Functional MRI (fMRI) for Resolving Cortical Layers' Functional Activity in Humans

This essay critically examines various arguments in favour of and against the fMRI application in the functional assessment of cortical layers in humans. It also recommends various strategies and approaches to mitigate the controversies related to the fMRI implications on the functional evaluation of the human brain. The essay explores the potential of fMRI in evaluating the physiology of cortical layers in the human brain and its effectiveness in brain’s cortical assessment and related functional exploration. It also discusses the capacity of fMRI in terms of evaluating the nausea-based sympathovagal shift that occurs under the impact of brain activity across the areas that handle the significant functions like higher cognitive function and emotion. The essay also advocates the potential of rt-fMRI (Real-time functional magnetic resonance imaging) neurofeedback training in terms of modulating the brain signals. This brain signal modulation assists in modifying the behavioral and neural outcomes in patients affected with stroke and associated clinical manifestations.

6/9/2018
Is it possible to resolve functional activity from specific cortical
layers in humans using fMRI? Discuss in relation to
contemporary evidence.

Introduction
The preliminary objective of functional MRI (i.e. fMRI) includes the assessment of brain cortical
circuits for evaluating their flow of information. The cortical layers of the human brain prove to
be the junction of efferent and afferent connections. Various research studies provide a multitude
of findings regarding the directional functional activities of these cortical layers. The human
motor cortex remains connected with the premotor and somatosensory areas of the human brain.
Functional Magnetic Resonance Imaging (fMRI) exhibits the capacity of recording
somatosensory input and cortico-spinal motor output from the deep cortical areas of the human
brain (Huber, et al., 2017). Cerebral blood volume-based fMRI utilization offers the scope of
recording the cortical activity of the human brain in the absence of vascular biases. fMRI
effectively measures the output and input activity of the primary motor cortex as well as the
laminar activity. Laminar resting-state fMRI has the potential to explore the directional
connectivity pattern across several regions of the human brain. fMRI explores the hemodynamic
changes that occur under the impact of blood vessel dilation and oxygen consumption in the
human brain. The fMRI-based recording of the resting state and stimulus-driven states of the
cortical layers substantiates the requirement enhancing the spatial resolution. The assessment by
(Lawrence, Formisano, Muckli, & de-Lange, 2017) reveals the capacity of fMRI to effectively
capture distinct cortical layers’ responses in the human brain. fMRI assists in evaluating the
feedback and feedforward brain responses separately. This indeed helps in exploring the
interactive pattern between various brain regions at a granular level as compared to the
conventional radiological intervention. The capacity of laminar fMRI to segregate the feedback
responses of various layers of the sensory cortex makes this technique as the most promising
intervention for resolving the functional activity from specific cortical layers in humans. The

intervention like fMRI might also assist in evaluating the neural causes of synaesthesia through
cortical assessment in the human population (Ramachandran & Hubbard, 2001). fMRI is a
systematic technique that provides excellent temporal resolution and non-invasively performs
cortical assessment in the absence of radiation. The unique functionality of fMRI expands its
scope of utilization for evaluating the physiology of cortical layers in human brain. Presented
argumentative essay critically examines various arguments in favour of and against the fMRI
application in the functional assessment of these cortical layers. The essay also recommends
various strategies and approaches to mitigate the controversies related to the fMRI implications
on the functional evaluation of the human brain.
fMRI extends applications in the brain circuitry assessment interventions used to evaluate the
response of the autonomous nervous system against nausea. Indeed, nausea leads to elevation in
the sympathetic response and a reduction in parasympathetic response that leads to the decrease
in cardiac function and enhancement of the cardiac rate (Kim, Napadow, Kuo, & Barbieri, 2012).
Positive correlations between fMRI signals in the pregenual anterior cingulate cortex, medial
prefrontal cortex, and elevated cortical/emotional function locations at the time of nausea
indicate the impact of motion sickness on the cardiovagal modulation cortical control in the
human brain. The study by (Kim, Napadow, Kuo, & Barbieri, 2012) reveals the capacity of fMRI
in terms of evaluating the nausea-based sympathovagal shift that occurs under the impact of
brain activity across the areas that handle the significant functions like higher cognitive function
and emotion. The nausea-based cardiovagal modulation varies in accordance with the functional
impact of effective, cognitive, and interceptive brain regions. fMRI assists in evaluating the
autonomic nervous system response of the cortical layers of the brain circuitry during nausea
episode. These evidence-based findings affirm the effectiveness of fMRI in brain’s cortical

