A cerebral origin for "directionality"

Laterality and visuospatial strategies among young children: A novel 3D-2D transcription task

Recent findings showed that children, like adults, exhibit directional biases leading to asymmetrical drawings. This appears to be the result of a complex interaction between several biological, motoric, and cultural factors. We created a drawing task designed to investigate the influence of laterality (i.e., hemispherical functional specialization and handedness) and sex on children's graphical asymmetries. This task consists of transcribing a symmetrical three-dimensional landscape model to a two-dimensional representation. Sixty-six French pre-school children, aged between 5 and 6 years, were asked to undertake the 3D-2D transcription task, as well as the classical Alter's directionality task. The novel task exhibited higher sensitivity than the Alter's directionality test when examining the spatial biases resulting from handedness, and sex. Specific drawing patterns related to these variables were identified. These results suggest that, in addition to the influence of biomechanical factors and handedness, sex plays a role in children's early graphomotor development. They also support the influence of laterality as a key factor underlying early directional biases.

Which Side Looks Better? Cultural Differences in Preference for Left- or Right-Facing Objects

An oblique view of three-dimensional objects is preferred over a frontal or lateral view, partly because it is more familiar and easily recognizable. However, which side of a symmetric object looks better remains unsolved. Reading direction, handedness, and the functionality of objects have been suggested as the potential sources of directional bias. In this study, participants of three online surveys (total N = 1082) were asked to choose one item that looked better or was more aesthetically pleasing; the test was performed between 100 pairs of left- and right-facing mirror-images. The results showed that Japanese participants (both vertical and left-to-right readers) and Israeli participants (right-to-left readers) preferred left-facing images over right-facing images, whereas American participants (left-to-right readers) preferred right-facing images over left-facing images. Weak effects of handedness and object functionality were also found: Left-handers tended to choose right-facing images more than right-handers, and the view of objects with a handle that is graspable by the dominant hand was more likely to be chosen over the opposite side view, regardless of culture. Although previous studies have emphasized the role of reading direction, a close look at the results suggests that it cannot fully account for the preferred facing direction of oblique objects.

Sources of Directional Spatial Biases in Hemi-Image Drawing

We examined the performance of right- and left-handed brain-intact adult readers of English or Farsi on a hemi-image generation task in which participants were to imagine and then draw halves of objects using either their dominant or nondominant hand. Which half of the object was drawn was examined in relation to biomechanical, cerebral laterality, and cultural predictors. Findings showed a differential side bias as a function of reading/writing direction and hand used to draw. Specifically, when the dominant hand was used to draw (Experiment 1), English left-handers produced more left hemi-images while Farsi right-handers produced more right hemi-images. Body specificity associated with hand used, however, drove spatial preference when enlisting the nondominant hand (Experiment 2) with English right-handers now showing a significant left hemi-image bias and English left-handers showing a right hemi-image bias. Farsi right-handers using their nondominant hand did not show a significant bias in either direction. Taken together, the findings suggest a joint influence of handedness and reading/writing direction, aligned with an embodiment account of directional spatial biases.

Greener synthesis of chemical compounds and materials

Modern trends in the greener synthesis and fabrication of inorganic, organic and coordination compounds, materials, nanomaterials, hybrids and nanocomposites are discussed. Green chemistry deals with synthesis procedures according to its classic 12 principles, contributing to the sustainability of chemical processes, energy savings, lesser toxicity of reagents and final products, lesser damage to the environment and human health, decreasing the risk of global overheating, and more rational use of natural resources and agricultural wastes. Greener techniques have been applied to synthesize both well-known chemical compounds by more sustainable routes and completely new materials. A range of nanosized materials and composites can be produced by greener routes, including nanoparticles of metals, non-metals, their oxides and salts, aerogels or quantum dots. At the same time, such classic materials as cement, ceramics, adsorbents, polymers, bioplastics and biocomposites can be improved or obtained by cleaner processes. Several non-contaminating physical methods, such as microwave heating, ultrasound-assisted and hydrothermal processes or ball milling, frequently in combination with the use of natural precursors, are of major importance in the greener synthesis, as well as solventless and biosynthesis techniques. Non-hazardous solvents including ionic liquids, use of plant extracts, fungi, yeasts, bacteria and viruses are also discussed in relation with materials fabrication. Availability, necessity and profitability of scaling up green processes are discussed.

