Small numbers in the right brain: Evidence from patients without and with spatial neglect

Background and Purpose: Delirium, an acute reduction in cognitive functioning, hinders stroke recovery and contributes to cognitive decline. Right-hemisphere stroke is linked with higher delirium incidence, likely, due to the prevalence of spatial neglect (SN), a right-brain disorder of spatial processing. This study tested if symptoms of delirium and SN after right-hemisphere stroke are associated with abnormal function of the right-dominant neural networks specialized for maintaining attention, orientation, and arousal. Methods: Twenty-nine participants with right-hemisphere ischemic stroke undergoing acute rehabilitation completed delirium and SN assessments and functional neuroimaging scans. Whole-brain functional connectivity of 4 right-hemisphere seed regions in the cortical-subcortical arousal and attention networks was assessed for its relationship to validated SN and delirium severity measures. Results: Of 29 patients, 6 (21%) met the diagnostic criteria for delirium and 16 (55%) for SN. Decreased connectivity of the right basal forebrain to brain stem and basal ganglia predicted more severe SN. Increased connectivity of the arousal and attention network regions with the parietal, frontal, and temporal structures in the unaffected hemisphere was also found in more severe delirium and SN. Conclusions: Delirium and SN are associated with decreased arousal network activity and an imbalance of cortico-subcortical hemispheric connectivity. Better understanding of neural correlates of poststroke delirium and SN will lead to improved neuroscience-based treatment development for these disorders.

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Orientation and lateralized cue use in pigeons navigating a large indoor environment

Journal of Experimental Biology ◽

10.1242/jeb.205.12.1795 ◽

2002 ◽

Vol 205 (12) ◽

pp. 1795-1805 ◽

Cited By ~ 1

Author(s):

Helmut Prior ◽

Frank Lingenauber ◽

Jörg Nitschke ◽

Onur Güntürkün

Keyword(s):

Reference Frame ◽

Brain Lateralization ◽

Spatial Cues ◽

Brain Hemisphere ◽

Brain Hemispheres ◽

Left Brain ◽

Right Brain ◽

Starting Location ◽

The Right ◽

Global Reference Frame

SUMMARY The pigeon's use of different visuo-spatial cues was studied under controlled laboratory conditions that simulated analogous aspects of a homing situation. The birds first learned the route to a goal that was not visible from the starting location, but became visible as it was approached. Birds could orientate within a mainly geometric global reference frame, using prominent landmarks within their range, or by `piloting' along local cues. After learning the route, the birds were tested from familiar and unfamiliar release points, and several aspects of the available cues were varied systematically. The study explored the contribution of the left and right brain hemispheres by performing tests with the right or left eye occluded. The results show that pigeons can establish accurate bearings towards a non-visible goal by using a global reference frame only. Furthermore, there was a peak of searching activity at the location predicted by the global reference frame. Search at this location and directedness of the bearings were equally high with both right and left eye, suggesting that both brain hemispheres have the same competence level for these components of the task. A lateralization effect occurred when prominent landmarks were removed or translated. While the right brain hemisphere completely ignored such changes,the left brain hemisphere was distracted by removal of landmarks. After translation of landmarks, the left but not the right brain hemisphere allocated part of the searching activity to the site predicted by the new landmark position. The results show that a mainly geometric global visual reference frame is sufficient to determine exact bearings from familiar and unfamiliar release points. Overall, the results suggest a model of brain lateralization with a well-developed global spatial reference system in either hemisphere and an extra capacity for the processing of object features in the left brain.

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Ventral attention and motor network connectivity is relevant to functional impairment in spatial neglect after right brain stroke

Brain and Cognition ◽

10.1016/j.bandc.2018.11.013 ◽

2019 ◽

Vol 129 ◽

pp. 16-24 ◽

Cited By ~ 6

Author(s):

A.M. Barrett ◽

Olga Boukrina ◽

Soha Saleh

Keyword(s):

Functional Impairment ◽

Network Connectivity ◽

Spatial Neglect ◽

Right Brain ◽

Motor Network ◽

Brain Stroke

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Asymmetrical Attention to Gambling-related Stimuli and Pupillary Dilation in Response to Wins and Losses in Problem Gamblers

10.21203/rs.3.rs-1080574/v1 ◽

2021 ◽

Author(s):

