56 research outputs found
Comments on "Tactus ≠Tempo: Some Dissociations Between Attentional Focus, Motor Behavior, and Tempo Judgment" by Justin London
Objective measures of musical tempo are linked to a particular metrical pulse, and this is most likely true for subjective tempo as well. Therefore, tapping along with a rhythm should be predictive of relative tempo judgments. The difficulty of such judgments may lie in the choice of a particular metrical level as the referent. Multiple levels may compete and create ambiguity. Analogies are drawn with pitch perception from certain types of complex tones
Embodied Rhythm: Commentary on "The Contribution of Anthropometric Factors to Individual Differences in the Perception of Rhythm" by Neil P. McAngus Todd, Rosanna Cousins, and Christopher S. Lee
Todd, Cousins, and Lee (2007) have presented some intriguing data
suggesting that body size, as measured by standard anthropometric indices, is related to
the preferred beat period in a perceptual task. Curiously, however, they did not find a
significant sex difference, even though the women in their sample were clearly smaller
than the men. Another recent study of preferred spontaneous tempo (McAuley et al.,
2006) likewise failed to find a sex difference in a large sample of young adults. It is
unclear why body size should have an effect only within each sex group
Measuring perceptual centers using the phase correction response
The perceptual center (P-center) is fundamental to
the timing of heterogeneous event sequences, including music
and speech. Unfortunately, there is currently no comprehensive
and reliable model of P-centers in acoustic events, so P-centers
must instead be measured empirically. This study reviews
existing measurement methods and evaluates two methods in
detail—the rhythm adjustment method and a new method
based on the phase correction response (PCR) in a synchronous
tapping task. The two methods yielded consistent
P-center estimates and showed no evidence of P-center context
dependence. The PCR method appears promising because it is
accurate and efficient and does not require explicit perceptual
judgments. As a secondary result, the magnitude of the PCR is
shown to vary systematically with the onset complexity of
speech sounds,which presumably reflects the perceived clarity
of a sound’s P-center
Categorical tendencies in imitating self-produced isolated vowels.
Abstract. An earlier experiment requlrlng literal imitation of synthetic isolated vowels from [uJ-[iJ and [iJ-[a=J continua (Repp &
A filled duration illusion in music: Effects of metrical subdivision on the perception and production of beat tempo.
This study replicates and extends previous findings suggesting that metrical
subdivision slows the perceived beat tempo (Repp, 2008). Here, musically trained participants produced the
subdivisions themselves and were found to speed up, thus compensating for the
perceived slowing. This was shown in a synchronization-continuation paradigm
(Experiment 1) and in a reproduction task (Experiment 2a). Participants also
judged the tempo of a subdivided sequence as being slower than that of a
preceding simple beat sequence (Experiment 2b). Experiment 2 also included
nonmusician participants, with similar results. Tempo measurements of famous
pianists’ recordings of two variation movements from Beethoven sonatas revealed
a strong tendency to play the first variation (subdivided beats) faster than the
theme (mostly simple beats). A similar tendency was found in musicians’
laboratory performances of a simple theme and variations, despite instruc-tions
to keep the tempo constant (Experiment 3a). When playing melodic sequences in
which only one of three beats per measure was subdivided, musicians tended to
play these beats faster and to perceive them as longer than adjacent beats, and
they played the whole sequence faster than a sequence without any subdivisions
(Experiments 3b and 3c). The results amply demonstrate a filled duration
illusion in rhythm perception and music performance: Intervals
containing events seem longer than empty intervals and thus must be shortened to
be perceived as equal in duration
Large-Scale Screening of a Targeted Enterococcus faecalis Mutant Library Identifies Envelope Fitness Factors
Spread of antibiotic resistance among bacteria responsible for nosocomial and community-acquired infections urges for novel therapeutic or prophylactic targets and for innovative pathogen-specific antibacterial compounds. Major challenges are posed by opportunistic pathogens belonging to the low GC% Gram-positive bacteria. Among those, Enterococcus faecalis is a leading cause of hospital-acquired infections associated with life-threatening issues and increased hospital costs. To better understand the molecular properties of enterococci that may be required for virulence, and that may explain the emergence of these bacteria in nosocomial infections, we performed the first large-scale functional analysis of E. faecalis V583, the first vancomycin-resistant isolate from a human bloodstream infection. E. faecalis V583 is within the high-risk clonal complex 2 group, which comprises mostly isolates derived from hospital infections worldwide. We conducted broad-range screenings of candidate genes likely involved in host adaptation (e.g., colonization and/or virulence). For this purpose, a library was constructed of targeted insertion mutations in 177 genes encoding putative surface or stress-response factors. Individual mutants were subsequently tested for their i) resistance to oxidative stress, ii) antibiotic resistance, iii) resistance to opsonophagocytosis, iv) adherence to the human colon carcinoma Caco-2 epithelial cells and v) virulence in a surrogate insect model. Our results identified a number of factors that are involved in the interaction between enterococci and their host environments. Their predicted functions highlight the importance of cell envelope glycopolymers in E. faecalis host adaptation. This study provides a valuable genetic database for understanding the steps leading E. faecalis to opportunistic virulence
Phase correction following a perturbation in sensorimotor synchronization depends on sensory information
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