Compare and contrast the methods used for research in Memory and Language Processes

Cognitive psychologists support the idea that behaviour cannot be understood until the discovery and comprehension of the basic mental processes that underlie it (Bernstein et al. 1988). To find out and understand how cognitive areas work, such as attention, language, learning, memory, problem solving and so on, psychologists conduct scientific research using many kinds of method. Cognitive psychologists established their subject specific methodology wherein they adopt methods of investigations which are used by more traditional sciences, such as physics laboratories or experiments conducted in biology or chemistry. Researchers choose research methods in order to investigate their hypotheses and to deepen and broaden their understanding of their chosen topics. Whichever method is used, must be efficient enough to produce appropriate data, from which the cognitive psychologists are able to make a statement on the research hypotheses and to draw their conclusions. It can be seen that the key aspect in opting for a type of method for an investigation is its ability to serve the goal of the research efficiently.

This essay is an attempt to compare and distinguish between the two applied research methods used in language and memory; one of them is a naturalistic observation study on the vervet monkeys which was conducted in their natural environment to find out whether their alarm calls represent a communication system; the other one is a case study carried out on the long-term memory system in a laboratory environment used to find out if there is a distinction between episodic memory and semantic memory, being the two components of the long-term memory system. Through these two pieces of research this essay will focus on the mentioned two types of method and will attempt to point out their similarities and differences. Firstly, some general information on research methods used in cognitive psychology will be presented including goals and procedures of experiments. Then the two mental processes, memory and language, will be discussed in sufficient depth that is essential for understanding the chosen experiments, and finally, the two pieces of research will be compared and contrasted in the aspects of their techniques, limitations, strengths and weaknesses, ecological values, and whether or not they give information on individual differences.

Various research methods are used by cognitive psychologists. and whichever is chosen, the aim must be to challenge common sense ideas by verifying the facts. The process of a research must begin with an initial hypothesis, based on previous knowledge and experience. To support or to reject this statement, data must be gathered and analysed. A careful consideration is required from the researcher in the decision of which research method is best to use in the investigation. Each method has its limitation, and researchers have to consider which best would serve the aim of the study. The design of a research project contains very important factors, which will have an affect on the outcome of the research; such as the size of the sample, the way the participants are selected, the degree they can represent the population, the given environment, the circumstances and the way the data is gathered. The all population obviously cannot possibly take part in a research project, but a group of people can be chosen to represent the population, and this procedure is called sampling. Psychologists study either groups of people to find out what they have in common in relation to a cognitive phenomenon, or individuals in order to identify what make each person unique. When groups are studied, the explanation for the behaviour experienced is generalised and said to be applicable to all members of the group. In contrast, when an individual is studied, the explanation for the behaviour of that individual cannot be applied to all people. Once the sample (a small group of people), or the target population (a large group of people) has been identified, various methods can be used for gathering data, and for drawing inferences (Coolican 2004a). These research methods are: controlled laboratory experiment, psycho-biological research, self-reports, case studies, naturalistic observation, also computer simulations and artificial intelligence (Sternberg, 1996a). This essay will detail only the case studies and the naturalistic observation which relate to the two experiments.

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The following two studies were chosen from the cognitive areas of memory and language, since they both have major roles and influences on humans' life. In our society most people spend at least eleven years in education based on using language as a medium in transmitting and testing knowledge; without language humans would not be able to write, read, follow instructions or express their needs and thoughts. Language is a complex phenomenon which is concerned with communication. Without using any form of language individuals cannot communicate or interact with their environment and would become isolated. In nature, if an individual becomes isolated, it often means that the animal becomes unprotected, which is not beneficial in the aspect of survival. There have been several attempts to define what language is, but this essay will only refer to the Aitchison's continuity theory. According Aitchison (1983), 'the human language is a sophisticated calling system that is not fundamentally differing from animal cries and calls'. Numerous studies have been conducted on the calling and communication systems used by animals, and this essay will discuss Seyfarth and his college’s (1980) experiment which in turn was a repetition of Struhsaker's (1967) earlier study on vervet monkeys.

