Comparative Cognition and Language Lecture Notes

Comparative Cognition

Comparative cognition is the study of the differences and similarities in how different species process information. Typically, this involves comparing animal information processing to human information processing. However, it can also involve comparing information processing across non-human species. Comparative cognition seeks to understand the cognitive mechanisms and processes that underlie behavior in both humans and animals.

Understanding how animals process information requires a serious consideration of how we define cognitive processes. For example, to study counting in dogs, we must first operationally define what counting is. Operational definitions help ensure that cognitive processes can be measured and compared across species in a reliable and valid way. Furthermore, defining cognitive processes allows researchers to develop experiments to test specific hypotheses about how animals think and learn.

Comparative cognition research can provide insights into human information processing by revealing shared evolutionary mechanisms. By identifying cognitive traits and mechanisms that are common across species, researchers can gain insights into the fundamental building blocks of cognition. This can lead to a better understanding of the adaptive functions of cognitive processes and how they have evolved over time.

Overlap with Cognitive Psychology

Comparative cognition overlaps with many areas of psychology, such as those typically found in a cognitive psychology course (e.g., Psych 340). However, comparative cognition differs from human cognitive research because it emphasizes the role of environmental events (e.g., reinforcement contingencies) on behavior, as opposed to internal events (e.g., thoughts or concepts). While human cognitive research often focuses on the internal mental processes that mediate behavior, comparative cognition places a greater emphasis on the role of external stimuli and consequences in shaping behavior. This focus on environmental factors has led to important insights into how animals learn and adapt to their environments.

Common Themes in Comparative Cognition Research

Two common themes in comparative cognition research are:

  1. Methodology: Ensuring that the methods used appropriately assess the cognitive abilities of the species being studied. For example, showing cows numbers on cards is not an appropriate method for assessing memory in cows. Methodological rigor is critical to ensure that research findings are valid and reliable. Researchers must carefully consider the perceptual and motor capabilities of the species being studied, as well as their natural behavior patterns, in order to develop appropriate tasks and measures.

  2. Objective Measures: The use of objective measures is essential to avoid anthropomorphizing animal behavior. It's easy to be non-objective when observing animal behavior, but scientific rigor is important. Objective measures help to minimize the influence of subjective biases and ensure that research findings are based on empirical evidence. Examples of objective measures include reaction time, accuracy rates, and physiological responses.

Animal Language

A major question in comparative cognition is whether non-human animals are capable of using language.

Two major approaches to studying this question:

  1. Assess the nature and purpose of communication between animals of a given species.

  2. Attempt to teach animals an artificial language.

This area of study is controversial, with debates about whether human language is unique. Some argue that specific elements must be present for language to qualify as "human-like". Others argue that animals may be capable of language but that we have not yet developed the appropriate methods to demonstrate this.

Communication vs. Language

It is important to distinguish between communication and language.

Animals communicate in various ways, including:

  • Body posturing (e.g., dogs sniffing and jumping).

  • Scent marking.

  • Vocalizations (e.g., bird calls).

All communication involves:

  • Production of a signal

  • Reception of a signal

  • Comprehension of meaning

For instance, a Siamese fighting fish producing a territorial display, another fish receiving the display, and then behaving in a way that shows comprehension of the signal (e.g., hiding).

Differences Between Human and Animal Communication

Researchers have proposed two key differences:

  1. Reflexivity: The argument that animal communication is reflexive (involuntary), whereas human communication is intentional.

    • Animal communication is often elicited by specific stimuli in the environment.

    • Human communication can be intentionally generated, even without specific environmental stimuli.

    Research with vervet monkeys suggests that their alarm calls are not reflexive. For instance, a vervet monkey will not make an alarm call if it sees a predator when it is alone. Additionally, the alarm calls vary depending on the type of predator (e.g., leopard, eagle, snake), and other monkeys respond appropriately to each call. The calls are distinct vocalizations, not imitations of the predator's sounds. These findings suggest that vervet monkeys are capable of using alarm calls in a flexible and intentional way, which challenges the assumption that animal communication is always reflexive.

  2. Grammar: The argument that animal communication lacks the complex rules (grammar) present in human language.

    • In English, word order is crucial for conveying meaning (e.g., "The dog chases the cat" vs. "The cat chases the dog."). This illustrates the subject-verb-object rule.

    Research on chickadees has revealed that their calls have different elements (A, B, C, D) that are strung together in certain permissible orders (e.g., ABCD, ACDD) and that some combinations never occur (e.g., BACD). This suggests the presence of structural rules in animal communication. Further research has shown that chickadees use these calls to communicate information about the size and threat level of predators. The number of "D" notes in a chickadee call is correlated with the size and proximity of the predator, with more "D" notes indicating a greater threat.

