Papers by donatella spinelli
Space perception was investigated in right brain damaged patients with (N=13) and without neglect... more Space perception was investigated in right brain damaged patients with (N=13) and without neglect (N=5; control group). Patients were requested to localise a target tachistoscopically flashed at various eccentricities along the horizontal meridian. All patients had an intact visual field and spared ability to manually point to a target. To segregate magno- and parvo-pathway activity, stimuli modulated in either luminance or chromatic contrast were used. Patients were required to verbally report the stimulus position (verbal task) or to manually point to the stimulus (pointing task). Neglect patients reported the stimuli in the left visual field closer to the centre than they actually were. In the verbal test, underestimation was about 7 deg at the most eccentric position tested (20 deg), and decreased linearly for smaller eccentricities. The effect was similar but less marked in the pointing task. No difference was found for stimuli with luminance or chromatic contrast. Space undere...
Patients with spatial heminattention (neglect) following right brain damage fail to orient to, or... more Patients with spatial heminattention (neglect) following right brain damage fail to orient to, or report stimuli located in the left contralesional space. Primary sensory areas are often spared; the disorder is considered a high-order deficit, rather than a sensory-perceptual one. In the present study we evaluated the hypothesis of normal vs abnormal visual processing for stimuli on the contralesional side. VEPs were recorded in eleven patients with neglect, with a dense electrode array. V1, dorsal V3A, and ventral V4 were activated by left and ...
Journal of Neurotrauma, 2019
Preparatory cortical activities were investigated in subjects with paraplegia attributed to spina... more Preparatory cortical activities were investigated in subjects with paraplegia attributed to spinal cord injury (SCI). Electroencephalogram (EEG) and behavioral data were recorded simultaneously in a visual-motor discrimination go/no-go task performed with the right upper limb. Eighteen SCI subjects participated to one, two, or three experimental sessions (Go/No-Go task), according to their availability and willingness to participate. To evaluate the effects of SCI on cortical activities as a function of time, we considered three SCI groups (9 individuals each), based on different time from the injury onset (acute, 1-2 months; subacute, 3-5 months; chronic, 6-9 months), and a control group of 9 healthy participants matched for age and sex. Results indicate that response time (RT) was slower and percentage of omissions was higher in SCI subjects than healthy, independently from time from lesion (TFL). Also, the proactive motor preparation, indexed by the Bereitschafts potential (BP), and the pre-frontal cognitive control, indexed by the pre-frontal negativity component, showed reduced amplitude in SCI subjects, independently from TFL. Conversely, TFL effect was observed in the BP topography, which showed a more posterior focus in subacute and chronic groups than healthies. Interestingly, despite this posteriorization, BP amplitudes maintained the well-known correlation with RTs. Overall, SCI affects cortical reorganization independently from TFL, regarding proactive activities for action inhibition and reaction time; conversely, a TFL effect was observed in the topography changes related to the cortical areas involved in proactive motor activity. Present data are in line with growing evidence of brain changes after SCI, in particular focusing on cognitive effects and evidencing possible functional mechanisms related to motor and cognitive readiness processing, relevant for SCI rehabilitation programs.
Brain structure & function, 2018
The present work follows recent evidences of studies showing that visual stimuli evoke two early ... more The present work follows recent evidences of studies showing that visual stimuli evoke two early prefrontal event-related potentials (ERP) concomitant to the canonical occipital activities, but originating within the anterior insula (the pN1 and the pP1 components). To clarify the exogenous/endogenous nature of these components, we performed two experiments in which stimulus physical features (Experiment 1) and motor demands of the task (Experiment 2) were considered. In a simple response task (SRT), low-visibility stimuli evoked larger pN1 over the prefrontal areas (Experiment 1) with respect to high-visibility stimuli; in contrast, the occipital P1 component (concomitant to the pN1) had reduced amplitude in the low-visibility condition as expected. Furthermore, the latency of the P1, pN1 and pP1 was slower in the low-visibility condition (from 8 to 18 ms), and the motor response was slowed down as well (on average 14 ms). Pre-stimulus analysis showed that low-visibility stimuli we...
Brain structure & function, Jan 9, 2017
Using two independent electrical neuroimaging techniques (BESA and sLORETA), we tested a fMRI-see... more Using two independent electrical neuroimaging techniques (BESA and sLORETA), we tested a fMRI-seeded source modeling indicating that in visual discriminative tasks the anterior insula (aIns) participates in the generation of three prefrontal ERP components: the pN1 (at 115 ms), the pP1 (at 170 ms), and the pP2 (at 300 ms). This latter component represented the focus of the present study. Results showed that the pP2 had different activation profiles across hemispheres. The left aIns activity peaked at 420 ms (30 ms before the response) for both Go and No-go trials, that is independently from the ultimate choice (response or inhibition). The right aIns activity started at about 250 ms and progressively increased for a time interval extending after the motor response; its amplitude was larger in case of Go than No-go stimuli. We suggest that the activation of the left aIns reflected the timing of the decision, and the right aIns the categorization and the performance monitoring process...
