Investigating multidimensionality of language lateralisation in left and right handed adults: an update on Woodhead et al. 2019

2020 ◽  
Author(s):  
Zoe Victoria Joan Woodhead ◽  
Paul Andrew Thompson ◽  
Emma Karlsson ◽  
Dorothy Vera Margaret Bishop

A previous study we reported in this journal suggested that left and right handers may differ in their patterns of lateralisation for different language tasks. However, it had too few left handers (N=7) to reach any conclusions. For this update paper, further participants were added to the sample to create separate groups of left (N=31) and right handers (N=43). Two hypotheses were tested: 1) that lateralisation would be weaker at the group level in left than right handers; and 2) that left handers would show weaker covariance in lateralisation between tasks, supporting a two factor model.All participants performed the same protocol as in our previous paper: lateralisation was measured using functional transcranial Doppler sonography during six different language tasks, on two separate testing sessions. The results supported hypothesis 1, with significant differences in laterality between groups for four out of six tasks. For hypothesis 2, structural equation modelling showed that there was stronger evidence for a two factor model in left than right handers; furthermore, examination of the factor loadings suggested that the pattern of laterality across tasks may also differ between handedness groups. These results expand on what is known about the differences in laterality between left and right handers.

2021 ◽  
Vol 8 (2) ◽  
pp. 200696
Author(s):  
Z. V. J. Woodhead ◽  
P. A. Thompson ◽  
E. M. Karlsson ◽  
D. V. M. Bishop

A previous study we reported in this journal suggested that left and right-handers may differ in their patterns of lateralization for different language tasks (Woodhead et al. 2019 R. Soc. Open Sci. 6 , 181801. ( doi:10.1098/rsos.181801 )). However, it had too few left-handers ( N = 7) to reach firm conclusions. For this update paper, further participants were added to the sample to create separate groups of left- ( N = 31) and right-handers ( N = 43). Two hypotheses were tested: (1) that lateralization would be weaker at the group level in left-than right-handers; and (2) that left-handers would show weaker covariance in lateralization between tasks, supporting a two-factor model. All participants performed the same protocol as in our previous paper: lateralization was measured using functional transcranial Doppler sonography during six different language tasks, on two separate testing sessions. The results supported hypothesis 1, with significant differences in laterality between groups for four out of six tasks. For hypothesis 2, structural equation modelling showed that there was stronger evidence for a two-factor model in left than right-handers; furthermore, examination of the factor loadings suggested that the pattern of laterality across tasks may also differ between handedness groups. These results expand on what is known about the differences in laterality between left- and right-handers.


2018 ◽  
Author(s):  
ZVJ Woodhead ◽  
AR Bradshaw ◽  
AC Wilson ◽  
PA Thompson ◽  
DVM Bishop

AbstractCerebral lateralisation for language can vary from task to task, but it is unclear if this reflects error of measurement or independent lateralisation of different language systems. We used functional transcranial Doppler sonography to assess language lateralisation in 37 adults (7 left-handers) on six tasks, each given on two occasions. Tasks taxed different aspects of language function. A preregistered structural equation analysis was used to compare models of means and covariances. For most people, a single lateralised factor explained most of the covariance between tasks. A minority, however, showed dissociation of asymmetry, giving a second factor. This was mostly derived from a receptive task, which was highly reliable but not lateralised. The results suggest that variation in strength of language lateralisation reflects true individual differences and not just error of measurement. Inclusion of several tasks in a laterality battery makes it easier to detect cases of atypical asymmetry.


