Publications by authors named "Martina Bracco"

7 Publications

  • Page 1 of 1

An analytical approach to identify indirect multisensory cortical activations elicited by TMS?

Brain Stimul 2021 Feb 10;14(2):376-378. Epub 2021 Feb 10.

Institute of Neuroscience & Psychology, Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow, G12 8QB, UK. Electronic address:

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http://dx.doi.org/10.1016/j.brs.2021.02.003DOI Listing
February 2021

A Common Task Structure Links Together the Fate of Different Types of Memories.

Curr Biol 2020 Jun 16;30(11):2139-2145.e5. Epub 2020 Apr 16.

Institute of Neuroscience & Psychology, Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow G12 8QB, UK. Electronic address:

Our memories frequently have features in common. For example, a learned sequence of words or actions can follow a common rule, which determines their serial order, despite being composed of very different events [1, 2]. This common abstract structure might link the fates of memories together. We tested this idea by creating different types of memory task: a sequence of words or actions that either did or did not have a common structure. Participants learned one of these memory tasks and then they learned another type of memory task 6 h later, either with or without the same structure. We then tested the newly formed memory's susceptibility to interference. We found that the newly formed memory was protected from interference when it shared a common structure with the earlier memory. Specifically, learning a sequence of words protected a subsequent sequence of actions learned hours later from interference, and conversely, learning a sequence of actions protected a subsequent sequence of words learned hours later from interference provided the sequences shared a common structure. Yet this protection of the newly formed memory came at a cost. The earlier memory had disrupted recall when it had the same rather than a different structure to the newly formed and protected memory. Thus, a common structure can determine what is retained (i.e., protected) and what is modified (i.e., disrupted). Our work reveals that a shared common structure links the fate of otherwise different types of memories together and identifies a novel mechanism for memory modification.
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http://dx.doi.org/10.1016/j.cub.2020.03.043DOI Listing
June 2020

Exploring the neural correlates of the reversed letter effect: Evidence from left and right parietal patients.

Neurosci Lett 2019 04 11;699:217-224. Epub 2019 Feb 11.

Department of Psychology, Educational Science and Human Movement, University of Palermo, Palermo, Italy; NeuroTeam Life and Science, Palermo, Italy; IRCCS Santa Lucia Foundation, Rome, Italy.

To investigate the hemispheric lateralization of attentional processes during visual search tasks depending on the stimulus material embedding the target, twelve patients with unilateral left (n = 7) or right (n = 5) parietal lesions and 20 age and education matched healthy controls (HC) were recruited. We used a visual search task for a uniquely tilted oblique bar embedded in an object shape 'N' or in its mirror reversal 'И'. The accuracy and the averaged reaction times (RTs) in each stimulus type ('N' or 'И') were analysed. HC presented significantly longer RTs when the target bar was embedded in 'N' among its mirror reversed 'И' (p < .05). This "reversed letter effect" was also found in the right parietal patients (p < .001), while no evidence of a reversed letter effect was found in the left parietal patients.
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http://dx.doi.org/10.1016/j.neulet.2019.02.017DOI Listing
April 2019

Prismatic Adaptation Modulates Oscillatory EEG Correlates of Motor Preparation but Not Visual Attention in Healthy Participants.

J Neurosci 2018 01 18;38(5):1189-1201. Epub 2017 Dec 18.

Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QB, United Kingdom

Prismatic adaption (PA) has been proposed as a tool to induce neural plasticity and is used to help neglect rehabilitation. It leads to a recalibration of visuomotor coordination during pointing as well as to aftereffects on a number of sensorimotor and attention tasks, but whether these effects originate at a motor or attentional level remains a matter of debate. Our aim was to further characterize PA aftereffects by using an approach that allows distinguishing between effects on attentional and motor processes. We recorded EEG in healthy human participants (9 females and 7 males) while performing a new double step, anticipatory attention/motor preparation paradigm before and after adaptation to rightward-shifting prisms, with neutral lenses as a control. We then examined PA aftereffects through changes in known oscillatory EEG signatures of spatial attention orienting and motor preparation in the alpha and beta frequency bands. Our results were twofold. First, we found PA to rightward-shifting prisms to selectively affect EEG signatures of motor but not attentional processes. More specifically, PA modulated preparatory motor EEG activity over central electrodes in the right hemisphere, contralateral to the PA-induced, compensatory leftward shift in pointing movements. No effects were found on EEG signatures of spatial attention orienting over occipitoparietal sites. Second, we found the PA effect on preparatory motor EEG activity to dominate in the beta frequency band. We conclude that changes to intentional visuomotor, rather than attentional visuospatial, processes underlie the PA aftereffect of rightward-deviating prisms in healthy participants. Prismatic adaptation (PA) has been proposed as a tool to induce neural plasticity in both healthy participants and patients, due to its aftereffect impacting on a number of visuospatial and visuomotor functions. However, the neural mechanisms underlying PA aftereffects are poorly understood as only little neuroimaging evidence is available. Here, we examined, for the first time, the origin of PA aftereffects studying oscillatory brain activity. Our results show a selective modulation of preparatory motor activity following PA in healthy participants but no effect on attention-related activity. This provides novel insight into the PA aftereffect in the healthy brain and may help to inform interventions in neglect patients.
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http://dx.doi.org/10.1523/JNEUROSCI.1422-17.2017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5792477PMC
January 2018

Modulating phonemic fluency performance in healthy subjects with transcranial magnetic stimulation over the left or right lateral frontal cortex.

