Entrainment: A domain general cognitive timing mechanism?

From an early age onwards we tend to synchronize to temporally regular and rhythmic stimuli, such as the beat in music, which inevitably leads to movement. Recently, such basic mapping of temporally regular sound and motor behavior has been critically discussed and the four speakers of this symposium will address extensions of a basic sensorimotor conceptualization of entrainment in their talks. M. Henry and colleagues discuss oscillatory entrainment in perception only, while E. Large puts to test whether oscillatory entrainment simply mirrors stimulus frequency when movement is coupled with syncopated rhythm. J. Grahn explores whether non-beat related factors impact synchronization in movement, while S. Dalla-Bella confers how stimulus complexity affects people's capacity to synchronize finger tapping but also perception. The symposium will be discussed by V. Penhune

The Role of Superior Temporal Cortex in Auditory Timing

Recently, there has been upsurge of interest in the neural mechanisms of time perception. A central question is whether the representation of time is distributed over brain regions as a function of stimulus modality, task and length of the duration used or whether it is centralized in a single specific and supramodal network. The answers seem to be converging on the former, and many areas not primarily considered as temporal processing areas remain to be investigated in the temporal domain. Here we asked whether the superior temporal gyrus, an auditory modality specific area, is involved in processing of auditory timing. Repetitive transcranial magnetic stimulation was applied over left and right superior temporal gyri while participants performed either a temporal or a frequency discrimination task of single tones. A significant decrease in performance accuracy was observed after stimulation of the right superior temporal gyrus, in addition to an increase in response uncertainty as measured by the Just Noticeable Difference. The results are specific to auditory temporal processing and performance on the frequency task was not affected. Our results further support the idea of distributed temporal processing and speak in favor of the existence of modality specific temporal regions in the human brain

Evidence for multiple rhythmic skills

Rhythms, or patterns in time, play a vital role in both speech and music. Proficiency in a number of rhythm skills has been linked to language ability, suggesting that certain rhythmic processes in music and language rely on overlapping resources. However, a lack of understanding about how rhythm skills relate to each other has impeded progress in understanding how language relies on rhythm processing. In particular, it is unknown whether all rhythm skills are linked together, forming a single broad rhythmic competence, or whether there are multiple dissociable rhythm skills. We hypothesized that beat tapping and rhythm memory/sequencing form two separate clusters of rhythm skills. This hypothesis was tested with a battery of two beat tapping and two rhythm memory tests. Here we show that tapping to a metronome and the ability to adjust to a changing tempo while tapping to a metronome are related skills. The ability to remember rhythms and to drum along to repeating rhythmic sequences are also related. However, we found no relationship between beat tapping skills and rhythm memory skills. Thus, beat tapping and rhythm memory are dissociable rhythmic aptitudes. This discovery may inform future research disambiguating how distinct rhythm competencies track with specific language functions

Vocal Accuracy and Neural Plasticity Following Micromelody-Discrimination Training

Recent behavioral studies report correlational evidence to suggest that non-musicians with good pitch discrimination sing more accurately than those with poorer auditory skills. However, other studies have reported a dissociation between perceptual and vocal production skills. In order to elucidate the relationship between auditory discrimination skills and vocal accuracy, we administered an auditory-discrimination training paradigm to a group of non-musicians to determine whether training-enhanced auditory discrimination would specifically result in improved vocal accuracy.We utilized micromelodies (i.e., melodies with seven different interval scales, each smaller than a semitone) as the main stimuli for auditory discrimination training and testing, and we used single-note and melodic singing tasks to assess vocal accuracy in two groups of non-musicians (experimental and control). To determine if any training-induced improvements in vocal accuracy would be accompanied by related modulations in cortical activity during singing, the experimental group of non-musicians also performed the singing tasks while undergoing functional magnetic resonance imaging (fMRI). Following training, the experimental group exhibited significant enhancements in micromelody discrimination compared to controls. However, we did not observe a correlated improvement in vocal accuracy during single-note or melodic singing, nor did we detect any training-induced changes in activity within brain regions associated with singing.Given the observations from our auditory training regimen, we therefore conclude that perceptual discrimination training alone is not sufficient to improve vocal accuracy in non-musicians, supporting the suggested dissociation between auditory perception and vocal production

