scholarly journals Inhibitory Control in the Absence of Awareness: Interactions Between Frontal and Motor Cortex Oscillations Mediate Implicitly Learned Responses

2021 ◽  
Vol 15 ◽  
Author(s):  
Silvia L. Isabella ◽  
J. Allan Cheyne ◽  
Douglas Cheyne
Keyword(s):  
Cognitive Control ◽  
Pupil Diameter ◽  
Reaction Times ◽  
Brain Regions ◽  
Cognitive Effort ◽  
Theta Activity ◽  
Theta Oscillations ◽  
Response Preparation ◽  
Experimental Conditions ◽  
Theta Power

Cognitive control of action is associated with conscious effort and is hypothesised to be reflected by increased frontal theta activity. However, the functional role of these increases in theta power, and how they contribute to cognitive control remains unknown. We conducted an MEG study to test the hypothesis that frontal theta oscillations interact with sensorimotor signals in order to produce controlled behaviour, and that the strength of these interactions will vary with the amount of control required. We measured neuromagnetic activity in 16 healthy adults performing a response inhibition (Go/Switch) task, known from previous work to modulate cognitive control requirements using hidden patterns of Go and Switch cues. Learning was confirmed by reduced reaction times (RT) to patterned compared to random Switch cues. Concurrent measures of pupil diameter revealed changes in subjective cognitive effort with stimulus probability, even in the absence of measurable behavioural differences, revealing instances of covert variations in cognitive effort. Significant theta oscillations were found in five frontal brain regions, with theta power in the right middle frontal and right premotor cortices parametrically increasing with cognitive effort. Similar increases in oscillatory power were also observed in motor cortical gamma, suggesting an interaction. Right middle frontal and right precentral theta activity predicted changes in pupil diameter across all experimental conditions, demonstrating a close relationship between frontal theta increases and cognitive control. Although no theta-gamma cross-frequency coupling was found, long-range theta phase coherence among the five significant sources between bilateral middle frontal, right inferior frontal, and bilateral premotor areas was found, thus providing a mechanism for the relay of cognitive control between frontal and motor areas via theta signalling. Furthermore, this provides the first evidence for the sensitivity of frontal theta oscillations to implicit motor learning and its effects on cognitive load. More generally these results present a possible a mechanism for this frontal theta network to coordinate response preparation, inhibition and execution.

Theta Oscillations in Primate Prefrontal and Anterior Cingulate Cortices in Forewarned Reaction Time Tasks

2010 ◽  
Vol 103 (2) ◽  
pp. 827-843 ◽  
Author(s):  
Toru Tsujimoto ◽  
Hideki Shimazu ◽  
Yoshikazu Isomura ◽  
Kazuo Sasaki
Keyword(s):  
Reaction Time ◽  
Hand Movement ◽  
Theta Activity ◽  
Anterior Cingulate ◽  
Theta Oscillations ◽  
Theta Power ◽  
Monkey Model ◽  
Period 2 ◽  
Reward Delivery ◽  
Frontal Midline Theta

Previously, we introduced a monkey model for human frontal midline theta oscillations as a possible neural correlate of attention. It was based on homologous theta oscillations found in the monkey's prefrontal and anterior cingulate cortices (areas 9 and 32) in a self-initiated hand-movement task. However, it has not been confirmed whether theta activity in the monkey model consistently appears in other situations demanding attention. Here, we examined the detailed properties of theta oscillations in four variations of forewarned reaction time tasks with warning (S1) and imperative (S2) stimuli. We characterized the theta oscillations generated exclusively in areas 9 and 32, as follows: 1) in the S1-S2 interval where movement preparation and reward expectation were presumably involved, the theta power was higher than in the pre-S1 period; 2) in the no-go trials of go/no-go tasks instructed by S1, the theta power in the S1-S2 interval was lower than in the pre-S1 period in an asymmetrical reward condition, whereas it was moderately higher in a symmetrical condition; 3) the theta power after reward delivery was higher than in the unrewarded trials; 4) the theta power in the pre-S1 period was higher than in the resting condition; and 5) when the monkey had to guess the S1-S2 duration internally without seeing S2, the theta power in the pre-S1 period was higher than in the original S1-S2 experiment. These findings suggest that attentional loads associated with different causes can induce the same theta activity, thereby supporting the consistency of attention-dependent theta oscillations in our model.

