Giovanni Mirabella | University of Brescia (original) (raw)

Papers by Giovanni Mirabella

Neuropsychologia, Jul 1, 2017

Parkinson's disease (PD) is often characterized by asymmetrical symptoms, which are more prominen... more Parkinson's disease (PD) is often characterized by asymmetrical symptoms, which are more prominent on the side of the body contralateral to the most extensively affected brain hemisphere. Therefore, lateralized PD presents an opportunity to examine the effects of asymmetric subcortical dopamine deficiencies on cognitive functioning. As it has been hypothesized that inhibitory control relies upon a right-lateralized pathway, we tested whether left-dominant PD (LPD) patients suffered from a more severe deficit in this key executive function than right-dominant PD patients (RPD). To this end, via a countermanding task, we assessed both proactive and reactive inhibition in 20 LPD and 20 RPD patients, and in 20 age-matched healthy subjects. As expected, we found that PD patients were significantly more impaired in both forms of inhibitory control than healthy subjects. However, there were no differences either in reactive or proactive inhibition between LPD and RPD patients. All in all, these data support the idea that brain regions affected by PD play a fundamental role in subserving inhibitory function, but do not sustain the hypothesis according to which this executive function is predominantly or solely computed by the brain regions of the right hemisphere.

Frontiers in Neurology, Jan 7, 2019

Despite the relevance of inhibitory control in shaping our behavior its neural substrates are sti... more Despite the relevance of inhibitory control in shaping our behavior its neural substrates are still hotly debated. In this regard, it has been suggested that inhibitory control relies upon a right-lateralized network which involves the right subthalamic nucleus (STN). To assess the role of STN, we took advantage of a relatively rare model, i.e., advanced Parkinson's patients who received unilateral deep-brain stimulation (DBS) of the STN either of the left (n = 10) or of the right (n = 10) hemisphere. We gave them a stop-signal reaching task, and we compared patients' performance in two experimental conditions, DBS-ON and DBS-OFF. In addition, we also tested 22 age-matched healthy participants. As expected, we found that inhibitory control is impaired in Parkinson's patients with respect to healthy participants. However, neither reactive nor proactive inhibition is improved when either the right or the left DBS is active. We interpreted these findings in light of the fact that previous studies, exploiting exactly the same task, have shown that only bilateral STN DBS restores a near-normal inhibitory control. Thus, although null results have to be interpreted with caution, our current findings confirm that the right STN does not play a key role in suppressing pending actions. However, on the ground of previous studies, it is very likely that this subcortical structure is part of the brain network subserving inhibition but to implement this executive function both subthalamic nuclei must be simultaneously active. Our findings are of significance to other researchers studying the effects of STN DBS on key executive functions, such as impulsivity and inhibition and they are also of clinical relevance for determining the therapeutic benefits of STN DBS as they suggest that, at least as far as inhibitory control is concerned, it is better to implant DBS bilaterally than unilaterally.

Theatre and Cognitive Neuroscience, 2016

Frontiers in Psychology

A classical theoretical frame to interpret motor reactions to emotional stimuli is that such stim... more A classical theoretical frame to interpret motor reactions to emotional stimuli is that such stimuli, particularly those threat-related, are processed preferentially, i.e., they are capable of capturing and grabbing attention automatically. Research has recently challenged this view, showing that the task relevance of emotional stimuli is crucial to having a reliable behavioral effect. Such evidence indicated that emotional facial expressions do not automatically influence motor responses in healthy young adults, but they do so only when intrinsically pertinent to the ongoing subject’s goals. Given the theoretical relevance of these findings, it is essential to assess their generalizability to different, socially relevant emotional stimuli such as emotional body postures. To address this issue, we compared the performance of 36 right-handed participants in two different versions of a Go/No-go task. In the Emotional Discrimination task, participants were required to withhold their re...

