Neuropsychologia最新文献

Our principal objective was to replicate the findings of Chi and Snyder (2012) who reported that subjects (45% of sample) receiving active transcranial direct current stimulation (tDCS) involving cathodal stimulation of the left anterior temporal lobe (ATL) and anodal stimulation of the right ATL were able to successfully complete a task considered exceedingly challenging to solve (i.e., the 9-dot problem) relative to participants receiving sham stimulation (solved problem = 0 %). There are, to our knowledge, no published replication studies of Chi and Snyder's original work targeting the ATL. A secondary objective was to determine whether participants who successfully complete the 9-dot problem following active tDCS demonstrate superior visuospatial skills pre-stimulation relative to subjects receiving genuine tDCS who are not able to identify the solution. Moreover, we determined whether active tDCS was associated with improved visuospatial task performance. Following Chi and Snyder (2012), participants received cathodal stimulation of the left ATL and anodal stimulation targeting right ATL, or sham tDCS, during one session of 10 minutes duration. Unexpectedly, groups did not differ on the 9-dot problem with only 1 of 24 subjects receiving active tDCS and 1 of 26 participants assigned to the sham group identifying the solution to the problem. Active-tDCS and sham-tDCS group differences on tests of visuospatial skills at baseline and following tDCS session did not approach significance. We conducted a second study that closely adhered to Chi and Snyder's (2012) original protocol. In the second study, active-tDCS and sham groups did not differ on the 9-dot problem with 2 of 13 subjects in each group successfully identifying the solution to the problem. Contrary to expectation, active and sham groups in both studies did not differ on the 9-dot problem. Given the striking increase in the use of neuromodulation technologies, investigators should report failures to replicate which will enhance our understanding of the limitations of non-invasive brain stimulation.

Little is known about how or when language and visuospatial processing lateralise in the brain, and if individual differences in lateralisation are related to early language or visuospatial abilities. We explored if patterns of language and visuospatial lateralisation are related to cognitive skills in young children. A large sample of 3-year-olds (n = 136) attempted two functional transcranial Doppler ultrasound (fTCD) tasks to estimate language and visuospatial lateralisation. At the group level, language was lateralised to the left hemisphere, but visuospatial processing was weakly lateralised to the right hemisphere. The relationship between patterns of lateralisation and cognitive skills was investigated using regression analyses with novel calculations of how typical a child's lateralisation pattern was, the degree of crowding of both functions to one hemisphere, or how strongly both functions were lateralised. Language and visuospatial abilities were not predicted by any of these measures. Degree of visuospatial lateralisation, and not language lateralisation, was associated with higher language ability. Future research should investigate if patterns of lateralisation are related to cognitive skills in older children, when lateralisation is more established.

Through real-time functional MRI neurofeedback training individuals can learn the voluntary regulation of a selected neural signal. However, it is unknown whether they have introspection in this targeted neural signal. We performed a feasibility study of a new insula-targeted neurofeedback paradigm, aimed at addressing the question of introspective abilities. Specifically, we tested the feasibility of (1) a heartbeat-counting task to localize the insula, (2) graded neurofeedback of the insula, and (3) participants' ability to estimate the level of activation of the target area. Ten healthy volunteers performed three neurofeedback sessions. Each session started with a heartbeat-counting (interoception) task, as a functional localizer of the insula. Next, a graded neurofeedback task was performed, in which participants were asked to activate the insula to a medium or high target level. After the participant estimated the achieved activity level, feedback was presented. We found (1) significant activation of the insula in the localizer in response to the interoceptive task (2) and increased activity in this target area during regulation, but without activity difference between both regulation levels. There was (3) a small association between estimated and actual activity levels but no improvement in introspective accuracy over the three sessions. These results show good feasibility of the interoceptive-based functional localizer procedure for the insula. Moreover, insula upregulation was achieved in the neurofeedback task, although not in a graded fashion. No clear evidence for introspection was found for the insula.

This study aimed to examine age-related differences in the vividness of visual and multisensory imagery in relation to the distribution of aphantasia and hyperphantasia. Individuals aged 20-79 (2558 Japanese people) completed the vividness of visual imagery questionnaire (VVIQ) and the questionnaire upon mental imagery (QMI) in an online setting. We compared these scores between age groups and calculated the prevalence ratios of aphantasia (VVIQ 16-23) and hyperphantasia (VVIQ 75-80) in each age group. The results showed that older adults (especially those in their 60s and 70s) had significantly higher VVIQ and QMI scores than did younger adults. Focusing on multisensory imagery, we extracted subtypes of aphantasia, such as visual and multisensory aphatansia, in terms of multisensory imagery in most age groups. Moreover, we calculated the prevalence of aphantasia and hyperphantasia in each age group and found that they were significantly more frequent among the 20s and 30s, and less frequent among the 60s and 70s in the aphantasia range, but not in the hyperphantasia range. This study shows that age differences should be considered in the vividness of visual and multisensory imagery related to the distribution of aphantasia.