Seyfarth and his colleges (1980) carried out a study to investigate the alarm calls of velvet monkeys to see if these represent a communication system. Vervet monkeys have a range of different alarm calls, which are used in the presence of different predators. A 'chirp', a loud barking call, is given for lions and leopards, a 'rraup', a cough like call, warns of an eagle and 'chutter' announces the presence of a snake. A concealed loudspeaker played recordings of these alarm calls and the behaviour of the monkeys was observed. Their finding was that, behaviour of the monkeys was related to the type of alarm call being played. When a 'chirp' was played, they rapidly climbed a tree, at the sound of a 'rraup' they ran into the vegetation as if to hide from an eagle, and when a 'chutter' was given, their stood on their hind legs and looked down at the ground. These results were taken to support the view that the vervet monkeys have a system of alarm calls, which signify specific predators. This study is an example of the experimental psychologist’s approach to language as a cognitive area.

A strong connection can be found between memory and language because they constantly interact with each other. For instance one would not be able to acquire or use a language unless are remembered the words and their meanings, or would not be able to gain specific knowledge, which reaches beyond the limitations of one's senses and requires explanation. Cognitive psychologists have a long term ambition to find out how memory works. Although memory is fragile and many of the memories are not permanent, human's memory represents a wide selections of data, knowledge and experience. According to Steve (2004) an average fourteen year old student knows about 14.000 words, whilst a university graduate might know about 50.000 words. Atkinson and Shiffrin (1968) developed the multi-store model of memory, their approach assumes that mental processes can be understood by comparing them with the operations of a computer, therefore can be interpreted as information progressing through a system of various stages. The 'input' information comes from the senses and is transmitted as an electric code to the first stage that is the 'sensory memory'. In the sensory memory the information is stored for a couple of seconds, or less, and then most of it is lost. The information selected for further processing is transferred into the second stage, the 'short-term memory' by the process of attention. Then the process of rehearsal enables selected information to be transferred from short-term memory into the last stage, the 'long-term memory', where it can be retained for many years. Tulving (1989) conducted an experiment on long-term memory, in order to support his earlier proposal (1972), that there is a distinction between episodic memory and semantic memory (Best, 1989a). The episodic memory refers to memories for events that an individual has experienced, in other words, episodes in an individual's life, for example, the first day at school, or a birthday party. Semantic memory focuses on general knowledge about the world and which includes knowledge about the meanings of words, as well as general knowledge (Best 1989b), for instance, where one can find Edinburgh on the map, and who first landed on the moon. Although common sense tells us that there is a distinction between these two kinds of memory, finding experimental evidence to support that view seems to be difficult. Some evidence has come from cognitive neuroscience studies monitoring blood flow in the brain while participants complete different tasks.

Tulving (1989) conducted an experiment on long-term memory to support his earlier proposal (1972), that there is a distinction between episodic memory and semantic memory. His aim was to investigate the extent to which episodic and semantic memory were independent memory systems located in different parts of the brain. Tulving used himself as a participant and small quantities of radioactive gold were injected into his blood stream. He then thought about semantic memories, e.g. historical facts, such as the work of famous astronomers. Following this he thought about episodic memories, e.g. what he did during vacation as a child. The blood flow within his brain was monitored by radioactivity detectors positioned around his head. His finding was that the two tasks gave different patterns of blood flow in the brain. Episodic memories were associated with increased blood flow in the front of the brain, whereas semantic memories were associated with an increase in blood flow in areas towards the back of the brain. These results were taken to support his view that episodic and semantic memory can be based in different parts of the brain. So Tulving's study represents the cognitive neuroscience approach in cognitive psychology.

