ABSTRACT In this comment to Ocklenburg et al.’s paper I stressed the contribution that computational ethology can provide to the accurate tracking of lateralized behaviour in a variety of species; I also discussed how current interest in so-called «minimal cognition» may help to disentangle shared and species-specific mechanisms of brain and behavioural asymmetries.

ABSTRACT We have identified the brain areas involved in Manual Preference (MP) in 143 left-handers (LH) and 144 right-handers (RH). First, we selected the pairs of homotopic regions of interest (hROIs) of the AICHA atlas with significant contralateral activation and asymmetry during the right hand and the left hand Finger-Tapping (FT) both in RH and LH. Thirteen hROIs were selected, including the primary

ABSTRACT This is a commentary on a paper by Ocklenburg et al. ([2020]. Laterality 2020: entering the next decade. Laterality). I discuss measurement and task selection issues that should not be neglected as we make our way through the next decade. I also comment further on a few pointed issues relevant to open science and meta-analysis.

ABSTRACT Open data initiatives such as the UK Biobank and Human Connectome Project provide researchers with access to neuroimaging, genetic, and other data for large samples of left-and right-handed participants, allowing for more robust investigations of handedness than ever before. Handedness inventories are universal tools for assessing participant handedness in these large-scale neuroimaging contexts

ABSTRACT Xenomelia is a rare condition characterized by a persistent and intense desire for amputation of one or more healthy limbs. Some frequent clinical manifestations suggest the involvement of distinct neural substrates. Specifically, recent aetiopathological hypotheses about xenomelia propose a neurodevelopmental origin, highlighting the putative contribution of the right parietal lobe and right

ABSTRACT Brain lateralization refers to hemispheric asymmetries in functions and/or neuroanatomical structures. Functional specialization in non-human animals has been mainly inferred through observation of lateralized motor responses and sensory perception. Only in a few cases has the influence of brain asymmetries on behaviour been described. Zebrafish has rapidly become a valuable model to investigate

ABSTRACT Studies of cerebral lateralization often involve participants completing a series of perceptual tasks under laboratory conditions. This has constrained the number of participants recruited in such studies. Online testing can allow for much larger sample sizes but limits the amount of experimental control that is feasible. Here we considered whether online testing could give valid and reliable

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

ABSTRACT Previous findings suggest a right hemispheric contribution to body image distortions only in women. Here we set out to replicate this finding and investigate whether the sex of the body image would play a role in this lateralization. We report here two experiments of body size estimation using the divided visual field methodology. In Experiment 1 we found no effect of visual field, participant

ABSTRACT Language is among the most studied functional asymmetries, yet little is known about right hemispheric language dominance. Because of its low prevalence, including a big sample of individuals with this variant of brain organization implies testing large groups, which may not be feasible when using expensive techniques. One solution involves screening a large sample using a cost-efficient method

(2020). Emotions and the Right Side of the Brain. Laterality: Vol. 25, No. 6, pp. 740-742.

ABSTRACT Previous research suggests that the right visual field advantage on the lexical decision task occurs independent of the visual quality of stimuli [Chiarello, C., Senehi, J., & Soulier, M. (1986). Viewing conditions and hemisphere asymmetry for the lexical decision. Neuropsychologia, 24(4), 521–529]. However, previous studies examining these effects have had methodological limitations that

ABSTRACT Behavioural and brain lateralization is widespread among non-human vertebrates. Motor lateralization has been investigated in the domestic dog, revealing that “pawedness” in this species seems to be sex and task related; however, few if any studies considered this asymmetry in wolves (Canis lupus). The aim of this study was to investigate the paw preference of seven wolves housed at Parco

ABSTRACT The visual system and lifestyle characteristics make the even-toed ungulates an excellent model for the studies of behavioural lateralization. Recent research has focused on these mammals providing evidence of lateralization in a wide range of behaviours. This provides an opportunity for the collation of the current theoretical assumptions and the existing empirical evidence for visual lateralization

ABSTRACT It is commonly assumed that cerebral asymmetry is unidimensional, but evidence increasingly suggests that different brain circuits are independently lateralized. This might explain why the search for a laterality gene has provided multiple candidates, each with weak linkage. An alternative possibility is that there is a single genetically invariant source of lateralization, perhaps cytoplasmic