assessment and related functional exploration. Researchers continue to utilize electrocortical
stimulation mapping to evaluate the sensory, motor, and language functions of the human brain
(Austermuehle, et al., 2017). Epilepsy patients require assessment of their executive functions
during pre-operative planning to reduce the risk of eloquent cortex deterioration following the
resective brain intervention. However, fMRI proves to be a significant intervention that
effectively excludes the critical language regions in the brain cortex. This technique helps in
evaluating language lateralization while streamlining the search parameters for articulate cortical
regions in the human brain. The outcomes eventually assist in the implantation of subdural
electrode during the intraoperative period. The analysis by (Burciu, et al., 2017) reveals the
potential of trihexyphenidyl in terms of impacting the fMRI output related to the somatosensory
cortex in patients affected with cervical dystonia (CD). The administration of trihexyphenidyl in
CD patients modifies the primary somatosensory cortex controls to a considerable extent. The
subsequent utilization of fMRI fails to record the original cortical signal deterioration that occurs
in CD patients without medication intervention. This defect in fMRI signal recording capacity
requires further exploration through prospective studies with the objective of evaluating the
fMRI capacity and precision to explore the cortical functions in CD patients.
The assessment by (Schaefer, et al., 2017) advocates the effectiveness of Markov Random Field-
based resting-state fMRI and task-fMRI interventions in undertaking cerebral cortex
parcellations with the objective of evaluating the visuotopic and somatotopic brain
characteristics. The researchers believe that the fMRI-based exploration of distinct
computational units (i.e. subareal cortical characteristics) will reveal the neurobiological
meaningful features of human brain across multiple dimensions. The fMRI-based multiresolution
parcellations offer promising results related to the functionality of various cortical layers. The

study outcomes however, lack scalability despite the large sample size. This is because the
scientific community needs to methodically explore the exact mechanism that the fMRI utilizes
while undertaking parcellation analysis of the neurobiological atoms in the human cerebral
cortex. Conventional MRI intervention captures occipitotemporal and occpitoparietal atrophy
across the right hemisphere of the human brain with the objective of evaluating posterior cortical
atrophy (da-Silva, Millington, Bridge, James-Galton, & Plant, 2017). However, this intervention
does not effectively demarcate disparate posterior volume loss in patients affected with
Alzheimer’s Dementia (AD). fMRI provides significant information regarding resting oxidative
metabolism, oxygen extraction fraction, resting blood flow, and cerebrovascular reactivity while
utilizing blood oxygen-dependent contrast and arterial spin-labeling (Lajoie, et al., 2017). These
findings raise questions regarding the credibility of fMRI in the direct evaluation of cortical
functions in AD patients. Contrarily, the assessment by (Wang, Mantini, & Gillebert, 2017)
advocates the potential of rt-fMRI (Real-time functional magnetic resonance imaging)
neurofeedback training in terms of modulating the brain signals. This brain signal modulation
assists in modifying the behavioral and neural outcomes in patients affected with stroke and
associated clinical manifestations. The study findings reveal the capacity of fMRI in terms of
delineating the subcortical and cortical regions of the human brain. This resultantly assists in
evaluating the resting state connectivity between these cortical/subcortical areas. The scale of
learned self-modulation varies inversely with the extent of motor impairment. The researchers
utilize these fMRI findings while conducting rt-fMRI neurofeedback studies in the human
population. fMRI based neurofeedback facilitates the self-regulation of cortical function in the
context of acquiring the desired behavioral outcomes in the treated subjects.

