fMRI Investigation Research Articles

Experience of negative emotions in Parkinson’s disease: An fMRI investigation

ObjectiveAmygdala abnormalities have been discussed as a possible mechanism underlying reduced reactivity to negative stimuli in Parkinson’s disease (PD). MethodsThe present investigation used functional magnetic resonance imaging (fMRI) in order to test this hypothesis. We compared brain activation of 17 nondepressed and nondemented PD patients with 22 healthy controls during the elicitation of negative affective states. The patients suffered from moderate motor symptoms for an average of 75 months and had stopped their antiparkinson medication 10–12h prior to the fMRI testing. All participants were shown images which depicted disgusting, fear-relevant and neutral contents and they answered self-report scales for the assessment of disgust proneness and trait anxiety. ResultsBoth groups did not differ from each other in affective state and trait ratings. In line with the self-report, the fMRI data showed similar activation (including the amygdala) in both groups during disgust and fear elicitation. ConclusionThis fMRI investigation found no indication of diminished disgust and fear experience in PD. SignificancePreviously reported affective processing deficits in PD might be due to insufficiently controlled confounding variables (medication, depression, cognitive impairment).

Fluctuation amplitude and local synchronization of brain activity in the ultra-low frequency band: An fMRI investigation of continuous feedback of finger force

Functional magnetic resonance imaging (fMRI) studies of motor feedback have suggested that brain activity in the ultra-low frequency band (0–0.01Hz) may be physiologically significant for various feedback conditions, i.e., real and sham feedback. However, the functional role of the ultra-low frequency band of brain activity during the feedback procedure remains unclear. Here, we carried out an fMRI study of continuous feedback (8min) of finger force and assessed two important properties of brain activity: the fluctuation amplitude and local synchronization in the ultra-low frequency band. Two intriguing results were obtained: (1) real feedback recruited a stronger fluctuation amplitude and local synchronization in the basal ganglia compared with sham feedback; however, no significant correlation was found between the two properties across subjects; and (2) the behavioral performance was significantly correlated with the fluctuation amplitude but was not correlated with local synchronization in the basal ganglia. These findings contribute to characterization of the functional role of brain activity in the ultra-low frequency band and further suggest that the fluctuation amplitude and local synchronization in the basal ganglia may contribute differently to motor feedback.

Chemosensory anxiety cues moderate the experience of social exclusion - an fMRI investigation with Cyberball.

Recent evidence suggests that the experience of stress can be communicated between individuals via chemosensory cues. Little is known, however, about the impact of these cues on neurophysiological responses during a socially threatening situation. In the current investigation we implemented a widely used paradigm to study social exclusion—Cyberball—to examine whether chemosensory cues signaling anxiety modulate the neuronal effects of ostracism. In a double-blind, within-subjects design, 24 healthy, normosmic participants were presented with chemosensory cues of anxiety (or control samples) and completed the Cyberball task while in a 3T fMRI scanner. Axillary sweat collected from male students awaiting an oral examination served as the anxiety cues while the chemosensory control stimuli consisted of sweat collected from the same individuals participating in an ergometer training session. The neuroimaging data revealed that under the control chemosensory condition, exclusion from Cyberball was associated with significantly higher orbitofrontal cortex and anterior cingulate cortex activity, which is consistent with previous studies in the field. However, when participants were primed with the anxiety sweat, the activity in these regions was not observed. Further, under exposure to anxiety cues during ostracism the participants showed deactivations in brain regions involved in memory (hippocampus), social cognition (middle temporal gyrus, superior temporal gyrus) and processing of salience (inferior frontal gyrus). These results suggest that successful communication of anxiety via the chemosensory domain may moderate the experience of social exclusion. It is possible that the anxiety signals make it easier for the individuals to detach from the group, pointing to the communicative role of chemosensory anxiety cues in enhancing adjustment mechanisms in light of a distressing situation.

