scholarly journals Increased insula activity precedes the formation of subjective Gestalt

2022 ◽  
Author(s):  
Marilena Wilding ◽  
Christof Koerner ◽  
Anja Ischebeck ◽  
Natalia Zaretskaya
Keyword(s):  
Sensory Input ◽  
Brain Activity ◽  
Human Perception ◽  
Resting State Fmri ◽  
Stimulus Onset ◽  
Neural Mechanisms ◽  
Superior Parietal Cortex ◽  
Increased Activity ◽  
Rare Opportunity

The constructive nature of human perception sometimes leads us to perceiving rather complex impressions from simple sensory input. Bistable stimuli give us a rare opportunity to study the neural mechanisms behind this process. Such stimuli can be visually interpreted as simple or as more complex on the basis of the same sensory input. Previous studies demonstrated increased activity in the superior parietal cortex when participants perceived an illusory Gestalt impression compared to a simpler interpretation of individual elements. Here we tested whether activity related to the illusory Gestalt can be detected not only during, but also prior to it, by examining the slow fluctuations of resting-state-fMRI activity before the stimulus onset. We presented 31 participants with a bistable motion stimulus, which can be perceived either as four moving dot pairs (local) or two moving illusory squares (global). This allowed us to isolate the specific neural mechanisms that accompany the experience of an illusion under matched sensory input. fMRI was used to measure brain activity in a sparse event-related design. We observed stronger IPS and putamen responses to the stimulus when participants perceived the global interpretation compared to local, confirming the previously reported role of these areas in perceptual grouping. Most importantly, we also observed that the global stimulus interpretation was preceded by an increased activity of the bilateral dorsal insula, which is known to process saliency and gate information for conscious access. Our data suggest an important role of the dorsal insula in shaping an internally generated illusory Gestalt percept.

scholarly journals Neural mechanisms underlying regulation of empathy and altruism by beliefs of others' pain

2021 ◽  
Author(s):  
Tao Yu ◽  
Shihui Han
Keyword(s):  
Real Life ◽  
Stimulus Onset ◽  
Neural Mechanisms ◽  
Altruistic Behavior ◽  
Emotional States ◽  
Neural Responses ◽  
Temporoparietal Junction ◽  
Subjective Estimation ◽  
Show Evidence

Perceived cues signaling others' pain induce empathy that in turn motivates altruistic behavior toward those who appear suffering. This perception-emotion-behavior reactivity is the core of human altruism but does not always occur in real life situations. Here, by integrating behavioral and multimodal neuroimaging measures, we investigate neural mechanisms underlying the functional role of beliefs of others' pain in modulating empathy and altruism. We show evidence that decreasing (or enhancing) beliefs of others' pain reduces (or increases) subjective estimation of others' painful emotional states and monetary donations to those who show pain expressions. Moreover, decreasing beliefs of others' pain attenuates neural responses to perceived cues signaling others' pain within 200 ms after stimulus onset and modulate neural responses to others' pain in the frontal cortices and temporoparietal junction. Our findings highlight beliefs of others' pain as a fundamental cognitive basis of human empathy and altruism and unravel the intermediate neural architecture.

The Cognitive Neuroscience of Source Monitoring

2015 ◽  
Author(s):  
Karen J. Mitchell
Keyword(s):  
Source Monitoring ◽  
Brain Activity ◽  
Historical Context ◽  
Neural Mechanisms ◽  
Multiple Features ◽  
Neural Architecture ◽  
Big Picture ◽  
Key Issues ◽  
Neuroimaging Techniques

Source monitoring is a metamemory function that includes processes for encoding and organizing the content of memories, and processes that selectively revive, cumulate, and evaluate that content in the service of making attributions about the origin of the information (e.g., perception vs imagination). Neuroimaging techniques, especially functional magnetic resonance imaging (fMRI), are encouraging rapid developments in understanding the neural mechanisms supporting source monitoring. This chapter reviews current findings, placing them in historical context. It highlights key issues of particular relevance, including: neural reinstatement—the match between brain activity at encoding and later remembering; the role of lateral parietal cortex in cumulating multiple features and attending to information during remembering; functional specificity of the prefrontal cortex with respect to cognitive control; and identifying functional networks that support source monitoring. Suggestions are made for clarifying the big picture and increasing the specificity of our understanding of source monitoring and its neural architecture.