Is Beauty in the Hand of the Writer? Influences of Aesthetic Preferences through Script Directions, Cultural, and Neurological Factors: A Literature Review

Human experience surrounding the appreciation of beauty is not static. Many factors such as script direction and cultural differences directly impact whether, how and why we consider images beautiful. In an earlier study, Pérez González showed that 19th-century Iranian and Spanish professional photographers manifest lateral biases linked to reading writing direction in their compositions. The present paper aims to provide a general review on this topic and intends to highlight the most relevant studies reporting preferences in the appreciation of beauty in individuals with different reading and writing directions and belonging to different cultural backgrounds.

How directional change in reading/writing habits relates to directional change in displayed pictures

It has been suggested that reading/writing habits may influence the appreciation of pictures. For example, people who read and write in a rightward direction have an aesthetic preference for pictures that face rightward over pictures that face leftward, and vice versa. However, correlations for this phenomenon have only been found in cross-cultural studies. Will a directional change in reading/writing habits within a culture relate to changes in picture preference? Korea is a good place to research this question because the country underwent gradual changes in reading/writing direction habits, from leftward to rightward, during the 20th century. In this study, we analyzed the direction of drawings and photos published in the two oldest newspapers in Korea from 1920-2013. The results show that the direction of the drawings underwent a clear shift from the left to the right, but the direction of the photos did not change. This finding suggests a close psychological link between the habits of reading/writing and drawing that cannot be accounted for simply by an accidental correspondence across different cultures.

What Affects Facing Direction in Human Facial Profile Drawing? A Meta-Analytic Inquiry

Two meta-analyses were conducted to examine two potential sources of spatial orientation biases in human profile drawings by brain-intact individuals. The first examined profile facing direction as function of hand used to draw. The second examined profile facing direction in relation to directional scanning biases related to reading/writing habits. Results of the first meta-analysis, based on 27 study samples with 4171 participants, showed that leftward facing of profiles (from the viewer's perspective) was significantly associated with using the right hand to draw. The reading/writing direction meta-analysis, based on 10 study samples with 1552 participants, suggested a modest relationship between leftward profile facing and primary use of a left-to-right reading/writing direction. These findings suggest that biomechanical and cultural factors jointly influence hand movement preferences and in turn the direction of facing of human profile drawings.

How Culture, Age, and Manual Dominance Affect Directionality in Drawing Side View Objects

The aim of the present experiment was to investigate the extent to which the orientation of objects drawn in side view is a function of culture, age, and manual dominance. Right-handed French and Syrian children aged between 6 and 10 years and right-handed adults from the same cultural groups were asked to produce side views of faces, vehicles (car and airplane), self-centered tools with a handle (mug and toothbrush), object-centered tools with a handle (jug and hammer), and animals (dog and fish) using their dominant and nondominant hands. The French participants exhibited a leftward directional bias, whereas their Syrian counterparts displayed a rightward bias. However, no differences between the two cultural groups were observed in the 6-year-olds, who did not present any systematic directional bias in their drawings. Furthermore, regardless of culture, the children did not modify the orientation of the objects in their drawings as a function of the hand used, whereas the hand effect was strong in adults. Finally, despite their directional bias toward the right, the Syrian participants tended to draw the self- and object-centered tools facing leftward. These results are discussed with reference to the current literature on this topic.

Script Directionality Affects Depiction of Depth in Representational Drawings

This research examined the influence of directional reading/writing habits on the representation of depth in a scene. Participants with English vs. Arabic language backgrounds were asked to represent an imagined scene containing two houses, a “near house” and a “far house.” Nearly all participants drew the near house larger than the far house and drew the near house before drawing the far house. However, significant group differences in spatial strategies and movement biases were noted. Whereas the majority of native English readers drew the near house on the left side of the page and the far house to the right of it, native Arabic readers showed a slight right bias in placement of the near house and tended to place the far house to the left of the near house. This effect of script direction characterized right-handed and left-handed users of each group. Taken together, the findings support a cultural account of asymmetries in representational drawing reflecting biases arising from prolonged experience in reading and writing in a particular direction.