Disrupted prefrontal activity during emotion processing in complicated grief: An fMRI investigation

Complicated Grief, marked by a persistent and intrusive grief lasting beyond the expected period of adaptation, is associated with a relative inability to disengage from idiographic loss-relevant stimuli (O'Connor and Arizmendi, 2014). In other populations, functional magnetic resonance imaging (fMRI) studies investigating the neural networks associated with this bias consistently implicate the anterior cingulate cortex (ACC) during emotion regulation. In the present study, twenty-eight older adults were categorized into three groups based on grief severity: Complicated Grief (n=8), Non-Complicated Grief (n=9), and Nonbereaved, married controls (n=11). Using a block design, all participants completed 8 blocks (20 stimuli per block) of the ecStroop task during fMRI data acquisition. Differences in neural activity during grief-related (as opposed to neutral) stimuli across groups were examined. Those with Complicated Grief showed an absence of increased rostral ACC (rACC) and fronto-cortical recruitment relative to Nonbereaved controls. Activity in the orbitofrontal cortex (x=6, y=54, z=−10) was significantly elevated in the Non-Complicated Grief group when compared to Nonbereaved controls. Post hoc analysis evidenced activity in the dorsal ACC in the Complicated Grief and Nonbereaved groups late in the task. These findings, supported by behavioral data, suggest a relative inability to recruit the regions necessary for successful completion of this emotional task in those with Complicated Grief. This deficit was not observed in recruitment of the orbitofrontal cortex and the rACC during processing of idiographic semantic stimuli in Non-Complicated Grief.

Antisaccade-related brain activation in children with attention-deficit/hyperactivity disorder – A pilot study

While antisaccade paradigms invoke circuitry associated with cognitive control and attention-deficit/hyperactivity disorder (ADHD), there is a dearth of functional magnetic resonance imaging (fMRI) investigations using antisaccade tasks among children with ADHD. Neural correlates associated with antisaccade performance were examined with fMRI in 11 children with ADHD (10 medicated) matched to 11 typically developing children. Significantly greater brain activation in regions in right dorsolateral prefrontal cortex and caudate nucleus was observed in children with ADHD relative to the control group. This pattern separated the children into their respective groups in a taxonomic manner. Sensitivity analyses probing comorbidity and medication-specific effects showed that results were consistent; however, the caudate nucleus difference was only detectable in the full sample, or in subsets with a more relaxed cluster threshold. Antisaccade performance did not significantly differ between the groups, perhaps as a result of greater brain activation or medication effects in the ADHD group. Thus, antisaccade paradigms may have sensitivity and specificity for the investigation of cognitive control deficits and associated neural correlates in ADHD, and may contribute towards the development of new treatment approaches for children with the disorder.

Design and Evaluation of a Cable-Driven fMRI-Compatible Haptic Interface to Investigate Precision Grip Control.

Our hands and fingers are involved in almost all activities of daily living and, as such, have a disproportionately large neural representation. Functional magnetic resonance imaging investigations into the neural control of the hand have revealed great advances, but the harsh MRI environment has proven to be a challenge to devices capable of delivering a large variety of stimuli necessary for well-controlled studies. This paper presents a fMRI-compatible haptic interface to investigate the neural mechanisms underlying precision grasp control. The interface, located at the scanner bore, is controlled remotely through a shielded electromagnetic actuation system positioned at the end of the scanner bed and then through a high stiffness, low inertia cable transmission. We present the system design, taking into account requirements defined by the biomechanics and dynamics of the human hand, as well as the fMRI environment. Performance evaluation revealed a structural stiffness of 3.3 N/mm, renderable forces up to 94 N, and a position control bandwidth of at least 19 Hz. MRI-compatibility tests showed no degradation in the operation of the haptic interface or the image quality. A preliminary fMRI experiment during a pilot study validated the usability of the haptic interface, illustrating the possibilities offered by this device.

