Lateralization

Brain lateralization is a common term used to describe dominance of one brain hemisphere over another for a specific function. The right hand dominance in writing, controlled by the left hemisphere, is preceded by development of communicative gesticulation and followed by development of speech in the same hemisphere. We assumed that some people are not aware of their own capability of using the other hand for tasks involving fine motor sequential movements. To prove this hypothesis, the participants were asked to perform one trained task (writing) and one less-trained task (drawing) with a dominant and a non-dominant hand. The final sample was comprised of 1189 children from 14 elementary schools and 8 high schools in the Osijek area, of which 685 elementary school children were attending 1st to 4th grade and 504 high school children were attending 3rd and 4th grade. The participants were asked to write two words, draw a specific object (a vase with flowers) and fill out a questionn...

Des origines de la latéralisation et des rapports entre latéralités manuelle et cérébrale Bulletin de psychologie, Tome XXXIII, n* 343 , Université de Paris, déc. 1979. Des origines de la latéralisation et des rapports entre latéralités manuelle et cérébrale Evolution. L'asymétrie dans la structure des organismes est un fait biologique bien connu qui se retrouve à tous les stades de l'évolution, même dans les formes animales les plus primitives (Monod, 1969). La signification de l'asymétrie, le problème de sa transmission génétique, enfin l'apparente contradiction entre asymétrie strucurale et symétrie comportementale sont autant d'énigmes pour le biologiste et pour le psychologue qui s'interroge sur la latéralité humaine. La symétrie que l'on observe tout au long du règne animal, — sphérique pour les créature primitives qui vivent en suspension dans l'eau, axiale pour celles qui vivent au fond de l'eau dans un milieu soumis à une force gravitationnelle, enfin bilatérale chez les organismes capables de mouvements dans une direction —, s'oppose toujours à quelques asymétries structurales, parfois grossières : coeur à gauche chez tous les vertébrés, asymétrie des pinces du crabe (Gardner, 1967), jusqu'à l'asymétrie des membres supérieurs et du visage humain (Gilbert et Bakan, 1973). Chez l'homme cependant l'asymétrie fonctionnelle, (c'est-à-dire la latéralité manuelle et cérébrale, est considérée comme récente dans l'évolution. T Comparés à l'homme, qui présente des signes de latéralisation corporelle systématique dès la naissance, les animaux sont répartis également entre gauchers et droitiers en ce qui concerne l'utilisation préférentielle de l'une des pattes. Il existe cependant quelques rares exceptions, notamment chez les oiseaux. Chaque animal tend à se latéraliser avec l'expérience. Lehman, 1978, par exemple, trouve un effet de l'âge sur la stabilité de la latérallsation chez le singe rhésus : il n'observe pas de préférence manuelle initiale chez les jeunes animaux, tandis que les singes plus âgés montrent une préférence manuelle spontanée qui reste stable aux essais suivants. En répétant la tâche de prendre une pièce de nourriture (l'observation s'étend sur 600 gestes par animal), les singes, jeunes et vieux, parviennent a une préférence manuelle d'environ 85 %. Au niveau de l'asymétrie cérébrale, Nottebohm, 1971, 1972, a montré que le chant des oiseaux est handicapé après section du nerf hypoglosse gauche et non pas après celle du droit. Chez le singe, plusieurs auteurs ont montré une asymétrie des lobes temporaux (démontrée précédemment chez les humains). Par conséquent, bien que la latéralité maluelle et cérébrale caractérise fortement les comportements humains, on ne peut pas affirmer qu'elle fasse la différence entre les animaux et les hommes. L'avantage d'une latéralisation manuelle et cérébrale pour l'homme est sujet de spéculations très controversées. Il semble que, dans l'histoire des hommes, l'asymétrie comportementale fût déjà présente, sinon apparût, à époque de la prolifération des outils fabriqués. De plus, la latéralisation cérébrale représente, au moins pour Brown, 1976, la continuation du processus non seulement phylogénétique d'encéphalisation, mais également ontogénétique, résultant dans l'émergence de territoires focalisés qui deviendront les zones du langage humain. L'homme hériterait un gradient de latéralisation Chez l'homme, on ne peut expliquer le fait que toutes les civilisations soient droitières qu'en postulant l'existence d'un gradient qui guide la maturation selon un ensemble de lois concernant la spécialisation de la gauche et de la droite du corps et en particulier du