ABSTRACT Portraits of humans favour the left cheek, with emotion thought to drive this posing asymmetry. In primates the emotion-dominant right hemisphere predominantly controls the left hemiface, rendering the left cheek anatomically more expressive than the right. As perceptions of nonhuman primates vary with genetic relatedness, depictions of nonhuman primates should theoretically be influenced

ABSTRACT Sleep and wakefulness are opposite brain and body conditions that accomplish different but complementary functions. However, these opposing conditions have been combined in some animals by the adoption of a sleep/wake strategy that allows them to survive, while maintaining both an interaction with the environment at the same time as enabling brain and body recovery. They sleep with half of

ABSTRACT Bees provide a good model to investigate the evolution of lateralization. So far, most studies focused on olfactory learning and memories in tethered bees. This study investigated possible behavioural biases in free-flying buff-tailed bumblebees (Bombus terrestris) by analysing their turning decisions in a T-maze. Bees of various size were trained to associate a syrup reward with a blue target

ABSTRACT A growing number of studies demonstrate that consistent handers, people who use their dominant hand for all or most manual tasks, are less cognitively flexible than inconsistent handers, people who use their non-dominant hands at least some of the time. A recent hypothesis suggests that differences in handedness emerged evolutionarily because populations benefited from a balance between cognitively

In the 2010s, significant progress has been made in several key areas of laterality research, including neuroimaging, genetics and comparative research. In the present article, we discuss which trends are likely to shape laterality research in the 2020s. These include, but are not limited to: (1) Finding laterality-specific solutions to the replication crisis. (2) Integrating non-W.E.I.R.D. (Western

ABSTRACT The left hemisphere is known to be generally predominant in verbal processing and the right hemisphere in non-verbal processing. We studied whether verbal and non-verbal lateralization is present in haptics by comparing discrimination performance between letters and nonsense shapes. We addressed stimulus complexity by introducing lower case letters, which are verbally identical with upper

ABSTRACT Researchers interested in hemispheric dominance frequently aim to infer latent functional differences between the hemispheres from observed lateral behavioural or brain-activation differences. To be valid, these inferences may not only rely on the observed laterality measures but also need to account for the antecedent probabilities of the studied latent classes. This fact is frequently ignored

Research shows decreased brain region activity in the right temporo-parietal junction (rTPJ) in people with migraine headache relative to headache-free controls when performing an orienting visuospatial attention task. Functional inactivation of the rTPJ has been associated with rightward performance deviations on laterality-based attention Landmark (LM) and greyscale (GRE) tasks in individuals with

People are frequently biased to use left-side information more than right-side information to inform their perceptual judgements. This research examined whether the leftward bias also applied to preferences for the arrangement of everyday consumer items. Pairs of consumer items were created where one item was more attractive than the other item. Using a two-alternative forced choice task, Experiment

Researchers have long been interested in whether lateral preference is associated with giftedness, season of birth, and/or ADHD constructs (short attention span, high level of activity, and impulsivity). The objective of this study was to examine these associations in a large, longitudinal sample of U.S. children (National Collaborative Perinatal Project (CPP), 1959–1973). Children born to women in

In order to face a constantly changing environment, animals need to be able to update their knowledge of the world on the basis of new information. Often, this means to inhibit a previously acquired response and flexibly change their behaviour to produce a new response. Here, we measured such abilities in young domestic chicks, employing a Colour Reversal Learning Task. During the acquisition phase

Until fairly late in the nineteenth century, it was held that the brain was bilaterally symmetrical. With the discovery of left-brain dominance for language, the so-called “laws of symmetry” were revoked, and asymmetry was then seen as critical to the human condition, with the left hemisphere, in particular, assuming superordinate properties. I trace this idea from the early discoveries of the late

(2020). Obituary for Dr. Marian Annett, 1931–2018. Laterality: Vol. 25, No. 4, pp. 405-412.

Recent studies indicate that individuals with consistent hand preference are more authoritarian than individuals whose preference is relatively inconsistent. We explored the role of epistemic needs in the handedness-authoritarianism relationship. Based on findings that consistent individuals are less cognitively flexible than inconsistent individuals, we hypothesized that consistent-handers would report

(2020). Reflections of a Neuropsychologist. Laterality: Vol. 25, No. 4, pp. 511-512.

