Left Hemisphere Dominance Research Articles

Fibre-specific laterality of white matter in left and right language dominant people

Language is the most commonly described lateralised cognitive function, relying more on the left hemisphere compared to the right hemisphere in over 90% of the population. Most research examining the structure-function relationship of language lateralisation only included people showing a left language hemisphere dominance. In this work, we applied a state-of-the-art "fixel-based" analysis approach, allowing statistical analysis of white matter micro- and macrostructure on a fibre-specific level in a sample of participants with left and right language dominance (LLD and RLD). Both groups showed a similar extensive pattern of white matter lateralisation including a comparable leftwards lateralisation of the arcuate fasciculus, regardless of their functional language lateralisation. These results suggest that lateralisation of language functioning and the arcuate fasciculus are driven by independent biases. Finally, a significant group difference of lateralisation was detected in the forceps minor, with a leftwards lateralisation in LLD and rightwards lateralisation for the RLD group.

Relations between hemispheric asymmetries of grey matter and auditory processing of spoken syllables in 281 healthy adults

Most people have a right-ear advantage for the perception of spoken syllables, consistent with left hemisphere dominance for speech processing. However, there is considerable variation, with some people showing left-ear advantage. The extent to which this variation is reflected in brain structure remains unclear. We tested for relations between hemispheric asymmetries of auditory processing and of grey matter in 281 adults, using dichotic listening and voxel-based morphometry. This was the largest study of this issue to date. Per-voxel asymmetry indexes were derived for each participant following registration of brain magnetic resonance images to a template that was symmetrized. The asymmetry index derived from dichotic listening was related to grey matter asymmetry in clusters of voxels corresponding to the amygdala and cerebellum lobule VI. There was also a smaller, non-significant cluster in the posterior superior temporal gyrus, a region of auditory cortex. These findings contribute to the mapping of asymmetrical structure–function links in the human brain and suggest that subcortical structures should be investigated in relation to hemispheric dominance for speech processing, in addition to auditory cortex.

Lateralızatıon of Non-Word Processıng in Monolınguals

A great bulk of research in the psycholinguistic literature has been dedicated to hemispheric organization of words. An overwhelming evidence suggests that the left hemisphere is primarily responsible for lexical processing. However, non-words, which look similar to real words but lack meaningful associations, is underrepresented in the laterality literature. This study investigated the lateralization of Turkish non-words. Fifty-three Turkish monolinguals performed a lexical decision task in a visual hemifield paradigm. An analysis of their response times revealed left-hemispheric dominance for non-words, adding further support to the literature. The accuracy of their answers, however, were comparable regardless of the field of presentation. The results were discussed in light of the psycholinguistic word processing views.

Lateralızatıon of Non-Word Processıng in Monolınguals

A great bulk of research in the psycholinguistic literature has been dedicated to hemispheric organization of words. An overwhelming evidence suggests that the left hemisphere is primarily responsible for lexical processing. However, non-words, which look similar to real words but lack meaningful associations, is underrepresented in the laterality literature. This study investigated the lateralization of Turkish non-words. Fifty-three Turkish monolinguals performed a lexical decision task in a visual hemifield paradigm. An analysis of their response times revealed left-hemispheric dominance for non-words, adding further support to the literature. The accuracy of their answers, however, were comparable regardless of the field of presentation. The results were discussed in light of the psycholinguistic word processing views.

Features of individual cognitive style of qualified badminton players

Aim: to determine of peculiarities of personal cognitive styles in qualified badminton players.
 Material and methods. The studies were carried out using the hardware-software computer complex "Multipsychometer-05". The modified Stroop test was selected. The indicators of the test "Field dependence" were determined: field independence, left hemispheric dominance, functional asymmetry, and the effectiveness of the test. The obtained results of the study were analyzed for the entire sample of badminton players, as well as separately for men and women.
 Results. According to the results of scientific research on the field dependence of qualified badminton players, it was found that all athletes in our sample demonstrate a slight bias towards field dependence; dominated by right hemisphere dominance; in functional asymmetry and efficiency, qualified badminton players demonstrate an average level. The analysis of test indicators, taking into account gender dimorphism, showed that among men 72% demonstrate a predominance of right hemispheric dominance of varying degrees, 28% have left hemispheric dominance. As for women, 54% demonstrate a predominance of right hemispheric dominance of varying degrees, and 37% demonstrate left hemispheric dominance of varying degrees.
 Conclusions. Men show a tendency towards better test performance and have more pronounced functional asymmetry. The cognitive style of skilled badminton players determines the strategy of selection and processing of information, problem solving, learning and other types of cognitive activities. Because human cognitive-activity styles are genetically determined and demonstrate a pronounced stability of cognitive-stylistic characteristics in ontogenesis, they can be used as prognostic and diagnostic criteria.