This study analyzes language impairment to children in Ivorian primary school. More specifically, the study looks at the difficulties of learning in reading and writing still called dyslexia and dysgraphia. The data collection instruments such as observation, interview and questionnaire are used in the process and the hypothesis formulated links learning difficulties with biological and cultural factors to children. The quantitative and qualitative methods used on the basis of an experimental approach allow us to conclude that dyslexia and dysgraphia are consecutive to the biological lateralization and cultural prejudices of society. Résumé La présente étude fait une analyse des troubles du langage chez des enfants à l'école primaire ivoirienne. Plus spécifiquement, l'étude se penche sur les difficultés d'apprentissage en lecture et en écriture encore appelées dyslexie et dysgraphie. Les instruments de recueil de données que sont l'observation, l'entretien et le questionnaire, sont utilisés dans la démarche. L'hypothèse formulée établit un lien entre les difficultés d'apprentissage et les facteurs biologiques et culturels chez l'enfant. Les méthodes quantitatives et qualitatives mises à contribution sur la base d'une approche expérimentale, permet de conclure que la dyslexie et la dysgraphie sont consécutives à la latéralisation biologique et aux préjugés culturels de la société.

According to Greimas, the semiotic square is far more than a heuristic for semantic and literary analysis. It represents the generative "deep structure" of human culture and cognition which "define the fundamental mode of existence of an individual or of a society, and subsequently the conditions of existence of semiotic objects". The veracity of this bold hypothesis has received little attention in the literature. In response, this paper traces the history and development of the square of opposition from Aristotle to Greimas and beyond, to propose that the relations modeled in these diagrams are rooted in gestalt memories of kinesthesia and proprioception from which we derive basic structural awareness of opposition and contrast-including verticality, bilaterality, transversality, markedness and analogy. The paper draws on findings in the phenomenology of movement, recent developments in the analysis of logical opposition, recent scholarship in (post)Greimasian semiotics and prescient insights from Greimas himself. The argument is further tested via multimodal content analyses of a popular music video-highlighting relationships the semiotic square shares with mundane cultural ideologies and showing how these relationships might be traced to memory structures of bodily movement. The paper highlights the neglected relevance of embodied chiasmus and illustrates the enduring relevance of Greimasean thought.

Fundamental breakthroughs in the neurosciences, combined with technical innovations for measuring brain activity, are shedding new light on the neural basis of second language (L2) processing, and on its relationship to native language processing (L1) (Perani & Abutalebi, 2005). Over the past two decades, a large body of neuroimaging studies has been devoted to the study of the neural organization of language (De´monet, Thierry, & Cardebat, 2005; Indefrey & Levelt, 2004; Price, 2000 as cited in Abutalebi, 2008). The value that functional neuroimaging adds to language research is to improve the perspective on the distributed anatomy of language. Thus, it can be used with considerable precision to identify the neural networks underlying the different domains of language processing. In this paper some main issues related to neurolinguistics and second language acquisition with a focus on bilingualism will be discussed.

Summary:  Purpose: Complex partial seizure is the characteristic seizure type observed in epilepsy arising from temporal lobe structures. The seizure evolution in adult patients is quite stereotyped and well characterized, manifesting initially with an aura, behavioral arrest, and oroalimentary and gestural automatism. A greater variability of semiology including motor features with tonic or myoclonic components, as well as a paucity of automatism, has been reported in young children with temporal lobe epilepsy. The aim of our study was to examine in more detail the effects of age on individual ictal features to be able to determine the critical age when lesional temporal lobe seizure semiology undergoes transition from the pediatric to the more adult-type clinical pattern.Methods: We performed a video analysis of 83 seizures from 15 children (aged 11–70 months) selected by post–temporal lobectomy seizure-free outcome, looking specifically at the motor and behavioral (nonmotor) manifestations in relation to age of the children.Results: All of the children younger than 42 months had seizures with early and marked motor features, which included tonic and myoclonic components and epileptic spasms. Parallel with age, the frequency of these motor components decreased, and in five of 11 children older than 3 years, motor features were totally absent. Analyzed quantitatively, we saw a linear and inverse correlation of the ratio of motor components with age at monitoring.Conclusions: These findings support the hypothesis that events in brain maturation significantly affect clinical seizure semiology and may override the more typical localizing features seen in adult-type temporal lobe epilepsy. These findings are important to consider in the early diagnosis of childhood temporal lobe epilepsy.