Neuroscience & Biobehavioral Reviews, 2017
We review EEG literature on motor-related cortical activity of the last 10 years The focus is o... more We review EEG literature on motor-related cortical activity of the last 10 years The focus is on the brain proactive cognitive control for complex interactive actions Prefrontal, frontal, parietal and insular cortices are involved in action planning In brain preparation phase, we can catch glimpses of cognitive functions foundation
Experimental brain research, Oct 25, 2017
We examined the slowing in vocal reaction times shown by dyslexic (compared to control) children ... more We examined the slowing in vocal reaction times shown by dyslexic (compared to control) children with that of older (compared to younger) adults using an approach focusing on the detection of global, non-task-specific components. To address this aim, data were analyzed with reference to the difference engine (DEM) and rate and amount (RAM) models. In Experiment 1, typically developing children, children with dyslexia (both attending sixth grade), younger adults and older adults read words and non-words and named pictures. In Experiment 2, word and picture conditions were presented to dyslexic and control children attending eighth grade. In both experiments, dyslexic children were delayed in reading conditions, while they were unimpaired in naming pictures (a finding which indicates spared access to the phonological lexicon). The reading difficulty was well accounted for by a single multiplicative factor while only the residual effect of length (but not frequency and lexicality) was ...
Psychonomic bulletin & review, Jan 9, 2017
We reanalyzed previous experiments based on lexical-decision and reading-aloud tasks in children ... more We reanalyzed previous experiments based on lexical-decision and reading-aloud tasks in children with dyslexia and control children and tested the prediction of the difference engine model (DEM) that mean condition reaction times (RTs) and standard deviations (SDs) would be linearly related (Myerson et al., 2003). Then we evaluated the slope and the intercept with the x-axis of these linear functions in comparison with previously reported values (i.e., slope of about 0.30 and intercept of about 300 ms). In the case of lexical decision, the parameters were close to these values; by contrast, in the case of reading aloud, a much steeper slope (0.66) and a greater intercept (482.6 ms) were found. Therefore, interindividual variability grows at a much faster rate as a function of condition difficulty for reading than for lexical-decision tasks (or for other tasks reported in the literature). According to the DEM, the slope of the regression that relates means and SDs indicates the degre...
Scientific reports, Aug 18, 2016
In cognitive tasks, error commission is usually followed by a performance characterized by post-e... more In cognitive tasks, error commission is usually followed by a performance characterized by post-error slowing (PES) and post-error improvement of accuracy (PIA). Three theoretical accounts were hypothesized to support these post-error adjustments: the cognitive, the inhibitory, and the orienting account. The aim of the present ERP study was to investigate the neural processes associated with the second error prevention. To this aim, we focused on the preparatory brain activities in a large sample of subjects performing a Go/No-go task. The main results were the enhancement of the prefrontal negativity (pN) component -especially on the right hemisphere- and the reduction of the Bereitschaftspotential (BP) -especially on the left hemisphere- in the post-error trials. The ERP data suggested an increased top-down and inhibitory control, such as the reduced excitability of the premotor areas in the preparation of the trials following error commission. The results were discussed in light ...
Proceedings. Biological sciences / The Royal Society, May 25, 2016
Recent evidence suggests that ongoing brain oscillations may be instrumental in binding and integ... more Recent evidence suggests that ongoing brain oscillations may be instrumental in binding and integrating multisensory signals. In this experiment, we investigated the temporal dynamics of visual-motor integration processes. We show that action modulates sensitivity to visual contrast discrimination in a rhythmic fashion at frequencies of about 5 Hz (in the theta range), for up to 1 s after execution of action. To understand the origin of the oscillations, we measured oscillations in contrast sensitivity at different levels of luminance, which is known to affect the endogenous brain rhythms, boosting the power of alpha-frequencies. We found that the frequency of oscillation in sensitivity increased at low luminance, probably reflecting the shift in mean endogenous brain rhythm towards higher frequencies. Importantly, both at high and at low luminance, contrast discrimination showed a rhythmic motor-induced suppression effect, with the suppression occurring earlier at low luminance. We...
Giornale italiano di psicologia, 1997
Giornale italiano di psicologia, Sep 1, 2012
PloS one, 2016
Adults read at high speed, but estimates of their reading rate vary greatly, i.e., from 100 to 15... more Adults read at high speed, but estimates of their reading rate vary greatly, i.e., from 100 to 1500 words per minute (wpm). This discrepancy is likely due to different recording methods and to the different perceptual and cognitive processes involved in specific test conditions. The present study investigated the origins of these notable differences in RSVP reading rate (RR). In six experiments we investigated the role of many different perceptual and cognitive variables. The presence of a mask caused a steep decline in reading rate, with an estimated masking cost of about 200 wpm. When the decoding process was isolated, RR approached values of 1200 wpm. When the number of stimuli exceeded the short-term memory span, RR decreased to 800 wpm. The semantic context contributed to reading speed only by a factor of 1.4. Finally, eye movements imposed an upper limit on RR (around 300 wpm). Overall, data indicate a speed limit of 300 wpm, which corresponds to the time needed for eye moveme...
Rassegna di Psicologia, 2011
NeuroImage, 2016
Deciding whether to act or not to act is a fundamental cognitive function. To avoid incorrect res... more Deciding whether to act or not to act is a fundamental cognitive function. To avoid incorrect responses, both re-22 active and proactive modes of control have been postulated. Little is known, however, regarding the brain imple-23 mentation of proactive mechanisms, which are deployed prior to an actual need to inhibit a response. Via a 24 combination of electrophysiological and neuroimaging measures (recorded in 21 and 16 participants, respective-25 ly), we describe the brain localization and timing of neural activity that underlies the anticipatory proactive 26 mechanism. From these results, we conclude that proactive control originates in the inferior Frontal gyrus, is 27 established well before stimulus perception, and is released concomitantly with stimulus appearance. Stimulus 28 perception triggers early activity in the anterior insula and intraparietal cortex contralateral to the responding 29 hand; these areas likely mediate the transition from perception to action. The neural activities leading to the de-30 cision to act or not to act are described in the framework of a three-stage model that includes perception, action, 31 and anticipatory functions taking place well before stimulus onset.
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Papers by donatella spinelli