scholarly journals Stimulus dependence of theta rhythmic activity in primate V1 and its potential relevance for visual perception

2021 ◽  
Author(s):  
Prasakti Tenri Fanyiwi ◽  
Beshoy Agayby ◽  
Ricardo Kienitz ◽  
Marcus Haag ◽  
Michael C. Schmid
Keyword(s):  
Visual Perception ◽  
Visual Stimulus ◽  
Neural Activity ◽  
Temporal Dynamics ◽  
Reaction Times ◽  
Rhythmic Activity ◽  
Peak Frequency ◽  
Theta Oscillations ◽  
Theta Power ◽  
Fixational Eye Movements

AbstractA growing body of psychophysical research reports theta (3-8 Hz) rhythmic fluctuations in visual perception that are often attributed to an attentional sampling mechanism arising from theta rhythmic neural activity in mid- to high-level cortical association areas. However, it remains unclear to what extent such neuronal theta oscillations might already emerge at early sensory cortex like the primary visual cortex (V1), e.g. from the stimulus filter properties of neurons. To address this question, we recorded multi-unit neural activity from V1 of two macaque monkeys viewing a static visual stimulus with variable sizes, orientations and contrasts. We found that among the visually responsive electrode sites, more than 50 % showed a spectral peak at theta frequencies. Theta power varied with varying basic stimulus properties. Within each of these stimulus property domains (e.g. size), there was usually a single stimulus value that induced the strongest theta activity. In addition to these variations in theta power, the peak frequency of theta oscillations increased with increasing stimulus size and also changed depending on the stimulus position in the visual field. Further analysis confirmed that this neural theta rhythm was indeed stimulus-induced and did not arise from small fixational eye movements (microsaccades). When the monkeys performed a detection task of a target embedded in a theta-generating visual stimulus, reaction times also tended to fluctuate at the same theta frequency as the one observed in the neural activity. The present study shows that a highly stimulus-dependent neuronal theta oscillation can be elicited in V1 that appears to influence the temporal dynamics of visual perception.

scholarly journals Tracking reading strategy utilisation through pupillometry

2016 ◽  
Vol 32 (6) ◽  
Author(s):  
Aaron Y. Wong ◽  
Jarrod Moss ◽  
Christian D. Schunn
Keyword(s):  
Cognitive Control ◽  
Reading Strategies ◽  
Pupil Diameter ◽  
Reading Strategy ◽  
Brain Regions ◽  
Expository Texts ◽  
Learning Gains ◽  
Norepinephrine System ◽  
Comprehension Tests

Explicit reading strategies help low-knowledge readers make the inferences necessary to comprehend expository texts. Self-explanation is a particularly effective strategy, but it is challenging to monitor how well a reader is applying self-explanation without requiring the reader to externalise the self-explanations being generated. Studies have shown that different reading strategies vary in the amount of cognitive control required as well as the engagement of brain regions involved in internally-directed attention. Pupil diameter is related to task engagement and cognitive control via the brain’s locus coeruleus-norepinephrine system. Therefore, pupil diameter could be a method to unobtrusively measure a reader’s use of self-explanation. The current study assessed whether pupil diameter can be used to distinguish between the use of different reading strategies and whether it is linked to the quality and effectiveness of the strategy in terms of learning gains. Participants reread, paraphrased, and self-explained texts while pupil diameter was recorded, and completed comprehension tests. Average pupil diameter differed between all three reading strategies, and pupil diameter was related to learning gains and the quality of strategy use. The results suggest that pupil diameter could be used to track effective reading strategy utilisation.

ERPs and Neural Oscillations during Volitional Suppression of Memory Retrieval

2013 ◽  
Vol 25 (10) ◽  
pp. 1624-1633 ◽  
Author(s):  
Brendan Eliot Depue ◽  
Nick Ketz ◽  
Matthew V. Mollison ◽  
Erika Nyhus ◽  
Marie T. Banich ◽  
...  
Keyword(s):  
Cognitive Control ◽  
Memory Retrieval ◽  
Spectral Power ◽  
Theta Oscillations ◽  
Neural Oscillations ◽  
Alpha Power ◽  
Theta Power ◽  
Eeg Spectral Power

