Probing Beat Perception with Event-Related Potentials (ERPs) in Human Adults, Newborns, and Nonhuman Primates.

The aim of this chapter is to give an overview of how the perception of rhythmic temporal regularity such as a regular beat in music can be studied in human adults, human newborns, and nonhuman primates using event-related brain potentials (ERPs). First, we discuss different aspects of temporal structure in general, and musical rhythm in particular, and we discuss the possible mechanisms underlying the perception of regularity (e.g.

Beat processing in newborn infants cannot be explained by statistical learning based on transition probabilities.

Newborn infants have been shown to extract temporal regularities from sound sequences, both in the form of learning regular sequential properties, and extracting periodicity in the input, commonly referred to as a regular pulse or the 'beat'. However, these two types of regularities are often indistinguishable in isochronous sequences, as both statistical learning and beat perception can be elicited by the regular alternation of accented and unaccented sounds. Here, we manipulated the isochrony of sound sequences in order to disentangle statistical learning from beat perception in sleeping newborn infants in an EEG experiment, as previously done in adults and macaque monkeys.

Auditory learning of recurrent tone sequences is present in the newborn's brain.

The seemingly effortless ability of our auditory system to rapidly detect new events in a dynamic environment is crucial for survival. Whether the underlying brain processes are innate is unknown. To answer this question, electroencephalography was recorded while regularly patterned (REG) versus random (RAND) tone sequences were presented to sleeping neonates.

Early maturation of sound duration processing in the infant's brain.

The ability to process sound duration is crucial already at a very early age for laying the foundation for the main functions of auditory perception, such as object perception and music and language acquisition. With the availability of age-appropriate structural anatomical templates, we can reconstruct EEG source activity with much-improved reliability. The current study capitalized on this possibility by reconstructing the sources of event-related potential (ERP) waveforms sensitive to sound duration in 4- and 9-month-old infants.

Relevance to the higher order structure may govern auditory statistical learning in neonates.

Hearing is one of the earliest senses to develop and is quite mature by birth. Contemporary theories assume that regularities in sound are exploited by the brain to create internal models of the environment. Through statistical learning, internal models extrapolate from patterns to predictions about subsequent experience.

Newborn infants differently process adult directed and infant directed speech.

Infant directed speech (IDS) may serve important functions in language acquisition and in adult-infant communication. The processing of IDS evolves during the first years of life. In order to serve as an effective tool of language acquisition, already very young infants should be able to distinguish IDS from adult directed speech (ADS).

Large-scale network organization of EEG functional connectivity in newborn infants.

The organization of functional brain networks changes across human lifespan. The present study analyzed functional brain networks in healthy full-term infants (N = 139) within 1-6 days from birth by measuring neural synchrony in EEG recordings during quiet sleep. Large-scale phase synchronization was measured in six frequency bands with the Phase Lag Index.

EEG signatures accompanying auditory figure-ground segregation.

In everyday acoustic scenes, figure-ground segregation typically requires one to group together sound elements over both time and frequency. Electroencephalogram was recorded while listeners detected repeating tonal complexes composed of a random set of pure tones within stimuli consisting of randomly varying tonal elements. The repeating pattern was perceived as a figure over the randomly changing background.

Relative Pitch Perception and the Detection of Deviant Tone Patterns.

Most people are able to recognise familiar tunes even when played in a different key. It is assumed that this depends on a general capacity for relative pitch perception; the ability to recognise the pattern of inter-note intervals that characterises the tune. However, when healthy adults are required to detect rare deviant melodic patterns in a sequence of randomly transposed standard patterns they perform close to chance.

Mismatch response (MMR) in neonates: Beyond refractoriness.

In the adult auditory system, deviant detection and updating the representation of the environment is reflected by the event-related potential (ERP) component termed the mismatch negativity (MMN). MMN is elicited when a rare-pitch deviant stimulus is presented amongst frequent standard pitch stimuli. The same stimuli also elicit a similar discriminative ERP component in sleeping newborn infants (termed the mismatch response: MMR).

Processing of Horizontal Sound Localization Cues in Newborn Infants.

Objectives: By measuring event-related brain potentials (ERPs), the authors tested the sensitivity of the newborn auditory cortex to sound lateralization and to the most common cues of horizontal sound localization.

Design: Sixty-eight healthy full-term newborn infants were presented with auditory oddball sequences composed of frequent and rare noise segments in four experimental conditions. The authors tested in them the detection of deviations in the primary cues of sound lateralization (interaural time and level difference) and in actual sound source location (free-field and monaural sound presentation).

Predictive processing of pitch trends in newborn infants.

The notion of predictive sound processing suggests that the auditory system prepares for upcoming sounds once it has detected regular features within a sequence. Here we investigated whether predictive processes are operating at birth in the human auditory system. Event-related potentials (ERP) were recorded from healthy newborns to occasional ascending pitch steps occurring in the 2nd or the 5th position within trains of tones with otherwise monotonously descending pitch.

Detecting the temporal structure of sound sequences in newborn infants.