fMRI effectively utilizes visual presentation paradigm to evaluate the sentence reading and word
reading capacity of the human subjects (Zhou & Shu, 2017). fMRI-based assessment facilitates
the evaluation of supplementary eye field, the frontal eye field, the parietal eye field, extrastriate
cortex, and primary visual cortex across medial frontal gyrus, superior prefrontal gyrus, and
posterior parietal cortex in the human brain. The eye movements and word reading tasks execute
through the coordination of occipitotemporal, parietal, and frontal cortices along with other
dorsal and ventral regions of the human brain. The assessment by (Zhou & Shu, 2017) reveals
the capacity of fMRI in terms of delineating these brain regions to evaluate the visual word
reading and eye movements in human subjects. The evaluation by (d-Heuvel, et al., 2016)
advocates the relationship of the resting‐state fMRI connectivity pattern with the cortical
regions’ inhibitory and excitatory chemoarchitecture in the human brain. This provides some
insight and understanding of the synchronization and neural communication patterns in the
human brain. These facts reveal the potential of fMRI in terms of analysing cortical functionality
in humans to a measurable extent. Capacity of fMRI in evaluating the impact of cortical brain
receptors and neurotransmitter type on the activity and responsiveness of post-synaptic neurons
requires evaluation by the scientific community. Researchers are unable to radically substantiate
the resting‐state fMRI functional connectivity patterns in the context of evaluating the complete
cortical activity of the human brain. fMRI can track and segregate the anatomical information in
the human brain. However, the mechanism of analysing this information along with its outcomes
warrants prospective research interventions by the scientific community.
The evaluation by (Cochereau, et al., 2016) affirms the relevance of the resting state connectivity
in the human brain in the context of assessing the responsive cortical stimulation in patients
affected with glioma. The study findings affirm the capacity of fMRI in terms of partially

undertaking the independent component analysis to identify the surgically removable as well as
eloquent cortical regions in the epilepsy patients. This raises the question regarding the
independent capacity of fMRI in undertaking the cortical functional assessment of the human
brain. The researchers need to evaluate the combination approaches that necessitate the
administration of mixed methods with the objective of improving the cortical evaluation capacity
of fMRI in the human subjects. The assessment by (Cichy, Pantazis, & Oliva, 2016) followed the
same integration strategy with the objective of evaluating the spatio-temporal dynamics of the
human brain. The study deployed fMRI and MEG (magnetoencephalography) interventions with
the objective of acquiring the temporally and spatially combined neuronal activation
characterization in the human subjects. The concomitant assessment by fMRI and MEG revealed
the occipital pole activity that anteriorly impacted the dorsal and ventral visual streams. The
researchers tracked the fMRI-MEG correspondence across the ventral and dorsal regions before
the initial visual cortex. Indeed, researchers need to comparatively analyze the sole capacity of
fMRI in determining similar outcomes as compared to the capacity of various integrative
approaches.
The assessment by (Brennan, Peck, & Holodny, 2016) reveals the fMRI-based challenge
encountered while evaluating speech localization during the DCS (direct cortical stimulation).
This challenge substantially impacts the presurgical planning of patients affected with various
cortical abnormalities. fMRI activation leads to a several scientific interpretations. The
researchers need to acquire the interpretation closest to the patient scenario for analysing the
cortical function. The excitatory regions that experience a high predisposition to the DCS
interruption require their functional evaluation through the fMRI intervention. However, these
excitatory regions might not experience reliable barricading during DCS since these areas might