The present study investigated electrocortical and cardiovascular reactivity during positive and negative emotion, and examined the relation of asymmetric frontal lobe activation to cardiovascular responses. Participants were 30 healthy, right-handed university students (mean age, 23.9; 60% female; 76% Caucasian). Electroencephalographic (EEG), blood pressure (BP), and heart rate (HR) responses were assessed while subjects engaged in laboratory tasks (personally-relevant recall tasks

To investigate the overlap between dissociative and bipolar disorders with reference to their neurophysiological foundations. Case reports of anomalous lateralization and shifts in handedness associated with both affective and dissociative conditions have intermittently surfaced in the literature. The two disorders are, however, usually considered to be distinct psychopathological entities. A case of co-occurring bipolar disorder and dissociative identity disorder (DID) is presented. The "switch" in personality coincided with manic or hypomanic symptoms and was associated with a change in handedness. A parallel between the "personality" shifts that characterize DID and the mood fluctuations that underlie bipolar disorder is drawn, suggesting some nosological overlap between the two disorders. The possibility that these two psychiatric conditions share a similar neurophysiological architecture is also raised.

Ultradian rhythms of alternating cerebral dominance have been demonstrated in humans and other mammals during waking and sleep. Human studies have used the methods of psychological testing and electroencephalography (EEG) as measurements to identify the phase of this natural endogenous rhythm. The periodicity of this rhythm approximates 1.5-3 hours in awake humans. This cerebral rhythm is tightly coupled to another ultradian rhythm known as the nasal cycle, which is regulated by the autonomic nervous system, and is exhibited by greater airflow in one nostril, later switching to the other side. This paper correlates uninostril airflow with varying ratios of verbal/spatial performance in 23 right-handed males. Relatively greater cognitive ability in one hemisphere corresponds to unilateral forced nostril breathing in the contralateral nostril. Cognitive performance ratios can be influenced by forcibly altering the breathing pattern.

The N170 component for visual word recognition is lateralized to the left hemisphere in occipitotemporal regions for hearing, right-­‐handed individuals and has been associated with highly automatic orthographic processing in accomplished adult readers (Maurer, Zevin, & McCandliss, 2008). Deaf individuals have distinct developmental experiences with written word acquisition due a lack of access to auditory language, and early neurophysiological studies suggest greater right hemisphere involvement in word reading for deaf individuals (e.g., Neville et al., 1984). We examined whether the lateralization of early visual ERP components, namely P100 and N170, differ for deaf and hearing readers and whether these effects are modulated by English vocabulary knowledge. Twenty hearing participants (M age = 24 yrs) and 20 deaf participants (M age = 29 yrs; all fluent users of American Sign Language) made same-­‐different judgments to pairs of four-­‐letter words (192 trials), where the first word was presented centrally and the second word was presented to either the left (LH) or right hemisphere (RH) (see Dundas et al., 2014). EEG was recorded to the centrally presented words (750ms) and referenced to the average of all 32 electrode sites. The P100 and N170 were measured by taking the average amplitude between 80 and 120 ms, and between 130-­‐230ms in the occipitotemporal sites respectively in both hemispheres. Participants also completed an offline measure of vocabulary size (Peabody Picture Vocabulary Test, Dunn & Dunn, 2007) adapted for use with deaf participants (written rather than spoken words were presented). A median split was used to categorize the participants into high and low vocabulary groups. The preliminary results revealed a larger N170 amplitude in LH over RH in hearing readers (F (1, 18) = 37.4, p < .001), but no effect of vocabulary skill on N170 lateralization was found (F (1, 18) = 1.1, p = .319). For deaf readers, the N170 was also LH-­‐lateralized (F (1, 18) = 12.1, p = .003), but interestingly, only the low vocabulary group showed a significantly greater N170 in LH than RH (p = .009). The deaf high vocabulary group showed a more bilateral N170 response (p = .13). This pattern suggests that deaf readers with larger vocabulary recruit both hemispheres during word recognition, in contrast to both deaf readers with smaller vocabulary and hearing readers with a similar vocabulary size who show a left hemisphere bias. The P1 amplitude was bilaterally distributed for hearing readers which is in line with previous studies suggesting that LH bias is specific to the N170 component. For deaf readers, the laterality of the P1 was impacted by vocabulary size. The high vocabulary deaf group exhibited a larger P1 in the RH over LH (p = .01), while the low vocabulary group showed a trend for a larger P1 in the LH over RH (p = .103). These unique P1 asymmetries suggest that for deaf readers vocabulary knowledge modulates early visual feature analysis of orthographic stimuli.

