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

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.

2012 ◽  
Vol 107 (12) ◽  
pp. 3458-3467 ◽  
Author(s):  
Iris Steinmann ◽  
Alexander Gutschalk

Human functional MRI (fMRI) and magnetoencephalography (MEG) studies indicate a pitch-specific area in lateral Heschl's gyrus. Single-cell recordings in monkey suggest that sustained-firing, pitch-specific neurons are located lateral to primary auditory cortex. We reevaluated whether pitch strength contrasts reveal sustained pitch-specific responses in human auditory cortex. Sustained BOLD activity in auditory cortex was found for iterated rippled noise (vs. noise or silence) but not for regular click trains (vs. jittered click trains or silence). In contrast, iterated rippled noise and click trains produced similar pitch responses in MEG. Subsequently performed time-frequency analysis of the MEG data suggested that the dissociation of cortical BOLD activity between iterated rippled noise and click trains is related to theta band activity. It appears that both sustained BOLD and theta activity are associated with slow non-pitch-specific stimulus fluctuations. BOLD activity in the inferior colliculus was sustained for both stimulus types and varied neither with pitch strength nor with the presence of slow stimulus fluctuations. These results suggest that BOLD activity in auditory cortex is much more sensitive to slow stimulus fluctuations than to constant pitch, compromising the accessibility of the latter. In contrast, pitch-related activity in MEG can easily be separated from theta band activity related to slow stimulus fluctuations.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Hannah Brauer ◽  
Navah Ester Kadish ◽  
Anya Pedersen ◽  
Michael Siniatchkin ◽  
Vera Moliadze

Response inhibition is the cognitive process required to cancel an intended action. During that process, a “go” reaction is intercepted particularly by the right inferior frontal gyrus (rIFG) and presupplementary motor area (pre-SMA). After the commission of inhibition errors, theta activity (4–8 Hz) is related to the adaption processes. In this study, we intend to examine whether the boosting of theta activity by electrical stimulation over rIFG reduces the number of errors and the reaction times in a response inhibition task (Go/NoGo paradigm) during and after stimulation. 23 healthy right-handed adults participated in the study. In three separate sessions, theta tACS at 6 Hz, transcranial random noise (tRNS) as a second stimulation condition, and sham stimulation were applied for 20 minutes. Based on behavioral data, this study could not show any effects of 6 Hz tACS as well as full spectrum tRNS on response inhibition in any of the conditions. Since many findings support the relevance of the rIFG for response inhibition, this could mean that 6 Hz activity is not important for response inhibition in that structure. Reasons for our null findings could also lie in the stimulation parameters, such as the electrode montage or the stimulation frequency, which are discussed in this article in more detail. Sharing negative findings will have (1) positive impact on future research questions and study design and will improve (2) knowledge acquisition of noninvasive transcranial brain stimulation techniques.


2021 ◽  
Vol 15 ◽  
Author(s):  
Silvia L. Isabella ◽  
J. Allan Cheyne ◽  
Douglas Cheyne

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.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Shenghong He ◽  
Abteen Mostofi ◽  
Emilie Syed ◽  
Flavie Torrecillos ◽  
Gerd Tinkhauser ◽  
...  

Previous studies have explored neurofeedback training for Parkinsonian patients to suppress beta oscillations in the subthalamic nucleus (STN). However, its impacts on movements and Parkinsonian tremor are unclear. We developed a neurofeedback paradigm targeting STN beta bursts and investigated whether neurofeedback training could improve motor initiation in Parkinson’s disease compared to passive observation. Our task additionally allowed us to test which endogenous changes in oscillatory STN activities are associated with trial-to-trial motor performance. Neurofeedback training reduced beta synchrony and increased gamma activity within the STN, and reduced beta band coupling between the STN and motor cortex. These changes were accompanied by reduced reaction times in subsequently cued movements. However, in Parkinsonian patients with pre-existing symptoms of tremor, successful volitional beta suppression was associated with an amplification of tremor which correlated with theta band activity in STN local field potentials, suggesting an additional cross-frequency interaction between STN beta and theta activities.


2019 ◽  
Author(s):  
Eelke Spaak ◽  
Floris P. de Lange

AbstractObservers rapidly and seemingly automatically learn to predict where to expect relevant items when those items are repeatedly presented in the same spatial context. This form of statistical learning in visual search has been studied extensively using a paradigm known as contextual cueing. The neural mechanisms underlying the learning and exploiting of such regularities remain unclear. We sought to elucidate these by examining behaviour and recording neural activity using magneto-encephalography (MEG) while observers were implicitly acquiring and exploiting statistical regularities. Computational modelling of behavioural data suggested that after repeated exposures to a spatial context, participants’ behaviour was marked by an abrupt switch to an exploitation strategy of the learnt regularities. MEG recordings showed that the initial learning phase was associated with larger hippocampal theta band activity for repeated scenes, while the subsequent exploitation phase showed larger prefrontal theta band activity for these repeated scenes. Strikingly, the behavioural benefit of repeated exposures to certain scenes was inversely related to explicit awareness of such repeats, demonstrating the implicit nature of the expectations acquired. This elucidates how theta activity in the hippocampus and prefrontal cortex underpins the implicit learning and exploitation of spatial statistical regularities to optimize visual search behaviour.