Lateral Biases in Aesthetic Preferences: Pictorial Dimensions and Neural Mechanisms

Observers often prefer one orientation of a stimulus over its mirror image; these lateral biases are assumed to reflect aspects of the observer's neural organisation. However, the precise dimensions of pictorial organisation that influence these preferences, as well as the underlying neural mechanisms, are not clear. The present experiments addressed these issues by employing a stimulus set allowing for a factorial combination of three dimensions of pictorial organisation: Weight, Interest, and Directionality. Experiments 1 and 2 found that subjects exhibited robust and consistent preferences for stimuli with left-to-right directionality, especially for stimuli with left-biased interest; right-biased interest eliminated the preference for left-to-right directionality. The dimension of weight had little effect. Inter-task correlations from Experiment 3 suggested that this preference for left-to-right directionality (i) reflects a stable, underlying directional bias in perceptuo-motor processing, and (ii) is not related to individual differences in hemispheric activation.

Cultural differences in drawing movements between right-handed Japanese and German participants

Differences in drawing movements with the dominant and nondominant hands by 41 right-handed students from Japan (9 men, 12 women; M age = 20.3 yr., SD = 1.4) and Germany (13 men, 7 women; M age = 23.4 yr., SD = 3.0) were investigated. Participants were asked to use each hand to draw a circle, a pentagon, and a rhombus in one stroke. Analysis showed that Japanese participants drew a circle clockwise with the dominant right hand, starting from 6 or 7 o'clock on the face of a clock, while the German participants drew the circle counterclockwise, starting from 11 or 12 o'clock. Moreover, when drawing a pentagon and a rhombus with the right hand, Japanese participants drew counterclockwise from the top-center vertex, whereas almost half of German participants drew clockwise from the left side and others drew counterclockwise from the top-center vertex. Using the left hand, no significant difference was found in starting positions or directionality. Cultural differences in the starting positions and directionality when using the dominant right hand probably reflect the influence of writing habits on the drawing movement of the dominant hand.

Measuring familial sinistrality: Problems with dichotomous classification

Familial sinistrality (FS), or familial left-handedness, is usually measured as a presence/absence dichotomy (FS+/FS-). Measuring FS as a dichotomy is problematic in at least two ways: (1) magnitude data are discarded and (2) there is an increased risk of violating statistical assumptions. We hypothesised that using a non-dichotomised FS measure would allow more sensitive statistical tests than using a dichotomised measure. The non-dichotomised measure examined was proportion of family that is left-handed, or Proportional FS (FSP). FS measures of 60 healthy adults were consistent with our hypothesis: (1) The effect size was 2.3 times larger when FSP was used than when Dichotomised FS (FSD) was used; (2) the observed relationship was statistically significant when FSP was used but not when FSD was used; and (3) statistical assumptions were violated when FSD was used but not when FSP was used. When cases were weighted to account for an increased likelihood of FS in large families, results were similar. Next, bootstrapping methods were used to estimate empirically the long-term differences in power between analyses incorporating FSP and those incorporating FSD. Using FSP was associated with long-term increases in both power and effect size of over 50% relative to using FSD. We conclude that using a proportional rather than a dichotomous measure of FS will enhance the accuracy of observed effect sizes, increase the sensitivity of statistical tests, and reduce the likelihood of violating statistical assumptions.

Impact of manual preference on directionality in children's drawings

The effects of handedness on directionality in drawing are already well documented in the literature, at least as far as adults are concerned. The present study investigates the impact of manual preference on directionality as seen in the drawing product and drawing process, from a developmental point of view. A total of 120 children aged 5 to 9, both right and left-handed drawers, volunteered for the study. Children were asked to draw twice from memory a set of six common objects. Results indicate that directionality in drawing product varies significantly according to manual preference in the 9-year-old children, but not in the younger age groups. The concomitant increase between 7 and 9 years of age in the use of preferred stroke directions and the impact of manual preference in the drawing process suggests that biomechanical factors might play an important role in behavioural asymmetries in drawing.

