Sustained BOLD and theta activity in auditory cortex are related to slow stimulus fluctuations rather than to pitch

2012 ◽  
Vol 107 (12) ◽  
pp. 3458-3467 ◽  
Author(s):  
Iris Steinmann ◽  
Alexander Gutschalk
Keyword(s):  
Auditory Cortex ◽  
Primary Auditory Cortex ◽  
Specific Area ◽  
Theta Activity ◽  
Theta Band ◽  
Related Activity ◽  
Specific Stimulus ◽  
Time Frequency ◽  
Constant Pitch ◽  
Band Activity

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.

Choice-related activity and neural encoding in primary auditory cortex and lateral belt during feature selective attention

2021 ◽  
Author(s):  
Jennifer Leigh Mohn ◽  
Joshua D Downer ◽  
Kevin N. O'Connor ◽  
Jeffrey Scott Johnson ◽  
Mitchell L Sutter
Keyword(s):  
Selective Attention ◽  
Auditory Cortex ◽  
Rhesus Macaques ◽  
Primary Auditory Cortex ◽  
Motor Preparation ◽  
Broadband Noise ◽  
Neural Encoding ◽  
Related Activity ◽  
Attention Task ◽  
The Relationship

Selective attention is necessary to sift through, form a coherent percept of, and make behavioral decisions on the vast amount of information present in most sensory environments. How and where selective attention is employed in cortex and how this perceptual information then informs the relevant behavioral decisions is still not well understood. Studies probing selective attention and decision making in visual cortex have been enlightening as to how sensory attention might work in that modality; whether or not similar mechanisms are employed in auditory attention is not yet clear. Therefore, we trained rhesus macaques on a feature selective attention task, where they switched between reporting changes in temporal (amplitude modulation, AM) and spectral (carrier bandwidth) features of a broadband noise stimulus. We investigated how the encoding of these features by single neurons in primary (A1) and secondary (middle lateral belt, ML) auditory cortex were affected by the different attention conditions. We found that neurons in A1 and ML showed mixed-selectivity to the sound and task features. We found no difference in AM encoding between the attention conditions. We found that choice-related activity in both A1 and ML neurons shifts between attentional conditions. This finding suggests that choice-related activity in auditory cortex does not simply reflect motor preparation or action, and supports the relationship between reported choice-related activity and the decision and perceptual process.

scholarly journals Implicit learning and exploitation of regularities involve hippocampal and prefrontal theta activity

2019 ◽  
Author(s):  
Eelke Spaak ◽  
Floris P. de Lange
Keyword(s):  
Visual Search ◽  
Implicit Learning ◽  
Computational Modelling ◽  
Theta Activity ◽  
Contextual Cueing ◽  
Spatial Context ◽  
Theta Band ◽  
Initial Learning ◽  
Statistical Regularities ◽  
Band Activity

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.

scholarly journals Lower trait frontal theta activity in mindfulness meditators

2014 ◽  
Vol 72 (9) ◽  
pp. 687-693 ◽  
Author(s):  
Guaraci Ken Tanaka ◽  
Caroline Peressutti ◽  
Silmar Teixeira ◽  
Mauricio Cagy ◽  
Roberto Piedade ◽  
...  
Keyword(s):  
Mindfulness Meditation ◽  
Theta Activity ◽  
Long Term Effects ◽  
Theta Band ◽  
Mindfulness Practices ◽  
Acute Increase ◽  
Concentration Properties ◽  
Acute Changes ◽  
Band Activity

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.

scholarly journals Correlation between 50-kHz band activity in primary auditory cortex and social interaction in rats

2014 ◽  
Vol 8 ◽  
Author(s):  
Kim Hengjun J ◽  
Cho Gyunggoo ◽  
Song Youngkyu ◽  
Chun Song-I ◽  
Lim Dongwan ◽  
...  
Keyword(s):  
Social Interaction ◽  
Auditory Cortex ◽  
Primary Auditory Cortex ◽  
Band Activity

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.

Intensity Tuning of Neurons in The Primary Auditory Cortex of Albino Mouse

2013 ◽  
Vol 40 (4) ◽  
pp. 365
Author(s):  
Qiao-Zhen QI ◽  
Wen-Juan SI ◽  
Feng LUO ◽  
Xin WANG
Keyword(s):  
Auditory Cortex ◽  
Primary Auditory Cortex

Influence of Primary Auditory Cortex in the Characterization of Autism Spectrum in Young Adults using Brain Connectivity Parameters and Deep Belief Networks: An fMRI Study

2020 ◽  
Vol 16 (9) ◽  
pp. 1059-1073
Author(s):  
Vidhusha Srinivasan ◽  
N. Udayakumar ◽  
Kavitha Anandan
Keyword(s):  
Functional Connectivity ◽  
Auditory Cortex ◽  
Language Processing ◽  
Brain Connectivity ◽  
Primary Auditory Cortex ◽  
Autism Spectrum ◽  
Belief Networks ◽  
Deep Belief Networks ◽  
High Functioning ◽  
Low Functioning

Background: The spectrum of autism encompasses High Functioning Autism (HFA) and Low Functioning Autism (LFA). Brain mapping studies have revealed that autism individuals have overlaps in brain behavioural characteristics. Generally, high functioning individuals are known to exhibit higher intelligence and better language processing abilities. However, specific mechanisms associated with their functional capabilities are still under research. Objective: This work addresses the overlapping phenomenon present in autism spectrum through functional connectivity patterns along with brain connectivity parameters and distinguishes the classes using deep belief networks. Methods: The task-based functional Magnetic Resonance Images (fMRI) of both high and low functioning autistic groups were acquired from ABIDE database, for 58 low functioning against 43 high functioning individuals while they were involved in a defined language processing task. The language processing regions of the brain, along with Default Mode Network (DMN) have been considered for the analysis. The functional connectivity maps have been plotted through graph theory procedures. Brain connectivity parameters such as Granger Causality (GC) and Phase Slope Index (PSI) have been calculated for the individual groups. These parameters have been fed to Deep Belief Networks (DBN) to classify the subjects under consideration as either LFA or HFA. Results: Results showed increased functional connectivity in high functioning subjects. It was found that the additional interaction of the Primary Auditory Cortex lying in the temporal lobe, with other regions of interest complimented their enhanced connectivity. Results were validated using DBN measuring the classification accuracy of 85.85% for high functioning and 81.71% for the low functioning group. Conclusion: Since it is known that autism involves enhanced, but imbalanced components of intelligence, the reason behind the supremacy of high functioning group in language processing and region responsible for enhanced connectivity has been recognized. Therefore, this work that suggests the effect of Primary Auditory Cortex in characterizing the dominance of language processing in high functioning young adults seems to be highly significant in discriminating different groups in autism spectrum.

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