Diversity of aphantasia revealed by multiple assessments of visual imagery, multisensory imagery, and cognitive style.

Aphantasia-a condition wherein individuals have a reduced or absent construction of voluntary visual imagery-is diagnosed using either the Vividness of Visual Imagery Questionnaire (VVIQ) or self-identification. However, a significant discrepancy exists between the proportions of aphantasia in the populations assessed using these two criteria. It is unclear why the reported proportions differ excessively and what percentage of people cannot form visual imagery. We investigated the replicability of the proportion of people with aphantasia using both criteria in the same population of participants. Therefore, we explored the potential causes of the discrepancy and characteristics of putative aphantasia in terms of multisensory imagery, cognitive style, and face recognition ability. First, we conducted an online sampling study (Study 1: N = 2,871) using the VVIQ, self-identification of a reduction in visual imagery, Questionnaire upon Mental Imagery (QMI), and Verbalizer-Visualizer Questionnaire (VVQ). We found that 3.7 and 12.1% fulfilled the VVIQ and self-identification criteria, respectively, roughly replicating the proportions reported in previous studies. The self-identification criterion-but not the VVIQ criterion-contains items related to face recognition; hence, we suspected that face recognition ability was factor contributing to this discrepancy and conducted another online sampling study (Study 2: N = 774). We found a significant correlation between VVIQ and face recognition ability in the control group with self-identification, but not in the group defined by low VVIQ (VVIQ ≤32). As the participants in the control group with self-identification tended to exhibit moderately high VVIQ scores but low face recognition ability, we reason that the discrepancy can be partially explained by the contamination of individual differences in face recognition ability. Additional analyses of Study 1 revealed that the aphantasia group included participants who lacked all types of sensory imagery or only visual imagery in multisensory imagery and exhibited a non-specific cognitive style. This study indicates that the VVIQ alone may be insufficient to diagnose individuals who report an inability to form visual imagery. Furthermore, we highlight the importance of multiple assessments-along with the VVIQ-to better understand the diversity of imagery in aphantasia.

Changes in negative and positive EEG shifts during slow cortical potential training in children with attention-deficit/hyperactivity disorder: a preliminary investigation.

We examined the effects of self-regulation of slow cortical potentials (SCP) in nine children with attention-deficit/hyperactivity disorder (ADHD) by focusing on the changes in electroencephalographic (EEG) shifts during SCP sessions. In SCP training, individuals learn to increase and decrease their cortical excitabilities (enhancement of negative and positive cortical shifts). To examine the efficiency of SCP training, we conducted an attention task and measured contingent negative variation, which relates to the attention maintenance ability. Moreover, to assess training effects at the behavioral level, the Japanese ADHD rating scale (SNAP-J) was completed by the parents. In SCP training, we analyzed changes in EEG shifts during 16 training sessions by calculating the peak amplitudes of positive and negative shifts. The results of EEG data showed that peak amplitudes increased in sessions 11 and 12 for negative shifts and in sessions 9 and 13 for positive shifts. Moreover, we found an enhancement of contingent negative variation amplitude in the attention task before and after training, suggesting that the ability of these children to maintain attention could be modified by SCP training. However, significant behavioral improvements were not observed on the Japanese ADHD rating scale. It has been proposed that the number of additional training sessions may affect both physiological and behavioral improvements. Our present results, however, suggest the possibility that even low numbers of training sessions, such as 16, can bring about physiological improvement, whereas greater numbers of training sessions may be needed to have an influence on behavioral changes.

Effects of non-native language exposure on the semantic processing of native language in preschool children.

We investigated the effects of non-native language (English) exposure on event-related potentials (ERPs) in first- and second-year (four- and five-year-old) preschool Japanese native speakers while they listened to semantically congruent and incongruent Japanese sentences. The children were divided into a non-native language exposed group (exposed group) and a group without such experiences (control group) on the basis of their exposure to non-native language. We compared the ERPs recorded from the two groups in each of the two preschool years. N400 was observed both in the first- and second-year preschoolers. Differences owing to exposure to non-native language appeared in the second-year preschoolers but not in the first-year preschoolers. In the second-year preschoolers, the N400 onset in the exposed group was shorter than that in the control group, but there was no difference in the N400 offset between the exposed and control groups. Furthermore, the scalp distribution of the N400 in the exposed group was broader than that in the control group. These results indicate that the time course and scalp distribution of semantic processing for native language sentences in young children fluctuated depending on exposure to non-native language.

Inhibitory effect of bucillamine on the increased leukocyte entrapment in the retinal microcirculation of diabetic rats.

PURPOSE: To evaluate quantitatively the effects of bucillamine on the entrapment of leukocytes in the retinal microcirculation of diabetic rats. METHODS: 13 male Brown Norway rats were injected with streptozotocin (STZ). After the animals developed diabetes, they were divided into two groups. Group 1 (n=7) received fresh drinking water without bucillamine, and group 2 (n=6) received fresh drinking water supplemented with bucillamine (200 mg/kg per day). Rats that were not injected with STZ and received water without bucillamine served as controls (n=6). Four weeks after the injection of STZ, the leukocytes in the retina were observed by acridine orange digital fluorography. The number of leukocytes trapped in the retinal vessels was compared among the three groups. RESULTS: In the untreated diabetic rats, the number of trapped leukocytes was significantly higher than in control rats or bucillamine-treated diabetic rats (P<0.05). CONCLUSIONS: We demonstrated an inhibitory effect of bucillamine on leukocyte entrapment in the retinal vessels of diabetic rats. Bucillamine may have therapeutic efficacy in preventing the development of diabetic retinopathy.