S14 小型專題:非侵入性神經調節技術(TMS, tDCS, tACS) 在前額葉與

S14 小型專題:非侵入性神經調節技術(TMS, tDCS, tACS)
在前額葉與頂葉功能的研究(二)
S14 小型專題:非侵入性神經調節技術(TMS, tDCS, tACS)在前額葉與頂葉功能的研究(二)
召集人: 曾祥非、徐慈妤
16:30~18:00
地點:南地 B
S14.1 Using tACS to investigate the
involvement of phase difference at
parietal and temporal cortex in
binding-visual working memory
Yu-Ting Chang、Kai-Chi
Iu、 Philip Tseng、
Chi-Hung Juan
S14.2 tDCS over right DLPFC protects
visuospatial working memory from
motor dual-task interference
Yi-Jen Wu、Philip Tseng、
Ming-Chyi Pai、Chou-Ching
Lin、 Chi-Hung Juan
S14.3 The application of mutiscale entropy 黃時霖、王靜秀、游家鑫、
in cognitive control
梁偉光、阮啟弘
S14.4 VMPFC as the neural locus for
tDCS-induced improvement in
cognitive control
Jiaxin Yu、Che-Yi Hsu、
Philip Tseng、Chi-Hung
Juan
Using tACS to investigate the involvement of phase difference at
parietal and temporal cortex in binding-visual working memory
Yu-Ting Chang1, Kai-Chi Iu1, Philip Tseng1, Chi-Hung Juan1
1. Institute of Cognitive Neuroscience, National Central University, Jhongli 320,
Taiwan
Visual working memory (VWM) is the memory ability to temporally sustain and
manipulate visual information to guide people’s goals and ongoing behaviors. Our previous
fMRI findings have demonstrated that bilateral posterior parietal cortex (PPC) has a robust
activation when anodal tDCS was applied over right PPC. These findings suggest that there
may be crosstalk between the left and right PPC to support VWM. Since previous research
has emphasized the importance of theta oscillation from the parietal region in mediating
VWM processes (Sauseng et al., 2010), we employed theta-frequency tACS to modulate
the oscillation between left and right PPC to confirm this conjecture. We found that
in-phase sinusoidal current stimulation can significantly ameliorate low performer’s VWM
ability but not in the sham and out-phase conditions.
In addition to using single-feature objects as units for indexing VWM, we also
investigated binding processes in VWM. Recent neuroimaging research has demonstrated
that both the left fusiform gyrus and the left parietal cortex are involved specifically during
the binding maintenance period (Parra et al., 2014). In addition, there is also evidence
suggesting that the intraparietal sulcus seems to play a vital role in visual grouping and
feature binding VWM. This motivates the hypothesis that feature binding in VWM may be
mediated by the communication between temporal and parietal regions, which is
responsible for the representation and “gluing” of these features. The causality of how
these brain regions operate together in storing multiple features of an object in VWM,
however, remains mostly unclear. Here we adopt gamma-frequency tACS to modulate left
fusiform gyrus and parietal cortex simultaneously to elucidate the causality between their
activation and binding VWM performance, since there is a wide range electrophysiological
evidence indicate gamma-frequency band is important for feature binding in not only
human but also animal studies (e.g., Jensen et al., 2007). Our preliminary results show a
significant interaction between task condition (shape only vs. binding) and stimulation
condition (out-phase stimulation vs. sham), which is driven by the selective improvement
of stimulation in binding condition but not in sham control. This finding supports the
hypothesis that binding VWM is established by the crosstalk between the left parietal and
temporal regions, of which gamma oscillation is a critical component.
Keywords: transcranial alternating current stimulation, binding-visual working memory,
parietal cortex, temporal cortex
tDCS over right DLPFC protects visuospatial working memory from
motor dual-task interference
Yi-Jen Wu1, Philip Tseng2, Ming-Chyi Pai3, Chou-Ching Lin3, Chi-Hung Juan2
1. National Cheng Kung University Hospital, Dou-Liou Branch, Yunlin, Taiwan
2. Institute Of Cognitive Neuroscience, National Central University, Jhongli 320,
Taiwan
3. Department of Neurology, National Cheng Kung University Hospital, Tainan,
Taiwan
Spatial working memory (SWM) is the ability to temporarily store and manipulate
spatial information, and its integrity is highly dependent on areas within the fronto-parietal
network. Within this network, anodal tDCS has been effective in improving SWM capacity
when applied over the parietal cortex (Tseng et al., 2012). Whether similar positive effects
can be observed over frontal regions, however, still remains unclear. To address this, here
we applied anodal tDCS over the right dorsolateral prefrontal cortex (DLPFC) before
participants performed a computerized Corsi Block Tapping task (CBT). Difficulty of the
task was manipulated with memory recall sequence (forward recall vs. backward recall),
and the inclusion of a motor concurrent interference task (modified Luria manual
sequencing task). We found that, in general, backward recall and motor interference
strongly impaired people’s performance in every condition. However, anodal tDCS over
right DLPFC minimized the detrimental effect in the most difficult contion (backward
recall plus motor interference). This effect was true for both memory span and reaction
time. The results here show that right anodal tDCS over right DLPFC protected SWM span
in the most difficult condition, or when cognitive demand was the highest. They suggest
that 1) the right DLPFC plays a crucial role in dealing with the cross-domain motor
interference for SWM, and 2) although anodal tDCS over right DLPFC and parietal cortex
both benefit SWM capacity, the patterns of results here suggest a distinctive role for
DLPFC (likely in the central executive system at the top-down attentional level) apart from
the parietal cortex within the fronto-parietal network.
