Optimal Tempo Research Articles

Spontaneous beat synchronization in rats: Neural dynamics and motor entrainment.

Beat perception and synchronization within 120 to 140 beats/min (BPM) are common in humans and frequently used in music composition. Why beat synchronization is uncommon in some species and the mechanism determining the optimal tempo are unclear. Here, we examined physical movements and neural activities in rats to determine their beat sensitivity. Close inspection of head movements and neural recordings revealed that rats displayed prominent beat synchronization and activities in the auditory cortex within 120 to 140 BPM. Mathematical modeling suggests that short-term adaptation underlies this beat tuning. Our results support the hypothesis that the optimal tempo for beat synchronization is determined by the time constant of neural dynamics conserved across species, rather than the species-specific time constant of physical movements. Thus, latent neural propensity for auditory motor entrainment may provide a basis for human entrainment that is much more widespread than currently thought. Further studies comparing humans and animals will offer insights into the origins of music and dancing.

Optimal Tempo for Groove: Its Relation to Directions of Body Movement and Japanese nori.

The tendency for groove-based music to induce body movements has been linked to multiple acoustical factors. However, it is unclear how or whether tempo affects groove, although tempo significantly affects other aspects of music perception. To address this issue, the present study investigated effects of tempo, specific rhythmic organizations of patterns, and syncopation on groove and the induction of the sensation of wanting to move. We focused on the directions of body movement in particular by taking into account nori, which is an indigenous Japanese musical term used not only synonymously with groove, but also as a spatial metaphor indicating vertical or horizontal movement directions. Thus, the present study explored how groove was felt and defined, as well as how musical factors induced the sensation of wanting to move in cross-cultural context. A listening experiment was conducted using drum breaks as stimuli. Stimuli consisted of various rhythm patterns at six tempi from 60 to 200 BPM. The main findings are that: (1) an optimal tempo for groove existed for drum breaks at around 100–120 BPM, (2) an optimal tempo existed for the sensation of wanting to move the body in specific directions (i.e., back-and-forth and side-to-side), (3) groove and nori shared a similar concept of wanting to move but differed on several points (i.e., association with sense of pulse and fast tempo). Overall, the present study suggests that there is an optimal tempo for body movement related to groove. This finding has implications for the use of music or rhythmic stimuli to induce smooth motion in rehabilitation, therapy, or dance.

Alkaline Cellulose Nanofibrils from Streamlined Alkali Treated Rice Straw

Alkali treatment (4% NaOH, 70 °C, 5 min, twice) of dewaxed rice straw was effective in removing most hemicelluloses, lignin and silica to yield 47.6% cellulose-rich solid. Optimal TEMPO oxidation (7.5 mmol NaClO per gram of alkaline cellulose) followed by mechanical defibrillation (30 min) produced 36.5% alkaline cellulose nanofibrils (ACNFs), higher than the 29.1% CNFs from sodium chlorite oxidation-alkali leaching as well as the 33.7% HCNFs from sodium chlorite oxidation. At the same 5 mmol NaClO level, ACNFs were similar in lateral dimensions (1.25 ± 0.47 nm) and crystallinity (68%), but less surface oxidized (65%) than CNFs and HCNFs (1.55 ± 0.54 and 1.36 ± 0.62 nm, 69% and 68% CrI, 85% and 69% surface oxidization, respectively). While the residual noncellulosics consumed oxidizing agents, their presence led to longer ACNFs and HCNFs, higher thermal stability, and thinner self-assembling fibers (197 and 94 nm, respectively) than CNFs (497 nm). Therefore, this facile alkali pretreatment is not only hig...

Tempo in Baroque Music and Dance

Growing interest in studies on the relationship between music and movement has given rise to many paradigms and theories, including embodied approaches that provide interesting methodologies in studies on music and dance. Insight into the relation between dance and music is particularly important for the Baroque period, as a direct connection between music and dance was omnipresent, even if music was not used to dance to. Many types of Baroque dances existed, each of them with particular dance steps and a specific character, requiring a specific tempo. However, in music performance practice today, the link with the original dance movement is often lost and the tempo variation can be very large. The aim of this study is to compare the interpretations of dancers and musicians regarding Baroque music and dance in an experimental setting. First, we investigate the influence of dance movement on the musical interpretation of a series of Baroque dances. The pieces were recorded both with and without dance accompaniment and the tempo and timing in the different versions were compared. In the second part, dancers performed a particular choreography to music that varied in tempo. Video analysis and questionnaire data were used to evaluate the different performances. The results were compared with the tempi of music recordings of the same dance types, showing a clear difference between music and dance performance. Musicians adapt their interpretation when performing together with the dancers, and the optimal tempo range found for certain Baroque dances coincides only partly with the tempi commonly found in music recordings. The direct link between music and movement and its mutual influence illustrates the importance of an embodied approach in music performance, where in this case dance movement gives concrete information for a “historically informed” performance.