Despite the two different types of research method used in these experiments and their unambiguous difference, they still show some similarities. On one hand the Tulving experiment is a case study, which means it is an intensive study of a single individual (in this case it is the researcher himself), trying to draw general conclusion about mental processes; on the other hand it is a psychobiological method since it is using psychophysiological recording procedure in order to monitor psychological processes. The Seyfarth experiment used the method of naturalistic observation to observe a group of vervet monkeys in their natural habitation. Because the conditions of an experiment play a very important role in the interpretation of the findings, it should be emphasised that, whilst the former study was conducted on a sample of the vervet monkeys in the wild, which is their natural environment, the latter study was carried out on one individual and in laboratory conditions which filters out all the attention withdrawing factors. The manipulation of the monkeys' behaviour was carried out by playing their pre-recorded alarm sounds to allow the researchers to observe their reactions to them and the changes in their behaviour. A tape-recorder was the only appliance used in the Seyfarth study, whereas radioactivity detectors were positioned around Tulving's head to monitor the blood flow in the brain. In contrast to the harmless naturalistic observation, Tulving injected a small quantity of radioactive gold into his blood stream, which is an intervention into the homeostasis of the body which should be mentioned. This method is widely used in the radiology to scan the brain and the blood flow in certain parts of the patient's body to find out the reason of the illness. When this technique is used in psychological research for the pure purpose of fulfilling the researcher's curiosity, the emotional affects of the process and the possible side effects must be taken into account, and assessed ethically to ensure that it will not cause any harm to the health of the participant.

The strengths of the Tulving study is to provide some evidence about the episodic memory and semantic memory and their locations in the brain, which has an inter-disciplinary benefit, e.g. it offers more knowledge about the anatomy and physiology of the brain, and can help in the diagnosis of brain damage in medicine. The weakness of this study is the small sample. In sciences, gaining experimental results on one participant is hardly sufficient to draw any general conclusion, but could help to build up a new hypothesis. Another weakness of this study is caused by the individual differences in cognitive abilities. For instance, it is difficult to make participants separate their thoughts in the same way so that only episodic memories or semantic memories are recalled at a time without any overlap. The strength of the Seyfarth study is its multidisciplinary benefit. Knowing more about the communication systems and their limitations in the animal kingdom is useful for other disciplines such as agriculture, zoology, etc. The weakness of this naturalistic observation is the lack of experimental control, since the interference of the environment cannot be left out of consideration, because even just the presence of the observer can influence the animals' naturalistic behaviour.

Despite the fundamental differences between the two studies, the methods used in the two experiments do show similarities in some aspects. Both case studies and naturalistic observations can offer high ecological value. 'Ecology is the study of the interactive relationship between an organism and its environment' (Sternberg, 1996b). For instance, there is a strong interaction between the cognitive process of memory and artificial intelligence; or knowing the effectiveness and the limitation of the bees' communication system has proved a great benefit for bee-keepers. Neither of the methods show validity of causal inferences; both the sample sizes are small therefore the results of these two studies cannot be representative, and therefore are not suitable for generalisation. Despite this fact, both the experiments have their own great value; the Tulving study, based on an earlier assumption, was carried out as a preliminary study to establish a research hypothesis, which was supported later by repeating this experiment several times with different participants. The Seyfarth study was based on some earlier findings on the signal system of the vervet monkeys by Struhsaker (1967) and was repeated later by Cheney and Seyfarth (1980, 1990) on both vervet and diana monkeys.

Cognitive psychology is generally defined as the scientific study of thought and mental processes; to discover and understand behaviour and thought, cognitive psychologists use many methods of investigation. This essay has compared and contrasted the naturalistic observation with the case study. The Tulving study was described as a case study, which used the means of a psychobiological research. The Seyfarth study is clearly representing the features of a naturalistic observation. They showed differences in their strengths, weaknesses and the number of the participants. In contrast, they showed similarities in the validity of causal inferences, sample representativeness and ecological validity. In conclusion it can be stated, that although methods are fundamentally different from each others, they are still overlapping in some aspects.

References

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