DISCOURSE, AND A RETURN TO UNDERSTANDING
Language consists of more than disconnected utterances. When sentences are put together to make a sensible message, the result is discourse. A substantial part of the psychology of language deals with discourse processing, especially when it concerns text. Many theories of discourse processing have been developed, for example by Gernsbacher (1990), Kintsch (1988), and Sanford and Garrod (1981).
The primary feature of discourse is that it is coherent – in other words, the individual sentences fit together in a meaningful way and do not contain any contradictions. Sometimes sentences are connected by explicit devices, called cohesion markers. Consider the following:
John fell off the cliff because he was walking too near the edge.
There are two cohesion markers here:
1. the connective ‘because’ indicates that the sentence ‘John fell off the cliff ’ portrays the result of a cause – i.e. ‘he was walking too near the edge’; and
2. the pronoun ‘he’ signals that some individual who is singular and male has been mentioned. The only thing that fits the bill is ‘John’, so we take it that it was ‘John’ who ‘was walking near the edge’.
But the establishment of coherence does not always rely on cues such as these. For instance: John was hit by a train. He had been walking down the track. This is coherent because ‘walking down the track’ was the condition that enabled ‘John’ to be ‘hit by a train’. But there is no explicit connector (‘because’): the connection is inferred. Coherence establishment may sometimes make use of cues in the text, but always relies on some degree of inference. As a final example, consider the following single sentence: John lent Harry some money because he was hard up. What is the referent of ‘he’? Obviously it is ‘Harry’, not ‘John’. Why? Because money is lent to people who are ‘hard up’, and this inference is automatically drawn and used to solve the reference problem.
These few examples show the complexity of the computational operations that underlie even the most mundane language processing at the discourse level, and they represent just a small sample of the issues. Inferences vs. scenarios Experimental work shows that it takes time to make inferences. Haviland and Clark (1974) asked people to read short texts made up of two sentences, and then measured the reading times for the second sentences. Compare the following pairs:
Inference version: Herb took the picnic supplies from the car.
The beer was warm.
Explicit control: Herb took the beer from the car.
The beer was warm.
The reading time for the second sentence was longer in the inference version, because participants had to infer that ‘The beer’ is part of the ‘picnic supplies’. The text demands that an inference be made, which demands cognitive resources.
But sometimes knowledge may be automatically recovered and included in the mental representation of the sentence. For instance, given ‘Harry drove to London’, there may be a default representation of the fact that a car was used. Subsequent mention of a car would not be a problem, because its default is already in the representation resulting from the sentence. This is what Garrod and Sanford (1982; 1983) found to be the case. In a fuller theory, Sanford and Garrod (1981; 1998) argued that we automatically relate what is being said to background knowledge, and that background knowledge is organized in long-term memory about specific situations. They called these structures ‘scenarios’, and argued that the basic, most fundamental operation of understanding is to recognize the situation in which the message is set. So, because we are retrieving further situation information from memory, sentences can lead to representations that go beyond their content.
As one final example of a study that seems to support this view, Garnham (1979) required participants to try to remember sentences they had seen previously: e.g. ‘The housewife cooked the chips.’ He found that participants remembered this sentence better if they saw the cue ‘fried’ than if they saw the cue ‘cooked’, even though ‘cooked’ is actually part of the original sentence. According to the scenario theory, this is because cooking chips has been implicitly represented as a situation in which frying is taking place. Of course, another possibility is that the word ‘fried’ simply provided more information, in terms of a cue for remembering. The ultimate questions For discourse studies, the ultimate questions are just which inferences are made (i.e. what knowledge is recruited) and when during language processing. Some theorists believe that sometimes there might not be much inferential activity taking place during natural discourse (McKoon & Ratcliff, 1992), and that inferences and elaborations will only ta e place when the relevant background knowledge is highly available in memory. Sanford and Garrod (1998) take the view that it is the task of the writer or speaker to say things in such a way that a scenario can easily be found, because this is essential for good message-level interpretation. Whatever they think about component processes, there would be few scientists who would disagree that understanding is based on bringing language input into contact with world knowledge – the basic question being how this is done. Noam Chomsky has been at the forefront of international thought over the past several decades regarding the individual development and intergenerational heritability of language. The classic Chomskian sentence ‘Curious green ideas sleep furiously’ is not intelligible at the message level, simply because it is hard to relate to anything we know about. But ‘The housewife cooked the chips’ is intelligible because we can easily relate it to many things we know about.