The Appropriate or Optimal Tempo for Music: A Comparison between Non-Musicians and Musicians

Musicians have enhanced skills that result from intensive training. Whilst musicians show enhanced auditory capabilities (Kraus and Chandrasekaran, 2010 Nature Reviews Neuroscience 11 599-605), non-musicians demonstrate an ability to perform musical tasks (eg listening, dancing, and singing). Non-musicians can also undertake tasks that would normally be reserved for musicians. For example, non-musicians can perceive optimal tempi (ie an appropriate speed) for music (Quinn and Watt, 2006 Perception 35 267-280; Quinn and Watt, 2012 Perception 41 236-238; Quinn et al, 2012 Journal of the Acoustical Society of America 131 3595-3598). This suggests that formalised musical training is not a prerequisite for developing a sense of the tempo that sounds right for a melody. The current studies examine this issue and compare the tempo that musicians choose to perform unfamiliar melodies with the tempo that non-musicians perceive to be optimal for the same melodies. The results demonstrate that the perceived optimal tempo is similar to the performed tempo.

How comparable are children and adults in perceiving an optimal tempo for music? (L)

This research compared the abilities of children and adults to perceive an optimal tempo for pieces of music. Participants heard eight melodies played at a range of tempi and made a 2AFC of "too fast" or "too slow" for each presentation. Children (aged between 5 to 11 years) and adults (aged between 17 to 54 years) showed the same variation in perceived optimal tempi across melodies. The same variation in optimal tempi was also observed when pitch variations were removed. This suggests that the rhythmical structure was responsible for the perceived optimal tempi for these pieces of music.

Brain wave synchronization and entrainment to periodic acoustic stimuli

As known, different brainwave frequencies show synchronies related to different perceptual, motor or cognitive states. Brainwaves have also been shown to synchronize with external stimuli with repetition rates of ca. 10-40 Hz. However, not much is known about responses to periodic auditory stimuli with periodicities found in human rhythmic behavior (i.e. 0.5-5 Hz). In an EEG study we compared responses to periodic stimulations (drum sounds and clicks with repetition rates of 1-8 Hz), silence, and random noise. Here we report inter-trial coherence measures taken at the Cz-electrode that show a significant increase in brainwave synchronization following periodic stimulation. Specifically, we found (1) a tonic synchronization response in the delta range with a maximum response at 2 Hz, (2) a phasic response covering the theta range, and (3) an augmented phase synchronization throughout the beta/gamma range (13-44 Hz) produced through increased activity in the lower gamma range and modulated by the stimulus periodicity. Periodic auditory stimulation produces a mixture of evoked and induced, rate-specific and rate-independent increases in stimulus related brainwave synchronization that are likely to affect various cognitive functions. The synchronization responses in the delta range may form part of the neurophysiological processes underlying time coupling between rhythmic sensory input and motor output; the tonic 2 Hz maximum corresponds to the optimal tempo identified in listening, tapping synchronization, and event-interval discrimination experiments. In addition, synchronization effects in the beta and gamma range may contribute to the reported influences of rhythmic entrainment on cognitive functions involved in learning and memory tasks.

The Perception of Tempo in Music

Tempo is one factor that is frequently associated with the expressive nature of a piece of music. Composers often indicate the tempo of a piece of music through the use of numerical markings (beats min(-1)) and subjective terms (adagio, allegro). Three studies were conducted to assess whether listeners were able to make consistent judgments about tempo that varied from piece to piece. Listeners heard short extracts of Scottish music played at a range of tempi and were asked to make a two-alternative forced choice of "too fast" or "too slow" for each extract. The responses for each study were plotted as proportion of too fast responses as a function of tempo for each piece, and cumulative normal curves were fitted to each data set. The point where these curves cross 0.5 is the tempo at which the music sounds right to the listeners, referred to as the optimal tempo. The results from each study show that listeners are capable of making consistent tempo judgments and that the optimal tempo varies across extracts. The results also revealed that rhythm plays a role, but not the only role in making temporal judgments.

Influence of Cadmium on the Performance of an Activated SBR Sludge Treatment

High concentration of heavy metals is a toxic factor for most microorganisms. As a result, such metals give rise to severe disruption in wastewater treatment operations. It has been noticed, however, that biological systems may adapt to heavy metals when their concentration is limited. In fact, such systems can even produce some degree of metal elimination provided that an optimal exposure tempo is guaranteed. On the other hand, irreversible damage may occur when metal concentration is sufficiently high. It is the aim of the present study to report on the inhibiting effects due to Cadmium on the activated sludge treatment method. To that end, different Cd concentrations were tested (ranging from 0.25 to 14 mg l−1) in a Sequential Biological Reactor, using synthetic wastewater without recirculation. The feed water providing 325 mg l−1 COD and 30 mg l−1 NH4 +-N. The process was screened by checking elimination percentages for COD and ammonia, as well as the evolution of ciliate protozoa. In addition, research was carried out on Cd assimilation by the activated sludge system by means of measuring in the mixed liquor and in the effluent. Results showed a marked decrease in purification efficiency when Cd-concentration rose over 14 mg l−1, in which case COD elimination dropped from 98% to 41% while ammonia elimination went down from 98% to 32%. The Sludge Biotic Index decreases to 0 at Cd concentrations above 10 mg l−1.

Tempo discrimination in infants

An habituation/dishabituation paradigm demonstrates that 2- and 4-month-old infants are able to discriminate auditory sequences that vary slightly in tempo. Discriminations were only observed for intermediate tempi (600 ms but not 100, 300, 1500 ms IOI), suggesting that infants have the same optimal tempo range as adults.