANOVA and Mediation Analysis test. The results indicated that hemispheric orientation had a statistically significant association with creative imagination, emotional sensitivity, psychological well-being and social adaptation. Moreover, social adaptation significantly mediated the association between hemispheric orientation and creative imagination. The study adds to our understanding of the role of hemispheric orientation, social adaptation and emotional sensitivity in predicting the well-being and creative imagination of artists.

The contralateral effects of anticipated stimuli on brain activity measured by ERP and fMRI.

The present study examined the effects of unilateral stimulus presentation on the right hemisphere preponderance of the stimulus-preceding negativity (SPN) in the event-related potential (ERP) experiment, and aimed to elucidate whether unilateral stimulus presentation affected activations in the bilateral anterior insula in the functional magnetic resonance imaging (fMRI) experiment. Separate fMRI and ERP experiments were conducted using visual and auditory stimuli by manipulating the position of stimulus presentation (left side or right side) with the time estimation task. The ERP experiment revealed a significant right hemisphere preponderance during left stimulation and no laterality during the right stimulation. The fMRI experiment revealed that the left anterior insula was activated only in the right stimulation of auditory and visual stimuli whereas the right anterior insula was activated by both left and right stimulations. The visual condition retained a contralateral dominance, but the auditory condition showed a right hemisphere dominance in a localized area. The results of this study indicate that the SPN reflects perceptual anticipation, and also that the anterior insula is involved in its occurrence.

Surgical techniques and function outcome for cingulate gyrus glioma, how we do it.

ObjectiveCingulate cortex and cingulum both play crucial roles in limbic system. The aim of study is to observe and analyze surgical outcomes of cingulate gyrus glioma through extents of resection (EORs), overall survival (OS), and postsurgical neurological outcome.MethodThe authors retrospectively studied 95 consecutive adult cases of primary cingulate gliomas that all underwent craniotomies and tumor resection. The patients were classified into unitary sub-region based on the four-division model. The information of clinical symptoms, pathology, EOR, postoperative neurological outcome and survival were analyzed through group comparison.ResultLow-grade gliomas (LGGs) were more prevalent (69.47%) for cingulate gyrus. Diffuse astrocytoma (40.00%) was most common histopathological diagnosis in total. Regarding sub-regions tumor involved in, midcingulate cortex (MCC) glioma was most prevalent (54.74%) followed by anterior cingulate cortex (ACC) glioma. Among all patients, 83 patients (87.37%) received EOR ≥ 90%. In LGG group, 58 patients (87.88%) received EOR ≥ 90%. The achievement of EOR significantly correlated with survival (P = 0.006). MCC cases were significantly associated with short-term morbidity in either language or motor function (P = 0.02). Majority of ACC cases (80.65%) escaped from any short-term deficits and nearly 90% free for permanent morbidity. Tumors in the dominant hemisphere were significantly associated with language dysfunction or cognition dysfunction, either short-term (P=0.0006) or long-term morbidity (P=0.0111). Age was the only postoperative susceptible predictor for all types of transient (P=0.021) and permanent (P=0.02) neurological deficit.ConclusionRegarding cingulate gyrus glioma, the management of surgical plans could be carried out into four sub-region level. In spite of short-term neurological dysfunction caused by surgical procedure, majority of transient dysfunction could be relieved or recovered in long-term. The necessary effort to prolong overall survival is still to achieve advisable EOR.