1
|
Sobczak-Edmans M, Lo YC, Hsu YC, Chen YJ, Kwok FY, Chuang KH, Tseng WYI, Chen SHA. Cerebro-Cerebellar Pathways for Verbal Working Memory. Front Hum Neurosci 2019; 12:530. [PMID: 30670957 PMCID: PMC6333010 DOI: 10.3389/fnhum.2018.00530] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 12/13/2018] [Indexed: 11/26/2022] Open
Abstract
The current study examined the structural and functional connectivity of the cerebro-cerebellar network of verbal working memory as proposed by Chen and Desmond (2005a). Diffusion spectrum imaging was employed to establish structural connectivity between cerebro-cerebellar regions co-activated during a verbal working memory task. The inferior frontal gyrus, inferior parietal lobule, pons, thalamus, superior cerebellum and inferior cerebellum were used as regions of interest to reconstruct and segment the contralateral white matter cerebro-cerebellar circuitry. The segmented pathways were examined further to establish the relationship between structural and effective connectivity as well as the relationship between structural connectivity and verbal working memory performance. No direct relationship between structural and effective connectivity was found but the results demonstrated that structural connectivity is indirectly related to effective connectivity as DCM models that resembled more closely with underlying white matter pathways had a higher degree of model inference confidence. Additionally, it was demonstrated that the structural connectivity of the ponto-cerebellar tract was associated with individual differences in response time for verbal working memory. The findings of the study contribute to further our understanding of the relationship between structural and functional connectivity and the impact of variability in verbal working memory performance.
Collapse
Affiliation(s)
| | - Yu-Chun Lo
- Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yung-Chin Hsu
- Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yu-Jen Chen
- Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Fu Yu Kwok
- Centre for Research in Child Development, National Institute of Education, Nanyang Technological University, Singapore, Singapore
| | - Kai-Hsiang Chuang
- The Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.,The Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Wen-Yih Isaac Tseng
- Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan.,Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan.,Department of Radiology, National Taiwan University College of Medicine, Taipei, Taiwan.,Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - S H Annabel Chen
- Psychology, School of Social Sciences, Nanyang Technological University, Singapore, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,Centre for Research and Development in Learning, Nanyang Technological University, Singapore, Singapore
| |
Collapse
|
2
|
Sobczak-Edmans M, Ng THB, Chan YC, Chew E, Chuang KH, Chen SHA. Temporal dynamics of visual working memory. Neuroimage 2015; 124:1021-1030. [PMID: 26427643 DOI: 10.1016/j.neuroimage.2015.09.038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/28/2015] [Accepted: 09/19/2015] [Indexed: 10/23/2022] Open
Abstract
The involvement of the human cerebellum in working memory has been well established in the last decade. However, the cerebro-cerebellar network for visual working memory is not as well defined. Our previous fMRI study showed superior and inferior cerebellar activations during a block design visual working memory task, but specific cerebellar contributions to cognitive processes in encoding, maintenance and retrieval have not yet been established. The current study examined cerebellar contributions to each of the components of visual working memory and presence of cerebellar hemispheric laterality was investigated. 40 young adults performed a Sternberg visual working memory task during fMRI scanning using a parametric paradigm. The contrast between high and low memory load during each phase was examined. We found that the most prominent activation was observed in vermal lobule VIIIb and bilateral lobule VI during encoding. Using a quantitative laterality index, we found that left-lateralized activation of lobule VIIIa was present in the encoding phase. In the maintenance phase, there was bilateral lobule VI and right-lateralized lobule VIIb activity. Changes in activation in right lobule VIIIa were present during the retrieval phase. The current results provide evidence that superior and inferior cerebellum contributes to visual working memory, with a tendency for left-lateralized activations in the inferior cerebellum during encoding and right-lateralized lobule VIIb activations during maintenance. The results of the study are in agreement with Baddeley's multi-component working memory model, but also suggest that stored visual representations are additionally supported by maintenance mechanisms that may employ verbal coding.
Collapse
Affiliation(s)
- M Sobczak-Edmans
- Division of Psychology, Nanyang Technological University, Singapore
| | - T H B Ng
- Division of Psychology, Nanyang Technological University, Singapore
| | - Y C Chan
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Division of Neurology, National University Hospital, National University Health System, Singapore
| | - E Chew
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Division of Neurology, National University Hospital, National University Health System, Singapore
| | - K H Chuang
- The Queensland Brain Institute, The University of Queensland, Australia; The Centre for Advanced Imaging, The University of Queensland, Australia
| | - S H A Chen
- Division of Psychology, Nanyang Technological University, Singapore; Centre for Research and Development in Learning, Nanyang Technological University, Singapore.
| |
Collapse
|
3
|
Abstract
Much of synaesthesia research focused on colour, but not all cross-domain correspondences reported by synaesthetes are strictly sensory. For example, some synaesthetes personify letters and numbers, in additional to visualizing them in colour. First reported in the 1890s, the phenomenon has been largely ignored by scientists for more than a century with the exception of a few single-case reports. In the present study, we collected detailed self-reports on grapheme personification using a questionnaire, providing us with a comprehensive description of the phenomenology of grapheme personification. Next, we documented the behavioural consequences of personifying graphemes using a congruity paradigm involving a gender judgement task; we also examined whether personification is associated with heightened empathy as measured using Empathy Quotient and found substantial individual differences within our sample. Lastly, we present the first neuroimaging case study of personification, indicating that the precuneus activation previously seen in other synaesthesia studies may be implicated in the process. We propose that frameworks for understanding synaesthesia could be extended into other domains of cognition and that grapheme personification shares more in common with normal cognition than may be readily apparent. This benign form of hyper-mentalizing may provide a unique point of view on one of the most central problems in human cognition - understanding others' state of mind.
Collapse
Affiliation(s)
- Maina Amin
- Department of Psychology, University College London, UK Centre for Cognition and Neuroimaging, Brunel University, London, UK
| | | | | | | | | | | | | |
Collapse
|