Who’s Got Rhythm?
Language, especially human language, is a continual area of study in the field of evolutionary psychology. In one study, Werker and Vouloumanos (2000) examine language through the idea of rhythm in this article. There are two fundamental premises that must be met to consider linguistic input to be a privileged stimulus for humans. They are 1. Human neonates should show an advantage in processing linguistic sounds and 2. This specialized linguistic processing should be unique to humans (Werker and Vouloumanos, 2000).
Background information for their article came from a study conducted by Ramus et al. (2000). In their study Ramus and his colleagues examine the perception of continuous speech and rhythm, as it exists in natural language. They did this through comparing the ability of non-human primate species, tamarin monkeys, and human infants to distinguish Dutch and Japanese played forward and backward. They found that adult tamarins and human infants were both able to differentiate between the two, but only when played forward. Also, the tamarins were able to process continuous speech and, but failed to discriminate the speech when played backwards like the human infants. Since it seems that this is not an area of language exclusive to humans, this may suggest that we re-examine the linguistic processing of human language.
Werker then looks to the concept of rhythm. Rhythm is defined as a “paramount for distinguishing one family of languages from another, and among other functions, helps the listener to decide whether the speaker belongs to the same social group” (2000). Werker (2000) uses rhythm to further understand the similarities between the tamarin monkeys and human perceptual systems. One understanding is that nonhuman primates share many mechanisms such as breathing and other rhythmic elements with humans. Also, adult tamarins have had exposure to human language throughout their lifetime, just as human infants have heard the rhythmic aspects of speech while in the womb.
Another idea that Werker examines is in regards to different brain areas. She explains that nonhuman primates possess cortical regions of the brain that are analogous to Wernike’s and Broca’s areas. It could be that our shared mammalian evolutionary history may have provided tamarins with the same types perceptual systems in humans.
Werker’s conclusion then seems to use the understanding that what is unique about human language perception is that humans have the ability to coordinate the auditory discriminations of language acquisition.
Ø Combined symbolic communication (ex: bats & echolocation, dolphins orient themselves and locate others, the dance of the honeybees is used to tell their mates where pollen is)
v Is Language Innate and Instinctive?
Ø 2 fundamental premises must be met if linguistic input is a privileged stimulus for humans, arising from distinct evolutionary specializations:
§ Human neonates (who have not yet had extensive exposure to language) should show and advantage in processing linguistic sounds.
§ This specialized linguistic processing should be unique to humans
Ø Language relies more than the discrimination of isolated minimal phonetic pairs
Ø Ramus and colleagues examine the perception of continuous speech and its constituent rhythm, as it exists in natural language.
Ø Ramus compared the ability of a nonhuman primate species and human infants to discriminate Dutch and Japanese played forward and backward.
Ø Major finding from research:
§ Adult tamarins, like human infants, can discriminate continuous speech from two rhythmically distinct languages, but only if the speech is played forward. When speech is played backward, both humans and tamarins fail to differentiate the two languages.
§ Tamarins are able to process not just isolated syllables, but also whole strings of continuous speech and to extract enough information to discriminate between Dutch and Japanese
§ Like newborns, tamarins fail to discriminate when speech is played backwards, suggests that their language discrimination capacity does not rely on trivial low-level cues, but rather on quite specific properties of speech
Ø Helps the listener to decide whether the speaker belongs to the same social group (ex: accents-Southern,
Ø Provides critical cues for parsing utterances into constituent elements, such as words, phrases, and clauses, which form the building blocks of human grammar.
v Results indicating similarities between tamarin and human perceptual systems, some reasons:
Ø Rhythm of human speech is of functional significance to both species
Ø Since nonhuman primates share many mechanisms of breath control with humans, similar rhythmic elements could characterize their own vocalizations
Ø Adult tamarins have had a lifetime exposure to human language
Ø Human infants heard the rhythmic aspects of speech while in the womb
v How would different processing mechanisms be manifest?
Ø Different brains areas might mediate the processes
§ Nonhuman primates possess cortical regions analogous to Wernicke’s and Broca’s areas
Ø Mammalian evolutionary history may have provided tamarins with perceptual systems that make all the same discriminations that human have for speech perception.
§ Perception of speech by tamarins might be analogous to human speech perception
v What’s unique to humans is the ability to coordinate these auditory discriminations in the service of language acquisition