Although investigations of memory and the dynamics of ERP components and neural oscillations as assessed through EEG have been well utilized, little research into the volitional nature of suppression over memory retrieval have used these methods. Oscillation analyses conducted on the Think/No-Think (TNT) task and volitional suppression of retrieval are of interest to broaden our knowledge of neural oscillations associated not only during successful memory retrieval but also when retrieval is unwanted or suppressed. In the current study, we measured EEG during a TNT task and performed ERP and EEG spectral power band analyses. ERP results replicated other researchers' observations of increases in 500–800 msec parietal effects for items where retrieval was instructed to be elaborated compared with being suppressed. Furthermore, EEG analyses indicated increased alpha (8–12 Hz) and theta (3–8 Hz) oscillations across parietal electrodes for items that were instructed to be suppressed versus those to be elaborated. Additionally, during the second half of the experiment (after repeated attempts at control), increases in theta oscillations were found across both frontal and parietal electrodes for items that were instructed to be suppressed and that were ultimately forgotten versus those ultimately remembered. Increased alpha power for items that were instructed to be suppressed versus elaborated may indicate reductions of retrieval attempts or lack of retrieval success. Increased theta power for items that were instructed to be suppressed versus elaborated may indicate increased or prolonged cognitive control to monitor retrieval events.

Behavioral correlates of human hippocampal delta and theta oscillations during navigation

2011 ◽  
Vol 105 (4) ◽  
pp. 1747-1755 ◽  
Author(s):  
Andrew J. Watrous ◽  
Itzhak Fried ◽  
Arne D. Ekstrom
Keyword(s):  
Low Frequency ◽  
Theta Activity ◽  
Theta Oscillations ◽  
Spatial Updating ◽  
Behavioral Correlates ◽  
Theta Power ◽  
Relevant Variables ◽  
Spatial View ◽  
Intracranial Electrodes

Previous rodent studies demonstrate movement-related increases in theta oscillations, and recent evidence suggests that multiple navigationally relevant variables are reflected in this activity. Human invasive recordings have revealed movement-related modulations in delta and theta activity, although it is unclear whether additional behavioral variables are responsible for modulating this neural activity during navigation. We tested the role of delta and theta oscillations during navigation by addressing whether spatial-related processing, in addition to speed and task variables, modulates delta and theta activity. Recording from 317 hippocampal intracranial electrodes in 10 patients undergoing seizure monitoring, we observed increasing delta and theta power with increasing virtual speed at significantly more electrodes than would be expected by chance, replicating previous findings in nonhuman mammals. Delta and theta power were more consistently modulated, however, as a function of spatial view, including when subjects looked at stores in the virtual environment both to find a relevant goal or for spatial updating. A significantly larger proportion of electrodes showed view-related effects than speed-related modulations. Although speed, task, and spatial view affected delta and theta activity, individual electrodes were most frequently modulated by only one variable, rather than a combination of variables. These electrodes likely sampled independent delta and theta generators, which reflected movement-related and allocentric processing, respectively. These results extend previous findings in nonhuman mammals and humans, expanding our knowledge of the role of human hippocampal low-frequency oscillations in navigation.

scholarly journals Atypical mediofrontal theta oscillations underlying cognitive control in kindergarteners with autism spectrum disorder

2020 ◽  
Author(s):  
George A. Buzzell ◽  
Hannah R. Thomas ◽  
Yeo Bi Choi ◽  
So Hyun Kim
Keyword(s):  
Autism Spectrum Disorder ◽  
Cognitive Control ◽  
Time Window ◽  
Selective Reduction ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Theta Oscillations ◽  
Theta Power ◽  
Children With Asd ◽  
Following Error

AbstractBackgroundChildren with autism spectrum disorder (ASD) often exhibit deficits in cognitive control. Neuroimaging approaches have implicated disruptions to medio-frontal cortex (MFC) structure and function. However, prior work has not directly tested whether young children with ASD exhibit disruptions to task-related theta oscillations thought to arise from the MFC.MethodsForty-three children with ASD and 24 age- and gender-matched typically developing (TD) peers performed a child-friendly Go/No-go task while 64-channel electroencephalography (EEG) was recorded at kindergarten-entry. Time-frequency approaches were employed to assess the magnitude of mediofrontal theta oscillations immediately following error (vs. correct) responses (“early theta”), as well as later emerging theta oscillations (“late theta”). We tested whether error-related mediofrontal theta oscillations differed as a function of diagnosis (ASD/typical) and timing (early/late theta). Additionally, links to social and academic outcomes were tested.ResultsOverall, children showed increased theta power following error vs. correct responses. Compared to TD children, children with ASD exhibited a selective reduction in error-related mediofrontal theta power during the late theta time window. There were no significant group differences for early theta power. Moreover, reduced error-related theta power during the late, but not early, time window significantly predicted poorer academic and social skills.ConclusionsKindergarteners with ASD demonstrated a selective reduction in error-related mediofrontal theta power during a relatively late time window, which is consistent with impairments in specific cognitive processes that recruit top-down control. Targeting these particular cognitive control processes via intervention prior to school-entry may promote more successful functional outcomes for children with ASD.