Language consists of more than disconnected utterances. When sentences are put together to make a sensible message, the result is discourse. A substantial part of the psychology of language deals with discourse processing, especially when it concerns text. Many theories of discourse processing have been developed, for example by Gernsbacher (1990), Kintsch (1988), and Sanford and Garrod (1981).
The primary feature of discourse is that it is coherent – in other words, the individual sentences fit together in a meaningful way and do not contain any contradictions. Sometimes sentences are connected by explicit devices, called cohesion markers. Consider the following:
John fell off the cliff because he was walking too near the edge.
There are two cohesion markers here:
1. the connective ‘because’ indicates that the sentence ‘John fell off the cliff ’ portrays the result of a cause – i.e. ‘he was walking too near the edge’; and
2. the pronoun ‘he’ signals that some individual who is singular and male has been mentioned. The only thing that fits the bill is ‘John’, so we take it that it was ‘John’ who ‘was walking near the edge’.
But the establishment of coherence does not always rely on cues such as these. For instance: John was hit by a train. He had been walking down the track. This is coherent because ‘walking down the track’ was the condition that enabled ‘John’ to be ‘hit by a train’. But there is no explicit connector (‘because’): the connection is inferred. Coherence establishment may sometimes make use of cues in the text, but always relies on some degree of inference. As a final example, consider the following single sentence: John lent Harry some money because he was hard up. What is the referent of ‘he’? Obviously it is ‘Harry’, not ‘John’. Why? Because money is lent to people who are ‘hard up’, and this inference is automatically drawn and used to solve the reference problem.
These few examples show the complexity of the computational operations that underlie even the most mundane language processing at the discourse level, and they represent just a small sample of the issues. Inferences vs. scenarios Experimental work shows that it takes time to make inferences. Haviland and Clark (1974) asked people to read short texts made up of two sentences, and then measured the reading times for the second sentences. Compare the following pairs:
Inference version: Herb took the picnic supplies from the car.
The beer was warm.
Explicit control: Herb took the beer from the car.
The beer was warm.
The reading time for the second sentence was longer in the inference version, because participants had to infer that ‘The beer’ is part of the ‘picnic supplies’. The text demands that an inference be made, which demands cognitive resources.
But sometimes knowledge may be automatically recovered and included in the mental representation of the sentence. For instance, given ‘Harry drove to London’, there may be a default representation of the fact that a car was used. Subsequent mention of a car would not be a problem, because its default is already in the representation resulting from the sentence. This is what Garrod and Sanford (1982; 1983) found to be the case. In a fuller theory, Sanford and Garrod (1981; 1998) argued that we automatically relate what is being said to background knowledge, and that background knowledge is organized in long-term memory about specific situations. They called these structures ‘scenarios’, and argued that the basic, most fundamental operation of understanding is to recognize the situation in which the message is set. So, because we are retrieving further situation information from memory, sentences can lead to representations that go beyond their content.
As one final example of a study that seems to support this view, Garnham (1979) required participants to try to remember sentences they had seen previously: e.g. ‘The housewife cooked the chips.’ He found that participants remembered this sentence better if they saw the cue ‘fried’ than if they saw the cue ‘cooked’, even though ‘cooked’ is actually part of the original sentence. According to the scenario theory, this is because cooking chips has been implicitly represented as a situation in which frying is taking place. Of course, another possibility is that the word ‘fried’ simply provided more information, in terms of a cue for remembering. The ultimate questions For discourse studies, the ultimate questions are just which inferences are made (i.e. what knowledge is recruited) and when during language processing. Some theorists believe that sometimes there might not be much inferential activity taking place during natural discourse (McKoon & Ratcliff, 1992), and that inferences and elaborations will only ta e place when the relevant background knowledge is highly available in memory. Sanford and Garrod (1998) take the view that it is the task of the writer or speaker to say things in such a way that a scenario can easily be found, because this is essential for good message-level interpretation. Whatever they think about component processes, there would be few scientists who would disagree that understanding is based on bringing language input into contact with world knowledge – the basic question being how this is done. Noam Chomsky has been at the forefront of international thought over the past several decades regarding the individual development and intergenerational heritability of language. The classic Chomskian sentence ‘Curious green ideas sleep furiously’ is not intelligible at the message level, simply because it is hard to relate to anything we know about. But ‘The housewife cooked the chips’ is intelligible because we can easily relate it to many things we know about.
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