When participants observed a rubber hand being touched, their sense of touch was activated . While this illusion might be caused by multi-modal integration, it may also be related to empathic function, which enables us to simulate the observed information. We examined individual differences in the RHI, including empathic and schizotypal personality traits, as previous research had suggested that schizophrenic patients would be more subject to the RHI. The results indicated that people who experience a stronger RHI might have stronger (...) empathic and schizotypal personalites simultaneously. We discussed these relationships in terms of self-other representations. (shrink)

Previous studies have suggested that auditory hallucination is closely related to thought insertion. In this study, we investigated the relationship between the external misattribution of thought and auditory hallucination-like experiences. We used the AHES-17, which measures auditory hallucination-like experiences in normal, healthy people, and the Deese–Roediger–McDermott paradigm, in which false alarms of critical lure are regarded as spontaneous external misattribution of thought. We found that critical lures elicited increased the number of false alarms as AHES-17 scores increased and that scores (...) of AHES-17 predicted the rate of false memory of critical lures. Furthermore, we revealed that the relationship between AHES-17 scores and the rates of false alarms to critical lures was strictly linear. Therefore, it might be said that individual differences in auditory hallucination-like experiences are highly related to the external misattribution of thought. We discussed these results from the perspective of the sense of agency over thought. (shrink)

We investigated output-monitoring errors over speech based on findings in the research on the sense of agency. Several words were presented one-by-one, and we asked participants to say the word aloud, mouth the word, or imagine saying the word aloud. Later, participants were asked whether each word was said aloud. We found that the “said aloud” response was higher for generated words than that for observed words; it was decreased when the pitch of the feedback was lowered but still higher (...) than when no feedback was received, and it was the same when no feedback was received and when feedback was replaced by another’s voice. Furthermore, we found that the “said aloud” response did not decrease even when the altered feedback was received with a short delay. These results were discussed according to the sense of agency and agency memory. (shrink)

Background. Positive schizophrenic symptoms, especially passivity phenomena, including auditory hallucinations, may be caused by an abnormal sense of agency, which people with schizotypal personality traits also tend to exhibit. A sense of agency asserts that it is oneself who is causing or generating an action. It is possible that this abnormal sense of self-agency is attributable to the abnormal prediction of one’s own movements in motor control. Method. We conducted an experiment using the “disappeared cursor” paradigm in which non-clinical, healthy (...) participants were required to click on a target using an invisible mouse cursor. Prediction error was defined as the distance between the target and the click point. Results. The results showed that schizotypal personality traits, but not depressive or anxious traits, were correlated with deficits in predicting movements of the subjects’ left hand. In particular, auditory hallucination proneness had the strongest relationship with movement prediction error. In this report, we also discuss the error tendency. Conclusions. This finding is in accordance with the idea that passivity phenomena or proneness may be caused by the abnormal prediction of one’s own actions or movements. (shrink)

Facial expressions influence our experience and perception of emotions—they not only tell other people what we are feeling but also might tell us what to feel via sensory feedback. We conducted three experiments to investigate the interaction between facial feedback phenomena and different environmental stimuli, by asking participants to remember emotional autobiographical memories. Moreover, we examined how people with schizotypal traits would be affected by their experience of emotional facial simulations. We found that using a directed approach (gripping a pencil (...) with teeth/lips) while remembering a specific autobiographical memory could successfully evoke participants’ positive (e.g. happy and excited)/negative (e.g. angry and sad) emotions (i.e. Experiment 1). When using indirective environmental stimuli (e.g. teardrop glasses), the results of our experiments (i.e. Experiments 2 and 3) investigating facial feedback and the effect of teardrop glasses showed that participants who scored low in schizotypy reported little effect from wearing teardrop glasses, while those with high schizotypy reported a much greater effect in both between- and within-subject conditions. The results are discussed from the perspective of sense of ownership, which people with schizophrenia are believed to have deficits in. (shrink)

We investigated the immediate and maintenance effects of mental-imagery-based mnemonic training on improving youths’ working memory, long-term memory, arithmetic and spatial abilities, and fluid intelligence. In Experiment 1, 26 Chinese participants aged 10–16 years were divided into an experimental group that received 8 days of mental-imagery-based mnemonic training and a no-contact control group. Participants completed pre-, post-, and three follow-up tests. In Experiment 2, 54 Chinese children, all 12 years old, were divided into experimental and control groups. Participants completed pre-, (...) post-, and follow-up tests. Results showed that the training significantly affected long-term memory-related task performance but no effects were observed on working memory, arithmetic or spatial ability, or fluid intelligence-related tasks. Moreover, the effect of the training on long-term memory lasted up to one year; the more frequently the training was used, the more effective it was. A content analysis of the feedback submitted by parents of participants in Experiment 2 three months after the training showed that the children used the strategy more for memorizing content such as Chinese and English, as well as for musical scores. Furthermore, there was also the possibility that the training improved abilities and academic performance such as concentration and math performance. Our results provide a basis for the further exploration of mental-imagery-based mnemonic training as a novel training modality. (shrink)