2014 ◽  
Vol 72 (9) ◽  
pp. 687-693 ◽  
Author(s):  
Guaraci Ken Tanaka ◽  
Caroline Peressutti ◽  
Silmar Teixeira ◽  
Mauricio Cagy ◽  
Roberto Piedade ◽  
...  

Acute and long-term effects of mindfulness meditation on theta-band activity are not clear. The aim of this study was to investigate frontal theta differences between long- and short-term mindfulness practitioners before, during, and after mindfulness meditation. Twenty participants were recruited, of which 10 were experienced Buddhist meditators. Despite an acute increase in the theta activity during meditation in both the groups, the meditators showed lower trait frontal theta activity. Therefore, we suggested that this finding is a neural correlate of the expert practitioners’ ability to limit the processing of unnecessary information (e.g., discursive thought) and increase the awareness of the essential content of the present experience. In conclusion, acute changes in the theta band throughout meditation did not appear to be a specific correlate of mindfulness but were rather related to the concentration properties of the meditation. Notwithstanding, lower frontal theta activity appeared to be a trait of mindfulness practices.


2021 ◽  
Vol 7 (12) ◽  
pp. eabf4355
Author(s):  
Patrick G. Bissett ◽  
Henry M. Jones ◽  
Russell A. Poldrack ◽  
Gordon D. Logan

The stop-signal paradigm, a primary experimental paradigm for understanding cognitive control and response inhibition, rests upon the theoretical foundation of race models, which assume that a go process races independently against a stop process that occurs after a stop-signal delay (SSD). We show that severe violations of this independence assumption at short SSDs occur systematically across a wide range of conditions, including fast and slow reaction times, auditory and visual stop signals, manual and saccadic responses, and especially in selective stopping. We also reanalyze existing data and show that conclusions can change when short SSDs are excluded. Last, we suggest experimental and analysis techniques to address this violation, and propose adjustments to extant models to accommodate this finding.


Author(s):  
Corey George Wadsley ◽  
John Cirillo ◽  
Arne Nieuwenhuys ◽  
Winston D Byblow

Response inhibition is essential for goal-directed behavior within dynamic environments. Selective stopping is a complex form of response inhibition where only part of a multi-effector response must be cancelled. A substantial response delay emerges on unstopped effectors when a cued effector is successfully stopped. This stopping-interference effect is indicative of nonselective response inhibition during selective stopping which may, in-part, be a consequence of functional coupling. The present study examined selective stopping of (de)coupled bimanual responses in healthy human participants of either sex. Participants performed synchronous and asynchronous versions of an anticipatory stop-signal paradigm across two sessions while mu (µ) and beta (β) rhythm were measured with electroencephalography. Results showed that responses were behaviorally decoupled during asynchronous go trials and the extent of response asynchrony was associated with lateralized sensorimotor µ and β desynchronization during response preparation. Selective stopping produced a stopping-interference effect and was marked by a nonselective increase and subsequent rebound in prefrontal and sensorimotor β. In support of the coupling account, stopping-interference was smaller during selective stopping of asynchronous responses, and negatively associated with the magnitude of decoupling. However, the increase in sensorimotor β during selective stopping was equivalent between the stopped and unstopped hand irrespective of response synchrony. Overall, the findings demonstrate that decoupling facilitates selective stopping after a global pause process and emphasizes the importance of considering the influence of both the go and stop context when investigating response inhibition.


2021 ◽  
Author(s):  
Milou J.L. van Helvert ◽  
Leonie Oostwoud Wijdenes ◽  
Linda Geerligs ◽  
W. Pieter Medendorp

AbstractWhile beta-band activity during motor planning is known to be modulated by uncertainty about where to act, less is known about its modulations to uncertainty about how to act. To investigate this issue, we recorded oscillatory brain activity with EEG while human participants (n = 17) performed a hand choice reaching task. The reaching hand was either predetermined or of participants’ choice, and the target was close to one of the two hands or at about equal distance from both. To measure neural activity in a motion-artifact-free time window, the location of the upcoming target was cued 1000-1500 ms before the presentation of the target, whereby the cue was valid in 50% of trials. As evidence for motor planning during the cueing phase, behavioral observations showed that the cue affected later hand choice. Furthermore, reaction times were longer in the choice than in the predetermined trials, supporting the notion of a competitive process for hand selection. Modulations of beta-band power over central cortical regions, but not alpha-band or theta-band power, were in line with these observations. During the cueing period, reaches in predetermined trials were preceded by larger decreases in beta-band power than reaches in choice trials. Cue direction did not affect reaction times or beta-band power, which may be due to the cue being invalid in 50% of trials, retaining effector uncertainty during motor planning. Our findings suggest that effector uncertainty, similar to target uncertainty, selectively modulates beta-band power during motor planning.New & NoteworthyWhile reach-related beta-band power in central cortical areas is known to modulate with the number of potential targets, here we show, using a cueing paradigm, that the power in this frequency band, but not in the alpha or theta-band, is also modulated by the uncertainty of which hand to use. This finding supports the notion that multiple possible effector-specific actions can be specified in parallel up to the level of motor preparation.


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