Frontiers in Neurology

Tourette syndrome (TS) and early-onset obsessive-compulsive disorder (OCD) are frequently associa... more Tourette syndrome (TS) and early-onset obsessive-compulsive disorder (OCD) are frequently associated and conceptualized as distinct phenotypes of a common disease spectrum. However, the nature of their relationship is still largely unknown on a pathophysiological level. In this study, early structural white matter (WM) changes investigated through diffusion tensor imaging (DTI) were compared across four groups of drug-naïve children: TS-pure (n = 16), TS+OCD (n = 14), OCD (n = 10), and 11 age-matched controls. We analyzed five WM tracts of interest, i.e., cortico-spinal tract (CST), anterior thalamic radiations (ATR), inferior longitudinal fasciculus (ILF), corpus callosum (CC), and cingulum and evaluated correlations of DTI changes to symptom severity. Compared to controls, TS-pure and TS+OCD showed a comparable pattern of increased fractional anisotropy (FA) in CST, ATR, ILF and CC, with FA changes displaying negative correlation to tic severity. Conversely, in OCD, FA decreased i...

Clinical Neurophysiology, 2016

Emotion

The ability to generate appropriate responses, especially in social contexts, requires integratin... more The ability to generate appropriate responses, especially in social contexts, requires integrating emotional information with ongoing cognitive processes. In particular, inhibitory control plays a crucial role in social interactions, preventing the execution of impulsive and inappropriate actions. In this study, we focused on the impact of facial emotional expressions on inhibition. Research in this field has provided highly mixed results. In our view, a crucial factor explaining such inconsistencies is the task-relevance of the emotional content of the stimuli. To clarify this issue, we gave two versions of a Go/No-go task to healthy participants. In the emotional version, participants had to withhold a reaching movement at the presentation of emotional facial expressions (fearful or happy) and move when neutral faces were shown. The same pictures were displayed in the other version, but participants had to act according to the actor's gender, ignoring the emotional valence of the faces. We found that happy expressions impaired inhibitory control with respect to fearful expressions, but only when they were relevant to the participants' goal. We interpret these results as suggesting that facial emotions do not influence behavioral responses automatically. They would instead do so only when they are intrinsically germane for ongoing goals.

Journal of Psychiatric Research

Previous studies in cohorts of Tourette syndrome (TS) or obsessive-compulsive disorder (OCD) pati... more Previous studies in cohorts of Tourette syndrome (TS) or obsessive-compulsive disorder (OCD) patients have not clarified whether these two disorders represent two clinical conditions or they are distinct clinical phenotypes of a common disease spectrum. The study aimed to compare functional connectivity (FC) patterns in a pediatric drug-naive cohort of 16 TS patients without any comorbidity (TS), 14 TS patients with OCD (TS þ OCD), and 10 pure OCD patients as well as 11 matched controls that underwent resting state fMRI. Via independent component analysis, we examined FC in the basal ganglia (BGN), sensorimotor (SMN), cerebellum (CBN), frontoparietal (FPN), default-mode (DMN), orbitofrontal (OBFN), and salience (SAN) networks among the above cohorts and their association with clinical measures. Compared to controls, TS and TS þ OCD patients showed higher FC in the BGN, SMN, CBN and DMN and lower FC in the FPN and SAN. The TS and TS þ OCD groups showed comparable FC in all networks. In contrast to controls, OCD patients exhibited increased FC in the BGN, SMN, CBN, DMN, FPN, and SAN. OCD patients also showed higher FC in CBN and FPN when compared with TS and TS þ OCD patients both separately and as one group. Tic severity negatively correlated with FC in CBN and FPN in the TS group, while the compulsiveness scores positively correlated with the same two networks in OCD patients. Our findings suggest common FC changes in TS and TS þ OCD patients. In contrast, OCD is characterized by a distinctive pattern of FC changes prominently involving the CBN and FPN.

Brain Sciences

Facial emotional expressions are a salient source of information for nonverbal social interaction... more Facial emotional expressions are a salient source of information for nonverbal social interactions. However, their impact on action planning and execution is highly controversial. In this vein, the effect of the two threatening facial expressions, i.e., angry and fearful faces, is still unclear. Frequently, fear and anger are used interchangeably as negative emotions. However, they convey different social signals. Unlike fear, anger indicates a direct threat toward the observer. To provide new evidence on this issue, we exploited a novel design based on two versions of a Go/No-go task. In the emotional version, healthy participants had to perform the same movement for pictures of fearful, angry, or happy faces and withhold it when neutral expressions were presented. The same pictures were shown in the control version, but participants had to move or suppress the movement, according to the actor’s gender. This experimental design allows us to test task relevance’s impact on emotional...