Using magnetoencephalography to examine word recognition, lateralization, and future language skills in 14-month-old infants

Word learning is a significant milestone in language acquisition. The second year of life marks a period of dramatic advances in infants’ expressive and receptive word-processing abilities. Studies show that in adulthood, language processing is left-hemisphere dominant. However, adults learning a second language activate right-hemisphere brain functions. In infancy, acquisition of a first language involves recruitment of bilateral brain networks, and strong left-hemisphere dominance emerges by the third year. In the current study we focus on 14-month-old infants in the earliest stages of word learning using infant magnetoencephalography (MEG) brain imagining to characterize neural activity in response to familiar and unfamiliar words. Specifically, we examine the relationship between right-hemisphere brain responses and prospective measures of vocabulary growth. As expected, MEG source modeling revealed a broadly distributed network in frontal, temporal and parietal cortex that distinguished word classes between 150–900 ms after word onset. Importantly, brain activity in the right frontal cortex in response to familiar words was highly correlated with vocabulary growth at 18, 21, 24, and 27 months. Specifically, higher activation to familiar words in the 150–300 ms interval was associated with faster vocabulary growth, reflecting processing efficiency, whereas higher activation to familiar words in the 600–900 ms interval was associated with slower vocabulary growth, reflecting cognitive effort. These findings inform research and theory on the involvement of right frontal cortex in specific cognitive processes and individual differences related to attention that may play an important role in the development of left-lateralized word processing.

Prolonged functional cerebral asymmetry as a consequence of dysfunctional parvocellular paraventricular hypothalamic nucleus signaling: An integrative model for the pathophysiology of bipolar disorder

Approximately 45 million people worldwide are diagnosed with bipolar disorder (BD). While there are many known risk factors and models of the pathologic processes influencing BD, the exact neurologic underpinnings of BD are unknown. We attempt to integrate the existing literature and create a unifying hypothesis regarding the pathophysiology of BD with the hope that a concrete model may potentially facilitate more specific diagnosis, prevention, and treatment of BD in the future. We hypothesize that dysfunctional signaling from the parvocellular neurons of the paraventricular hypothalamic nucleus (PVN) results in the clinical presentation of BD. Functional damage to this nucleus and its signaling pathways may be mediated by myriad factors (e.g. immune dysregulation and auto-immune processes, polygenetic variation, dysfunctional interhemispheric connections, and impaired or overactivated hypothalamic axes) which could help explain the wide variety of clinical presentations along the BD spectrum. The neurons of the PVN regulate ultradian rhythms, which are observed in cyclic variations in healthy individuals, and mediate changes in functional hemispheric lateralization. Theoretically, dysfunctional PVN signaling results in prolonged functional hemispheric dominance. In this model, prolonged right hemispheric dominance leads to depressive symptoms, whereas left hemispheric dominance correlated to the clinical picture of mania. Subsequently, physiologic processes that increase signaling through the PVN (hypothalamic-pituitaryadrenal axis, hypothalamic- pituitary-gonadal axis, and hypothalamic-pituitary-thyroid axis activity, suprachiasmatic nucleus pathways) as well as, neuro-endocrine induced excito-toxicity, auto-immune and inflammatory flairs may induce mood episodes in susceptible individuals. Potentially, ultradian rhythms slowing with age, in combination with changes in hypothalamic axes and maturation of neural circuitry, accounts for BD clinically presenting more frequently in young adulthood than later in life.