Keywords: VSTM, memory interference, individual differences
The application of mutiscale entropy in cognitive control
(多尺度熵與認知控制的關聯性)
黃時霖 1，王靜秀 1，游家鑫 2，梁偉光 1，阮啟弘 1
1. Institute of Cognitive Neuroscience, National Central University, Jhongli 320,
Taiwan
2. Institute of Neuroscience, National Yang-Ming University, Taipei 112, Taiwan
多尺度熵(Multiscale Entropy, MSE)是一種可以量化訊號中的複雜度或資訊量的資
料分析方法。在許多認知歷程所收集的腦訊號上，傳統的 ERP 分析雖然能反映實驗
操弄下不同條件之間的不同，卻很難表達複雜且快速的神經網路的效率及對環境的適
應能力，而多尺度熵無論在理論上及實際上都可適當的表達出這些神經網路動力學的
特徵。我們應用這種多尺度熵在認知歷程所收集的 EEG 的訊號上：1) 對於抑制控制
以及 tDCS，我們發現陽極 tDCS 可有效的提升抑制控制過程中腦額葉上方 EEG 頻道
的多尺度熵，也因此提升了受試者抑制控制的能力(Liang and Juan, 2013; Liang et al.,
2014)；2) 對於抑制控制中的錯誤後減慢(Post-error slowing)現象(抑制失敗的下一個測
驗的反應時間較抑制成功來的長)，從抑制訊號出現後的 450ms 到 950ms 之間的多尺
度熵顯示受測者在抑制失敗時的腦波多尺度熵較抑制成功時高；3) 對於老年人視覺
工作記憶的能力，我們發現有規律運動習慣的老年人的腦訊號多尺度熵顯著的高於沒
有規律運動習慣的老年人，也因此有較好的工作記憶能力(Wang et al., under revision)。
因此多尺度熵是一種在理論上與實用上都能量化大腦的適應能力及效率的指標，
與認知歷程中的表現有關，並且能用以研究老化、疾病等議題。
Keywords: entropy, variability, EEG, stop signal, inhibitory control
VMPFC as the neural locus for tDCS-induced improvement in
cognitive control
Jiaxin Yu1, Che-Yi Hsu2, Philip Tseng2, Chi-Hung Juan2
1. Institute of Neuroscience, National Yang-Ming University, Taipei 112, Taiwan
2. Institute of Cognitive Neuroscience, National Central University, Jhongli 320,
Taiwan
Abstract
Previous research has demonstrated the importance of brain stimulation in improving
self-control. However, the neural substrates underlying such artificially-induced
improvement remain unclear. Here, by coupling transcranial direct current stimulation
(tDCS) with functional MRI, we show that positively-charged electrical stimulation can
effectively shorten stop signal reaction time, an index of improved inhibitory control.
Without tDCS, contrasts between stop and go trials showed activations in the
supplementary motor complex (preSMA) and right inferior frontal gyrus (rIFG), which is
consistent with prior research. Importantly, by contrasting successful inhibition trials
between the tDCS and sham condition within each individual, we observed activation in
bilateral ventromedial prefrontal cortex (vmPFC), an area that is often inferred in the
processing of decision making, but rarely associated with inhibitory control. These results
implicate specific neural mechanisms whereby brain stimulation improves inhibitory
control. Activation from vmPFC may better represent improvement in cognitive control
within each specific individual than previously-reported preSMA and rIFG that perhaps
better represent inter-individual differences. We are currently using tACS of different
frequencies to modulate the crosstalk between preSMA and rIFG to probe the interactions
between these two regions of interest.
Keywords: response inhibition, tDCS, fMRI, preSMA, vmPFC

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