Binding versus coreference

In Chapter 2, I discussed the interpretation of pronouns in simple transitive and ECM constructions by individuals with Broca’s aphasia and I pointed out that the pattern of errors exhibited by these aphasic patients mirrors the error pattern found in pre-school children. To summarise, previous experimental studies on the acquisition of reference have shown that children aged 4 to 6, like agrammatic patients, exhibit adult-like performance with regard to the interpretation of reflexives. The interpretation of pronouns, on the other hand, seems to be more problematic. From the numerous studies on the acquisition of

pronominal elements a particular pattern has emerged, known as the Delay of Principle B Effect (DPBE): Children often allow pronouns to refer to local c-commanding antecedents (e.g. for English: Jakubowicz 1984; Chien & Wexler, 1990; for Dutch: Koster 1993, Sigurjónsdóttir & Coopmans, 1996; Philip & Coopmans 1996; for Icelandic: Sigurjónsdóttir, 1992 and for Russian: Avrutin & Wexler, 1992).1 As was originally

observed by Chien & Wexler (1990), children’s performance on pronouns in simple transitive sentences, such as (1), where the local c-commanding antecedent is a referential expression, is at chance level. However, in structures where the local antecedent is quantified as in (2), children’s performance is much more adult-like (85%); they reject binding between the pronoun him and the local quantified DP every boy.2

(1) *The boy pointed at him. (2) *Every boy pointed at him.

These findings suggest that, like agrammatic aphasic patients, children have problems with coreference and not with binding.3 Local coreference

rests on the interpretation of pronouns as free variables and it is not completely impossible in languages such as English and Dutch, but it is limited to special contexts (see Chapter 2, footnote 11). As was discussed in Chapter 2 in detail, both children and agrammatic patients allow local coreference in contexts where non-brain-damaged adults reject it; and children and agrammatic patients do this as a consequence of a failure to implement Rule-I (Grodzinsky & Reinhart, 1993; Grodzinsky et al., 1993).

1_{Baauw & Cuetos (2003) point out that the term Delay of Principle B Effect used to}

refer to this phenomenon is inappropriate for two reasons. First, the same effect is found in agrammatic patients where there can be no delay because they are not acquiring language. The second reason is related to the observation that children do know binding principles but fail in instances where coreference is an option. For these reasons the authors refer to DPBE as the Pronoun Interpretation Problem (PIP), following Coopmans (2000).

2 _{Elbourne (2005) questions the reality of the distinction between referential and}

quantified antecedents that has been claimed to be reflected in the experimental findings of numerous studies examining children’s interpretation of pronouns with these antecedents, Chien & Wexler (1990); Thornton (1990); Boster (1991); Avrutin & Thornton (1994); Philip & Coopmans (1996); Thornton & Wexler (1999). He claims that a few experimental factors lessen the force of these studies.

3_{As observed by Bloom, Barss, Nicol & Conway (1994), Principle B Delay does not}

show up in children’s spontaneous speech. This supports the claim that children observe Principle B. Apparently, when children want to express reflexivity, they use reflexive pronouns. Only when they are “forced” to judge the possibility of local coreference, as in an experimental setting, do they (often) allow this reading.

In addition, children exhibit an extra strong DPBE in ECM constructions. Philip & Coopmans (1996) and Baauw (2000) have shown that Dutch children allow the pronoun in ECM sentences, such as (3), to refer to the local antecedent in around 80% of cases tested. Reference assignment in these sentences is constrained by the A-chain condition of the Reflexivity model. This contrasts with the chance performance (50%) observed in simple transitive structures in (1) where Principle B of the Reflexivity model applies.4

(3) *Mary saw her dance.

According to Philip & Coopmans, the extra strong DPBE in ECM sentences is a consequence of the incomplete acquisition of the [case] feature, which results in faulty assumption children make with regard to the [+/- R] property of the pronoun. Children misanalyse the pronoun as referentially deficient [-R], which in turn permits the matrix subject to bind the pronoun without violating the A-chain condition (for details see Philip & Coopmans, 1996). Philip & Coopmans also offer an elegant explanation for the 80% non-adult like performance in ECM structures. As children are supposed to be guessing with regard to whether a pronoun is [+R] or [- R], half of the time they will assume that it is [+R] and half of the time that it is [-R] (50% non-adult like performance). In the 50% of cases where they correctly assign [+R] to the pronoun, half of the times they will fail to implement Rule-I and therefore will still perform in a non-adult like fashion. This adds up to 75% non-adult like responses in total.