2019 ◽  
Vol 6 (3) ◽  
pp. 181801 ◽  
Author(s):  
Z. V. J. Woodhead ◽  
A. R. Bradshaw ◽  
A. C. Wilson ◽  
P. A. Thompson ◽  
D. V. M. Bishop

Hemispheric dominance for language can vary from task to task, but it is unclear if this reflects error of measurement or independent lateralization of different language systems. We used functional transcranial Doppler sonography to assess language lateralization within the middle cerebral artery territory in 37 adults (seven left-handers) on six tasks, each given on two occasions. Tasks taxed different aspects of language function. A pre-registered structural equation analysis was used to compare models of means and covariances. For most people, a single lateralized factor explained most of the covariance between tasks. A minority, however, showed dissociation of asymmetry, giving a second factor. This was mostly derived from a receptive task, which was highly reliable but not lateralized. The results suggest that variation in the strength of language lateralization reflects true individual differences and not just error of measurement. The inclusion of several tasks in a laterality battery makes it easier to detect cases of atypical asymmetry.


2016 ◽  
Vol 33 (S1) ◽  
pp. S107-S107 ◽  
Author(s):  
D. Schuepbach ◽  
S. Egger ◽  
S.C. Herpertz

IntroductionSchizophrenia is a severe mental disorder, with complex symptoms involving psychosis, negative symptoms and cognitive impairment. The Trail Making Test (TMT) has been widely used to assess attention and executive function. Functional transcranial Doppler sonography (fTCD) of basal cerebral arteries allows monitoring of aberrant cerebral hemodynamics during cognitive tasks in this patient group.ObjectivesWe assessed cerebral hemodynamics in the middle cerebral arteries (MCA) using fTCD while patients with schizophrenia and healthy subjects performed the TMT and a control task.MethodsFifteen patients with chronic schizophrenia and 15 healthy controls performed the TMT-A and -B during fTCD measurements of the MCA. Dependent measures were performance, mean cerebral blood flow velocity (MFV) and the lateralization.ResultsPatients demonstrated an overall decreased speed of solution (P = 0.002), and there was no significant effect of age. They showed a significantly increased flow pattern for the TMT-B (P = 0.005). There were no lateralization differences between diagnostic groups.ConclusionsThere was a performance deficit in patients with schizophrenia for both TMT-A and -B that fits well with results of existing literature. The aberrant hemodynamic response supports the idea that cognitive performance elicits an aberrant cerebral hemodynamic correlate. It adds to the notion that fTCD is a valuable tool to correlate psychological paradigms with brain perfusion in patients with schizophrenia.Disclosure of interestThe authors have not supplied their declaration of competing interest.


2021 ◽  
Vol 65 (1) ◽  
pp. 86-100
Author(s):  
Vít Gabrhel ◽  
◽  
Stanislav Ježek ◽  
Petr Zámečník

Objectives. This study attempts to introduce the Driving Locus of Control (DLoC), a method focused on the internal or external source of attribution of the driving behaviour, to the Czech context. This study also relates DLoC to attitudes towards autonomous vehicles (AVs). Participants and setting. Out of the general population, 59 inquirers personally interviewed (CAPI) 1 065 respondents (49% women) in the age range between 15 and 92 years (M = 50, SD = 17). The respondents were sampled via multistage random sampling procedure, based on the list of addresses in the Czech Republic. Hypotheses. The authors hypothesised to replicate the original two-factor structure of the DLoC Scale and that the higher levels of internal DLoC result in not considering the improvement in traffic safety as the AVs replace human drivers. Statistical analysis. Confirmatory factor analysis was used to analyse the factor structure of DLoC Scale. Hypotheses related to the empirical validity of the method were assessed via structural equation modelling. The reliability of DLoC Scale was calculated in terms of internal consistency (McDonald coefficient). Results. Confirmatory factor analysis revealed reasonably good support for structural validity of the one-dimensional DLoC-CZ15 factor model (χ2 = 426.967, df = 90, CFI = 0.964, TLI = 0.958, SRMR = 0.066, RMSEA = 0.065). In addition, the one-dimensional DLoC-CZ15 factor model showed acceptable internal consistency - ω = 0.9 (95% CI [0.89, 0.91]). The structural equation modelling found a relationship between DLoC and some of the items capturing attitudes towards AVs, too. Study limitations. The analysed data were obtained via interviews between respondents and inquirers. As a result, the study does not contain indicators of empirical validity measured by a methodologically different approach, such as an observation of driving behaviour.


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