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New Commentary in Behavioral and Brain Science

Congratulations to
David, whose latest paper has just been published in Behavioral and Brain Science!

Burr, D. C. (2017). Evidence for a number sense, Behavioral and Brain Sciences, (40), 18-19. PDF

Numerosity is inherently confounded by related stimulus attributes such as density and area, and many studies have reported interactions of various strengths between area, density, and numerosity. However, direct measurements of sensitivity within the area-density-numerosity space show that numerosity emerges as the most spontaneous and sensitive dimension, strongly supporting the existence of a dedicated number sense.

New Commentary in Behavioral and Brain Science

Congratulations to
Elisa, whose latest paper has just been published in Behavioral and Brain Science!

de Hevia, M. D., Castaldi, E., Streri, A., Eger, E. & Izard, V. (2017). Perceiving numerosity from birth, Behavioral and Brain Sciences, (40), 21-22. PDF

Leibovich et al. opened up an important discussion on the nature and origins of numerosity perception. The authors rightly point out that non-numerical features of stimuli influence this ability. Despite these biases, there is evidence that from birth, humans perceive and represent numerosities, and not just non-numerical quantitative features such as item size, density, and convex hull.

New Spotlight published on Trends in Neuroscience!

Congratulation to Paola who just published a new paper on Trends in Neuroscience!

Binda, P. & Gamlin, P. D. (2017). Renewed Attention on the Pupil Light Reflex, Trends Neurosci, PDF

In a recent study, Ebitz and Moore described how subthreshold electrical microstimulation of the macaque frontal eye fields (FEF) modulates the pupillary light reflex. This elegant study suggests that the influence of the FEF and prefrontal cortex on attentional modulation of cortical visual processing extends to the subcortical circuit that mediates a very basic reflex, the pupillary light reflex.



New Research published on Journal of Neurophysiology!

Congratulation to Concetta who just published a new paper on Journal of Neurophysiology!

Sani, I., Santandrea, E., Morrone, M. C. & Chelazzi, L. (2017). Temporally Evolving Gain Mechanisms of Attention in Macaque Area V4, J Neurophysiol, jn 00522 02016. PDF

Cognitive attention and perceptual saliency jointly govern our interaction with the environment. Yet, we still lack a universally accepted account of the interplay between attention and luminance contrast - a fundamental dimension of saliency. We measured the attentional modulation of V4 neurons' Contrast Response Functions (CRFs) in awake, behaving macaque monkeys and applied a new approach which emphasizes the temporal dynamics of cell responses. We found that attention modulates CRFs via different gain mechanisms during subsequent epochs of visually driven activity: an early contrast-gain - strongly dependent on pre-stimulus activity changes (baseline shift), a time-limited stimulus-dependent multiplicative modulation, reaching its maximal expression around 150 ms after stimulus onset, and a late resurgence of contrast-gain modulation. Attention produced comparable time-dependent attentional gain changes on cells heterogeneously coding contrast, supporting the notion that the same circuits mediate attention mechanisms in V4 regardless of the form of contrast selectivity expressed by the given neuron. Surprisingly, attention was also sometimes capable of inducing radical transformations in the shape of CRFs. These findings offer important insights into the mechanisms that underlie contrast coding and attention in primate visual cortex and a new perspective on their interplay, one in which time becomes a fundamental factor.



New Research published on Journal of Neuropsychology!

Congratulation to Marco who just published a new paper on Journal of Neuropsychology!

Chilosi, A. M., Bulgheroni, S., Turi, M., Cristofani, P., Biagi, L., Erbetta, A., et al. (2017). Hemispheric language organization after congenital left brain lesions: A comparison between functional transcranial Doppler and functional MRI, J Neuropsychol, PDF

This study investigated whether functional transcranial Doppler ultrasound (fTCD) is a suitable tool for studying hemispheric lateralization of language in patients with pre-perinatal left hemisphere (LH) lesions and right hemiparesis. Eighteen left-hemisphere-damaged children and young adults and 18 healthy controls were assessed by fTCD and fMRI to evaluate hemispheric activation during two language tasks: a fTCD animation description task and a fMRI covert rhyme generation task. Lateralization indices (LIs), measured by the two methods, differed significantly between the two groups, for a clear LH dominance in healthy participants and a prevalent activation of right hemisphere in more than 80% of brain-damaged patients. Distribution of participants in terms of left, right, and bilateral lateralization was highly concordant between fTCD and fMRI values. Moreover, right hemisphere language dominance in patients with left hemispheric lesions was significantly associated with severity of cortical and subcortical damage in LH. This study suggests that fTCD is an easily applicable tool that might be a valid alternative to fMRI for large-scale studies of patients with congenital brain lesions.