Orthographic directionality and thematic role illustration in English and Arabic

This study tested the hypotheses that people had a bias for drawing agents on the left of a picture when given a verb stimulus targeting an active or passive event (e.g., "kicked" or "is kicked") and that orthographic directionality would influence the way events were illustrated. Monolingual English speakers, who read and write left-to-right, and Arabic speakers, who read and write right-to-left, drew agents and patients in response to verb stimuli. We found no significant orthographic directionality effects and no preference for positioning agents on the left of pictures in either group or sentence type. Instead, participants drew agents on the right regardless of language or sentence type, and this was exaggerated in English speakers illustrating passive verbs. These findings support the existence of a preference for placing agents in the right hemispace that may result from asymmetrical hemispheric (i.e., left>right) activation induced by language processing. Our results are consistent with findings that people prefer pictures in which focus is on the right, a preference strongest in pictures with no implicit directionality of movement. This suggests that the methodology of the current study encouraged a static rather than dynamic interpretation of the verb in most participants.

Response to Taguchi and Noma on "relationship between directionality and orientation in drawings by young children and adults

When assessing the relationship between direction and orientation in drawings by young children and adults, Taguchi and Noma used a fish-drawing task. However, the fish is not convenient enough as an object for such a task so it is highly preferable to use, instead of a single object, a set of several objects to assess directionality quantitatively. These authors' conclusions do not acknowledge alternative explanations.

Cinema seating in right, mixed and left handers

Two hundred and sixty four right-handed, 246 mixed-handed and 360 left-handed students were requested to indicate on five maps of cinema halls what place they would choose. All three handedness groups showed a preference for the right and a corresponding directional bias towards the left space. However, they differed significantly from each other on the magnitude of this bias which was most pronounced in right and less in left handers. It is assumed that lateralized mechanisms underlying such biases have developed evolutionarily and serve right-handed persons best. Non-dextrality considerably reduces their phenotypic expressions, but even left-handedness does not reverse the directional bias towards the left. It is also hypothesized that right, mixed and left handers differ in a large number of behavioral choices and strategies, modeled by cerebrally lateralized mechanisms and that the cinema seating preference is only one of them.

Directionality in right, mixed and left handers

Directionality in right, mixed and left handers was studied, asking subjects to draw 6 familiar objects. All three handedness classes showed left directional bias, but they differed significantly in this respect, right handers being the most and left handers the least left directed. Directionality is related to handedness, but it seems to be governed by an autonomous underlying mechanism, which probably developed in the course of evolution to facilitate the perceptuo-motor relationships of the subject with the environment.

Relation between motor asymmetry and direction of rotational behaviour under amphetamine and apomorphine in rats with unilateral degeneration of the nigrostriatal dopamine system

The study examines whether in rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of the substantia nigra, the direction of amphetamine- and apomorphine-induced rotations is determined by a bias to step more frequently with one hindleg. Results show that there is a strong asymmetry in usage of hindlegs under apomorphine but a weak one under amphetamine. Moreover, under apomorphine, virtually all steps are backward. Under amphetamine, however, steps are directed both backward and forward, although backward steps are relatively more prevalent when striatal dopamine depletion is nearly total. The different styles of rotation reflect the activation of pure turning under apomorphine, and turning combined with forward progression under amphetamine. It is suggested that presence of forward progression during turning depends on the capacity to modulate striatal activation. Moreover, the different styles of rotation are inconsistent with the hypothesis that a bias in leg usage sets the direction of turning. Instead, it seems that unilateral striatal activation sets the directionality of turning, independent of any hindlimb motor asymmetries.

A directional bias for studies of laterality

We have shown that a directional bias (D), previously thought to be unrelated to cerebral lateralization, is, in fact, intimately associated with it. In a group of fully consistent dextrals without familial sinistrality, the direction of lateral asymmetries depended upon the direction of D. Left-directed dextrals manifested the usual visual field advantages for linguistic and spatial material, while right-directed dextrals did not. D is therefore recommended as moderator variable for future studies of laterality.