A Systematic Review on the Interaction between Emotion and Pseudoneglect

Background: A large body of research has shown brain asymmetries in spatial attention. Specifically, there is an attention-processing advantage for the left visual field in healthy, right-handed subjects, known as “pseudoneglect.” Several studies have revealed that emotions modulate this basic spatial phenomenon, but the direction of the effect is still unclear. Here we systematically review empirical evidence on the behavioral effects of emotion on pseudoneglect. Methods: We searched through Pubmed, Scopus, PsycINFO, and PsychArticles. Original peer-reviewed articles published until February 2021 were included if they (1) were written in English; (2) were conducted on adults; (3) included at least one task to measure pseudoneglect, and (4) included at least one task with emotional stimuli or employed a measure of emotional state/trait, as they relate to pseudoneglect. Results: Fifteen studies were included, and 784 healthy participants took part in all studies reviewed. Discussion: The results show some evidence of emotion modulation of pseudoneglect, but evidence on the direction of the effect is mixed. We discuss the role of methodological factors that could account for the available findings and the implications for emotion asymmetry hypotheses such as the right-hemisphere hypothesis, the valence-specific hypothesis, as well as neural and arousal frameworks of attention–emotion interactions.

Visual Field Test With Gaze Check Tasks: Application in a Homonymous Hemianopic Patient Unaware of the Visual Defects

Gaze control is required for applying visual stimuli to a particular area of the visual field. We developed a visual field test with gaze check tasks to investigate hemianopia. In this test, participants must report the presence or absence of visual stimuli when a small object at the fixation point vibrates. Trials in the absence of visual stimuli were used as gaze check tasks, since the vibration could be observed only when the gaze was directed at the fixation point. We evaluated the efficacy of our test in four control participants and one patient with homonymous hemianopia who was unaware of the defects in the left visual field. This patient presented hemianopia in the test with gaze check tasks, but not when the gaze check tasks were omitted. The patient showed spontaneous gaze movements from the fixation point to the upper left direction, as well as scanning of the left visual field during the test without gaze check tasks. Thus, we concluded that the visual defects in this patient were compensated in daily life by spontaneous eye movements coordinated with visual information processing. The present results show the usefulness of the visual field test with gaze check tasks.

A Case of Relapse of Lymphocytic Hypophysitis Triggered by the Pregnancy of the Second Child

Lymphocytic hypophysitis is a rare immune-mediated inflammatory disorder that causes pituitary dysfunction. It has been reported that lymphocytic hypophysitis onset during pregnancy rarely relapses or exacerbates in subsequent pregnancies. We herein report a patient with relapse of lymphocytic hypophysitis triggered by the pregnancy of the second child. Case Presentation: At the age of 34, at 28 weeks of gestation of the first child, she became aware of left visual field disorder and was diagnosed as an upper left visual field defect. An MRI scan revealed an enlargement of the pituitary gland and the thickening of the stalk. She was referred to our hospital for diagnosis and treatment. Laboratory data showed central adrenocortical dysfunction and central hypothyroidism. Based on the course of the disease, MRI findings and laboratory data, we diagnosed her as lymphocytic hypophysitis occurred during pregnancy. With a replacement dose of hydrocortisone and levothyroxine, she gave birth by cesarean section at 38 weeks of gestation. We performed detailed assessment of anterior pituitary functions with hypothalamic hormone challenges after giving birth. It showed panhypopituitarism without diabetes insipidus. An MRI scan found the compression of the optic chiasm remained after childbirth, the patient underwent steroid pulse therapy. After that, visual field defect improved rapidly, and the patient continued to receive oral prednisolone with gradually reduced amount. An MRI scan performed over time and found the pituitary swelling gradually improved. The pituitary was completely intact 3 years after the onset of disease. At the age of 38, the patient became pregnant with her second child, showed no signs of hypopituitarism at the time of pregnancy. She still had been administrated with 3.5mg/day prednisolone. At the 21 weeks of pregnancy, she became aware of blurred vision and was diagnosed as a left paracenter scotoma. Laboratory data showed a decrease in blood glucose and neutrophil count, suggesting the occurrence of central adrenocortical insufficiency. Therefore, we suspected the relapse of hypophysitis due to second pregnancy. We started hydrocortisone supplementation in addition to prednisolone. No MRI scan was performed during pregnancy, since no progression of visual impairment was observed. She gave birth at 37 weeks of gestation, and postpartum MRI scan showed mild thickening of the stalk. Steroid pulse therapy was not performed because the visual field abnormality was spontaneously improved. Lymphocytic hypophysitis has a diverse course, and there is currently no confirmed risk factor for recurrence. In this case, hypophysitis recurred due to pregnancy despite the continuation of prednisolone administration, and the pathogenic mechanism may be different from the previously reported cases of recurrence of hypophysitis.