New Research published on Current Biology!

Congratulation to David who just published on Current Biology!

Kagan, I. & Burr, D. C. (2017). Active Vision: Dynamic Reformatting of Visual Information by the Saccade-Drift Cycle, Curr Biol, 9 (27), R341-R344. PDF

Visual processing depends on rapid parsing of global features followed by analysis of fine detail. A new study suggests that this transformation is enabled by a cycle of saccades and fixational drifts, which reformat visual input to match the spatiotemporal sensitivity of fast and slow neuronal pathways.


New Research published in Journal of Physiology

Congratulations to Maria Concetta, whose work has been published on Frontiers in System Neuroscience!

Bourne, J. A. & Morrone, M. C. (2017). Plasticity of Visual Pathways and Function in the Developing Brain: Is the Pulvinar a Crucial Player?, Front Syst Neurosci, (11), 3. PDF

The pulvinar is the largest of the thalamic nuclei in the primates, including humans. In the primates, two of the three major subdivisions, the lateral and inferior pulvinar, are heavily interconnected with a significant proportion of the visual association cortex. However, while we now have a better understanding of the bidirectional connectivity of these pulvinar subdivisions, its functions remain somewhat of an enigma. Over the past few years, researchers have started to tackle this problem by addressing it from the angle of development and visual cortical lesions. In this review, we will draw together literature from the realms of studies in nonhuman primates and humans that have informed much of the current understanding. This literature has been responsible for changing many long-held opinions on the development of the visual cortex and how the pulvinar interacts dynamically with cortices during early life to ensure rapid development and functional capacity Furthermore, there is evidence to suggest involvement of the pulvinar following lesions of the primary visual cortex (V1) and geniculostriate pathway in early life which have far better functional outcomes than identical lesions obtained in adulthood. Shedding new light on the pulvinar and its role following lesions of the visual brain has implications for our understanding of visual brain disorders and the potential for recovery.

New Research published in Journal of Cognitive Neuroscience!

Congratulation to Luca, Concetta and Claudia who just published a new paper on the Journal of Cognitive Neuroscience!

Lo Verde, L., Morrone, M. C. & Lunghi, C. (2017). Early Cross-modal Plasticity in Adults, J Cogn Neurosci, 3 (29), 520-529. PDF

It is known that, after a prolonged period of visual deprivation, the adult visual cortex can be recruited for nonvisual processing, reflecting cross-modal plasticity. Here, we investigated whether cross-modal plasticity can occur at short timescales in the typical adult brain by comparing the interaction between vision and touch during binocular rivalry before and after a brief period of monocular deprivation, which strongly alters ocular balance favoring the deprived eye. While viewing dichoptically two gratings of orthogonal orientation, participants were asked to actively explore a haptic grating congruent in orientation to one of the two rivalrous stimuli. We repeated this procedure before and after 150 min of monocular deprivation. We first confirmed that haptic stimulation interacted with vision during rivalry promoting dominance of the congruent visuo-haptic stimulus and that monocular deprivation increased the deprived eye and decreased the nondeprived eye dominance. Interestingly, after deprivation, we found that the effect of touch did not change for the nondeprived eye, whereas it disappeared for the deprived eye, which was potentiated after deprivation. The absence of visuo-haptic interaction for the deprived eye lasted for over 1 hr and was not attributable to a masking induced by the stronger response of the deprived eye as confirmed by a control experiment. Taken together, our results demonstrate that the adult human visual cortex retains a high degree of cross-modal plasticity, which can occur even at very short timescales.


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