FMRI investigation of response inhibition, emotion, impulsivity, and clinical high-risk behavior in adolescents.

High-risk behavior in adolescents is associated with injury, mental health problems, and poor outcomes in later life. Improved understanding of the neurobiology of high-risk behavior and impulsivity shows promise for informing clinical treatment and prevention as well as policy to better address high-risk behavior. We recruited 21 adolescents (age 14–17) with a wide range of high-risk behavior tendencies, including medically high-risk participants recruited from psychiatric clinics. Risk tendencies were assessed using the Adolescent Risk Behavior Screen (ARBS). ARBS risk scores correlated highly (0.78) with impulsivity scores from the Barratt Impulsivity scale (BIS). Participants underwent 4.7 Tesla functional magnetic resonance imaging (fMRI) while performing an emotional Go/NoGo task. This task presented an aversive or neutral distractor image simultaneously with each Go or NoGo stimulus. Risk behavior and impulsivity tendencies exhibited similar but not identical associations with fMRI activation patterns in prefrontal brain regions. We interpret these results as reflecting differences in response inhibition, emotional stimulus processing, and emotion regulation in relation to participant risk behavior tendencies and impulsivity levels. The results are consistent with high impulsivity playing an important role in determining high risk tendencies in this sample containing clinically high-risk adolescents.

The Response of the Left Ventral Attentional System to Invalid Targets and its Implication for the Spatial Neglect Syndrome: a Multivariate fMRI Investigation.

In humans, invalid visual targets that mismatch spatial expectations induced by attentional cues are considered to selectively engage a right hemispheric "reorienting" network that includes the temporal parietal junction (TPJ), the inferior frontal gyrus (IFG), and the medial frontal gyrus (MFG). However, recent findings suggest that this hemispheric dominance is not absolute and that it is rather observed because the TPJ and IFG areas in the left hemisphere are engaged both by invalid and valid cued targets. Because of this, the BOLD response of the left hemisphere to invalid targets is usually cancelled out by the standard "invalid versus valid" contrast used in functional magnetic resonance imaging investigations of spatial attention. Here, we used multivariate pattern recognition analysis (MVPA) to gain finer insight into the role played by the left TPJ and IFG in reorienting to invalid targets. We found that in left TPJ and IFG blood oxygen level-dependent (BOLD) responses to invalid and valid targets were associated to different patterns of neural activity, possibly reflecting the presence of functionally distinct neuronal populations. Pattern segregation was significant at group level, it was present in almost all of the participants to the study and was observed both for targets in the left and right side of space. A control whole-brain MVPA ("Searchlight" analysis) confirmed the results obtained in predefined regions of interest and highlighted that also other areas, that is, superior parietal and frontal-polar cortex, show different patterns of BOLD response to valid and invalid targets. These results confirm and expand previous evidence highlighting the involvement of the left hemisphere in reorienting of visual attention (Doricchi et al. 2010; Dragone et al. 2015). These findings suggest that asymmetrical reorienting deficits suffered by right brain damaged patients with left spatial neglect, who have severe impairments in contralesional reorienting and less severe impairments in ipsilesional reorienting, are due to preserved reorienting abilities in the intact left hemisphere.

Brain, Mind, and Media

Brain, Mind, and Media

Brain oxygenation responses to an autonomic challenge: a quantitative fMRI investigation of the Valsalva manoeuvre.

