Laterality最新文献

The behavioural outcomes associated with atypical cerebral lateralization during the early stages of cognitive development is an interesting research venture. However, there are few tasks for assessing lateralization in young children. The current study describes the Magic Hat task and the Teddy Bear Picnic task, which were designed to measure the lateralization of language and visuospatial attention, respectively, in children as young as three years old. Forty-five adults were recruited to complete the child-friendly tasks as well as the Word Generation and Landmark tasks whilst functional Transcranial Doppler ultrasound (fTCD) measured cerebral blood flow velocity. As expected, at the group level, the Magic Hat task produced left hemisphere lateralization, and the Teddy Bear Picnic task produced right hemisphere lateralization. Both tasks demonstrated high internal reliability (α > .80). The laterality indices produced by the Magic Hat task correlated with the Word Generation task, ρ = .52, p = .001. Likewise, the laterality indices produced by the Teddy Bear Picnic task correlated with the Landmark task, ρ = .45, p = .028. Thus, the Magic Hat and Teddy Bear Picnic tasks are reliable and valid measures of language and visuospatial lateralization, suitable for toddlers and young children using fTCD.

This study examines patterns of ear advantage and attentional capacity among religious teachers of the Ethiopian Orthodox Church versus adults who are not religious teachers. Religious education, rooted mainly in Christianity and Islam, has a long history in Ethiopia. Most of such education has been practised through recitations and oral presentations, which demand perceptual vigour particularly on the part of the teachers. The present study employed a dichotic listening paradigm, using monosyllabic word and CV-syllables listening tasks, administered in three attentional conditions: non-forced (NF), forced-right (FR) and forced-left (FL). 54 right-handed male adults (27 teachers and 27 non-teachers) served as participants. Percentages of correct responses per ear, as well as Laterality Index (LI) were calculated and analysed using a repeated measures analysis of variance (ANOVA) statistical procedure. Results showed that, on both listening tasks, the religious teachers demonstrated a higher ear advantage in all conditions, indicative of stronger language asymmetry (in non-forced condition) and better ability to focus on one specific ear (in forced conditions). The findings of the present study are very much in support of the theory of neuroplasticity in human cognition (Konorski, 1948).

Spatial processing deficits are the reason for many daily life problems of schizophrenia (SCZ) patients. In this study, we aimed to examine the possibility of abnormal bias to one hemifield, in form of hemispatial neglect and extinction, in auditory modality in SCZ. Twenty-five SCZ patients and 25 healthy individuals were compared on speech tasks to study the auditory neglect and extinction, as well as an auditory localization task for studying neglect. In the speech tasks, participants reproduced some nonsense syllables, played from one or two speakers on the right and/or left sides. On the localization task, examinees discriminated the subjective location of the noise stimuli presented randomly from five speakers. On the speech task, patients had significantly lower hit rates for the right ear compared with controls (p = 0.01). While healthy controls showed right ear advantage, SCZs showed a left ear priority. In the localization task, although both groups had a left-side bias, this bias was much more prominent for the patients (all p < 0.05). SCZ could potentially alter the auditory spatial function, which may appear in the form of auditory neglect and extinction on the right side, depending on the characteristics of patient population.

Background: While right-left hemispheric valence dichotomies have been demosntrated in various lesion stidues, it not entirely known if these dichotomies are portrayed in art. Methods: We examined 192 paintings to learn if there is an association between paintings that portray happy-positive or sad-negative scenes and the agent looking to the right or left side relative to their head's midsagittal plane. Results: There were 38 paintings with a positive valence and 32 with a negative valence in which the eyes were turned rightward or leftward. Of 38 positive valence paintings, 28 had the agent looking rightward, and 10 looking leftward. Of 32 negative valence paintings, 15 had the agent looking rightward and 17 leftward. Discussion: Hemisphere activation is associated with contralateral deviation of the eyes. Whereas the right hemisphere mediates negative emotions allocates spatial attention to both left and right hemispace, the left hemisphere primarily allocates attention to the right. Since the left hemisphere appears to mediate positive emotions and the right hemisphere negative emotions, results from this study are consistent with hemispheric emotional valence attentional hypotheses. However, the relationship between artist knowledge about gaze and the utilization of gaze direction to portray emotional experiences is not known.

