1,721,103 research outputs found
The role of preSMA and STS in face recognition: A transcranial magnetic stimulation (TMS) study
No full textCurrent models propose that facial recognition is mediated by two independent yet interacting anatomo-functional systems: one processing facial features mainly mediated by the Fusiform Face Area and the other involved in the extraction of dynamic information from faces, subserved by Superior Temporal Sulcus (STS). Also, the pre-Supplementary Motor Area (pre-SMA) is implicated in facial expression processing as it is involved in its motor mimicry. However, the literature only shows evidence of the implication of STS and preSMA for facial expression recognition, without relating it to face recognition. In addition, the literature shows a facilitatory role of facial motion in the recognition of unfamiliar faces, particularly for poor recognizers. The present study aimed at studying the role of STS and preSMA in unfamiliar face recognition in people with different face recognition skills. 34 healthy participants received repetitive transcranial magnetic stimulation over the right posterior STS, pre-SMA and as sham during a task of matching of faces encoded through: facial expression, rigid head movement or as static (i.e., absence of any facial or head motion). All faces were represented without emotional content. Results indicate that STS has a direct role in recognizing identities through rigid head movement and an indirect role in facial expression processing. This dissociation represents a step forward with respect to current face processing models suggesting that different types of motion involve separate brain and cognitive processes. PreSMA interacts with face recognition skills, increasing the performance of poor recognizers and decreasing that of good recognizers in all presentation conditions. Together, the results suggest the use of at least partially different mechanisms for face recognition in poor and good recognizers and a different role of STS and preSMA in face recognition
Instrumental expertise and musical timbre modulate the spatial representation of pitch
No full textHumans show a tendency to represent pitch in a spatial format. A classical finding supporting this spatial representation is the Spatial–Musical Association of Response Codes (SMARC) effect, reflecting faster responses to low tones when pressing a left/bottom-side key and to high tones when pressing a right/top-side key. Despite available evidence suggesting that the horizontal and vertical SMARC effect may be differently modulated by instrumental expertise and musical timbre, no study has so far directly explored this hypothesis in a unified framework. Here, we investigated this possibility by comparing the performance of professional pianists, professional clarinettists and non-musicians in an implicit timbre judgement task, in both horizontal and vertical response settings. Results showed that instrumental expertise significantly modulates the SMARC effect: whereas in the vertical plane a comparable SMARC effect was observed in all groups, in the horizontal plane the SMARC effect was significantly modulated by the specific instrumental expertise, with pianists showing a stronger pitch–space association compared to clarinettists and non-musicians. Moreover, the influence of pitch along the horizontal dimension was stronger in those pianists who started the instrumental training at a younger age. Results also showed an influence of musical timbre in driving the horizontal, but not the vertical, SMARC effect, with only piano notes inducing a pitch–space association. Taken together, these findings suggest that sensorimotor experience due to instrumental training and musical timbre affect the mental representation of pitch on the horizontal space, whereas the one on the vertical space would be mainly independent from musical practice
Listening to white noise counteracts visual and haptic pseudoneglect
No full textNeurologically intact individuals usually show a leftward bias in line bisection, a tendency known as "pseudoneglect", likely reflecting a right-hemisphere dominance in controlling the allocation of spatial attention. Studies in brain-damaged patients with left visuospatial neglect have reported that auditory stimulation may reduce the deficit, both in a spatially dependent and in a spatially independent way. Here we show for the first time that the concurrent binaural presentation of auditory white noise affects healthy individuals' performance in both visual and haptic bisection, reducing their leftward error. We suggest that this effect depends on the noise boosting alertness and restoring the hemispheric activation balance. Our data clearly show that task-irrelevant auditory noise crossmodally affects the allocation of spatial resources in both the haptic and the visual space; future research may clarify whether these effects are specific for the type of auditory stimulatio
Star formation histories of z~1 galaxies in LEGA-C
