scholarly journals No Evidence of Perceptual Pseudoneglect in Alexithymia

2021 ◽  
Vol 11 (3) ◽  
pp. 376
Author(s):  
Carmelo Mario Vicario ◽  
Gabriella Martino ◽  
Alex Marcuzzo ◽  
Giuseppe Craparo

Neuroscience research links alexithymia, the difficulty in identifying and describing feelings and emotions, with left hemisphere dominance and/or right hemisphere deficit. To provide behavioral evidence for this neuroscientific hypothesis, we explored the relationship between alexithymia and performance in a line bisection task, a standard method for evaluating visuospatial processing in relation to right hemisphere functioning. We enrolled 222 healthy participants who completed a version of the 20-item Toronto Alexithymia Scale (TAS-20), which measures alexithymia, and were asked to mark (bisect) the center of a 10-cm horizontal segment. The results document a significant rightward shift in the center of the line in participants with borderline and manifest alexithymia compared with non-alexithymic individuals. The higher the TAS-20 score, the greater the rightward shift in the line bisection task. This finding supports the right hemisphere deficit hypothesis in alexithymia and suggests that visuospatial abnormalities may be an important component of this mental condition.

Author(s):  
Carmelo Mario Vicario ◽  
Gabriella Martino ◽  
Alex Marcuzzo ◽  
Giuseppe Craparo

The research in neuroscience links alexithymia, the difficulty of identifying and describing feelings and emotions, with a left hemisphere preference and/or a right hemisphere deficit. To provide a neuropsychological support to this finding, we explored the relationship between alexithymia and the performance in a line bisection task, a standard method to evaluate spatial attention in relation with the functioning of the right hemisphere. 222 healthy participants completed a version of the TAS-20 scale, which measures alexithymia, and were asked to mark (bisect) the center of a 10 cm horizontal segment. The results document a significant rightward shift of the line center in borderline and manifest alexithymic participants, as compared to non-alexithymic individuals. Moreover, the higher the TAS-20 score the greater the rightward shift in the line bisection task. This result supports the right-hemisphere deficit hypothesis in alexithymia and suggests that visuospatial abnormalities may be an inner component of their profile.


2018 ◽  
Vol 71 (11) ◽  
pp. 2325-2333 ◽  
Author(s):  
Zaira Cattaneo ◽  
Luca Rinaldi ◽  
Carlo Geraci ◽  
Carlo Cecchetto ◽  
Costanza Papagno

In this study, we investigated whether auditory deprivation leads to a more balanced bilateral control of spatial attention in the haptic space. We tested four groups of participants: early deaf, early blind, deafblind, and control (normally hearing and sighted) participants. Using a haptic line bisection task, we found that while normally hearing individuals (even when blind) showed a significant tendency to bisect to the left of the veridical midpoint (i.e., pseudoneglect), deaf individuals did not show any significant directional bias. This was the case of both deaf signers and non-signers, in line with prior findings obtained using a visual line bisection task. Interestingly, deafblind individuals also erred significantly to the left, resembling the pattern of early blind and control participants. Overall, these data critically suggest that deafness induces changes in the hemispheric asymmetry subtending the orientation of spatial attention also in the haptic modality. Moreover, our findings indicate that what counterbalances the right-hemisphere dominance in the control of spatial attention is not the lack of auditory input per se, nor sign language use, but rather the heavier reliance on visual experience induced by early auditory deprivation.


Author(s):  
Gemma Learmonth ◽  
Marietta Papadatou-Pastou

AbstractYoung adults exhibit a small asymmetry of visuospatial attention that favours the left side of space relative to the right (pseudoneglect). However, it remains unclear whether this leftward bias is maintained, eliminated or shifted rightward in older age. Here we present two meta-analyses that aimed to identify whether adults aged ≥50 years old display a group-level spatial attention bias, as indexed by the line bisection and the landmark tasks. A total of 69 datasets from 65 studies, involving 1654 participants, were analysed. In the meta-analysis of the line bisection task (n = 63), no bias was identified for studies where the mean age was ≥50, but there was a clear leftward bias in a subset where all individual participants were aged ≥50. There was no moderating effect of the participant’s age or sex, line length, line position, nor the presence of left or right cues. There was a small publication bias in favour of reporting rightward biases. Of note, biases were slightly more leftward in studies where participants had been recruited as part of a stand-alone older group, compared to studies where participants were recruited as controls for a clinical study. Similarly, no spatial bias was observed in the meta-analysis of the landmark task, although the number of studies included was small (n = 6). Overall, these results indicate that over 50s maintain a group-level leftward bias on the line bisection task, but more studies are needed to determine whether this bias can be modulated by stimulus- or state-dependent factors.