SURG-08. AWAKE CRANIOTOMY WITH BRAIN MAPPING FOR DIFFUSE LOW-GRADE GLIOMA: CASE REPORT OF INSTITUTIONAL EXPERIENCE IN OVERCOMING HURDLES IN A LOW-RESOURCE SETTING

Abstract Maximal safe resection of low-grade gliomas located in functional areas of the cortex while avoiding postsurgical neurologic deficits can be achieved by awake craniotomy with brain mapping. The effectiveness of this surgical technique is fairly established in the developed world, however it remains to be routinely applied in low-middle income countries due to limited resources and lack of equipment. We present the case of a 44 year-old, right-handed male who had a 2-year history of focal aware motor seizures but was otherwise neurologically intact. Neuropsychological testing revealed no cognitive impairment. Cranial magnetic resonance imaging (MRI) revealed a non-enhancing, ill-defined tumor centered on the left insula and extending into the frontotemporal opercula, corona radiata, and posterior limb of the internal capsule—hypointense by T1-weighted sequence and hyperintense by T2-weighted sequence, thus radiographically consistent with diffuse low-grade glioma. Blood-oxygen-level-dependent functional MRI revealed left hemispheric language dominance in the cortex overlying the tumor, but with no motor cortex involvement. The patient underwent a protocol-driven awake craniotomy, intraoperative positive brain mapping using standard cortical stimulator, transsylvian and transcortical transopercular microsurgical approaches to achieve greater than 80% excision of the tumor. Postoperatively, the patient was seizure-free and with similar neurocognitive status prior to the surgery. The patient had been following up for standard adjuvant chemotherapy and radiotherapy. Avoidance of postsurgical neurologic deficits and maximal cytoreduction can still be achieved by awake craniotomy with brain mapping in settings with limited resources. Despite the lack of other perioperative tools and adjuncts such as diffusion tensor imaging, intraoperative ultrasonography, and even intraoperative MRI that are routinely available in high-resource settings, we illustrate in this case that comparable outcomes could be achieved by overcoming hurdles and aiming for the asymptote to the up-to-date and ideal neurosurgical treatment for diffuse low-grade gliomas.

Language Mapping With Magnetoencephalography: An Update on the Current State of Clinical Research and Practice With Considerations for Clinical Practice Guidelines.

Numerous studies have shown that language processing is not limited to a few brain areas. Visual or auditory stimuli activate corresponding cortical areas, then memory identifies the word or image, Wernicke's and Broca's areas support the processing for either reading/listening or speaking and many areas of the brain are recruited. Determining how a normal person processes language helps clinicians and scientist to understand how brain pathologies such as tumor or stroke can affect changes in language processing. Patients with epilepsy may develop atypical language organization. Over time, the chronic nature of epileptic activity, or changes from a tumor or stroke, can result in a shift of language processing area from the left to the right hemisphere, or re-routing of language pathways from traditional to non-traditional areas within the dominant left hemisphere. It is important to determine where these language areas are prior to brain surgery. MEG evoked responses reflecting cerebral activation of receptive and expressive language processing can be localized using several different techniques: Single equivalent current dipole, current distribution techniques or beamformer techniques. Over the past 20 years there have been at least 25 validated MEG studies that indicate MEG can be used to determine the dominant hemisphere for language processing. The use of MEG neuroimaging techniques is needed to reliably predict altered language networks in patients and to provide identification of language eloquent cortices for localization and lateralization necessary for clinical care.

Phonology and orthography in deaf readers: Evidence from a lateralized ambiguity resolution paradigm

ABSTRACT This study explored differences between the two hemispheres in processing written words among deaf readers. The main hypothesis was that impoverished phonological abilities of deaf readers may lead to atypical patterns of hemispheric involvement. To test this, deaf participants completed a metalinguistic awareness test to evaluate their orthographic and phonological awareness. Additionally, they were asked to read biased or neutral target sentences ending with an ambiguous homograph, with each sentence followed by the request to make a rapid lexical decision on a target word presented either to the left (LH) or right hemisphere (RH). Targets were either related to the more frequent, dominant, meaning of the homograph, to the less frequent, subordinate, meaning of the homograph or were not related at all. An Inverse Efficiency Score based on both response latency and accuracy was calculated and revealed that deaf readers’ RH perform better than their LH. In contrast to hearing readers who in previous studies manifested left hemisphere dominance when completed the same research design. The apparent divergence of deaf readers’ hemisphere lateralization from that of hearing counterparts seems to validate previous findings suggesting greater reliance on RH involvement among deaf individuals during visual word recognition.