Many studies have highlighted evidence of lateralized behaviours in vertebrates and invertebrates, indicating that cerebral lateralization might not be uniquely human. Flamingos, as highly social species, might represent an interesting model in the study of lateralization, as this trait appears to be useful in gregarious animals. This study aims to investigate the presence of lateralized behaviours

(2020). Right brain psychotherapy. Laterality: Vol. 25, No. 2, pp. 255-258.

Comparative studies can help understand better brain functional lateralization for manipulation and language. This study investigated and compared, for the first time, human adults' laterality for manipulation and gestures in a non-experimental social context. We analysed the manual laterality of 48 beach volleyball athletes for four frequently expressed behaviours: a complex throwing action (jump

Pitch height is thought to be mentally represented along the vertical and the horizontal axes. This is based on a well-described effect: the Spatial Pitch Association of Response Codes (SPARC) effect. A low pitch is more easily associated with a left or a low location and a high pitch with a right or a high location. While much of the evidence supports the existence of these two "mental pitch lines"

Earlier research suggested that gaze direction has an impact on cognitive processing. It is likely that horizontal gaze direction increases activation in specific areas of the contralateral cerebral hemisphere. Consistent with the lateralization of memory functions, we previously showed that shifting gaze to the left improves visuo-spatial short-term memory. In the current study, we investigated the

Studies of brain lateralization in individuals with non-specific intellectual disability and Down syndrome suggest atypical brain lateralization to speech perception. According to the biological dissociation model, the right hemisphere (RH) mediates speech perception and the left hemisphere (LH) mediates motor control in Down syndrome. The current study aimed to test, for the first time, brain lateralization

In this study, we coded art painted on rocks located in southern Africa, which was painted with a mixture of ochre, blood, and clay by the San, a Neolithic culture with no written language. These images depict a mixture of humans and animals in a variety of contexts, including (but not limited to) hunts and dances. We calculated a laterality index for the collected available art from each region, finding

As the right hemisphere is dominant for emotion processing, the left cheek expresses emotion more intensely than the right cheek. This prompts a leftward bias: people offer the left cheek to communicate emotion and viewers perceive left cheek poses as more emotive. Perceptions of trustworthiness are positively influenced by emotional expressivity, with smiling faces deemed more trustworthy than neutral

The causes of developmental stuttering, a neurodevelopmental communicative disorder, have not been elucidated to date. Neuroimaging studies suggest that atypical cerebral laterality could be one of such causal factors. Moreover, handedness, a behavioural index for cerebral laterality, has been linked to stuttering and recovery from it. However, findings are conflicting, possibly due to sample selection

Previous studies found that valence and visual half-field have an influence on word reading: Words are processed more efficiently when they evoke positive feelings and when they appear in the right visual field. In the present study we tried to address previous (contradictory) reports of an interaction between valence and visual half-field.A group of 39 right-handed undergraduates completed a lexical

Although a population bias toward right-hand preference is observed at the early stage of grasping, hand preference fluctuates in infancy. Given these fluctuations, one can wonder whether testing a young infant on a single occasion gives reliable results of its handedness. Very few studies have evaluated short-term test-retest reliability. This was the goal of this study in which 21 infants aged 9–15

Researchers have utilized reaching paradigms to measure infant handedness for more than a century. However, methods vary widely. Recent research has identified that the number of trials used in assessment is critical with the recommendation that at least 15 trials are necessary to reliably classify infants into handedness categories via statistical cutoffs. As a first step towards establishing best

In this study, we investigated age differences in manual force production to explore their neurophysiological basis. Manual pinching and gripping forces were first measured during unilateral and bilateral efforts in two groups of right-handed adults (young, n = 12, senior, n = 11). Then, transcranial magnetic stimulation (TMS) was applied to each hemisphere to assess central motor inhibition via the

Brain–computer interfaces (BCI) decode user’s intentions to control external devices. However, performance variations across individuals have limited their use to laboratory environments. Handedness could contribute to these variations, especially when motor imagery (MI) tasks are used for BCI control. To further understand how handedness affects BCI control, performance differences between two monozygotic

Age-related changes have been identified in neural and motor level. A prominent change is reduced asymmetry in cortical activation as well as motor performance. Cortical activation models have been established based on cognitive research utilizing neuroimaging techniques to explain age-related effects on neural recruitment and reduced brain asymmetry. Recently, researchers in motor behaviour attempted

The unilateral contractions procedure (i.e., squeezing a ball with one hand) supposedly enhances a wide variety of cognitive functions, from episodic recall to choking under pressure. The practicality and affordability of this procedure makes it highly appealing. But does it work? We addressed this question by testing whether intermittent and sustained unilateral contractions shifted a well-supported

(2020). Dyslexia and neuroscience: the geschwind-galaburda hypothesis 30 years later. Laterality: Vol. 25, No. 3, pp. 390-392.