scholarly journals Effect of Acupuncture ‘dose— on Modulation of the Default Mode Network of the Brain

2016 ◽  
Vol 34 (6) ◽  
pp. 425-432 ◽  
Author(s):  
Yii-Jeng Lin ◽  
Yen-Ying Kung ◽  
Wen-Jui Kuo ◽  
David M Niddam ◽  
Chih-Che Chou ◽  
...  
Keyword(s):  
Default Mode Network ◽  
Brain Activity ◽  
Resting State Fmri ◽  
Default Mode ◽  
Left Hand ◽  
Conventional Methods ◽  
The Right ◽  
Active Controls ◽  
Increased Activity ◽  
Needle Acupuncture

Objective Recent functional MRI (fMRI) studies show that brain activity, including the default mode network (DMN), can be modulated by acupuncture. Conventional means to enhance the neurophysiological ‘dose’ of acupuncture, including an increased number of needles and manual needle manipulation, are expected to enhance its physiological effects. The aim of this study was to compare the effects of both methods on brain activity. Methods 58 healthy volunteers were randomly assigned into four groups that received single needle acupuncture (SNA, n=15) or transcutaneous electrical nerve stimulation (TENS, n=13) as active controls, or enhanced acupuncture by way of three needle acupuncture (TNA, n=17) or SNA plus manual stimulation (SNA+MS, n=13). Treatment-associated sensations were evaluated using a visual analogue scale. Central responses were recorded before, during, and after treatment at LI4 on the left hand using resting state fMRI. Results TNA and SNA+MS induced DMN-insula activity and extensive DMN activity compared to SNA, despite comparable levels of de qi sensation. The TNA and SNA+MS groups exhibited a delayed and enhanced modulation of the DMN, which was not observed followed SNA and TENS. Furthermore, TNA increased precuneus activity and increased the DMN-related activity of the cuneus and left insula, while SNA+MS increased activity in the right insula. Conclusions The results showed that conventional methods to enhance the acupuncture dose induce different DMN modulatory effects. TNA induces the most extensive DMN modulation, compared with other methods. Conventional methods of enhancing the acupuncture dose could potentially be applied as a means of modulating brain activity.

scholarly journals Selective Attention and Multisensory Integration: Multiple Phases of Effects on the Evoked Brain Activity

2005 ◽  
Vol 17 (7) ◽  
pp. 1098-1114 ◽  
Author(s):  
Durk Talsma ◽  
Marty G. Woldorff
Keyword(s):  
Multisensory Integration ◽  
Brain Activity ◽  
Event Related Potentials ◽  
Random Order ◽  
Stimulus Onset ◽  
Variable Stimulus ◽  
Processing Negativity ◽  
Related Potentials ◽  
Anticipatory Activity

We used event-related potentials (ERPs) to evaluate the role of attention in the integration of visual and auditory features of multisensory objects. This was done by contrasting the ERPs to multisensory stimuli (AV) to the sum of the ERPs to the corresponding auditory-only (A) and visual-only (V) stimuli [i.e., AV vs. (A + V)]. V, A, and VA stimuli were presented in random order to the left and right hemispaces. Subjects attended to a designated side to detect infrequent target stimuli in either modality there. The focus of this report is on the ERPs to the standard (i.e., nontarget) stimuli. We used rapid variable stimulus onset asynchronies (350-650 msec) to mitigate anticipatory activity and included “no-stim” trials to estimate and remove ERP overlap from residual anticipatory processes and from adjacent stimuli in the sequence. Spatial attention effects on the processing of the unisensory stimuli consisted of a modulation of visual P1 and N1 components (at 90-130 msec and 160-200 msec, respectively) and of the auditory N1 and processing negativity (100-200 msec). Attended versus unattended multisensory ERPs elicited a combination of these effects. Multisensory integration effects consisted of an initial frontal positivity around 100 msec that was larger for attended stimuli. This was followed by three phases of centro-medially distributed effects of integration and/or attention beginning at around 160 msec, and peaking at 190 (scalp positivity), 250 (negativity), and 300-500 msec (positivity) after stimulus onset. These integration effects were larger in amplitude for attended than for unattended stimuli, providing neural evidence that attention can modulate multisensory-integration processes at multiple stages.