Cognitive Control in Semantic Memory

2018 ◽  
Author(s):  
Jason Geller ◽  
Daniel Mirman ◽  
Jon-Frederick Landrigan
Keyword(s):  
Cognitive Control ◽  
Reaction Times ◽  
Semantic Knowledge ◽  
Cognitive Effort ◽  
Pupillary Responses ◽  
Thematic Relations ◽  
Lower Accuracy ◽  
Sensory Motor ◽  
Low Strength ◽  
Taxonomic Relations

Semantic cognition includes taxonomic and thematic relationships, as well as control systems to retrieve and manipulate semantic knowledge to suit specific tasks or contexts. A recent report (Thompson et al., 2017) suggested that retrieving thematic relationships (i.e., relations based on participation in the same event or scenarios) requires more effort or cognitive control, especially when the relevant relations are weak, than retrieving identity relations that are based on sensory-motor features. It is not clear whether the same contrast applies to the broader set of taxonomic relations, which are also based on shared sensory-motor features. In this study we tested cognitive control requirements of retrieving taxonomic and thematic knowledge using a physiological measure of cognitive effort: pupil dilation. Participants completed a semantic relatedness judgement task that manipulated semantic type (thematic vs. taxonomic) and relatedness strength (high vs. low) of word pairs. Cognitive control in the similarity task was examined using task-evoked pupillary responses (TEPRs), as well as standard behavioral measures (reaction times and accuracy). Compared with high-strength relations, low-strength semantic relations elicited larger TERPs, slower reaction times, and lower accuracy, consistent with higher control demands. Compared to thematic relations, taxonomic relations also elicited larger TERPs and slower reaction times, suggesting that retrieving taxonomic relations required more cognitive effort. Critically, our pupillometric data indicated that controlled processing was particularly important for low-strength taxonomic pairs rather than low-strength thematic pairs. These findings indicate that semantic control demands are primarily determined by relatedness strength, not whether the relationship is taxonomic or thematic.

scholarly journals Unconscious learning and automatic inhibition are accompanied by frontal theta and sensorimotor interactions

2019 ◽  
Author(s):  
Silvia L. Isabella ◽  
J. Allan Cheyne ◽  
Douglas Cheyne
Keyword(s):  
Response Inhibition ◽  
Cognitive Activity ◽  
Reaction Times ◽  
Theta Activity ◽  
Pattern Learning ◽  
Stimulus Probability ◽  
Theta Band ◽  
Response Preparation ◽  
Frontal Activity ◽  
Band Activity

AbstractCognitive control of behavior is often accompanied by theta-band activity in the frontal cortex, and is crucial for overriding habits and producing desired actions. However, the functional role of theta activity in controlled behavior remains to be determined. Here, we used a behavioral task (Isabella et al., 2019) that covertly manipulated the ability to inhibit (and switch) motor responses using a repeating pattern of stimuli that reduced reaction times (RT) to probable over unexpected stimuli, without participants’ awareness of the pattern. We combined this task with concurrent measures of brain activity and pupil diameter (as a measure of cognitive activity) of 16 healthy adults during response preparation and inhibition during changes in stimulus probability. Observed RT provided evidence of pattern learning and pupillometry revealed parametric changes in cognitive activity with stimulus probability. Critically, reliable pupillary effects (Hedge’s g = 1.38) in the absence of RT differences (g = 0.10) indicated that cognitive activity increased without overt changes in behavior (RT). Such increased cognitive activity was accompanied by parametric increases in frontal theta and sensorimotor gamma. In addition, correlation between pre-stimulus beta and pre-response gamma in the motor cortex and post-stimulus frontal theta activity suggest bidirectional interactions between motor and frontal areas. These interactions likely underlie recruitment of preparatory and inhibitory neural activity during rapid motor control. Furthermore, pupillary and frontal theta effects during learned switches demonstrate that increases in inhibitory control of behavior can occur automatically, without conscious awareness.Significance StatementGoal-directed control is crucial for overriding habits and producing desired actions, which can fail during errors and accidents, and may be impaired in addiction, attention-deficit disorders, or dementia. This type of control, including response inhibition, is typically accompanied by frontal theta-band activity. We examined the relationship between frontal theta and response inhibition during unconscious pattern learning. First, we found that frontal activity was sensitive to changes in control and correlated with reaction times. Second, insufficient motor preparation predicted greater frontal activity, reflecting a greater need for control, which in turn predicted greater response-related motor activity. These results link the frontal and motor cortices, providing possible mechanisms for controlled behavior while demonstrating that goal-directed control can proceed automatically and unconsciously.