Attentional Bias for the Left Visual Field in Ambiguous Necker Cube Processing

There is a view that people better react to the stimuli presented in their left visual field (LVF) due to the right lateralization of the ventral attentional network (VAN). Previous studies used color-deviant stimuli and reported LVF bias for a bottom-up attentional component. Here we examined this effect for ambiguous stimuli, Necker cubes whose processing requires bottom-up and top-down attention. We instructed subjects to report cube’s orientation, left or right, while manipulated their ambiguity. In line with other works, we suggested that ambiguity enhanced reliance on the top-down mechanisms. For low ambiguity, subjects responded faster to the left-oriented cubes. EEG power increased in the right temporoparietal junction (TPJ) for 0.3 s post-stimulus onset. For high ambiguity, we found no difference in response time and EEG power. These results may evidence VAN activation when processing the bottom-up stimulus features. The eye-tracking confirmed that subjects focused on the center of the stimulus. We hypothesized that they used peripheral vision to acquire sensory information. Therefore, the LVF attentional bias might influence the evidence accumulation process. Our results support the bottom-up attentional bias to the left visual field and provide evidence for the vital role of right TPJ in controlling bottom-up attention.

Single-Case Neuropsychological Assessment of a Patient with a Posterior Parietal Lesion Using Behavioral Testing and Resting-State fMRI

This study integrated functional connectivity measures using resting-state fMRI and behavioral data from a single-case observation of patient (PER) one year after right-hemispheric hemorrhage in the intraparietal sulcus and superior parietal lobule (IPS/SPL). PER showed no sign of clinical neglect. Her behavioral performance in the visuo-manual pointing task and in the letter discrimination task under conditions of endogenous and exogenous attentional cueing was compared between the left (affected) and right (unaffected/control) peripheral visual fields. The resting-state fMRI demonstrated an imbalance between the right and left hemispheric frontoparietal functional connectivity within the dorsal attentional and motor networks. Although the frontal and occipital cortices were not structurally damaged, specific fronto-occipital functional connectivity was imbalanced, which was strongly associated with the behavioral changes. First, the activity in the right frontal eye field showed weaker correlations with the activity in the right inferior occipital area compared to the correlation with the activity in the left inferior occipital area. This imbalanced fronto-occipital functional connectivity was accompanied by a specific impairment in endogenous covert attention in the left visual field. Second, the activity within M1 in both hemispheres showed weaker correlations with the activity of the right cuneus compared to the correlation with the activity in the left cuneus. The imbalanced fronto-occipital functional connectivity was associated with the impairment of the reaching movement of the left and right hands towards the left visual field (optic ataxia). Altogether, our results showed that a lesion to the posterior parietal cortex affects the relationship between distal regions underlying the sensorimotor and attentional abilities

Visual duration bisection in profoundly deaf individuals

Background Previous research has been designed to study the effect of hearing loss on supra-second duration estimation in the visual channel and position effect of visual abilities among deaf populations. The current study aimed to investigate the sub-second duration perception of different visual fields in profoundly deaf individuals. Methods A total of 16 profoundly deaf undergraduates and 16 hearing undergraduates completed a visual duration bisection task in which participants made judgments about whether a series of probe durations that were linearly spaced from 200 ms to 800 ms at 100 ms intervals were more similar to a standard short duration (200 ms) or a standard long duration (800 ms). The probe stimuli were presented in the center, left, or right of the screen. A repeated measure analysis of variance (ANOVA) with a between-participants factor of group and a within-participants factor of position, and a one-sample t-test were conducted. Results The Weber ratio (WR) values of deaf participants were significantly higher than those of hearing participants, regardless of the presented positions of the visual stimulus. The bisection point (BP) value of deaf participants was significantly lower than 500 ms (average mean of 200/800 ms) and the BP value of hearing participants did not significantly differ from 500 ms, although the overall difference of BP values between the deaf group and hearing group did not reach significance. For deaf participants, the BP value in the center condition was significantly lower than 500 ms; however, the difference between the BP value in the left condition and 500 ms did not reach significance, indicating that their duration discrimination accuracy in the left visual field was better than that in the center visual field. Conclusions Hearing loss impaired visual sub-second duration perception, and deaf individuals showed a left visual field advantage of duration discrimination accuracy during the visual duration bisection task.

Low-frequency electroencephalogram oscillations govern left-eye lateralization during anti-predatory responses in the music frog

ABSTRACTVisual lateralization is widespread for prey and anti-predation in numerous taxa. However, it is still unknown how the brain governs this asymmetry. In this study, we conducted behavioral and electrophysiological experiments to evaluate anti-predatory behaviors and dynamic brain activities in Emei music frogs (Nidirana daunchina), to explore the potential eye bias for anti-predation and the underlying neural mechanisms. To do this, predator stimuli (a model snake head and a leaf as a control) were moved around the subjects in clockwise and anti-clockwise directions at steady velocity. We counted the number of anti-predatory responses and measured electroencephalogram (EEG) power spectra for each band and brain area (telencephalon, diencephalon and mesencephalon). Our results showed that (1) no significant eye preferences could be found for the control (leaf); however, the laterality index was significantly lower than zero when the predator stimulus was moved anti-clockwise, suggesting that left-eye advantage exists in this species for anti-predation; (2) compared with no stimulus in the visual field, the power spectra of delta and alpha bands were significantly greater when the predator stimulus was moved into the left visual field anti-clockwise; and, (3) generally, the power spectra of each band in the right-hemisphere for the left visual field were higher than those in the left counterpart. These results support that the left eye mediates the monitoring of a predator in music frogs and lower-frequency EEG oscillations govern this visual lateralization.