In late age, the autonomic nervous system (ANS) has diminished ability to maintain physiological homeostasis in the brain in response to challenges such as to systemic blood pressure changes caused by standing. We devised an fMRI experiment aiming to map the cerebral effects of an ANS challenge (Valsalva manoeuvre (VM)). We used dual-echo fMRI to measure the effective transverse relaxation rate (R2*, which is inversely proportional to brain tissue oxygenation levels) in 45 elderly subjects (median age 80 years old, total range 75-89) during performance of the VM. In addition, we collected fluid-attenuated inversion recovery (FLAIR) data from which we quantified white matter hyperintensity (WMH) volumes. We conducted voxelwise analysis of the dynamic changes in R2* during the VM to determine the distribution of oxygenation changes due to the autonomic stressor. In white matter, we observed significant decreases in oxygenation levels. These effects were predominantly located in posterior white matter and to a lesser degree in the right anterior brain, both concentrated around the border zones (watersheds) between cerebral perfusion territories. These areas are known to be particularly vulnerable to hypoxia and are prone to formation of white matter hyperintensities. Although we observed overlap between localisation of WMH and triggered deoxygenation on the group level, we did not find significant association between these independent variables using subjectwise statistics. This could suggest other than recurrent transient hypoxia mechanisms causing/contributing to the formation of WMH.

An fMRI investigation of the effects of culture on evaluations of stigmatized individuals

Certain groups (e.g., women, older adults, and the economically disadvantaged) are universally stigmatized. Numerous studies, however, have identified cross-cultural differences in the attitudes expressed toward stigmatized groups. These differences may potentially be due to existing cross-cultural dissimilarities in social status for some groups. The current study used fMRI to examine whether Chinese and Caucasian-American participants engage the same cognitive and affective mechanisms when perceiving stigmatized individuals with similarly low social status in both cultures (homeless individuals), but different cognitive and/or affective processes when evaluating stigmatized individuals whose status differs across cultures (older adults). Using a social neuroscience approach can provide unique insight into this question because the neural regions involved in cognitive and affective evaluations of stigmatized individuals have been well characterized. Results revealed that Chinese participants and Caucasian-American participants engaged similar patterns of negative affective processing associated with disgust (left anterior insula) when evaluating homeless individuals. Moreover, self-reported negative explicit attitudes toward homeless individuals were associated with increased activity in the insula. However, Chinese participants and Caucasian-American participants engaged increased activity in neural regions associated with status (ventral striatum) when they evaluated older adults. Moreover, self-reported attitudes toward older adults and ventral striatal activity were correlated with the extent to which participants reported being affiliated with their respective cultural traditions.

The motor inhibition system in Parkinson's disease with levodopa-induced dyskinesias.

Parkinson's disease is primarily a disorder of response initiation characterized by an excessive motor inhibition, whereas levodopa-induced dyskinesias are clearly a clinical expression of disinhibition of movements. That levodopa-induced dyskinesias are linked to dysfunctions of inhibitory brain network has recently been proposed, but no investigation of behavioral performance during action inhibition task in these patients has been published. Twenty-four Parkinson's disease patients with or without levodopa-induced dyskinesias tested on or off their medications underwent functional magnetic resonance imaging investigation during the execution of a stop-signal inhibition task. In particular, we were interested in evaluating the neural correlates of stop-related conditions: StopInhibit task (in which patients had to successfully inhibit their responses) and StopRespond task (Stop trials with erroneous button press). Both tasks were compared against Go trials. Levodopa intake in dyskinetic patients tended to worsen inhibitory control during the StopInhibit task, while significantly affecting the ability to monitor motor responses when patients failed to stop (StopRespond task). Functional analysis showed that, during the StopInhibit task, dyskinetic patients were characterized by decreased activity of the right inferior frontal cortex after levodopa intake, whereas patients without dyskinesias showed a reverse effect. A similar group × levodopa interaction effect was detected in the medial frontal cortex during the execution of the StopRespond task, in which dyskinetic patients showed increased activity after dopaminergic therapy Our study demonstrated that levodopa intake in dyskinetic patients tends to alter the functioning of some parts of the neural network involved in motor inhibition.

Altered functional neuronal activity in neuropsychiatric lupus: A systematic review of the fMRI investigations.

