Estimation of Skin Blood Flow Artefacts in NIRS Signals During a Verbal Fluency Task

Author(s):  
Akitoshi Seiyama ◽  
Kotona Higaki ◽  
Nao Takeuchi ◽  
Masahiro Uehara ◽  
Naoko Takayama
NeuroImage ◽  
2011 ◽  
Vol 57 (3) ◽  
pp. 991-1002 ◽  
Author(s):  
Toshimitsu Takahashi ◽  
Yoriko Takikawa ◽  
Reiko Kawagoe ◽  
Satoshi Shibuya ◽  
Takayuki Iwano ◽  
...  

1998 ◽  
Vol 173 (1) ◽  
pp. 69-74 ◽  
Author(s):  
John D. C. Mellers ◽  
Naoto Adachi ◽  
Noriyoshi Takei ◽  
Alice Cluckie ◽  
Brian K. Toone ◽  
...  

BackgroundThe association between temporal lobe epilepsy and schizophrenia suggests that the critical abnormality may be pathology within the temporal lobes. People with schizophrenia-like psychosis of epilepsy (SLPE) provide a useful group in which to examine the importance of temporal and frontal lobe dysfunction in schizophrenia.MethodA verbal fluency activation paradigm and a 99mTc HMPAO SPET were used to study frontotemporal function in people with SLPE (n = 12), schizophrenia (n = 11) and epilepsy (n = 16).ResultsPeople with SLPE differed from both other groups by showing lower blood flow in the left superior temporal gyrus during performance of a verbal fluency task compared with a word repetition task (F=5.4, P=0.01). During the verbal fluency task people with primary schizophrenia showed a greater increase in blood flow in anterior cingulate (F=4.5, P=0.02) than the other two groups. There were no between-group differences in frontal brain regions.ConclusionOur findings support an association between left temporal lobe abnormality and SLPE. The different patterns of activation observed in people with primary schizophrenia and SLPE suggests that different pathophysiological mechanisms may operate in these two groups. In SLPE the pathophysiology may be relatively confined to the dominant temporal lobe.


1995 ◽  
Vol 167 (3) ◽  
pp. 343-349 ◽  
Author(s):  
C. D. Frith ◽  
K. J. Friston ◽  
S. Herold ◽  
D. Silbersweig ◽  
P. Fletcher ◽  
...  

BackgroundThis study examined the pattern of cerebral blood flow observed in chronic schizophrenic patients while they performed a paced verbal fluency task. Such tasks engage a distributed brain system associated with willed action. Since willed action is impaired in many chronic schizophrenic patients we hypothesised that task performance would be associated with an abnormal pattern of blood flow.MethodPositron emission tomography (PET) was applied to 18 chronic schizophrenic patients stratified into three groups on the basis of verbal fluency performance and current symptoms. Regional cerebral blood flow (rCBF) was measured while the patients performed (a) verbal fluency, (b) word categorisation, and (c) word repetition. Results were compared with six normal controls matched for age, sex and premorbid IQ. Analysis was restricted to six brain regions previously identified in studies of normal volunteers.ResultsIn five brain areas, including the left dorsolateral prefrontal cortex, the patients showed the same pattern of activation as control subjects. However, in the left superior temporal cortex, all patient groups failed to show the normal decrease in blood flow when verbal fluency was compared with word repetition.ConclusionThese observations suggest that (a) chronic schizophrenic patients can show a normal magnitude of frontal activation when matched for performance with controls, and (b) they fail to show the expected reductions of activity in the superior temporal cortex. This latter result may reflect abnormal functional connectivity between frontal and temporal cortex.


2021 ◽  
Vol 15 ◽  
Author(s):  
Naoto Kunii ◽  
Tomoyuki Koizumi ◽  
Kensuke Kawai ◽  
Seijiro Shimada ◽  
Nobuhito Saito

BackgroundVagus nerve stimulation (VNS) is an established palliative surgical treatment for refractory epilepsy. Recently, pairing VNS with rehabilitation received growing attention for their joint effect on neural plasticity. However, objective biological measurements proving the interaction between VNS effects and cortical recruitment are lacking. Studies reported that VNS induced little blood flow increase in the cerebral cortex.ObjectiveThis study tested the hypothesis that pairing VNS with a cognitive task amplifies task-induced cerebral blood flow (CBF).MethodsThis study included 21 patients implanted with vagus nerve stimulator to treat refractory epilepsy. Near-infrared spectroscopy (NIRS) with sensors on the forehead measured CBF changes in the frontal cortices in response to VNS. Cerebral blood flow was measured when VNS was delivered during a resting state or a verbal fluency task. We analyzed the VNS effect on CBF in relation to stimulation intensity and clinical responsiveness.ResultsWe observed no CBF change when VNS was delivered during rest, irrespective of stimulation intensity or responsiveness. Cerebral blood flow changed significantly when a verbal fluency task was paired with VNS in a stimulation intensity-dependent manner. Cerebral blood flow changes in the non-responders showed no intensity-dependency.ConclusionOur results could be an important biological proof of the interaction between VNS effects and cortical recruitment, supporting the validity of pairing VNS with rehabilitation.