Dissociated face- and word-selective intracerebral responses in the human ventral occipito-temporal cortex

The extent to which faces and written words share neural circuitry in the human brain is actively debated. We provide an original contribution to this debate by comparing face-selective and word-selective responses in a large group of patients (N=37) implanted with intracerebral electrodes in the ventral occipito-temporal cortex (VOTC). Both face-selective (i.e., significantly different responses to faces vs. nonface objects) and word-selective (i.e., significantly different responses to words vs. pseudofonts) neural activity is isolated through frequency-tagging (Jonas et al., 2016; Lochy et al., 2018, respectively). Critically, this approach allows disentangling category-selective neural responses from general visual responses. Overall, we find that 69.26% of significant contacts show either face- or word-selectivity, with the expected right and left hemispheric dominance, respectively (Fig.1A,B). Moreover, the center of mass for word-contacts is more lateral than for face-contacts, with no differences in postero-anterior axis (Fig.2A). Spatial dissociations are also found within core regions of face and word processing, with a medio-lateral dissociation in the fusiform gyrus (FG) and surrounding sulci (FG+sulci;Fig.2B), while a postero-anterior dissociation is found in the inferior occipital gyrus (IOG;Fig.2C). Despite their spatial dissociations in the FG+sulci and IOG, most overlap in category-selective responses is found in these regions (Fig.1C). Critically, in the overlap-contacts, across the whole brain or specifically in the FG+sulci, between-category (word-face) selective-amplitudes showed no-to-weak correlations, despite strong correlations for within-category (face-face, word-word) selective-amplitudes (Fig.3A), and a strong correlation in non-selective general-amplitudes to words-faces. Moreover, substantial overlap and no-to-weak correlations were observed between faces and a control category (houses) known to be functionally dissociated from faces. Overall, we conclude that category-selectivity for faces and words is largely dissociated in the human VOTC, with a limited spatial overlap likely due to the distant recording of dissociated populations of neurons rather than to shared category-selective representations.

Interactive relations among time, music and emotion

Research so far has shown that the emotional content of information affects time perception, through the mechanism of subjectivisation (i.e. shrinking or expanding temporal duration as a result of positive and negative emotional valence, respectively). Additionally, preliminary studies suggest that musically trained individuals compared to untrained ones tend to make more accurate duration judgements. Finally, it is known that music can induce specific moods; two of the main factors that determine the relationship between music and emotion are the structural features of the song and the features of the listener. However, it is not clear whether any interactive relations exist among these factors. In this study we attempted to address this particular gap in our current knowledge. As neuroscience studies show, when non musicians are listening to music there is activation of right cerebral areas while musicians show left hemispheric dominance. Right cerebral areas arerelated to the recognition and the expression of emotions and their activation suggests a cognitive processing based on the emotional valence of songs. Thus, it seems that musical training affects emotion(by inducing certain moods) that, consecutively, affects time estimation.

Pigeon nidopallium caudolaterale, entopallium, and mesopallium ventrolaterale neural responses during categorisation of Monet and Picasso paintings

Pigeons can successfully discriminate between sets of Picasso and Monet paintings. We recorded from three pallial brain areas: the nidopallium caudolaterale (NCL), an analogue of mammalian prefrontal cortex; the entopallium (ENTO), an intermediary visual area similar to primate extrastriate cortex; and the mesopallium ventrolaterale (MVL), a higher-order visual area similar to primate higher-order extrastriate cortex, while pigeons performed an S+/S− Picasso versus Monet discrimination task. In NCL, we found that activity reflected reward-driven categorisation, with a strong left-hemisphere dominance. In ENTO, we found that activity reflected stimulus-driven categorisation, also with a strong left-hemisphere dominance. Finally, in MVL, we found that activity reflected stimulus-driven categorisation, but no hemispheric differences were apparent. We argue that while NCL and ENTO primarily use reward and stimulus information, respectively, to discriminate Picasso and Monet paintings, both areas are also capable of integrating the other type of information during categorisation. We also argue that MVL functions similarly to ENTO in that it uses stimulus information to discriminate paintings, although not in an identical way. The current study adds some preliminary evidence to previous literature which emphasises visual lateralisation during discrimination learning in pigeons.

Hemispheric dominance for visuospatial attention does not predict the direction of pseudoneglect

Pseudoneglect refers to a tendency of neurologically healthy individuals to produce leftward perceptual biases during spatial tasks, which is traditionally measured using line bisection tasks. This behavioral asymmetry is often explained as a consequence of right hemispheric dominance for visuospatial attention. The present study directly tested this notion by comparing line bisection performance between left-handers with either right hemispheric dominance (RVSD, N = 40) or “atypical” left hemispheric dominance (LVSD, N = 23) for visuospatial attention as determined by fMRI. Although we expected a reversal of pseudoneglect in participants with LVSD, our results show that they equally often err to the left of the true center compared to RVSD controls (74% of LVSD participants and 80% of RVSD participants). However, the magnitude of misbisections was found to be slightly, but significantly, smaller in the LVSD subgroup.We conclude that hemispheric asymmetry for visuospatial attention is not the main determinant of pseudoneglect as is commonly thought, but rather only constitutes one of the multiple factors which (subtly) contributes to its direction and magnitude.

