Similarity in activity and laterality patterns in the angular gyrus during autobiographical memory retrieval and self-referential processing

Elucidating the difference between mind-wandering and day-dreaming terms

Self-generated thoughts have been widely investigated in recent years, while the terms "mind-wandering" and "day-dreaming" are usually used interchangeably. But are these terms equivalent? To test this, online study participants were presented with situations of a protagonist engaged in self-generated thoughts. The scenarios differed with regard to type of situation, the activity in which the protagonist was engaged in, and the properties of the self-generated thoughts. Two different groups evaluated the same situations; one group evaluated the extent to which the protagonist mind-wandered and another the extent to which the protagonist day-dreamt. Our key findings were that the situations were perceived differently with regard to mind-wandering and day-dreaming, depending on whether self-generated thoughts occurred when the protagonist was busy with another activity and the type of self-generated thoughts. In particular, while planning, worrying, and ruminating thoughts were perceived more as mind-wandering in situations involving another activity/task, the situations without another activity/task involving recalling past events and fantasizing thoughts were perceived more as day-dreaming. In the additional experiment, we investigated laypeople's reasons for classifying the situation as mind-wandering or day-dreaming. Our results altogether indicate that mind-wandering and day-dreaming might not be fully equivalent terms.

Common and distinct patterns underlying different linguistic tasks: multivariate disconnectome symptom mapping in poststroke patients

Numerous studies have been devoted to neural mechanisms of a variety of linguistic tasks (e.g. speech comprehension and production). To date, however, whether and how the neural patterns underlying different linguistic tasks are similar or differ remains elusive. In this study, we compared the neural patterns underlying 3 linguistic tasks mainly concerning speech comprehension and production. To address this, multivariate regression approaches with lesion/disconnection symptom mapping were applied to data from 216 stroke patients with damage to the left hemisphere. The results showed that lesion/disconnection patterns could predict both poststroke scores of speech comprehension and production tasks; these patterns exhibited shared regions on the temporal pole of the left hemisphere as well as unique regions contributing to the prediction for each domain. Lower scores in speech comprehension tasks were associated with lesions/abnormalities in the superior temporal gyrus and middle temporal gyrus, while lower scores in speech production tasks were associated with lesions/abnormalities in the left inferior parietal lobe and frontal lobe. These results suggested an important role of the ventral and dorsal stream pathways in speech comprehension and production (i.e. supporting the dual stream model) and highlighted the applicability of the novel multivariate disconnectome-based symptom mapping in cognitive neuroscience research.