Dorsolateral Prefrontal Cortex Enables Updating of Established Memories

2018 ◽  
Vol 29 (10) ◽  
pp. 4154-4168 ◽  
Author(s):  
Lisa Marieke Kluen ◽  
Lisa Catherine Dandolo ◽  
Gerhard Jocham ◽  
Lars Schwabe
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Neural Mechanisms ◽  
Related Activity ◽  
Future Behavior ◽  
New Information ◽  
Dorsolateral Prefrontal ◽  
Increased Activity ◽  
The Brain

Abstract Updating established memories in light of new information is fundamental for memory to guide future behavior. However, little is known about the brain mechanisms by which existing memories can be updated. Here, we combined functional magnetic resonance imaging and multivariate representational similarity analysis to elucidate the neural mechanisms underlying the updating of consolidated memories. To this end, participants first learned face–city name pairs. Twenty-four hours later, while lying in the MRI scanner, participants were required to update some of these associations, but not others, and to encode entirely new pairs. Updating success was tested again 24 h later. Our results showed increased activity of the dorsolateral prefrontal cortex (dlPFC) specifically during the updating of existing associations that was significantly stronger than when simple retrieval or new encoding was required. The updating-related activity of the dlPFC and its functional connectivity with the hippocampus were directly linked to updating success. Furthermore, neural similarity for updated items was markedly higher in the dlPFC and this increase in dlPFC neural similarity distinguished individuals with high updating performance from those with low updating performance. Together, these findings suggest a key role of the dlPFC, presumably in interaction with the hippocampus, in the updating of established memories.

scholarly journals From visual awareness to consciousness without sensory input: The role of spontaneous brain activity

2020 ◽  
Vol 37 (3-4) ◽  
pp. 216-219
Author(s):  
Marine Vernet ◽  
Romain Quentin ◽  
Shruti Japee ◽  
Leslie G. Ungerleider
Keyword(s):  
Sensory Input ◽  
Brain Activity ◽  
Visual Awareness ◽  
Spontaneous Brain Activity

scholarly journals Role of Prefrontal Cortex during Sudoku task: fNIRS study

2020 ◽  
Author(s):  
Patil Ashlesh ◽  
K K Deepak ◽  
Kochhar Kanwal Preet
Keyword(s):  
Prefrontal Cortex ◽  
Near Infrared ◽  
Brain Activity ◽  
Neural Substrates ◽  
List Type ◽  
Heuristic Rules ◽  
Functional Near Infrared Spectroscopy ◽  
Time Activity ◽  
Increased Activity

AbstractSudoku is a popular leisure time activity that involves no math, but is based on logic based combinatorial number placement in a matrix. Many studies have been dedicated towards finding an algorithm to solve Sudoku but investigation of the neural substrates involved in Sudoku has been challenging. It is difficult to measure the brain activity during 9×9 Sudoku using traditional fMRI technique due to the procedural constraints. 16 optodes fNIRS (functional near infrared spectroscopy) forms an excellent alternative to study the activity of prefrontal cortex (PFC) during Sudoku task. Sudoku task was divided into two steps to understand the differential function of the PFC while applying heuristic rules. Classical two-way ANOVA as well as General Linear Model based approach was used to analyze the data. 28-noise free recording from right-handed participants revealed increased activity in all 16 optode locations during step 1 (3 × 3 subgrids) and step 2 (easy level 9×9 Sudoku) as compared to rest. Contrasting the step2-step1 revealed that medial regions of PFC were preferentially activated. These findings suggest the role of these regions, while applying multiple heuristic rules to solve 9×9 Sudoku puzzle.Graphical abstractHighlightsThis is first fNIRS study that tried to unravel the role of PFC during Sudoku task.Uniquely divided the Sudoku task into two steps to understand the differential role of PFC while applying multiple heuristic rules.Both the medial and lateral regions of PFC are activated during Sudoku task.However, the medial regions of PFC play a differential role, especially when we consider the row and the column rule of Sudoku.

