Clustering and switching in divergent thinking: Neurophysiological correlates underlying flexibility during idea generation

2021 ◽  
Author(s):  
Serena Mastria ◽  
Sergio Agnoli ◽  
Marco Zanon ◽  
Selcuk Acar ◽  
Mark Runco ◽  
...  

EEG alpha synchronization, especially in posterior parietal cortical regions of the right hemisphere, is indicative of high internal processing demands that are typically involved in divergent thinking (DT). During the course of DT, as ideation proceeds, ideas tend to become more creative, being more likely to be drawn from new conceptual categories through the use of the cognitive mechanism of flexibility. The present study investigated whether EEG alpha synchronization can be modulated by flexibility in DT by comparing cortical activation patterns during the switch of category (switching) and the stay in the same category (clustering). Twenty participants were required to generate alternative uses of everyday objects during EEG recording. Differential results were specifically found in the lower alpha band (8-10 Hz): whereas clustering showed synchronization typically lateralized in the right posterior parietal areas, switching induced posterior parietal synchronization over both right and left hemispheres. These findings indicate that the two distinct cognitive mechanisms subsuming flexibility (switching and clustering) are associated with a different hemispheric modulation of lower alpha activity, as switching, in comparison to clustering, is related to higher power in the lower alpha band over the left hemisphere. Switching in comparison to clustering may thus require a larger investment of cognitive resources due to the exploratory process of moving from one semantic conceptual category to another in the course of creative ideation.

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Selene Schintu ◽  
Elisa Martín-Arévalo ◽  
Michael Vesia ◽  
Yves Rossetti ◽  
Romeo Salemme ◽  
...  

Rightward prism adaptation ameliorates neglect symptoms while leftward prism adaptation (LPA) induces neglect-like biases in healthy individuals. Similarly, inhibitory repetitive transcranial magnetic stimulation (rTMS) on the right posterior parietal cortex (PPC) induces neglect-like behavior, whereas on the left PPC it ameliorates neglect symptoms and normalizes hyperexcitability of left hemisphere parietal-motor (PPC-M1) connectivity. Based on this analogy we hypothesized that LPA increases PPC-M1 excitability in the left hemisphere and decreases it in the right one. In an attempt to shed some light on the mechanisms underlying LPA’s effects on cognition, we investigated this hypothesis in healthy individuals measuring PPC-M1 excitability with dual-site paired-pulse TMS (ppTMS). We found a left hemisphere increase and a right hemisphere decrease in the amplitude of motor evoked potentials elicited by paired as well as single pulses on M1. While this could indicate that LPA biases interhemispheric connectivity, it contradicts previous evidence that M1-only MEPs are unchanged after LPA. A control experiment showed that input-output curves were not affected by LPAper se. We conclude that LPA combined with ppTMS on PPC-M1 differentially alters the excitability of the left and right M1.


2011 ◽  
Vol 366 (1564) ◽  
pp. 572-585 ◽  
Author(s):  
L. Pisella ◽  
N. Alahyane ◽  
A. Blangero ◽  
F. Thery ◽  
S. Blanc ◽  
...  

We review evidence showing a right-hemispheric dominance for visuo-spatial processing and representation in humans. Accordingly, visual disorganization symptoms (intuitively related to remapping impairments) are observed in both neglect and constructional apraxia. More specifically, we review findings from the intervening saccade paradigm in humans—and present additional original data—which suggest a specific role of the asymmetrical network at the temporo-parietal junction (TPJ) in the right hemisphere in visual remapping: following damage to the right dorsal posterior parietal cortex (PPC) as well as part of the corpus callosum connecting the PPC to the frontal lobes, patient OK in a double-step saccadic task exhibited an impairment when the second saccade had to be directed rightward . This singular and lateralized deficit cannot result solely from the patient's cortical lesion and, therefore, we propose that it is due to his callosal lesion that may specifically interrupt the interhemispheric transfer of information necessary to execute accurate rightward saccades towards a remapped target location. This suggests a specialized right-hemispheric network for visuo-spatial remapping that subsequently transfers target location information to downstream planning regions, which are symmetrically organized.


2012 ◽  
Vol 69 (8) ◽  
pp. 681-685
Author(s):  
Natasa Djukic-Macut ◽  
Slobodan Malobabic ◽  
Natalija Stefanovic ◽  
Predrag Mandic ◽  
Tatjana Filipovic ◽  
...  

Background/Aim. Both superior parietal lobule (SPL) of dorsolateral hemispheric surface and precuneus (PEC) of medial surface are the parts of posterior parietal cortex. The aim of this study was to determine the numerical density (NV) of pyramidal neurons in the layer V of SPL and PEC and their potential differences. Methods. From 20 (40 hemispheres) formaline fixed human brains (both sexes; 27- 65 years) tissue blocks from SPL and PEC from the left and right hemisphere were used. According to their size the brains were divided into two groups, the group I with the larger left (15 brains) and the group II with the larger right hemisphere (5 brains). Serial Nissl sections (5 ?m) of the left and right SPL and PEC were used for stereological estimation of NV of the layer V pyramidal neurons. Results. NV of pyramidal neurons in the layer V in the left SPL of brains with larger left hemispheres was significantly higher than in the left SPL of brains with larger right hemisphere. Comparing sides in brains with larger left hemisphere, the left SPL had higher NV than the right one, and then the left PEC, and the right SPL had significantly higher NV than the right PEC. Comparing sides in brains with the larger right hemisphere, the left SPL had significantly higher NV than left PEC, but the right SPL had significantly higher NV than left SPL and the right PEC. Conclusion. Generally, there is an inverse relationship of NV between the medial and lateral areas of the human posterior parietal cortex. The obtained values were different between the brains with larger left and right hemispheres, as well as between the SPL and PEC. In all the comparisons the left SPL had the highest values of NV of pyramidal neurons in the layer V (4771.80 mm-3), except in brains with the larger right hemisphere.