2000 ◽  
Vol 12 (3) ◽  
pp. 415-420 ◽  
Author(s):  
Anna Berti ◽  
Francesca Frassinetti

Far (extrapersonal) and near (peripersonal) spaces are behaviorally defined as the space outside the hand-reaching distance and the space within the hand-reaching distance. Animal and human studies have confirmed this distinction, showing that space is not homogeneously represented in the brain. In this paper we demonstrate that the coding of space as “far” and “near” is not only determined by the hand-reaching distance, but it is also dependent on how the brain represents the extension of the body space. We will show that when the cerebral representation of body space is extended to include objects or tools used by the subject, space previously mapped as far can be remapped as near. Patient P.P., after a right hemisphere stroke, showed a dissociation between near and far spaces in the manifestation of neglect. Indeed, in a line bisection task, neglect was apparent in near space, but not in far space when bisection in the far space was performed with a projection lightpen. However, when in the far space bisection was performed with a stick, used by the patient to reach the line, neglect appeared and was as severe as neglect in the near space. An artificial extension of the patient's body (the stick) caused a remapping of far space as near space.


2021 ◽  
Author(s):  
Gemma Learmonth ◽  
Marietta Papadatou-Pastou

Young adults exhibit a small asymmetry of visuospatial attention that favours the left side of space relative to the right (pseudoneglect). However, it remains unclear whether this leftward bias is maintained, eliminated or shifted rightward in older age. Here we present two meta-analyses that aimed to identify whether adults aged ≥50 years old display a group-level spatial attention bias, as indexed by the line bisection and the landmark tasks. A total of 69 datasets from 65 studies, involving 1654 participants, were analysed. In the meta-analysis of the line bisection task (n = 63), no bias was identified for studies where the mean age was ≥50, but there was a clear leftward bias in a subset where all individual participants were aged ≥50. There was no moderating effect of the participant’s age or sex, line length, line position, nor the presence of left or right cues. There was a small publication bias in favour of reporting rightward biases. Of note, biases were slightly more leftward in studies where participants had been recruited as part of a stand-alone older group, compared to studies where participants were recruited as controls for a clinical study. Similarly, no spatial bias was observed in the meta-analysis of the landmark task, although the number of studies included was small (n = 6). Overall, these results indicate that over 50s maintain a group-level leftward bias on the line bisection task, but more studies are needed to determine whether this bias can be modulated by stimulus- and/or state-dependent factors.


2020 ◽  
Vol 33 (4-5) ◽  
pp. 549-567 ◽  
Author(s):  
Andrea Ciricugno ◽  
Luca Rinaldi ◽  
Tomaso Vecchi ◽  
Lotfi B. Merabet ◽  
Zaira Cattaneo

Abstract Prior studies have shown that strabismic amblyopes do not exhibit pseudoneglect in visual line bisection, suggesting that the right-hemisphere dominance in the control of spatial attention may depend on a normally developing binocular vision. In this study, we aimed to investigate whether an abnormal binocular childhood experience also affects spatial attention in the haptic modality, thus reflecting a supramodal effect. To this aim, we compared the performance of normally sighted, strabismic and early monocular blind participants in a visual and a haptic line bisection task. In visual line bisection, strabismic individuals tended to err to the right of the veridical midpoint, in contrast with normally sighted participants who showed pseudoneglect. Monocular blind participants exhibited high variability in their visual performance, with a tendency to bisect toward the direction of the functioning eye. In turn, in haptic bisection, all participants consistently erred towards the left of the veridical midpoint. Taken together, our findings support the view that pseudoneglect in the visual and haptic modality relies on different functional and neural mechanisms.