Atypical language representation as a protective factor against verbal memory decline following epilepsy surgery

ObjectiveAn important role of neuropsychology in the preoperative evaluation of epilepsy surgery candidates is to assess risk for postoperative memory decline. One factor associated with postoperative verbal memory decline is surgery in the language-dominant temporal lobe (TL). The aim of the study was to determine whether atypical language representation has a protective effect against verbal memory decline following left temporal, frontotemporal, or hippocampal excision. MethodsData from 61 patients with medically refractory epilepsy, Wada testing, and pre- and postsurgical memory assessment from four comprehensive epilepsy surgery centers were gathered and examined for pre- to postsurgical memory change. Wada testing was used to determine language dominance (left vs. atypical [bilateral + right]). Postoperative memory change was examined at both the individual (using nonparametric analyses) and group (using parametric analyses) levels for the two language dominance groups. ResultsSignificant postoperative verbal memory decline was observed in the left hemisphere language-dominant group, while the atypical language group showed verbal memory improvement. Individuals with left hemisphere language dominance were more likely to show postoperative declines in verbal memory, whereas individuals with atypical language dominance were significantly less likely to decline. As expected, there were no significant differences between language groups with regard to postoperative visuospatial memory outcome. ConclusionPatients with atypical language dominance had better verbal memory outcomes following left hemisphere resections than those with left hemisphere language dominance suggesting that typical memory substrates likely reorganized along with language. Thus, atypical cerebral organization of language may be considered a protective factor against verbal memory decline following epilepsy surgery involving the left TL.

Perceptual and Electrophysiological Correlates of Fixed Versus Moving Sound Source Lateralization.

Purpose The aims of the study were (a) to evaluate the effects of systematically varied factors of stimulus duration, interaural-level difference (ILD), and direction on perceptual and electrophysiological metrics of lateralization for fixed versus moving targets and (b) to evaluate the hemispheric activity underlying perception of fixed versus moving auditory targets. Method Twelve normal-hearing, young adult listeners were evaluated using perceptual and P300 tests of lateralization. Both perceptual and P300 tests utilized stimuli that varied for type (fixed and moving), direction (right and left), duration (100 and 500 ms), and magnitude of ILD (9 and 18 dB). Listeners provided laterality judgments and stimulus-type discrimination (fixed vs. moving) judgments for all combinations of acoustic factors. During P300 recordings, listeners discriminated between left- versus right-directed targets, as the other acoustic parameters were varied. Results ILD magnitude and stimulus type had statistically significant effects on laterality ratings, with larger magnitude ILDs and fixed type resulting in greater lateralization. Discriminability between fixed versus moving targets was dependent on stimulus duration and ILD magnitude. ILD magnitude was a significant predictor of P300 amplitude. There was a statistically significant inverse relationship between the perceived velocity of targets and P300 latency. Lateralized targets evoked contralateral hemispheric P300 activity. Moreover, a right-hemisphere enhancement was observed for fixed-type lateralized deviant stimuli. Conclusions Perceptual and P300 findings indicate that lateralization of auditory movement is highly dependent on temporal integration. Both the behavioral and physiological findings of this study suggest that moving auditory targets with ecologically valid velocities are processed by the central auditory nervous system within a window of temporal integration that is greater than that for fixed auditory targets. Furthermore, these findings lend support for a left hemispatial perceptual bias and right hemispheric dominance for spatial listening.

Temporal lobe regions essential for preserved picture naming after left temporal epilepsy surgery.