Neuropsychologia 2017 Jul 10;102:109-115. Epub 2017 Jun 10.

Dipartimento di Scienze Psicologiche, Pedagogiche e della Formazione, Università degli Studi di Palermo, Palermo, Italy; NeuroTeam Life and Science, Palermo, Italy; Department of Neuropsychology, National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom.

A growing body of evidence have suggested that non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), can improve the performance of aphasic patients in language tasks. For example, application of inhibitory rTMS or tDCs over the right frontal lobe of dysphasic patients resulted in improved naming abilities. Several studies have also reported that in healthy controls (HC) tDCS application over the left prefrontal cortex (PFC) improve performance in naming and semantic fluency tasks. The aim of this study was to investigate in HC, for the first time, the effects of inhibitory repetitive TMS (rTMS) over left and right lateral frontal cortex (BA 47) on two phonemic fluency tasks (FAS or FPL). 44 right-handed HCs were administered rTMS or sham over the left or right lateral frontal cortex in two separate testing sessions, with a 24h interval, followed by the two phonemic fluency tasks. To account for possible practice effects, an additional 22 HCs were tested on only the phonemic fluency task across two sessions with no stimulation. We found that rTMS-inhibition over the left lateral frontal cortex significantly worsened phonemic fluency performance when compared to sham. In contrast, rTMS-inhibition over the right lateral frontal cortex significantly improved phonemic fluency performance when compared to sham. These results were not accounted for practice effects. We speculated that rTMS over the right lateral frontal cortex may induce plastic neural changes to the left lateral frontal cortex by suppressing interhemispheric inhibitory interactions. This resulted in an increased excitability (disinhibition) of the contralateral unstimulated left lateral frontal cortex, consequently enhancing phonemic fluency performance. Conversely, application of rTMS over the left lateral frontal cortex may induce a temporary, virtual lesion, with effects similar to those reported in left frontal patients.
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http://dx.doi.org/10.1016/j.neuropsychologia.2017.06.006DOI Listing
July 2017

Combining tDCS with prismatic adaptation for non-invasive neuromodulation of the motor cortex.

Neuropsychologia 2017 Jul 6;101:30-38. Epub 2017 May 6.

Dipartimento di Scienze Psicologiche, Pedagogiche e della Formazione, Università degli Studi di Palermo, Italy; NeuroTeam Life and Science, Palermo, Italy.

Background: Prismatic adaptation (PA) shifts visual field laterally and induces lateralized deviations of spatial attention. Recently, it has been suggested that prismatic goggles are also able to modulate brain excitability, with cognitive after-effects documented even in tasks not necessarily spatial in nature.

Objective: The aim of the present study was to test whether neuromodulatory effects obtained from tDCS and prismatic goggles could interact and induce homeostatic changes in corticospinal excitability.

Methods: Thirty-four subjects were submitted to single-pulse transcranial magnetic stimulation (TMS) over the right primary motor cortex to measure Input-Output (IO) curve as a measure of corticospinal excitability. Assessment was made in three experimental conditions: before and after rightward PA and anodal tDCS of the right motor cortex; before and after rightward PA; before and after anodal tDCS of the right motor cortex.

Results: A significant decrease of MEPs amplitude and of IO curve slope steepness was found after the combination of rightward PA and anodal tDCS; on the other hand, an increase of MEPs amplitude and of the steepness of IO curve slope on the right motor cortex was found following either rightward PA or anodal tDCS.

Conclusion: These findings suggest that priming of motor cortex excitability using PA could be an additional tool to modulate cortical metaplasticity.
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http://dx.doi.org/10.1016/j.neuropsychologia.2017.05.006DOI Listing
July 2017

Relationship between physiological excitatory and inhibitory measures of excitability in the left vs. right human motor cortex and peripheral electrodermal activity.

Neurosci Lett 2017 02 16;641:45-50. Epub 2017 Jan 16.

Dipartimento di Scienze Psicologiche, Pedagogiche e della Formazione, Università degli Studi di Palermo, Italy; NeuroTeam Life and Science, Palermo, Italy. Electronic address:

The current study was aimed at investigating the relationships of excitatory and inhibitory circuits of the left vs. right primary motor cortex with peripheral electrodermal activity (EDA). Ten healthy subjects participated in two experimental sessions. In each session, EDA was recorded for 10min from the palmar surface of the left hand. Immediately after EDA recording, Transcranial Magnetic Stimulation (TMS) was used to probe excitatory and inhibitory circuits of the left or right primary motor cortex using two protocols of stimulation: the input-output curve for recording of motor evoked potentials, for testing excitatory circuits; the long-interval cortical inhibition (LICI) protocol, for testing inhibitory circuits. In both cases, motor evoked potentials were recorded with surface electrodes from a contralateral hand muscle. The main results showed that in the right motor cortex, excitatory circuits directly correlate and inhibitory circuits inversely correlate with sympathetic activation. In the left motor cortex, both excitatory and inhibitory circuits are inversely correlated with sympathetic activation. These findings may suggest a bi-hemispheric mode of control of vegetative system by motor cortices, with the right hemisphere mainly involved in sympathetic control.
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http://dx.doi.org/10.1016/j.neulet.2017.01.027DOI Listing
February 2017