2021 ◽  
pp. 174702182110341
Author(s):  
Maryll Fournet ◽  
Michaela Pernon ◽  
Sabina Catalano Chiuvé ◽  
Ursula Lopez ◽  
Marina Laganaro

There is a general agreement that speaking requires attention at least for conceptual and lexical processes of utterance production. However, conflicting results have been obtained with dual-task paradigms using either repetition tasks or more generally tasks involving limited loading of lexical selection. This study aimed to investigate whether post-lexical processes recruit attentional resources. We used a new dual-task paradigm in a set of experiments where a continuous verbal production task involved either high or low demand on lexical selection processes. Experiment 1 evaluates lexical and post-lexical processes with a semantic verbal fluency task, whereas experiments 2 and 3 focus on post-lexical processes with a non-propositional speech task. In each experiment, two types of non-verbal secondary tasks were used: processing speed (simple manual reaction times) or inhibition (Go/No-go). In Experiment 1, a dual-task cost was observed on the semantic verbal fluency task and each non-verbal task. In Experiment 2, a dual-task cost appeared on the non-verbal tasks but not on the speech task. The same paradigm was used with older adults (Experiment 3), as increased effort in post-lexical processes has been associated with ageing. For older adults, a dual-task cost was also observed on the non-propositional verbal task when speech was produced with the inhibition non-verbal task. The results suggest an attentional cost on post-lexical processes and strategic effects in the resolution of the dual-task.


2021 ◽  
Vol 15 (2) ◽  
pp. 137-148
Author(s):  
Tatiana B. Freitas ◽  
José Eduardo Pompeu ◽  
Briana R. B. Moraes ◽  
Sandra M. A. A. Pompeu ◽  
Keyte G. Silva ◽  
...  

BACKGROUND: Parkinson's disease (PD) causes loss of automaticity and impairment in dual task (DT) performance. AIM: To investigate the performance and pattern of prioritization of individuals with PD in motor and cognitive DT. METHOD: An observational, transversal, comparative study assessed 20 individuals with PD between stages 1.5 to 3 of the modified Hoehn and Yahr scale. Performance was assessed during the execution of manual dexterity and sit-to-stand tasks, in a single task or in association with a verbal fluency task. RESULTS: There was a loss of performance in both dual task conditions. The cost of verbal fluency was higher than the cost of manual dexterity function. CONCLUSION: Individuals with PD showed worse DT performance and prioritized the manual dexterity task. There was no prioritization between sit-to-stand and verbal fluency. These findings suggest that the nature of tasks can influence the prioritization of dual tasks.


2005 ◽  
Vol 11 (4) ◽  
pp. 408-415 ◽  
Author(s):  
STEVEN PAUL WOODS ◽  
J. COBB SCOTT ◽  
DANIELLE A. SIRES ◽  
IGOR GRANT ◽  
ROBERT K. HEATON ◽  
...  

Action (verb) fluency is a newly developed verbal fluency task that requires the examinee to rapidly generate as many verbs (i.e., “things that people do”) as possible within 1 min. Existing literature indicates that action fluency may be more sensitive to frontal–basal ganglia loop pathophysiology than traditional noun fluency tasks (e.g., animal fluency), which is consistent with the hypothesized neural dissociation between noun and verb retrieval. In the current study, a series of analyses were undertaken to examine the psychometric properties of action fluency in a sample of 174 younger healthy participants. The first set of analyses describes the development of demographically adjusted normative data for action fluency. Next, a group of hypothesis-driven correlational analyses reveals significant associations between action fluency and putative tests of executive functions, verbal working memory, verbal fluency, and information processing speed, but not between action fluency and tests of learning or constructional praxis. The final set of analyses demonstrates the test–retest stability of the action fluency test and provides standards for determining statistically reliable changes in performance. In sum, this study enhances the potential clinical applicability of action fluency by providing demographically adjusted normative data and demonstrating evidence for its reliability and construct validity. (JINS, 2005,11, 408–415.)


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