scholarly journals Antagonism between brain regions relevant for cognitive control and emotional memory facilitates the generation of humorous ideas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Florian Bitsch ◽  
Philipp Berger ◽  
Andreas Fink ◽  
Arne Nagels ◽  
Benjamin Straube ◽  
...  
Keyword(s):  
Cognitive Control ◽  
Positive Emotions ◽  
Emotional Memory ◽  
Brain Regions ◽  
Neural Mechanisms ◽  
Functional Magnetic Resonance ◽  
Frontal Brain ◽  
Successful Resolution ◽  
Neural Underpinnings ◽  
The Brain

AbstractThe ability to generate humor gives rise to positive emotions and thus facilitate the successful resolution of adversity. Although there is consensus that inhibitory processes might be related to broaden the way of thinking, the neural underpinnings of these mechanisms are largely unknown. Here, we use functional Magnetic Resonance Imaging, a humorous alternative uses task and a stroop task, to investigate the brain mechanisms underlying the emergence of humorous ideas in 24 subjects. Neuroimaging results indicate that greater cognitive control abilities are associated with increased activation in the amygdala, the hippocampus and the superior and medial frontal gyrus during the generation of humorous ideas. Examining the neural mechanisms more closely shows that the hypoactivation of frontal brain regions is associated with an hyperactivation in the amygdala and vice versa. This antagonistic connectivity is concurrently linked with an increased number of humorous ideas and enhanced amygdala responses during the task. Our data therefore suggests that a neural antagonism previously related to the emergence and regulation of negative affective responses, is linked with the generation of emotionally positive ideas and may represent an important neural pathway supporting mental health.

scholarly journals Recovery of Platinum from a Spent Automotive Catalyst through Chloride Leaching and Solvent Extraction

Recycling ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 27
Author(s):  
Ana Méndez ◽  
Carlos A. Nogueira ◽  
Ana Paula Paiva
Keyword(s):  
Solvent Extraction ◽  
Environmental Sustainability ◽  
Catalytic Converter ◽  
Reaction Times ◽  
Model Solution ◽  
Critical Metals ◽  
Experimental Conditions ◽  
Chloride Leaching ◽  
Good Potential ◽  
Hydrometallurgical Treatment

Considering economics and environmental sustainability, recycling of critical metals from end-of-life devices should be a priority. In this work the hydrometallurgical treatment of a spent automotive catalytic converter (SACC) using HCl with CaCl2 as a leaching medium, and solvent extraction (SX) with a thiodiglycolamide derivative, is reported. The aim was to develop a leaching scheme allowing high Pt recoveries and minimizing Al dissolution, facilitating the application of SX. The replacement of part of HCl by CaCl2 in the leaching step is viable, without compromising Pt recovery (in the range 75–85%), as found for the mixture 2 M CaCl2 + 8 M HCl when compared to 11.6 M HCl. All leaching media showed good potential to recover Ce, particularly for higher reaction times and temperatures. Regarding SX, results achieved with a model solution were promising, but SX for Pt separation from the real SACC solution did not work as expected. For the adopted experimental conditions, the tested thiodiglycolamide derivative in toluene revealed a very good loading performance for both Pt and Fe, but Fe removal and Pt stripping from the organic phases after contact with the SACC solution were not successfully accomplished. Hence, the reutilization of the organic solvent needs improvement.

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