In human social interaction, affective touch plays an integral role to communicate intentions and emotions. Three of the most important forms of social touch are embracing, cradling and kissing. These behaviours have been demonstrated to be lateralized, but the underlying mechanisms are still not well understood. Both motor and emotive biases have been suggested to affect laterality of social touch

Based on numerous findings of an abnormal laterality in schizophrenia disorder, we hypothesized that handedness and lateral preferences may affect the age at onset in schizophrenia patients. Two samples of schizophrenia patients, the first a sample of 34 right-handers and 42 left-handers and a replication set of 84 right-handers, were examined with regard to age at onset considering handedness and

Studies have found a tendency for heads in portraits to be oriented so that more of the left side than the right side of the face is visible, though it is stronger in female than in male portraits. Two studies are reported that set head orientation in the context of body and gaze orientation, and additionally look at effects of artistic medium (paintings, photographs, and drawings) and changes in the

A remarkable feature of human handedness at the population level is specialization of the hands, the right hand performing usually better than the left. This specialization might have an evolutionary advantage, because it provides the individual and population with a wider range of skill. We therefore investigated the relationships between hand skill asymmetry and potential markers of Darwinian fitness

Although olfactory laterality in canids has been demonstrated experimentally, the extent to which nostril bias occurs in "nature" is not well known. We tested whether there was olfactory laterality of untrained dogs in various off-leash dog parks within Victoria, British Columbia to manipulated scents placed at the tail base of full-size dog replica. Using video-playback, we found that of 192 separate

Handedness ontogenesis is still under debate in science. This systematic review analyzed articles regarding the theories and basis of handedness formation, highlighting the historical knowledge path that this literature underwent. Cochrane Library, LILACS, Web of Sciences, Science Direct and PubMed databases were searched. This review included review studies with handedness as the main topic. Only

Left and inconsistent hand preferences are the markers of atypical brain organization that relate with cognitive and behavioural traits as well as with developmental disorders, whereas intolerance of uncertainty is the trait of inability to bear future uncertainty that mediates anxiety disorders and depression. In the present study, relationship of hand preference with intolerance of uncertainty was

Liaison between neuroscience and education has resulted in significant advances in our understanding of the neurobiological learning requirements of individuals with reading disability, the neuroplasticity of the developing brain, and the participation of the right hemisphere in reading. Research in neural network theory and cortical oscillations suggests that the hemispheres collaborate in high-level

People exhibit consistent leftward spatial biases across a variety of tasks. However, individuals with a native reading direction other than left-to-right (LTR) show an attenuation of the leftward bias. The current study used procedurally similar tasks to examine spatial ability and aesthetic preferences in LTR and right-to-left (RTL) groups. In the spatial task participants viewed a centred rectangle

When posing for portraits, humans favour the left cheek. This preference is argued to stem from the left cheek’s greater expressivity: as the left hemiface is predominantly controlled by the emotion-dominant right hemisphere, it expresses emotion more intensely than the right hemiface. Whether this left cheek bias extends to our closest primate relatives, chimpanzees, has yet to be determined. Given

(2020). Obituary for Professor Richard J. Andrew, 1932–2018. Laterality: Vol. 25, No. 4, pp. 393-404.

The aim of this study was to determine the rate and types of lifetime psychiatric disorders, as well as their predictors, in a sample of people with refractory epilepsy. Demographic, neurological, psychiatric and neuropsychological data, from people with refractory epilepsy, were registered at the pre-surgical interview. Linear regression was used to determine predictors. One hundred and ninety-one

ABSTRACT The two halves of the brain are believed to play different roles in emotional processing. In studies involving chimeric faces, emotional expressions in the left visual field are more strongly perceived as emotional than those in the right visual field. Notably, the role of facial mimicry has not been studied in relation to hemispheric lateralization. In the current study, which used a novel