Right Hemisphere Functions

Two questions were addressed in the present study: (1) Do autistic and normally developing children exhibit regionally specific differences in electroencephalographic (EEG) activity? (2) Do subgroups of autistic children classified according to Wing and Gould's (1979) system which emphasizes degree of social impairment exhibit distinct patterns of EEG activity? Twenty-eight children with autism (5 to 18 years of age) and two groups of normally developing children (one matched on chronological age and the other on receptive language level) participated. EEG was recorded from left and right frontal, temporal, and parietal regions during an alert baseline condition. Compared to normally developing children, autistic children exhibited reduced EEG power in the frontal and temporal regions, but not in the parietal region. Differences were more prominent in the left than the right hemisphere. Furthermore, subgroups of autistic children based on Wing and Gould's system displayed distinct patterns of brain activity. Compared to autistic children classified as “active-but-odd,” “passive” autistic children displayed reduced alpha EEG power in the frontal region.

Cerebral organization during sentence processing in English and in American Sign Language (ASL) was characterized by employing functional magnetic resonance imaging (fMRI) at 4 T. Effects of deafness, age of language acquisition, and bilingualism were assessed by comparing results from (i) normally hearing, monolingual, native speakers of English, (ii) congenitally, genetically deaf, native signers of ASL who learned English late and through the visual modality, and (iii) normally hearing bilinguals who were native signers of ASL and speakers of English. All groups, hearing and deaf, processing their native language, English or ASL, displayed strong and repeated activation within classical language areas of the left hemisphere. Deaf subjects reading English did not display activation in these regions. These results suggest that the early acquisition of a natural language is important in the expression of the strong bias for these areas to mediate language, independently of the form of the language. In addition, native signers, hearing and deaf, displayed extensive activation of homologous areas within the right hemisphere, indicating that the specific processing requirements of the language also in part determine the organization of the language systems of the brain.

EEG intrahemispheric coherences (HCohs) in the resting state in twenty-four 4 Hz frequency windows between 1 and 51 Hz were studied in 18 children with "non-verbal learning disorder" (NLD) and compared to a group of 18 children with "verbal learning disorder" (VLD). New facts were found in the NLD group. These concern hemispheric balance, expressed as left minus right (L-R) homologous HCohs: 1a). In the high frequencies (25-51 HZ) the number of long-distance HCohs, higher in the right hemisphere (RH), is lower than HCohs, which are higher in the left hemisphere (LH). A reversed interhemispheric asymmetry is seen for short distance HCohs in that band. These asymmetries are not found in the VLD group, and the tendency is even reversed. 1b). In the low frequencies (1-27 Hz) all higher HCohs are more numerous in the RH, irrespective of interelectrode distance (IED). In these bands there are no NLD-VLD group differences; 2). In NLD there is a significant inverse relat...

Simple negation in natural languages represents a complex interrelationship of syntax, prosody, semantics and pragmatics, and may be realised in various ways: lexically, morphologically and prosodically. In almost all spoken languages, the first two of these are the primary realisations of syntactic negation. In contrast, in many signed languages negation can occur without lexical or morphological marking. Thus, in British Sign Language (BSL), negation is obligatorily expressed using face–head actions alone (facial negation) with the option of articulating a manual form alongside the required face–head actions (lexical negation). What are the processes underlying facial negation? Here, we explore this question neuropsychologically. If facial negation reflects lexico-syntactic processing in BSL, it may be relatively spared in people with unilateral right hemisphere (RH) lesions, as has been suggested for other ‘grammatical facial actions’ [Language and Speech 42 (1999) 307; Emmorey, K. (2002). Language, cognition and the brain: Insights from sign language research. Mahwah, NJ: Erlbaum (Lawrence)].Three BSL users with RH lesions were specifically impaired in perceiving facial compared with manual (lexical and morphological) negation. This dissociation was absent in three users of BSL with left hemisphere lesions and different degrees of language disorder, who also showed relative sparing of negation comprehension. We conclude that, in contrast to some analyses [Applied Psycholinguistics 18 (1997) 411; Emmorey, K. (2002). Language, cognition and the brain: Insights from sign language research. Mahwah, NJ: Erlbaum (Lawrence); Archives of Neurology 36 (1979) 837], non-manual negation in sign may not be a direct surface realisation of syntax [Language and Speech 42 (1999) 143; Language and Speech 42 (1999) 127].Difficulties with facial negation in the RH-lesion group were associated with specific impairments in processing facial images, including facial expressions. However, they did not reflect generalised ‘face-blindness’, since the reading of (English) speech patterns from faces was spared in this group. We propose that some aspects of the linguistic analysis of sign language are achieved by prosodic analysis systems (analysis of face and head gestures), which are lateralised to the minor hemisphere.