To define left temporal lobe regions where surgical resection produces a persistent postoperative decline in naming visual objects. Pre- and postoperative brain magnetic resonance imaging data and picture naming (Boston Naming Test) scores were obtained prospectively from 59 people with drug-resistant left temporal lobe epilepsy. All patients had left hemisphere language dominance at baseline and underwent surgical resection or ablation in the left temporal lobe. Postoperative naming assessment occurred approximately 7months after surgery. Surgical lesions were mapped to a standard template, and the relationship between presence or absence of a lesion and the degree of naming decline was tested at each template voxel while controlling for effects of overall lesion size. Patients declined by an average of 15% in their naming score, with wide variation across individuals. Decline was significantly related to damage in a cluster of voxels in the ventral temporal lobe, located mainly in the fusiform gyrus approximately 4-6cm posterior to the temporal tip. Extent of damage to this region explained roughly 50% of the variance in outcome. Picture naming decline was not related to hippocampal or temporal pole damage. The results provide the first statistical map relating lesion location in left temporal lobe epilepsy surgery to picture naming decline, and they support previous observations of transient naming deficits from electrical stimulation in the basal temporal cortex. The critical lesion is relatively posterior and could be avoided in many patients undergoing left temporal lobe surgery for intractable epilepsy.

Hemisphere-specific, differential effects of lateralized, occipital\u2013parietal \u03b1- versus \u03b3-tACS on endogenous but not exogenous visual-spatial attention

Orienting spatial attention has been associated with interhemispheric asymmetry of power in the α- and γ-band. Specifically, increased α-power has been linked to the inhibition of unattended sensory streams (e.g. the unattended visual field), while increased γ-power is associated with active sensory processing. Here, we aimed to differentially modulate endogenous and exogenous visual-spatial attention using transcranial alternating current stimulation (tACS). In a single-blind, within-subject design, participants performed several blocks of a spatial cueing task comprised of endogenous and exogenous cues while receiving lateralized α- or γ-tACS or no stimulation over left or right occipital-parietal areas. We found a significant, differential effect of α- and γ-tACS on endogenous (top-down) spatial attention but not on exogenous (bottom-up) attention. The effect was specific to tACS applied to the left hemisphere and driven by a modulation of attentional disengagement and re-orientation as measured during invalid trials. Our results indicate a causal role of α-/γ-oscillations for top-down (endogenous) attention. They may further suggest a left hemispheric dominance in controlling interhemispheric α-/γ-power asymmetry. The absence of an effect on exogenous attention may be indicative of a differential role of α-/γ-oscillations during different attention types or spatially distinct attentional subsystems.

Lateralization of Auditory Processing of Silbo Gomero

Left-hemispheric language dominance is a well-known characteristic of the human language system. However, it has been shown that leftward language lateralization decreases dramatically when people communicate using whistles. Whistled languages present a transformation of a spoken language into whistles, facilitating communication over great distances. In order to investigate the laterality of Silbo Gomero, a form of whistled Spanish, we used a vocal and a whistled dichotic listening task in a sample of 75 healthy Spanish speakers. Both individuals that were able to whistle and to understand Silbo Gomero and a non-whistling control group showed a clear right-ear advantage for vocal dichotic listening. For whistled dichotic listening, the control group did not show any hemispheric asymmetries. In contrast, the whistlers’ group showed a right-ear advantage for whistled stimuli. This right-ear advantage was, however, smaller compared to the right-ear advantage found for vocal dichotic listening. In line with a previous study on language lateralization of whistled Turkish, these findings suggest that whistled language processing is associated with a decrease in left and a relative increase in right hemispheric processing. This shows that bihemispheric processing of whistled language stimuli occurs independent of language.

Electrophysiological correlates of the Categorization Working Memory Span task in older adults

Older adults typically show poor performance in tasks assessing working memory (WM), a crucial cognitive mechanism. The present study examined the electrophysiological correlates of a classic complex WM task often used in studies involving older adults, the Categorization Working Memory Span task (CWMS), by means of event-related potentials. Thirty-five healthy, right-handed older adults (64–75 years) were presented the CWMS task while a 38-channel EEG was measured, and the N1, P1, and word recognition potential (RP) were analyzed on four regions of interest (ROIs) of 5 electrodes each. Additionally, late positive components (P200 and P300) were analyzed in midline ROIs of 3 electrodes each. Participants also executed an n-back task (2-back condition) and an objective performance-based task (the Ability to solve Problems in Everyday life [APE]). At a behavioral level, significant correlations were found between the CWMS, the 2-back, and the APE tests. At a physiological level, N1 and word RP showed greater bilateral amplitude in posterior electrodes, but the better the CWMS and the 2-back performance, the greater the RP amplitude on posterior left sites. The CWMS task induced a clear P200 component, but its amplitude was not correlated with participants’ behavioral performance. Altogether, notwithstanding that the bilateral RP pattern elicited by the CWMS is a clear marker of WM processing in older adults, better elderly performers on this complex WM test showed greater left hemisphere dominance to the automatic word RP.