Recent years have seen a rapid increase in the investigation of neuropsychiatric lupus (NPSLE) through the use of functional magnetic resonance imaging (fMRI). Measuring specific neuronal activity in regional brain structures during a cognitive task may identify possible biomarker for NPSLE. A systematic review of fMRI studies of systemic lupus erythematosus (SLE) is carried out to address common findings that characterize NPSLE. A disturbance to the working memory and executive function brain regions is among the most well-replicated finding. Differences in brain activation may relate to an early primary dysfunction of these regions. Increased functional connectivity strength in the fronto-parietal cortex in the resting state is correlated with SLE disease activity in one study. Decrease functional connectivity is observed in lupus patients with long-term disease. However, there is strong evidence that points toward a lack of effective integration of distributed functional brain regions and disruptions in the subtle modulation of brain function in relation to task demands in SLE. Limitations of the literature to date include the use of small sample size and the lack of addressing the effect of confounding variables, including immunosuppressive treatment. Careful definitions of the fMRI technique used both in the design, analyses, and interpretation of high dimensional data is needed, when dealing with a limited number of SLE subjects with heterogeneous manifestations and unknown pathophysiology.

Which visual functions depend on intermediate visual regions? Insights from a case of developmental visual form agnosia

A key question in visual neuroscience is the causal link between specific brain areas and perceptual functions; which regions are necessary for which visual functions? While the contribution of primary visual cortex and high-level visual regions to visual perception has been extensively investigated, the contribution of intermediate visual areas (e.g. V2/V3) to visual processes remains unclear. Here I review more than 20 visual functions (early, mid, and high-level) of LG, a developmental visual agnosic and prosopagnosic young adult, whose intermediate visual regions function in a significantly abnormal fashion as revealed through extensive fMRI and ERP investigations. While expectedly, some of LG's visual functions are significantly impaired, some of his visual functions are surprisingly normal (e.g. stereopsis, color, reading, biological motion). During the period of eight-year testing described here, LG trained on a perceptual learning paradigm that was successful in improving some but not all of his visual functions. Following LG's visual performance and taking into account additional findings in the field, I propose a framework for how different visual areas contribute to different visual functions, with an emphasis on intermediate visual regions. Thus, although rewiring and plasticity in the brain can occur during development to overcome and compensate for hindering developmental factors, LG's case seems to indicate that some visual functions are much less dependent on strict hierarchical flow than others, and can develop normally in spite of abnormal mid-level visual areas, thereby probably less dependent on intermediate visual regions.

Different cerebral plasticity of intrinsic and extrinsic hand muscles after peripheral neurotization in a patient with brachial plexus injury: A TMS and fMRI study

Contralateral C7 (CC7) neurotization has been an important approach for brachial plexus injury (BPI). Patients can achieve relatively good grasping function driven by the proximal extrinsic hand muscle (flexor digitorum, FD) after CC7 neurotization, whereas the thumb opposition function driven by the distal intrinsic muscle (abductor pollicis brevis, APB) is poor. The present study aimed to investigate the brain reorganization patterns of the recovery processes of intrinsic and extrinsic hand functions after repairing the median nerve by CC7 neurotization. Transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) were used to evaluate the cerebral plasticity in one BPI patient after CC7 neurotization. After the CC7 neurotization, the patient showed improvements in the paralyzed hand. Combination of TMS and fMRI investigations demonstrated different cortical reshaping patterns of APB and FD. It was also found that the activated cortical areas of FD were located in bilateral motor cortices, but the area of APB was only located in ipsilateral motor cortex. The cerebral plasticity procedure appeared to be different in the gross and fine motor function recovery processes. It provided a new perspective into the cerebral plasticity induced by CC7 neurotization.