support the cortical function after their deployment by several downstream/upstream regions.
fMRI activations also require localization in accordance with brain lesions to facilitate their
precise assessment. fMRI activations also extend the scope of evaluating atypical hemispheric
dominance. Researchers need to consider the paradigms where the patients need to vocalize their
outputs during fMRI interventions. The conventional paradigms indeed disallow head motion
during the cortical assessment. However, the fMRI-based behavioural paradigms exhibit
comparable results for the localization and lateralization studies in the human population. The
assessment by (Gilson, Moreno-Bote, Ponce-Alvarez, Ritter, & Deco, 2016) reveals the non-
reciprocal nature of various cortical interactions in the human brain. Cortical effective
connectivity is indeed based on the feeder and receptor hubs that do not substantially indicate
outgoing or incoming connections. These findings indicate the non-uniformity of activity
propagation patterns across the cortical regions. fMRI effectively the time-shifted covariances
across the spatial and temporal components of the human brain. This provides a clue of the
anatomical connectivity pattern across the cortical regions. These findings however, do not
provide significant insight of the mechanisms that dominate while evaluating the functional non-
uniformity of specific cortical layers in the human brain. Researchers need to explore these facts
to understand and evaluate the true potential of fMRI in terms of resolving the functional cortical
outcomes.
The assessment by (Dirkx, et al., 2016) reveals the requirement of simultaneous utilization of
fMRI and EMG for sampling the brain activity in tremor dominant patients affected with
Parkinson’s disease. The resting tremors in Parkinson patients are based on the
pathophysiological alterations across cerebello-thalamo-cortical motor loop and basal ganglia.
fMRI-EMG intervention exhibits the potential to explore these alterations for understanding the

circuitry mechanisms that dominate the tremor initiation in Parkinson patients. Tremor amplitude
substantially impacts the cerebral activity across the cortical and thalamic regions. This change
in cerebral function impacts the network functionality of the basal ganglia that eventually
disrupts the cerebello-thalamo-cortical motor loop in the affected patients. fMRI-EMG
utilization systematically evaluates these activity changes that assist in analysing the etiology and
neural complications of Parkinson’s disease. These findings again raise the question of single-
handed capacity of fMRI in undertaking cortical functional analysis in the absence of the parallel
approaches. The evaluation by (Wise, Frangos, & Komisaruk, 2016) affirms the effectiveness of
fMRI in terms of exploring the therapeutic imagery applications in the human brain. The
findings provide substantial evidence for exploring the impact of fMRI-based neurofeedback
intervention to enhance the erogenous human experience. The study reveals the fMRI capacity in
terms of evaluating the imagined tactile self-stimulation across the cortical brain regions. The
study findings advocate the effectiveness of fMRI in terms of exploring the activities of the
reward system components, limbic structures, sensory-motor integration regions and
primary/secondary sensory cortices of the human brain. However, the study methodology does
not elaboratively specify the mechanistic rationale that facilitates these fMRI implications in
studying the impact of erogenous stimulation on the cortical layers in humans. These findings
reaffirm the requirement of mechanistic exploration of fMRI implications and effectiveness in
the context of resolving the cortical functionality.
The assessment by (Ferenczi, et al., 2016) affirms the potential of fMRI in terms of evaluating
the expression modulation caused by the medial prefrontal cortex in patients affected with
anhedonia. The study findings reveal the fMRI-based assessment of overactivity that
substantially overrides the reward-motivated behaviors and associated functional interactions in

the cortical regions. fMRI exhibits the potential to capture the medial prefrontal cortex-based
fluctuations in the striatal response that potentially degrades the behavioral motivation related to
the dopaminergic stimulation. Similarly, the findings by (Schneider, et al., 2016) affirm the
potential of resting-state fMRI in terms of non-invasively evaluating the functional areas of the
sensorimotor cortex of the human brain. fMRI intervention does not necessitate the
accomplishment of goal-directed tasks before undertaking the cortical functional assessment.
Indeed, the pre-surgical evaluation of the sensorimotor cortex function in a range of clinical
scenarios offers the potential implications on the assessment and treatment of numerous patients
affected with various pathological conditions.
Conclusion
This evidence-based essay critically explored the capacity of fMRI in terms of evaluating the
neuronal activation pattern across the cortical regions of the human brain. Numerous research
findings advocate the potential of volume-based fMRI in identifying the defects in cortical
function and their active networks. However, limited studies have elaborated the detailed
functional mechanism utilized by fMRI approach for effectively undertaking the cortical
functional analysis. Furthermore, effective utilization of fMRI in various integrative approaches
to evaluate cortical function necessitates the requirement of undertaking prospective studies to
delineate the true capacity and potential of this technique in undertaking the cortical assessment.
Researchers need to explore and establish scientific underpinnings in the context of enhancing
the meaningful and scalable utilization of fMRI for single-handedly resolving the functional
activity from specific cortical layers in the human brain.

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