Yayoi Shigemune ◽

Akira Midorikawa

Keyword(s):

Gambling Behavior ◽

Spatial Neglect ◽

Pupillary Dilation ◽

Left Hand ◽

Problem Gamblers ◽

Monetary Rewards ◽

Pupillary Responses ◽

Problematic Gambling ◽

The Right ◽

To Receive

Abstract Gambling disorder and problem gambling are characterized by persistent and repetitive problematic gambling behavior. Attentional bias toward gambling-related stimuli such as casino chips, dice, roulette, etc. have been observed in problem gamblers (PGs), but it remains unclear whether stimuli in gambling tasks elicit greater attention and pupillary responses in PGs. To address this issue, we administrated PGs and non-problem gamblers (NPGs) a gambling task accompanied by eye-tracking measurements, in which the participants were required to choose one of the paired pictures to receive monetary rewards and avoid punishments. Concerning attentional allocation, PG showed a greater attentional preference for the right-hand pictures in the decision and feedback phases, and compared to NPGs, PGs’ attention was narrower and more focused on the left-hand pictures in the decision phase. Concerning pupillary dynamics indicative of noradrenergic locus coeruleus activity, pupillary dilation in response to rewards and punishments was observed only in PGs. Studies of unilateral spatial neglect have proposed that asymmetric attention is induced by hemispheric imbalance. Accordingly, asymmetrical allocation of attention by PGs may reflect hemispheric imbalance, and pupillary dynamics may reflect sensitivity to wins and losses.

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Experience of The Rehabilitation for Sign Language Aphasia due to The Damage of The Right Brain in A Left-handed Deaf Japanese Signer

Higher Brain Function Research ◽

10.2496/hbfr.40.393 ◽

2020 ◽

Vol 40 (3) ◽

pp. 393-398

Author(s):

Miwa Honda ◽

Yoshihiro Kushihashi ◽

Hirokazu Kawano ◽

Masako Hayashida ◽

Megumi Shimodozono

Keyword(s):

Sign Language ◽

Left Handed ◽

Right Brain ◽

The Right

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Dysregulation of the Right Brain: A Fundamental Mechanism of Traumatic Attachment and the Psychopathogenesis of Posttraumatic Stress Disorder

Australian & New Zealand Journal of Psychiatry ◽

10.1046/j.1440-1614.2002.00996.x ◽

2002 ◽

Vol 36 (1) ◽

pp. 9-30 ◽

Cited By ~ 242

Author(s):

Allan N Schore

Keyword(s):

Posttraumatic Stress Disorder ◽

Posttraumatic Stress ◽

Stress Disorder ◽

Developmental Trajectory ◽

Stress Disorders ◽

Developmental Stress ◽

Posttraumatic Stress Disorders ◽

Autonomic Nervous ◽

Right Brain ◽

The Right

Objective: This review integrates recent advances in attachment theory, affective neuroscience, developmental stress research, and infant psychiatry in order to delineate the developmental precursors of posttraumatic stress disorder. Method: Existing attachment, stress physiology, trauma, and neuroscience literatures were collected using Index Medicus/Medline and Psychological Abstracts. This converging interdisciplinary data was used as a theoretical base for modelling the effects of early relational trauma on the developing central and autonomic nervous system activities that drive attachment functions. Results: Current trends that integrate neuropsychiatry, infant psychiatry, and clinical psychiatry are generating more powerful models of the early genesis of a predisposition to psychiatric disorders, including PTSD. Data are presented which suggest that traumatic attachments, expressed in episodes of hyperarousal and dissociation, are imprinted into the developing limbic and autonomic nervous systems of the early maturing right brain. These enduring structural changes lead to the inefficient stress coping mechanisms that lie at the core of infant, child, and adult posttraumatic stress disorders. Conclusions: Disorganised-disoriented insecure attachment, a pattern common in infants abused in the first 2 years of life, is psychologically manifest as an inability to generate a coherent strategy for coping with relational stress. Early abuse negatively impacts the developmental trajectory of the right brain, dominant for attachment, affect regulation, and stress modulation, thereby setting a template for the coping deficits of both mind and body that characterise PTSD symptomatology. These data suggest that early intervention programs can significantly alter the intergenerational transmission of posttraumatic stress disorders.

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