Related Experiment Video
Updated: May 25, 2026
07:52
Electroencephalography Measurements in Awake Marmosets Listening to Conspecific Vocalizations
Published on: July 26, 2024
Affect intensity in voice recognized by tree shrews (Tupaia belangeri)
Simone Schehka1, Elke Zimmermann
1Institute of Zoology, University of Veterinary Medicine, Hannover, Germany.
Emotion (Washington, D.C.)
|February 8, 2012
Summary
Tree shrews can distinguish between high and low emotional intensity in conspecific vocalizations. This suggests that the perception of affect intensity in animal sounds has deep evolutionary roots in mammals.
Area of Science:
- Ethology
- Bioacoustics
- Animal Communication
Background:
- Shared acoustic cues in human emotional communication suggest a prehuman origin of affective prosody.
- Investigating affective prosody in non-human mammals can provide insights into its evolutionary history.
Purpose of the Study:
- To determine if tree shrews can discriminate between different affect intensities (low vs. high) in conspecific vocalizations.
- To test the hypothesis that affective prosody has prehuman origins.
Main Methods:
- Playback experiments using a habituation-dishabituation paradigm with tree shrew vocalizations.
- Two call types (chatter and scream) were presented at low and high affect intensities.
Main Results:
- Habituated tree shrews dishabituated to chatter and scream calls presented at high affect intensity, indicating perception of intensity differences.
- Findings suggest listeners perceive acoustic variations linked to affect intensity within the same call type.
Conclusions:
- Acoustically conveyed affect intensity is biologically relevant for tree shrews, even without other sensory cues.
- Perception of vocal affect intensity is a shared mammalian trait, supporting deep phylogenetic roots for affective prosody in human communication.
More Related Videos
Related Concept Videos
00:53Sound Intensity Level
Humans perceive sound by hearing. The human ear helps sound waves reach the brain, which then interprets the waves and creates the perception of hearing. The loudness of the environment in which a person is located determines whether they can distinguish between different sound sources.
The human ear can perceive an extensive range of sound intensity, necessitating the use of the logarithmic scale to define a physical quantity—the intensity level. It is a ratio of two intensities and hence a...
The human ear can perceive an extensive range of sound intensity, necessitating the use of the logarithmic scale to define a physical quantity—the intensity level. It is a ratio of two intensities and hence a...
00:58Sound Intensity
The loudness of a sound source is related to how energetically the source is vibrating, consequently making the molecules of the propagation medium vibrate. To measure the loudness of a source, the physical quantity of interest is the intensity. This is defined as the energy emitted per unit of time per unit of area perpendicular to the sound wave's propagation direction. Since the total energy is greater if the source vibrates for a longer duration and over a larger area, dividing the emitted...
01:21Testing a Claim about Mean: Unknown Population SD
A complete procedure of testing a hypothesis about a population mean when the population standard deviation is unknown is explained here.
Estimating a population mean requires the samples to be approximately normally distributed. The data should be collected from the randomly selected samples having no sampling bias. There is no specific requirement for sample size. But if the sample size is less than 30, and we don't know the population standard deviation, a different approach is used; instead...
Estimating a population mean requires the samples to be approximately normally distributed. The data should be collected from the randomly selected samples having no sampling bias. There is no specific requirement for sample size. But if the sample size is less than 30, and we don't know the population standard deviation, a different approach is used; instead...
01:24Facial Feedback Hypothesis
Charles Darwin proposed that facial expressions are an evolutionary adaptation for communication. He argued that these expressions are not influenced by culture but are universal across species. For example, a snarling expression with exposed teeth signals a threat in many animals, including humans. Darwin also suggested that displaying an emotion can intensify the feeling. Smiling, for example, could enhance one's sense of happiness. This idea laid the foundation for understanding the role of...
01:05Intensity and Pressure of Sound Waves
The intensity of sound waves can be related to displacement and pressure amplitudes by using their wave expressions and the definition of intensity. The critical step to achieve this is to write the power delivered by the particles on the wave as the product of force and velocity and simplify the force per unit area as the pressure. The velocity of the medium's particles can be derived from the displacement.
Unlike the time average of a sinusoidal term, which is zero since it is positive and...
Unlike the time average of a sinusoidal term, which is zero since it is positive and...