The abilities to identify with others and to distinguish between self and other play a pivotal role in intersubjective transactions. Here, we marshall evidence from developmental science, social psychology and neuroscience (including clinical neuropsychology) that support the view of a common representation network (both at the computational and neural levels) between self and other. However, sharedness does not mean identicality, otherwise representations of self and others would completely overlap, and lead to confusion. We argue that self-awareness and agency are integral components for navigating within these shared representations. We suggest that within this shared neural network the inferior parietal cortex and the prefrontal cortex in the right hemisphere play a special role in interpersonal awareness.

As individuals who abuse methamphetamine (MA) often exhibit socially maladaptive behaviors such as violence and aggression, it is possible that they respond abnormally to social cues. To investigate this issue, we exposed 12 MA-dependent participants (abstinent 5-16 days) and 12 healthy comparison participants to fearful and angry faces while they performed an affect matching task during functional magnetic resonance imaging (fMRI). Although the groups did not differ in task performance, the healthy participants showed more task-related activity than the MA-dependent participants in a set of cortical regions consisting of the ventrolateral prefrontal cortex (VLPFC), temporoparietal junction (TPJ), anterior and posterior temporal cortex, and fusiform gyrus in the right hemisphere, and the cuneus in the left hemisphere. In contrast, the MA-dependent participants showed more task-related activity than the healthy participants in the dorsal anterior cingulate cortex (dACC). As expected, the task elicited activation of the amygdala in both groups; however, contrary to expectation, we found no difference between groups in this activation. Dorsal ACC hyperactivity, along with high self-ratings of hostility and interpersonal sensitivity in the MA-dependent group, suggest a hyper-sensitivity to socially threatening cues in the MA-dependent participants, while lower VLPFC activation could point to a deficit in integrating socio-emotional information and/or regulating this limbic hyperactivity. Additional activation differences in neural circuitry related to social cognition (TPJ, anterior, and posterior temporal cortex) suggest further socio-emotional deficits. Together, the results point to cortical abnormalities that could underlie the socially inappropriate behaviors often shown by individuals who abuse MA.

Evidence has indicated that the right frontal cortex is preferentially involved in self-face recognition. To test this further, we employed a face identification task and examined hand response differences (N=10). Pictures of famous faces were combined with pictures of the participants’ faces (self) and their co-workers’ faces (familiar). These images were presented as a ‘movie’ in which one face transformed

In addition to repeated reexperiencing of the event, the delayed effects of severe psychological trauma, i.e., post traumatic stress disorder (PTSD), present a paradoxical mix of symptoms. There is enhancement of the self-preservative catecholamine states; anger and fear with a contrasting sense of meaninglessness and a blunting of the emotional responses of the attachment behavior so critical for species preservation. Hormonally, there is a striking separation of the catecholamine response, which stays elevated and that of the hypothalamo-pituitary-adrenal (HPA) axis, which may remain at normal levels. Pathophysiologically, the reexperiencing of the trauma and the arousal may be associated with dysfunction of the locus coeruleus, amygdala and hippocampal systems. This article explores the consequences of an additional dysfunction: a dissociation of the hemispheres that appears to be responsible for the alexithymic avoidance and failure of the cortisol response that so often follow severe psychological trauma. There is neurophysiological evidence that the left and right hemispheres subserve different emotional sets that correspond to “control” and “appraisal,” i.e., very approximately to the self and species preservative behavioral complexes, respectively. Several studies point to physiological dissociation of hemispheric functions during alexithymia. This raises the question: What has been lost if in this condition the right side no longer fully contributes to integrated cerebral function? Right hemispheric damaged children lose critical social skills and in adults the related sense of familiarity critical for bonding is lost. Such losses of social sensibilities may account for the lack of empathy and difficulties with bonding found in sociopathy and borderline personality: conditions now believed to result from repeated psychological trauma during development. On the other hand, systems that promote right hemispheric contributions provide solacing access to a “Higher Power.” They also appear to protect against socially disordered behavior, substance abuse, the failure of the HPA axis and some aspects of the pathophysiology of chronic disease.