PCC characteristics at rest in 10-year memory decliners

The present research sought to characterize the intrinsic functional networks associated with a 10-year episodic memory decline in elderly using data from a longitudinal population-based cohort (Bordeaux-3City). Complementary measures of whole-brain resting-state functional magnetic resonance imaging investigations were combined to compare functional architecture of brain networks both at connectional and topological levels in 22 decliners to 22 nondecliners; episodic memory decline being assessed through a multiple time point Free and Cued Selective Reminding Test. The decliners presented differences in functional architecture centered on the posterior cingulate cortex, characterized by a significant decrease of connectivity intensity, a significant increased centrality. In accordance, a decrease of the functional connectivity inside the default mode network was observed in the decliners. Our results highlight the central role of the posterior cingulate cortex in a slow but reliable memory decline in elderly. Because functional alterations of this region are currently described in Alzheimer's disease, this functional signature could constitute a risk for Alzheimer's disease.

Individual differences in verbal creative thinking are reflected in the precuneus

There have been many structural and functional imaging studies of creative thinking, but combining structural and functional magnetic resonance imaging (MRI) investigations with respect to creative thinking is still lacking. Thus, the aim of the present study was to explore the associations among inter-individual verbal creative thinking and both regional homogeneity and cortical morphology of the brain surface. We related the local functional homogeneity of spontaneous brain activity to verbal creative thinking and its dimensions—fluency, originality, and flexibility—by examining these inter-individual differences in a large sample of 268 healthy college students. Results revealed that people with high verbal creative ability and high scores for the three dimensions of creativity exhibited lower regional functional homogeneity in the right precuneus. Both cortical volume and thickness of the right precuneus were positively associated with individual verbal creativity and its dimensions. Moreover, originality was negatively correlated with functional homogeneity in the left superior frontal gyrus and positively correlated with functional homogeneity in the right occipito-temporal gyrus. In contrast, flexibility was positively correlated with functional homogeneity in the left superior and middle occipital gyrus. These findings provide additional evidence of a link between verbal creative thinking and brain structure in the right precuneus—a region involved in internally-focused attention and effective semantic retrieval—and further suggest that local functional homogeneity of verbal creative thinking has neurobiological relevance that is likely based on anatomical substrates.

Intrinsic functional connectivity differentiates minimally conscious from unresponsive patients.

Despite advances in resting state functional magnetic resonance imaging investigations, clinicians remain with the challenge of how to implement this paradigm on an individualized basis. Here, we assessed the clinical relevance of resting state functional magnetic resonance imaging acquisitions in patients with disorders of consciousness by means of a systems-level approach. Three clinical centres collected data from 73 patients in minimally conscious state, vegetative state/unresponsive wakefulness syndrome and coma. The main analysis was performed on the data set coming from one centre (Liège) including 51 patients (26 minimally conscious state, 19 vegetative state/unresponsive wakefulness syndrome, six coma; 15 females; mean age 49 ± 18 years, range 11-87; 16 traumatic, 32 non-traumatic of which 13 anoxic, three mixed; 35 patients assessed >1 month post-insult) for whom the clinical diagnosis with the Coma Recovery Scale-Revised was congruent with positron emission tomography scanning. Group-level functional connectivity was investigated for the default mode, frontoparietal, salience, auditory, sensorimotor and visual networks using a multiple-seed correlation approach. Between-group inferential statistics and machine learning were used to identify each network's capacity to discriminate between patients in minimally conscious state and vegetative state/unresponsive wakefulness syndrome. Data collected from 22 patients scanned in two other centres (Salzburg: 10 minimally conscious state, five vegetative state/unresponsive wakefulness syndrome; New York: five minimally conscious state, one vegetative state/unresponsive wakefulness syndrome, one emerged from minimally conscious state) were used to validate the classification with the selected features. Coma Recovery Scale-Revised total scores correlated with key regions of each network reflecting their involvement in consciousness-related processes. All networks had a high discriminative capacity (>80%) for separating patients in a minimally conscious state and vegetative state/unresponsive wakefulness syndrome. Among them, the auditory network was ranked the most highly. The regions of the auditory network which were more functionally connected in patients in minimally conscious state compared to vegetative state/unresponsive wakefulness syndrome encompassed bilateral auditory and visual cortices. Connectivity values in these three regions discriminated congruently 20 of 22 independently assessed patients. Our findings point to the significance of preserved abilities for multisensory integration and top-down processing in minimal consciousness seemingly supported by auditory-visual crossmodal connectivity, and promote the clinical utility of the resting paradigm for single-patient diagnostics.