Developmental Medicine & Child Neurology

This paper proposes a dynamic joint scheduling for the ultra-reliable low-latency communication (... more This paper proposes a dynamic joint scheduling for the ultra-reliable low-latency communication (URLLC) and enhanced mobile broadband (eMBB) traffic at a sub-frame level with a queuing mechanism, which monitors and controls the latency of each URLLC packet in real time to ensure its strict requirements. We analytically derive the outage probability (i.e., the probability of any URLLC packet drop over all transmission channels) and URLLC expected throughput in addition to the expected value of served URLLC packets. Then, a stochastic optimization problem is formulated to maximize the total throughput for the eMBB services, constraining the URLLC outage probability. Numerical results confirm effectiveness of our queuing policy to significantly reduce the URLLC loss rate while ensuring that the total eMBB throughput is not affected.

Psychiatry Research: Neuroimaging

Reactive inhibition correlates with the severity of symptoms in paediatric patients with Obsessiv... more Reactive inhibition correlates with the severity of symptoms in paediatric patients with Obsessive-Compulsive Disorder (OCD) though not in those with Tourette syndrome (TS). Here we assessed whether structural alterations in both grey (GM) and white matter (WM) volumes correlate with a measure of reactive inhibition, i.e. the stop-signal reaction time (SSRT), and with clinical scale scores. Nine OCD and 11 TS uncomplicated drug-naïve paediatric patients and 12 age-matched controls underwent 3T magnetic resonance imaging scanning. Between-group differences in GM and WM volumes across the whole brain were assessed. Outside the scanner, patients performed a reaching version of the stop-signal task. Both behavioural inhibitory control and neuroimaging measures were normal in TS patients. By contrast, OCD patients exhibited a significant loss in GM volume in five areas. The GM volume of the left inferior frontal gyrus was inversely correlated with the length of the SSRT, the left mid-cingulate gyrus and the right middle frontal gyrus were inversely correlated with the severity of OCD symptoms, and the left insula and the right medial orbitofrontal gyrus were inversely correlated with both. These results indicate that cortical areas showing GM loss in OCD patients are also involved in the network subserving reactive inhibition.

Frontiers in psychology, 2018

Modern theories of behavioral control converge with the idea that goal-directed/voluntary behavio... more Modern theories of behavioral control converge with the idea that goal-directed/voluntary behaviors are intimately tied to the evaluation of resources. Of key relevance in the decision-making processes that underlie action selection are those stimuli that bear emotional content. However, even though it is acknowledged that emotional information affects behavioral control, the exact way in which emotions impact on action planning is largely unknown. To clarify this issue, I gave an emotional version of a go/no-go task to healthy participants, in which they had to perform the same arm reaching movement when pictures of fearful or happy faces were presented, and to withhold it when pictures of faces with neutral expressions were presented. This task allows for the investigation of the effects of emotional stimuli when they are task-relevant without conflating movement planning with target detection and task switching. It was found that both the reaction times (RTs) and the percentages ...

Parkinson's disease, 2017

Conventional medical treatments of Parkinson's disease (PD) are effective on motor disturbanc... more Conventional medical treatments of Parkinson's disease (PD) are effective on motor disturbances but may have little impact on nonmotor symptoms, especially psychiatric ones. Thus, even when motor symptomatology improves, patients might experience deterioration in their quality of life. We have shown that 3 years of active theatre is a valid complementary intervention for PD as it significantly improves the well-being of patients in comparison to patients undergoing conventional physiotherapy. Our aim was to replicate these findings while improving the efficacy of the treatment. We ran a single-blinded pilot study lasting 15 months on 24 subjects with moderate idiopathic PD. 12 were assigned to a theatre program in which patients underwent "emotional" training. The other 12 underwent group physiotherapy. Patients were evaluated at the beginning and at the end of their treatments, using a battery of eight clinical and five neuropsychological scales. We found that the emo...