Performing music requires fast auditory and motor processing. Regarding professional musicians, recent brain imaging studies have demonstrated that auditory stimulation produces a co-activation of motor areas, whereas silent tapping of musical phrases evokes a co-activation in auditory regions. Whether this is obtained via a specific cerebral relay station is unclear. Furthermore, the time course of plasticity has not yet been addressed. Changes in cortical activation patterns (DC-EEG potentials) induced by short (20 minute) and long term (5 week) piano learning were investigated during auditory and motoric tasks. Two beginner groups were trained. The 'map' group was allowed to learn the standard piano key-to-pitch map. For the 'no-map' group, random assignment of keys to tones prevented such a map. Auditory-sensorimotor EEG co-activity occurred within only 20 minutes. The effect was enhanced after 5-week training, contributing elements of both perception and action ...

Twenty individuals solved a visual oddball task in two response conditions: while listening to the Mozart's sonata K. 448, and while listening to nothing. The recorded event-related potentials (ERP) were analyzed in the time and frequency domains. In the music response condition the ERP peak latencies on the left hemisphere increased, whereas on the right hemisphere a decrease of peak latencies as compared with the silence response condition was observed. In the theta, lower-1 alpha and gamma band increases in induced event-related coherences were observed while respondents solved the oddball task and listened to music, whereas a decoupling of brain areas in the gamma band was observed in the silence response condition. It is suggested that auditory background stimulation can influence visual brain activity, even if both stimuli are unrelated.

To describe the morphological stages of insular sulci and gyri development we carried out a macroscopical study on 21 human fetal brains, showing no anomalies, from 13 to 28 gestational weeks (GWs). Particular focus was given to morphological appearance during the development of insular and periinsular structures, especially the gyration and sulcation of the insula, central cerebral region and opercula, as well as the vascularization of these regions. The periinsular sulci and the central (insular and cerebral) sulci were the first macroscopical structures identified on the lateral surface of the human fetal cerebral hemisphere with earlier development on the right hemisphere. Here we describe five stages of insular gyral and sulcal development closely related to gestational age: stage 1: appearance of the first sulcus at 13-17 GWs, stage 2: development of the periinsular sulci at 18–19 GWs, stage 3: central sulci and opercularization of the insula at 20–22 GWs, stage 4: covering of the posterior insula at 24–26 GWs, stage 5: closure of the sylvian fissure at 27–28 GWs. We provide evidence that cortical maturation (sulcation and gyration) and vascularization of the lateral surface of the brain starts with the insular region, suggesting that this region is a central area of cortical development.

The acclaimed Italian directors Luchino Visconti and Federico Fellini had very different life trajectories that led them to become major figures in the history of cinema. Similarities, however, can be found in their debuts with the neorealist genre, their personalities, creative styles and politicocultural involvement, and ultimately in the neurological disease that struck them at the end of their careers. Both suffered a right-hemispheric stroke that left them hemiplegic on the left side. We review their life and career to put that event into perspective, and then discuss its aftermath for both artists in the light of our current knowledge of right-hemispheric functions. Visconti showed a tremendous resilience following the accident and managed to direct several films and plays as an infirm, whereas Fellini had to put an end to his career but still was able to display his talents to the neuropsychologists that treated him. A speculative account is given of the links between right-hemispheric symptomatology and the premorbid personality of these highly prolific patients.

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There have been multiple historical and cross-cultural reports of excess correlation of specific experiences between individuals separated by thousands of kilometers. Recently there have been experimental demonstrations of excess correlations between measurable cerebral events for small percentages of test subjects. More reliable effects can be elicited when electromagnetic fields and photons are involved. In this experiment completed during the summer of 2015, 5 pairs of volunteers separated by more than 6,000 km wore identical cerebral toroids through which patterns of phase shifting, 30 nT magnetic fields that diminished the local magnetic field in both loci by 1-5 nT were exposed to the sequences that produced excess correlation in chemiluminescent reactions and shifts in pH. Compared to the various baselines and control procedures enhanced power between the right hemispheres of pairs of participants occurred during the interval documented to produce excess correlation. Specific analyses indicated diminished coherence within the theta band only within the right temporal lobes of the pairs. Sequential block analyses revealed that the paired brains’ responses to pulsed tones at 6.5 Hz occurred within the 30-40 Hz band over the caudal temporal lobes during the exposures to the effector field. Primary independent component analyses verified these patterns. During the 6.5 Hz tones there was a peak in the spectral power density (SPD) at that frequency over the right temporal lobe of the person listening but a trough in (SPD) over this region for the person who was not. Even subjective experiences, as measured by the Profile of Mood States (POMS), indicated significantly increased excess correlation for scales by which increased anger and decreased vigour are inferred. This experiment, based upon physical principles, suggests there is a technology that can generate reliable excess correlation of brain activity (and potentially consciousness and specific experiences) between two people separated by thousands of kilometers.