Most high-level auditory functions require one to detect the onset and offset of sound sequences as well as registering the rate at which sounds are presented within the sound trains. By recording event-related brain potentials to onsets and offsets of tone trains as well as to changes in the presentation rate, we tested whether these fundamental auditory capabilities are functional at birth. Each of these events elicited significant event-related potential components in sleeping healthy neonates.

Newborn infants detect cues of concurrent sound segregation.

Separating concurrent sounds is fundamental for a veridical perception of one's auditory surroundings. Sound components that are harmonically related and start at the same time are usually grouped into a common perceptual object, whereas components that are not in harmonic relation or have different onset times are more likely to be perceived in terms of separate objects. Here we tested whether neonates are able to pick up the cues supporting this sound organization principle.

Perceiving temporal regularity in music: the role of auditory event-related potentials (ERPs) in probing beat perception.

The aim of this chapter is to give an overview of how the perception of a regular beat in music can be studied in humans adults, human newborns, and nonhuman primates using event-related brain potentials (ERPs). Next to a review of the recent literature on the perception of temporal regularity in music, we will discuss in how far ERPs, and especially the component called mismatch negativity (MMN), can be instrumental in probing beat perception. We conclude with a discussion on the pitfalls and prospects of using ERPs to probe the perception of a regular beat, in which we present possible constraints on stimulus design and discuss future perspectives.

Context effects on processing widely deviant sounds in newborn infants.

Detecting and orienting toward sounds carrying new information is a crucial feature of the human brain that supports adaptation to the environment. Rare, acoustically widely deviant sounds presented amongst frequent tones elicit large event-related brain potentials (ERPs) in neonates. Here we tested whether these discriminative ERP responses reflect only the activation of fresh afferent neuronal populations (i.

Rhesus monkeys (Macaca mulatta) detect rhythmic groups in music, but not the beat.

It was recently shown that rhythmic entrainment, long considered a human-specific mechanism, can be demonstrated in a selected group of bird species, and, somewhat surprisingly, not in more closely related species such as nonhuman primates. This observation supports the vocal learning hypothesis that suggests rhythmic entrainment to be a by-product of the vocal learning mechanisms that are shared by several bird and mammal species, including humans, but that are only weakly developed, or missing entirely, in nonhuman primates. To test this hypothesis we measured auditory event-related potentials (ERPs) in two rhesus monkeys (Macaca mulatta), probing a well-documented component in humans, the mismatch negativity (MMN) to study rhythmic expectation.

Cognitive functions in ataxia with oculomotor apraxia type 2.

Background: Ataxia with oculomotor apraxia type 2 (AOA2) is characterized by cerebellar atrophy, peripheral neuropathy, oculomotor apraxia, and elevated serum alpha-fetoprotein (AFP) levels. The disease is caused by a recessive mutation in the senataxin gene. Since it is a very rare cerebellar disorder, no detailed examination of cognitive functions in AOA2 has been published to date.

Is beat induction innate or learned? Probing emergent meter perception in adults and newborns using event-related brain potentials.

Meter is considered an important structuring mechanism in the perception and experience of rhythm in music. Combining behavioral and electrophysiological measures, in the present study we investigate whether meter is more likely a learned phenomenon, possibly a result of musical expertise, or whether sensitivity to meter is also active in adult nonmusicians and newborn infants. The results provide evidence that meter induction is active in adult nonmusicians and that beat induction is already functional right after birth.

Auditory size-deviant detection in adults and newborn infants.

Auditory size perception refers to the ability to make accurate judgements of the size of a sound source based solely upon the sound emitted from the source. Electro-physiological and behavioural data were collected to test whether sound-source size parameters are detected from task-irrelevant sequences in adults and newborn infants. The mismatch negativity (MMN) obtained from adults indexed automatic detection of changes in size for voices, musical instruments and animal calls, regardless of whether the acoustic change indicated larger or smaller sources.

Newborn infants detect the beat in music.

To shed light on how humans can learn to understand music, we need to discover what the perceptual capabilities with which infants are born. Beat induction, the detection of a regular pulse in an auditory signal, is considered a fundamental human trait that, arguably, played a decisive role in the origin of music. Theorists are divided on the issue whether this ability is innate or learned.

Newborn infants process pitch intervals.

Objective: We investigated whether the auditory system of newborn babies extracts the constancy of a pitch interval from exemplars varying in absolute pitch.

Methods: Event-related brain potentials (ERP) were recorded from healthy newborn infants in an oddball paradigm consisting of frequent standard and infrequent deviant tone pairs. Tone pairs varied in absolute frequency.

Timbre-independent extraction of pitch in newborn infants.

The ability to separate pitch from other spectral sound features, such as timbre, is an important prerequisite of veridical auditory perception underlying speech acquisition and music cognition. The current study investigated whether or not newborn infants generalize pitch across different timbres. Perceived resonator size is an aspect of timbre that informs the listener about the size of the sound source, a cue that may be important already at birth.

Auditory temporal grouping in newborn infants.

Adults normally perceive auditory scenes in terms of sound patterns emitted by concurrently active sources. Thus pattern formation is an important process of auditory object perception. The aim of the present study was to determine whether neonates group sounds by repeating pitch patterns.