Advantages and disadvantages of a fast fMRI sequence in the context of EEG–fMRI investigation of epilepsy patients: A realistic simulation study

EEG–fMRI is an established technique to allow mapping BOLD changes in response to interictal discharges recorded in the EEG of epilepsy patients. Traditional fMRI experiments rely on an echo planar imaging (EPI) sequence with a time resolution given by its time-to-repetition (TR) of ~2s. Recently, multiple fast fMRI sequences have been developed to get around the limited temporal resolution of the EPI sequence, and achieved a TR in the 100ms range or lower. One such sequence is called Magnetic Resonance EncephaloGraphy (MREG). Its high temporal resolution should offer increased detection sensitivity and statistical power in the context of epilepsy studies and in fMRI experiments in general. The aim of this work was to investigate the advantages and disadvantages offered by MREG. This was done by superimposing artificial event-related BOLD responses on EPI and MREG background signals, from 5 epileptic patients, that were free of epileptic discharges (spikes) on simultaneously recorded EEG. These functional datasets simulated different spiking rates and hemodynamic response amplitudes, and were analyzed with the commonly used General Linear Model (GLM) with the canonical hemodynamic response function (HRF) as a fixed model of the response. Robustness to violation of the assumptions of the GLM was additionally assessed with similar simulations using variable spike-to-spike response amplitudes and 8 non-canonical HRFs. Consistent with previous work, MREG yields higher maximum statistical t-values than EPI, but our simulations showed these statistics to be inflated, as the false positive rate at a standard threshold was high. At thresholds set to appropriately control specificity, EPI showed better true positive rate and larger cluster size than MREG. However, the lack of an appropriate calibration of the amplitude of the responses across the sequences precludes definitive judgment on their relative sensitivity. In addition, we show that a mismatch between the assumed and actual HRF impairs more MREG detection performance, but that EPI is more affected by non-modeled spike-to-spike variations of response amplitude. Filtering-out physiological noise, which is not aliased at the fast sampling rate of MREG, and the modeling of temporal autocorrelation are advantageous in increasing the detection power of MREG. This simulation study 1) warrants care when interpreting statistical t-values from fast fMRI sequences, 2) proposes thresholds for valid inferences and processing methods for maximal sensitivities, and 3) demonstrates the relative robustness/susceptibility of MREG and EPI to violation of the GLM's assumptions.

An fMRI investigation of moral cognition in healthcare decision making.

This study used fMRI to investigate the neural substrates of moral cognition in health resource allocation decision problems. In particular, it investigated the cognitive and emotional processes that underpin utilitarian approaches to health care rationing such as Quality Adjusted Life Years (QALYs). Participants viewed hypothetical medical and nonmedical resource allocation scenarios which described equal or unequal allocation of resources to different groups. In addition, participants were assigned to 1 of 2 treatments in which they either did or did not receive advanced instructions about the principles of utilitarianism. In all cases, participants were asked to judged the proposed allocations as “fair” or “unfair.” More brain activity was observed within the superior parietal lobe, angular gyrus, middle temporal gyrus, and bilateral caudate nucleus when participants viewed scenarios depicting equal divisions of resources. Conversely, unequal resource divisions were associated with more activity in the inferior frontal gyrus and insula cortex. Furthermore, instructions about the principles of utilitarianism led to significant activation differences within the inferior frontal gyrus and the middle frontal gyrus. Significant differences in activity were also found within the inferior frontal cortex and anterior insula between medical and nonmedical scenarios. The implications for cognitive control mechanisms and the cognitive and neural bases of utilitarian ethical judgment are discussed.