Full text linkUsing high resolution spectra from the VLT LEGA-C program, we reconstruct the star formation histories (SFHs) of 607 galaxies at redshifts z = 0.6 − 1.0 and stellar masses 10^10 M⊙ using a custom full spectrum fitting algorithm that incorporates the emcee and FSPS packages. We show that the mass-weighted age of a galaxy correlates strongly with stellar velocity dispersion (σ∗) and ongoing star-formation (SF) activity, with the stellar content in higher-σ∗ galaxies having formed earlier and faster. The SFHs of quiescent galaxies are generally consistent with passive evolution since their main SF epoch, but a minority show clear evidence of a rejuvenation event in their recent past. The mean age of stars in galaxies that are star-forming is generally significantly younger, with SF peaking after z 100 Myrs. This indicates that z > 2 progenitors of z ∼ 1 star-forming galaxies are generally far less massive. Finally, despite considerable variance in the individual SFHs, we show that the current SF activity of massive galaxies (> L∗ ) at z ∼ 1 correlates with SF levels at least 3 Gyrs prior: SFHs retain ‘memory’ on a large fraction of the Hubble time. Our results illustrate a novel approach to resolve the formation phase of galaxies, and in identifying their individual evolutionary paths, connects progenitors and descendants across cosmic time. This is uniquely enabled by the high-quality continuum spectroscopy provided by the LEGA-C survey
L'influenza dell'esperienza musicale sulla rappresentazione dello spazio peripersonale: uno studio di bisezione tattile
No full text
The Gas-phase Mass–Metallicity Relation for Massive Galaxies at z ∼ 0.7 with the LEGA-C Survey
No full textThe massive end of the gas-phase mass–metallicity relation (MZR) is a sensitive probe of active galactic nuclei (AGN) feedback that is a crucial but highly uncertain component of galaxy evolution models. In this paper, we extend the z ∼ 0.7 MZR by ∼0.5 dex up to log ( M _⋆ / M _⊙ ) ∼ 11.1. We use extremely deep VLT VIMOS spectra from the Large Early Galaxy Astrophysics Census (LEGA-C) survey to measure metallicities for 145 galaxies. The LEGA-C MZR matches the normalization of the z ∼ 0.8 DEEP2 MZR where they overlap, so we combine the two to create an MZR spanning from 9.3 to 11.1 log ( M _⋆ / M _⊙ ). The LEGA-C+DEEP2 MZR at z ∼ 0.7 is offset to slightly lower metallicities (0.05–0.13 dex) than the z ∼ 0 MZR, but it otherwise mirrors the established power-law rise at low/intermediate stellar masses and asymptotic flattening at high stellar masses. We compare the LEGA-C+DEEP2 MZR to the MZR from two cosmological simulations (IllustrisTNG and SIMBA), which predict qualitatively different metallicity trends for high-mass galaxies. This comparison highlights that our extended MZR provides a crucial observational constraint for galaxy evolution models in a mass regime where the MZR is very sensitive to choices about the implementation of AGN feedback
Recommended from our members
The Gas-phase Mass–Metallicity Relation for Massive Galaxies at z ∼ 0.7 with the LEGA-C Survey
Full text linkThe massive end of the gas-phase mass–metallicity relation (MZR) is a sensitive probe of active galactic nuclei (AGN) feedback that is a crucial but highly uncertain component of galaxy evolution models. In this paper, we extend the z ∼ 0.7 MZR by ∼0.5 dex up to log (M ⋆/M ⊙) ∼ 11.1. We use extremely deep VLT VIMOS spectra from the Large Early Galaxy Astrophysics Census (LEGA-C) survey to measure metallicities for 145 galaxies. The LEGA-C MZR matches the normalization of the z ∼ 0.8 DEEP2 MZR where they overlap, so we combine the two to create an MZR spanning from 9.3 to 11.1 log (M ⋆/M ⊙). The LEGA-C+DEEP2 MZR at z ∼ 0.7 is offset to slightly lower metallicities (0.05–0.13 dex) than the z ∼ 0 MZR, but it otherwise mirrors the established power-law rise at low/intermediate stellar masses and asymptotic flattening at high stellar masses. We compare the LEGA-C+DEEP2 MZR to the MZR from two cosmological simulations (IllustrisTNG and SIMBA), which predict qualitatively different metallicity trends for high-mass galaxies. This comparison highlights that our extended MZR provides a crucial observational constraint for galaxy evolution models in a mass regime where the MZR is very sensitive to choices about the implementation of AGN feedback
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Towards precise galaxy evolution : a comparison between spectral indices of galaxies in the IllustrisTNG simulation and the LEGA-C survey
Full text linkWe present the first comparison of observed stellar continuum spectra of high-redshift galaxies and mock galaxy spectra generated from hydrodynamical simulations. The mock spectra are produced from the IllustrisTNG TNG100 simulation combined with stellar population models and take into account dust attenuation and realistic observational effects (aperture effects and noise). We compare the simulated and EW(H) of galaxies with at to the observed distributions from the LEGA-C survey. TNG100 globally reproduces the observed distributions of spectral indices, implying that the age distribution of galaxies in TNG100 is generally realistic. Yet there are small but significant differences. For old galaxies, TNG100 shows small when compared to LEGA-C, while LEGA-C galaxies have larger EW(H) at fixed . There are several possible explanations: 1) LEGA-C galaxies have overall older ages combined with small contributions (a few percent in mass) from younger (
- …