2020 ◽  
Author(s):  
Carl E. Stevens ◽  
Darya Zabelina

Prior research has shown that greater EEG alpha power (8-13 Hz) is characteristic of more creative individuals, and more creative task conditions. The present study investigated the potential for machine learning to classify more and less creative brain states. Participants completed an Alternate Uses Task, in which they thought of Normal or Uncommon (more creative) uses for everyday objects (e.g., brick). We hypothesized that alpha power would be greater for Uncommon (vs. Common) uses, and that a machine learning (ML) approach would enable the reliable classification data from the two conditions. Further, we expected that ML would be successful at classifying more (vs. less) creative individuals. As expected, alpha power was significantly greater for the Uncommon than for the Normal condition. Using spectrally weighted common spatial patterns to extract EEG features, and quadratic discriminant analysis, we found that classification accuracy for the two conditions varied widely among individuals, with a mean of 63.9%. For more vs. less creative individuals, 82.3% classification accuracy was attained. These findings indicate the potential for broader adoption of machine learning in creativity research.


2019 ◽  
Vol 70 ◽  
pp. 09006
Author(s):  
Sergei Makhin ◽  
Elena Birukova ◽  
Elena Chuyan ◽  
Oleg Kubryak

The study of the EEG alpha reactivity patterns in the prefrontal, central, parietal and occipital regions involved 25 healthy male subjects who participated in four training sessions of controlling the power platform with visual feedback. A significant prefrontal alpha rhythm synchronization was found which was not essentially modulated in a series of subsequent trainings. A significant desynchronization of the occipital alpha was registered for the second session which gradually increased up to the fourth session. The sensorimotor alpha rhythm didn’t show regular patterns. The use of the dominant (right) hand resulted in a significant desynchronization of the parietal alpha in the right hemisphere in the third and the fourth training sessions.


Author(s):  
K.A. Morenova ◽  
O.A. Vedyasova

The objective of the paper is to analyze changes in electroencephalogram (EEG) pattern in right- and left-handers during imaginary movements of leading and non-leading legs. Materials and Methods. The authors examined 40 right-handers and 20 left-handers, whose motor domination profile was determined by standard tests. EEGs were recorded at rest and during imaginary rotational movements of the right and left legs. NVX 36 digital DC EEG neurovisor, “10–20” system, was used for this perpose. The authors also analyzed the amplitude of the EEG rhythms (standard frequency ranges), evaluated changes in hemispheric asymmetry coefficients of frontal and central alpha and beta1 rhythms as EEG correlates of imaginary activity. Results. Imaginary movements caused a decrease in the amplitude of alpha, beta1, theta and delta rhythms on EEG in all trial subjects. The intensity of observed changes in right- and left-handers differed in symmetrical leads. As for frontal and central alpha and beta1 rhythms, which marked changes in the EEG pattern during imaginary movements, right-handers demonstrated that their depression level in symmetric cortical areas depended significantly on the imaginary movements of leading and non-leading legs and dominated in left or right hemispheres, respectively. For left-handers, changes in alpha and beta1 waves during imaginary movements of leading and non-leading legs did not differ significantly and in both cases dominated in the right hemisphere. Conclusion. Thus, the intra- and inter-hemispheric dynamics of the EEG pattern, while forming the concept and program of complex motor leg actions in left-handers, is alternative in comparison to right-handers. Keywords: EEG, alpha rhythm, beta1 rhythm, imaginary leg movements, hemispheric asymmetry, right-handers, left-handers.


1992 ◽  
Vol 75 (2) ◽  
pp. 403-412 ◽  
Author(s):  
Mitsuo Hayashi ◽  
Toshio Morikawa ◽  
Tadao Hori

The relationship between hallucinatory experiences under sensory deprivation and EEG alpha activities was studied. Each of seven male students lived alone in an air conditioned, soundproof dark room for 72 hours. When hallucinatory experiences occurred, the students pressed a button at once. If they could not press the button during the experience, they were required to press it two times when the hallucinatory experience was finished. Spectral analysis was performed on the consecutive EEG samples from just before button-presses to 10 min. before them, and the average alpha band amplitudes were obtained for the four epochs (0-.5, .5-2, 2-5, 5-10 min.). For the single button-presses, the amplitude of alpha band increased 2 min. before the button-presses. Right-hemisphere EEG activation was observed in the occipital area for the double button-presses. The results suggest an association between the hallucinatory experiences under sensory deprivation and the amount of EEG alpha activity.


Author(s):  
Janet Brenya ◽  
Katherine Chavarria ◽  
Elizabeth Murray ◽  
Karen Kelly ◽  
Anjel Friest ◽  
...  

Only by understanding the ability to take third-person perspective can we begin to elucidate the neural processes responsible for one’s inimitable conscious experience. The current study examined differences in hemispheric laterality during a first-person perspective (1PP) and third-person perspective (3PP) taking task, when using Transcranial Magnetic Stimulation (TMS). Participants were asked to take either the 1PP or 3PP when identifying the number of spheres in a virtual scene. During this task, single-pulse TMS was delivered to the motor cortex of both the left and right hemispheres of 10 healthy volunteers. Measures of TMS-induced motor-evoked potentials (MEPs) of the contralateral abductor pollicis brevis (APB) were employed as an indicator of lateralized cortical activation. The data suggest that the right hemisphere is more important in discriminating between 1PP and 3PP. These data add a novel method for determining perspective taking and add to the literature supporting the role of the right hemisphere in meta representation.


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