An alternative explanation but similar in spirit was offered by Baauw (2000), who proposed that the [number] feature is not fully acquired or cannot be accessed in children. As a result of an underspecification of the [nubmer] feature, children often misanalyse third person pronouns as [- R] elements, treating them as SE-anaphors such as Dutch zich, which, in principle does not violate the A-chain condition. This proposal will be discussed in detail in section 5.3, where the results of the experiment testing children’s ability to use the number and gender information on pronouns will be presented.

The aim of the experimental study discussed here is to replicate the results that have been found for children in the previous studies, examining comprehension of pronouns in simple transitive and ECM sentences using a picture selection task. In order to compare children’s

results with the results obtained from the Broca’s aphasic patients, the same method and materials were used in experiments with both populations. Agrammatic patients performed at chance level with pronouns in ECM constructions and were above chance when interpreting pronouns and reflexives in simple transitive sentences. If the cause of the problems with pronouns is similar in children and agrammatic aphasic patients (i.e. a lack of processing resources, as has been proposed Grodzinsky et al. 1993), it is expected that the pattern found in agrammatic aphasic patients will also show up in children. Crucially, a difference in children’s performance on pronouns in transitive and ECM constructions should be found, where the latter should be more problematic (in line with Philip & Coopmans, 1996 and Baauw, 2000). Such a pattern would be the same as the pattern found by the agrammatic patients as discussed in Chapter 2.

5.2.2 Experiment 5

5.2.2.1 Subjects

28 Dutch children (age 4:3-6:2, mean age 5.7) and 15 Dutch non-brain- damaged adults (age 35-84, mean age 56.6) participated in this experiment.

5.2.2.2 Materials and procedure

Children were tested using the same method as administered to agrammatic patients, picture selection task, discussed in detail in section 2.1.4.2. Chapter 2. However, the materials used with children differed form the ones used with agrammatic speakers in two ways. First, the characters performing the actions were different. In order to make the experiment appear as a game, which made it more enjoyable for the children to do, the four puppets from the TV programme Teletubbies were used instead of the characters used in the experiment with agrammatic speakers. These puppets were Tinky-Winky, Lala, Dipsy and Po (see Appendix F for all test sentences).

The experiment with the children also had one condition less than Experiment 1 (see examples of conditions in (4), (5), and (6)); the reflexives in ECM constructions were not tested in children because they had been tested extensively in children in many different languages and the same results had been replicated in all these languages; children do not have problems in interpreting reflexives (for references, see footnote 22).

(4) Pronoun in a transitive sentence:

Eerst hebben Dipsy en Tinky-Winky gespeeld en daarna heeft Tinky-Winky hem geknuffeld.

First Dipsy and Tinky-Winky played and then Tinky-Winky hugged him.

[Picture on the left side showed both characters playing and the other three pictures on the right side showed Tinky-Winky hugging Dipsy (correct response), an unrelated filler and Tinky-Winky hugging himself (e.g. Figure 5.1).]

(5) Reflexive in a transitive sentence:

Eerst hebben Dipsy en Tinky-Winky gespeeld en daarna heeft Tinky-Winky zichzelf geknuffeld.

First Dipsy and Tinky-Winky played and then Tinky-Winky hugged himself.

[Picture on the left side showed both characters playing and the other three pictures on the right side showed Tinky-Winky hugging Dipsy, an unrelated filler and Tinky-Winky hugging himself (correct response) (e.g. Figure 5.1).]

(6) Pronoun in an ECM construction:

Eerst hebben Dipsy en Tinky-Winky gespeeld en daarna zag Dipsy hem dansen.

First Dipsy and Tinky-Winky played and then Dipsy saw him dancing.

[Picture on the left side showed both characters playing and the other three pictures on the right side showed that Dipsy sees (in a mirror) Tinky-Winky dancing (correct response), an unrelated filler and one that shows that Dipsy sees himself (in mirror) dancing (e.g. Figure 5.2).]