2020 ◽  
Vol 79 (1) ◽  
pp. 5-14
Author(s):  
Giulia Pugnaghi ◽  
Robert Schnuerch ◽  
Henning Gibbons ◽  
Daniel Memmert ◽  
Carina Kreitz

Abstract. The two hemispheres of the human brain are asymmetrically involved in representing a person’s motivational orientation: Approach motivation is reflected in greater activation of the left hemisphere, whereas avoidance motivation more strongly activates the right hemisphere. Visuospatial bias, as assessed in the line-bisection task, is often used as a simple behavioral measure of relative hemispheric activation. In three experiments, we investigated whether affect-induced approach and avoidance motivation are associated with spatial biases in line-bisection performance. Happy or terrifying pictures (Experiment 1, N = 70), happy or sad music (Experiment 2, N = 50), and joyful or frightening videos (Experiment 3, N = 90) were used to induce negative and positive affect. Mood-induction procedures successfully changed emotional states in the intended direction. However, our analyses revealed no effect of mood on visuospatial biases in the line-bisection task. Additional Bayesian analyses also provided more evidence against the hypothesized effect than in favor of it. Thus, visuospatial bias in line bisection does not seem to be a sensitive measure of approach and avoidance motivation induced by positive and negative affect.


2021 ◽  
Author(s):  
Danishta Kaul ◽  
Marietta Papadatou-Pastou ◽  
Gemma Learmonth

Young adults exhibit a subtle, group-level asymmetry of lateral spatial attention favouring the left hemispace over the right (pseudoneglect). We have recently shown that leftward biases are maintained in older adults aged ≥50 when measured using the line bisection task (Learmonth and Papadatou-Pastou 2021). Here we present a meta-analysis of spatial biases in children aged ≤16 years. Databases (PsycINFO, Web of Science, and Scopus) and pre-print servers (bioRxiv, medRxiv, and PsyArXiv) were searched up to 8th March 2021 for studies involving children aged ≤16, who were tested using the line bisection or landmark task, and who had not been recruited as an atypically developing group. Thirty-six datasets from 33 studies, involving 2515 children, were included. A small leftward bias was identified overall (Cohen’s d = -.18, 95% CI = -.36, -.01). No spatial bias was identified when the 33 line bisection studies were analysed separately (d = -.16, 95% CI = -.35, .04). Moderator analysis of the line bisection task found a strong influence of the hand that was used to bisect the line, with right-handed actions resulting in right-biased bisections, and left-handed actions in left-biased bisections (symmetrical neglect). Bisections were slightly more leftward in studies that included a higher percentage of boys relative to girls. Age, hand preference, and the control group status of the children did not moderate spatial biases and we found no evidence of small study publication bias. However, the number of studies included in each moderator analysis was small. This meta-analysis confirms that pseudoneglect is present in children, but its detection is dependent on the task that is used.


1996 ◽  
Vol 2 (5) ◽  
pp. 412-418 ◽  
Author(s):  
John C. Marshall ◽  
Peter W. Halligan

AbstractWe report a case of severe visuo-spatial neglect consequent upon right-hemisphere stroke. At the time of testing, the patient had no visual field cut and no significant hemiparesis. Conventional testing on cancellation tasks with the right hand revealed reliable left neglect, but performance was significantly improved when the left hand was used. Investigations of (manual) line bisection showed normal performance with the right hand but right neglect when the left hand was used. Right neglect was also observed on a purely perceptual version of the line bisection task. We argue that the attentional vectors of the cerebral hemispheres can be modulated by (perceptual) task-demands and by (motorie) response demands. (JINS, 1996, 2, 412–418.)


2020 ◽  
Author(s):  
Daniel Wiesen ◽  
Hans-Otto Karnath ◽  
Christoph Sperber

AbstractLine Bisection is a simple task frequently used in stroke patients to diagnose disorders of spatial perception characterized by a directional bisection bias to the ipsilesional side. However, previous anatomical and behavioural findings are contradictory, and the diagnostic validity of the line bisection task has been challenged. We hereby aimed to re-analyse the anatomical basis of pathological line bisection by using multivariate lesion-symptom mapping and disconnection-symptom mapping based on support vector regression in a sample of 163 right hemispheric acute stroke patients. In line with some previous studies, we observed that pathological line bisection was related to more than a single focal lesion location. Cortical damage primarily to right parietal areas, particularly the inferior parietal lobe, including the angular gyrus, as well as damage to the right basal ganglia contributed to the pathology. In contrast to some previous studies, an involvement of frontal cortical brain areas in the line bisection task was not observed. Subcortically, damage to the right superior longitudinal fasciculus (I, II and III) and arcuate fasciculus as well as the internal capsule was associated with line bisection errors. Moreover, white matter damage of interhemispheric fibre bundles, such as the anterior commissure and posterior parts of the corpus callosum projecting into the left hemisphere, was predictive of pathological deviation in the line bisection task.


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