One of the intriguing and sometimes controversial findings in figurative language research is a right- hemisphere processing advantage for novel metaphors. The current divided visual field study introduced novel literal expressions as a control condition to assess processing novelty independent of figurativeness. Participants evaluated word pairs belonging to one of the five categories: (1) conventional metaphorical, (2) conventional literal, (3) novel metaphorical, (4) novel literal, and (5) unrelated expressions in a semantic decision task. We presented expressions without sentence context and controlled for additional factors including emotional valence, arousal, and imageability that could potentially influence hemispheric processing. We also utilized an eye-tracker to ensure lateralized presentation. We did not find the previously reported right-hemispherical processing advantage for novel metaphors. Processing was faster in the left hemisphere for all types of word pairs, and accuracy was also higher in the right visual field - left hemisphere. Novel metaphors were processed just as fast as novel literal expressions, suggesting that the primary challenge during the comprehension of novel expressions is not a serial processing of salience, but perhaps a more left hemisphere weighted semantic integration. Our results cast doubt on the right- hemisphere theory of metaphors, and raise the possibility that other uncontrolled variables were responsible for previous results. The lateralization of processing of two word expressions seems to be more contingent on the specific task at hand than their figurativeness or saliency.

Individuals show marked variation in their responses to threat. Such individual differences in behavioral inhibition play a profound role in mental and physical well-being. Behavioral inhibition is thought to reflect variation in the sensitivity of a distributed neural system responsible for generating anxiety and organizing defensive responses to threat and punishment. Although progress has been made in identifying the key constituents of this behavioral inhibition system in humans, the involvement of dorsolateral prefrontal cortex (DLPFC) remains unclear. Here, we acquired self-reported Behavioral Inhibition System Sensitivity scores and high-resolution electroencephalography from a large sample (n= 51). Using the enhanced spatial resolution afforded by source modeling techniques, we show that individuals with greater tonic (resting) activity in right-posterior DLPFC rate themselves as more behaviorally inhibited. This observation provides novel support for recent conceptualizations of behavioral inhibition and clues to the mechanisms that might underlie variation in threat-induced negative affect.

Planned and reflexive behaviors often occur in the presence of emotional stimuli and within the context of an individual’s acute emotional state. Therefore, determining the manner in which emotion and attention interact is an important step toward understanding how we function in the real world. Participants in the current investigation viewed centrally displayed, task-irrelevant, face distractors (angry, neutral, happy) while performing a lateralized go/no-go continuous performance task. Lateralized go targets and no-go lures that did not spatially overlap with the faces were employed to differentially probe processing in the left (LH) and right (RH) cerebral hemispheres. There was a significant interaction between expression and hemisphere, with an overall pattern such that angry distractors were associated with relatively more RH inhibitory errors than neutral or happy distractors and happy distractors with relatively more LH inhibitory errors than angry or neutral distractors. Simple effects analyses confirmed that angry faces differentially interfered with RH relative to LH inhibition and with inhibition in the RH relative to happy faces. A significant three-way interaction further revealed that state anxiety moderated relations between emotional expression and hemisphere. Under conditions of low cognitive load, more intense anxiety was associated with relatively greater RH than LH impairment in the presence of both happy and threatening distractors. By contrast, under high load, only angry distractors produced greater RH than LH interference as a function of anxiety.