Limitations of Animal Communication

Despite similarities, animal communication seems to be missing key features of human language:

  • Complexity: Human grammatical rules are more complicated.

  • Function: Animal communication is primarily for signaling purposes (e.g., "eagle above," "food over here"), rather than engaging in conversations or expressing complex thoughts.

  • Novelty: Animals do not generate novel phrases or engage in conversations.

Researchers have questioned whether these differences reflect the limited needs of animals in their natural habitats or whether animals are simply incapable of more complex language use. It is possible that animals have the capacity for more complex language use but lack the ecological pressures or social structures that would favor the development of such abilities. Alternatively, it is possible that there are fundamental differences in the cognitive architecture of humans and animals that limit the complexity of animal communication.

Teaching Artificial Languages to Animals

Taking animals out of their natural environment and teaching them new artificial languages has been used as another method to explore language.

Early attempts involved teaching chimpanzees to speak. For example, Hayes and Hayes (1950s) tried to teach a chimpanzee named Vicki to generate human speech by manipulating her mouth. After several years, Vicki could only produce three words: "mama," "papa," and "cup." This approach wasn't successful given the differences in chimpanzee physiology. Chimpanzees lack the vocal apparatus necessary to produce the complex sounds of human speech.

Project Washoe (1960s) was launched, where Gardner and Gardner trained a chimp named Washoe to use sign language. Washoe was raised in an enriched environment and communicated with using American Sign Language. After four years, Washoe knew over 100 signs. Independent observers confirmed the accuracy of Washoe's sign usage over 80% of the time. This led to others trying to teach language to gorillas, sea lions and even dolphins. The success of Project Washoe demonstrated that chimpanzees are capable of learning and using symbolic communication systems.

Herb Terrence trained a chimp named Nim Chimsky to use sign language. Nim learned 125 signs and could string signs together to make primitive sentences (e.g., "eat Nim eat"). However, Terrence argued that Nim's use of signs was simply a mechanism to access reinforcement, with no evidence of grammar. Terrence's critique of Project Nim raised important questions about the nature of animal language and the criteria that should be used to assess linguistic abilities.

Sarah was a chimpanzee trained to use plastic shapes as symbols to communicate. She had about 130 words and appeared to understand some aspects of grammar. However, she rarely initiated conversations and only seemed to use language when her trainer was present. Sarah's performance suggested that chimpanzees are capable of learning and using symbolic communication systems, but that their use of language may be limited by motivational and social factors.

Alex was an African grey parrot trained to use over 100 English words appropriately. Alex could identify colors and materials, count up to around four, and follow instructions. Alex seemed to have an understanding of concepts and some grammar. Alex's abilities challenged the assumption that only primates are capable of learning and using language. His performance suggested that birds may also have the cognitive capacity for symbolic communication.

Key Elements of Human Language

To assess the extent to which animal language is similar to human language, it's important to consider elements such as the following:

  • Symbolic: Uses arbitrary symbols to represent things.

  • Semantic: Words have meanings associated with them.

  • Generative: Humans can generate spontaneous new communications from existing elements.

  • Structured: Follows basic grammatical rules.

When it comes to animal grammar, there is often inconsistency in the order of words expressed. The order words are strung together does not seem to matter. And the sentences generated are really short. While vocabulary increased over time in some of the trained animals, the length of the sentences did not.

Animals also rarely initiated language, and there was a lot of redundancy and repetition in communication.

Kanzi

Kanzi was a Bonobo chimpanzee that used hand gestures and symbols presented on a keypad called a lexigram. Kanzi showed evidence of spontaneous language use and followed grammatical rules. He learned language as youngster, by watching his mother get language training. He was great at it, his mother wasn't. Most of the instances were also spontaneous and not reactive. He also created his own grammar. Kanzi's abilities challenged the assumption that language learning requires explicit instruction. His performance suggested that language can be acquired through observation and immersion in a communicative environment.

Conclusion

Language is a complex phenomenon. While animals may demonstrate some elements of language, these elements are often not as complex as those seen in human language. More research into assessment techniques is needed to discover the true potential of language in animals. Future research should focus on developing more ecologically valid assessment techniques that take into account the natural behavior patterns and cognitive abilities of different species. Additionally, researchers should continue to explore the neural and genetic mechanisms that underlie language and communication in both humans and animals.