Figure 5.2

The experiment contained 6 items per condition, which after repeating the test two weeks later, led to a score of 0-12 for each of these conditions.5 Above chance performance on the various categories was

5 _{This experiment was embedded in another experiment testing the effect of}

contrastive stress on the interpretation of pronouns, which will be discussed in section 5.4, with five additional conditions and six filler sentences (6 items each x 2 sessions). Each of the two sessions of the test contained 54 sentences in total.

taken as evidence that children know the relevant principle and are able to implement it.6

5.2.2.3 Results

Table 5.1 shows the results of the experiment (for individual data, see Appendix F, Table F.1). Children performed significantly above chance on both pronouns (binomial test – p<0.0001) and reflexives (binomial test – p<0.0001) in simple transitive conditions. They performed at chance level with pronouns in ECM sentences (binomial test – p<0.25). They made significantly fewer errors when interpreting pronouns in simple transitive sentences than in ECM constructions (t-test - t=7.018, df=27, p<0.001). Moreover, they performed worse than the control group, with regard to the interpretation of pronouns in general (Mann Whitney U test - pronouns in simple transitives - Z=-4.357, p<0.01; reflexives in simple transitives - Z=-3.225, p<0.01 pronouns in ECM - Z=-5.206, p<0.01).

The results reveal the same pattern as in agrammatic patients, who also performed above chance on both pronouns and reflexives in transitive sentences. Broca’s patients’ performance with pronouns in ECM sentences was at chance level as well (see Chapter 2, section 2.1.4.3.).

Table 5.1

Percentages correct on four experimental conditions. N.A.= not available. *Data from another control group of 13 Dutch speakers (mean age 42.6). **Data from 4 of the 8 Broca’s subjects.

Transitive sentence ECM construction Reflexive Pronoun Reflexive Pronoun

Children 92.3 75.0 N.A. 46.7

Controls 98.7 98.2 100* 97.8

Broca’s 93.3 91.7 96.7** 56.7

5.2.3 Discussion

In this experimental study two sets of results from previous studies have been replicated. First, children’s performance on reflexives in simple transitive sentences was significantly better than their performance on pronouns in the same constructions. Second, the interpretation of pronouns in transitive sentences was less problematic for them than the

6 _{The chance performance was considered to be 50%, although there were three}

pictures to choose from, since all children avoided choosing the unrelated filler pictures.

interpretation of pronouns in ECM sentences. Children performed at chance level on pronouns in ECM sentences.

Unlike in many other previous studies on pronouns in children, in the present experiment children performed above chance (75%) when interpreting pronouns in simple transitive constructions. The better performance in this particular experiment can possibly be ascribed to the difference in tasks used in the present study, a picture selection task, and other studies that have mainly used the truth-value judgment task or a variant of this task (apart from Koster, 1993). There are two other experimental studies where a difference in scores was found for pronouns in simple transitive sentences. Baauw & Cuetos (2003) tested Spanish children and found that when using a picture selection task, children’s scores were higher than the scores obtained using a truth- value judgment paradigm. Zuckerman, Baauw & Avrutin (2003) tested the same group of Dutch children with the same materials twice, once using a picture selection task and the second time using a truth-value judgment task. They found a task effect; children’s scores were higher when tested with a picture selection task.7 In a truth-value judgment

paradigm, the crucial condition is the one that elicits NO as the correct answer. According to Zuckerman et al. (2003), after hearing the target sentence in this condition, a child must search through all possible representations for that particular sentence in order to find out that there is no interpretation matching the picture that accompanies the target sentence. A picture selection task, on the other hand, is a less demanding task than the truth-value judgment task. Children search until they find the corresponding interpretation. They do not have to check all possible interpretations, some of which may be more difficult for them to process, such as the coreference interpretation in the case of the present experiment. They can simply opt for the interpretation whose acceptability they can check when they encounter the picture of this particular interpretation, such as the pronoun referring to an antecedent outside the sentence.

Comparing the children’s results with those obtained from the agrammatic patients reveals similarities in the pattern of errors on these two types of sentences. Similar to children, agrammatic patients perform significantly better on reflexives than on pronouns in simple transitive sentences and their performance on pronouns in these sentences is above chance. In Chapter 2, we saw that for agrammatic patients the

7 _{See also Crain & Thornton (1998) for a detailed explanation of differences between}

methodology did not affect their scores on simple transitive sentences with pronouns. However, as will become clear from the experiment examining the knowledge and use of morphosyntactic features in