Parallel contributions of cerebellar, striatal and M1 mechanisms to motor sequence learning

When learning a new motor sequence, we must execute the correct order of movements while simultaneously optimizing sensorimotor parameters such as trajectory, timing, velocity and force. Neurophysiological studies in animals and humans have identified the major brain regions involved in sequence learning, including the motor cortex (M1), basal ganglia (BG}) and cerebellum. Current models link these regions to different stages of learning (early vs. late) or different components of performance (spatial vs. sensorimotor). At the same time, research in motor control has given rise to the concept that internal models at different levels of the motor system may contribute to learning. The goal of this review is to develop a new framework for motor sequence learning that combines stage and component models within the context of internal models. To do this, we review behavioral and neuroimaging studies in humans and neurophysiological studies in animals. Based on this evidence, we present a model proposing that sequence learning is underwritten by parallel, interacting processes, including internal model formation and sequence representation, that are instantiated in specific cerebellar, {BG or M1 mechanisms depending on task demands and the stage of learning. The striatal system learns predictive stimulus–response associations and is critical for motor chunking. The role of the cerebellum is to acquire the optimal internal model for sequence performance in a particular context, and to contribute to error correction and control of on-going movement. M1 acts to store the representation of a learned sequence, likely as part of a distributed network including the parietal lobe and premotor cortex

Gesture imitation in musicians and non-musicians

Imitation plays a crucial role in the learning of many complex motor skills. Recent behavioral and neuroimaging evidence suggests that the ability to imitate is influenced by past experience, such as musical training. To investigate the impact of musical training on motor imitation, musicians and non-musicians were tested on their ability to imitate videoclips of simple and complex two-handed gestures taken from American Sign Language. Participants viewed a set of 30 gestures, one at a time, and imitated them immediately after presentation. Participants’ imitations were videotaped and scored off-line by raters blind to participant group. Imitation performance was assessed by a rating of performance accuracy, where the arm, hand, and finger components of the gestures were rated separately on a 5-point scale (1 = unrecognizable; 5 = exact imitation). A global accuracy score (PAglobal) was calculated by summing the three components. Response duration compared to the model (%MTdiff), and reaction time (RT) were also assessed. Results indicated that musicians were able to imitate more accurately than non-musicians, reflected by significantly higher PAglobal and lower %MTdiff scores. Furthermore, the greatest difference in performance was for the fine-motor (finger) gesture component. These findings support the view that the ability to imitate is influenced by experience. This is consistent with generalist theories of motor imitation, which explain imitation in terms of links between perceptual and motor action representations that become strengthened through experience. It is also likely that musical training contributed to the ability to imitate manual gestures by influencing the personal action repertoire of musicians

The role of auditory cortex in retention of rhythmic patterns as studied in patients with temporal lobe removals including Heschl|s gyrus

Abstract This experiment examined the participation of the auditory cortex of the temporal lobe in the perception and retention of rhythmic patterns[ Four patient groups were tested on a paradigm contrasting reproduction of auditory and visual rhythms] those with right or left anterior temporal lobe removals which included Heschl|s gyrus "HG#\ the region of primary auditory cortex "RT!A and LT! A#^and patients with right or left anterior temporal lobe removals which did not include HG "RT!a and LT!a#[ Estimation of lesion extent in HG using an MRI!based probabilistic map indicated that\ in the majority of subjects\ the lesion was con_ned to the anterior secondary auditory cortex located on the anterior!lateral extent of HG[ On the rhythm reproduction task\ RT!A patients were impaired in retention of auditory but not visual rhythms\ particularly when accurate reproduction of stimulus durations was required[ In contrast\ LT!A patients as well as both RT!a and LT!a patients were relatively unimpaired on this task[ None of the patient groups was impaired in the ability to make an adequate motor response[ Further\ they were unimpaired when using a dichotomous response mode\ indicating that they were able to adequately di}erentiate the stimulus durations and\ when given an alternative method of encoding\ to retain them[ Taken together\ these results point to a speci_c role for the right anterior secondary auditory cortex in the retention of a precise analogue representation of auditory tonal patterns[ Þ 0888 Elsevier Science Ltd[ All rights reserved