Lateralization of hand use in primates has been extensively studied in a variety of contexts, and starts to be investigated in other species and organs in order to understand the evolution of the laterality according to different tasks. In elephants, the orientation of the movements of the trunk has been observed mainly in feeding and social contexts, in free conditions. However, little is known about the influence of task complexity on trunk laterality. In this study, we compared the lateralization of the trunk in two conditions: standardized and free. We offered granules to six African elephants on each side of an opened trapdoor to create a constraining environment and reported the different behaviours employed and their orientation. In addition, we observed the same individuals in free conditions and noted the lateralization of the use of their trunk. We revealed a common right side preference in all our elephants, both in standardized and free conditions. This side bias was stronger in our constraining task, adding evidence for the task complexity theory. We finally described laterality in new behaviours in the literature on elephants, such as pinching, gathering or exploration with the trunk.

People tend to show the left cheek to broadly express emotions while they tend to show the right cheek to hide emotions because emotions were expressed more on the left than on the right side of the face. The present study investigated the level of awareness on the left- and right-cheek poses using the method of structural knowledge attributions. When asked to broadly express emotions for a family portrait, right-handed participants were more likely to show the left cheek than the right. On the other hand, when asked to conceal emotions to show a calm and reassuring attitude as a scientist, they were more likely to show the right cheek. After the posing session, participants selected the conscious level of their knowledge about posing from five categories: Random, intuition, familiarity, recollection, and rules. Most participants rated their knowledge as unconscious (i.e., either as random, intuition, or familiarity). The choice of the conscious level did not differ across posing orientations and posing instructions. These results suggest that although people do not have an acute awareness of their lateral posing preference, they reliably show one side of their faces to express or hide emotions.

The onset of motor symptoms in Parkinson disease (PD) is typically unilateral. Previous work has suggested that laterality of motor symptoms may also influence non-motor symptoms including cognition and emotion perception. In line with hemispheric differences in emotion processing, we tested whether left side/right brain motor onset was associated with worse expression of facial affect when compared to right side/left brain motor onset. We evaluated movement changes associated with facial affect in 30 patients with idiopathic PD (15 left-sided motor onset, 15 right-sided motor onset) and 20 healthy controls. Participants were videotaped while posing three facial expressions: fear, anger, and happiness. Expressions were digitized and analyzed using software that extracted three variables: two measures of dynamic movement change (total entropy and entropy percent change) and a measure of time to initiate facial expression (latency). The groups did not differ in overall amount of movement change or percentchange. However, left-sided onset PD patients were significantly slower in initiating anger and happiness facial expressions than were right-sided onset PD patients and controls. Our results indicated PD patients with left-sided symptom onset had greater latency in initiating two of three facial expressions, which may reflect laterality effects in intentional behaviour.

Brain lateralization is generally considered adaptive for an individual and it can be ascertained, for example, by measuring the preferential use of limbs. Avian models have been extensively used to investigate the evolution and the advantages of brain lateralization. Birds of prey are a good model to study motor laterality, however to date they have been studied almost exclusively in the context of predatory behaviour. In this study, we tested lateralization in Gyrfalcon (Falco rusticolus) across multiple contexts, and collected the following measures:(1) standing leg preference when sleeping, (2) wing preference to position the head while sleeping and (3) leg preference to grasp food. At the population level, we found left-leg lateralization while sleeping and no preference for placing the head under the left or the right wing. In the context of the predatory behaviour, we found a trend towards using the left leg to grasp food. Across the behaviours observed, we did not find evidence of lateralization at an individual level, as most of the subjects were ambidextrous. This study highlights the importance of the behavioural context when investigating side-bias and hemispheric laterality.

This study investigated the validity and reliability of Turkish versions of the Waterloo Handedness and Footedness Questionnaire-Revised (WHQ-R and WFQ-R). Turkish versions of the WHQ-R and the WFQ-R, and other assessments (the Handedness Questionnaire and the Footedness Preference Test) were applied to 444 healthy participants aged between 18 and 65 years. The translation and cultural adaptation process of the WHQ-R and the WFQ-R was provided by the following proposed guideline. For test-retest reliability, translated versions were re-applied to 88 participants in a 7-day interval. Cronbach's alpha of the WHQ-R was 0.984 and that of the WFQ was 0.905. The test-retest intra-class correlation coefficients (ICC) of the WHQ-R varied from 0.741 to 0.933 and those of the WFQ-R from 0.649 to 0.814. There were moderate to strong correlations between the WHQ-R and the Handedness Questionnaire (r = -853, p < 0.001) and between the WFQ-R and the Footedness Preference Test (r = -0.687, p < 0.001). Confirmatory factor analysis revealed a two-factor structure of the WHQ-R and the WFQ-R. The results of this study demonstrated that Turkish versions of the WHQ-R and the WFQ-R are reliable and valid inventories for assessing handedness and footedness in this population.