scholarly journals Social network positions, trust behavior and its neural mechanisms in young adolescents

2020 ◽  
Author(s):  
Hester Sijtsma ◽  
Mariet van Buuren ◽  
Miriam Hollarek ◽  
Reubs J Walsh ◽  
Nikki Lee ◽  
...  
Keyword(s):  
Social Network ◽  
Brain Activity ◽  
Neural Mechanisms ◽  
Trust Game ◽  
Young Adolescents ◽  
Fmri Study ◽  
Current Interaction ◽  
Fmri Analysis ◽  
Reward Network ◽  
Increased Activity

Assessing the trustworthiness of others to learn who you can and cannot trust is important for social relationships. During early adolescence, the social environment becomes increasingly complex. The number and nature of one’s friendships may help to shape, and may be facilitated by, adequate trust behavior. In the current fMRI study, we investigated in 49 young adolescents (Mage=12.8, SDage=0.4, 18 boys) the ability to adapt trust behavior when interacting with an untrustworthy partner as well as the neural mechanisms of trust using a trust game. Furthermore, we examined how trust behavior, the neural mechanisms of trust, and the position in a social network are related. Results indicate that adolescents decreased their trust behavior throughout the game. fMRI analysis showed no increased activity in regions of interest when making trust decisions. When receiving feedback, increased activity in the cognitive control and reward network was shown. Furthermore, less central social network positions (eigencentrality) were associated with lower overall trust behavior, which was the better strategy in the current interaction. In contrast, eigencentrality was not related to the adaptation of trust behavior or to brain activity. The current study provides insights in trust behavior and the neural mechanisms of trust in young adolescents.

Brain activity during externally and internally guided movements in patients with Parkinsons disease

2020 ◽  
Author(s):  
Veronika Filyushkina ◽  
Valentin S Popov ◽  
Vadim Y. Ushakov ◽  
Artem Batalov ◽  
Alexey Tomskiy ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Basal Ganglia ◽  
Brain Activity ◽  
Neural Mechanisms ◽  
Voluntary Movements ◽  
Parkinsons Disease ◽  
Ipsilateral Hemisphere ◽  
Healthy Participants

An imbalance in the activity of the basal ganglia in Parkinsons disease is known to result in disturbance of the planning and initiation of mainly self-initiated voluntary movements. The effectiveness of self-initiated movements can be improved by adding an external stimulus. Despite a large number of studies in this area, the neural mechanisms of motor control of these movements and the role of the basal ganglia in their implementation remain unknown. The aim of the study was to compare brain activity during the execution of externally triggered (ET) and internally guided (IG) movements in normal state and Parkinson's disease. We used functional MRI with block designed paradigm to analyze brain activity caused by voluntary movements. Twenty healthy participants and twenty Parkinson's disease patients (OFF-state) were asked to perform hand movements in response to sound stimuli (ET) and in advance of the stimuli (IG). We showed that brain activity during externally induced movements is lateralized mainly in the contralateral hemisphere, both in normal and in Parkinson's disease. During the IG movement, brain activity was observed also in the ipsilateral hemisphere, to a greater extent in patients, which indicates difficulty in performing this test. At the same time, in patients, activation was observed not only in the posterior parts of the putamen but also in the anterior ones during IG movements. These results showed that IG movements in patients with PD were made with the participation of both sensorimotor and associative basal ganglia-thalamocortical loops. This work was supported by RFBR 19-315-90097 .

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