Pronominal reference and agrammatic comprehension

Susan Edwards,* Spyridoula Varlokosta, and Elizabeth Payne

School of Linguistics and Applied Language Studies, University of Reading, Reading RG6 6AA, UK

Introduction

The apparent good comprehension of individuals with Broca’s

aphasia is known to be vulnerable for certain syntactic structures

(passives, object clefts, and relatives, some wh-questions). A common

factor in these structures is that an element has been moved and that

the grammatical operation of co-indexing between the moved element

and the gap that is vital for interpretation of the sentence is not

available. Subjects with Broca’s aphasia also have difficulty in on-line

and off-line tasks involving pronouns and reflexives. However, in off-

line tasks, they have been shown to make more errors with pronouns

than with reflexives (Grodzinsky, Wexler, Chien, Marakovitz, & Sol-

omon, 1993) while the reverse has been found in an on-line study

(Love, Nicol, Swinney, Hickok, & Zurif, 1998). The findings of

Grodzinsky and Reinhart (1993) were similar to that found for young

children and older SLI children, a pattern of performance that has

been claimed to be due to processing difficulties in computing Rule I, a

pragmatic rule that determines co-reference between a pronoun and a

referential NP. The high performance of aphasic subjects on reflexives

and bound pronouns is taken as evidence that their knowledge of

binding principles A and B is intact.

In a preliminary study, Varlokosta and Edwards (2003) found that

listeners with Broca’s aphasia had problems with reflexives rather than

pronouns, as in the Love et al.’s study. The picture, then, is confused

possibly because the number of subjects in each study has been small.

Varlokosta and Edwards and Love et al. each had three subjects while

Grodzinsky et al. used the results from six of his agrammatic subjects.

We now report on a study using a larger group of agrammatic subjects

and consider our results in light of previous explanations. We will

discuss our results within the larger domain of processing difficulties

with syntactic dependencies in an effort to seek a parsimonious

explanation.

Method

Subjects

Seven new subjects were recruited. All were identified as non-fluent

aphasic speakers by their clinicians and the diagnosis of agrammatism

was confirmed by their spoken output and performance on a sentence

comprehension test. Results were pooled with those obtained by

Varlokosta and Edwards (2003) giving a total of 10 subjects.

Procedures

Subjects were first screened to ensure they could understand the

lexical items (nouns, verbs, quantifiers, and pronouns) used in the

trials. They were then given a truth value judgement task involving 56

sentences. There were 5 types of sentences: (1) those containing pro-

nouns is the mother looking at her; (2) reflexives is the mother looking at

herself; (3) pronouns with a quantified antecedent is every mother

looking at her; (4) reflexives with a quantified antecedent is every mo-

ther looking at herself; and (5) complex predicate constructions (CPC)

does the father see him dance. This last construction was included be-

cause the interpretation of pronouns in complex sentences like these

that involve a main and an embedded predicate has been found to

cause difficulties to young children. Subjects were asked to listen to

each sentence and judge whether it matched the picture shown. Half

the pictures provided matches and half mis-matches. There were 6

trials for each condition (match/mis-match) for the first 4 sentence

types and 4 trials for each condition (match/mis-match) for the CPC

condition. Delivery of the sentence types was randomised.

Results and discussion

Scores were tallied for matches and mis-matches and can be seen in

Table 1.

Subjects were better at judging in the match than in the mis-match

condition so we will focus on performance in the mis-match condition

where difficulties are revealed. Our subjects found it harder to judge

reflexives than pronouns in both match and mis-match conditions

although the difference between the two in the mis-match condition is

very small. Performance fell for pronouns and reflexives when the

sentence contained a quantificational antecedent. In these conditions

the difference between the pronoun and the reflexive sentences becomes

larger but the relationship stays the same: subjects make more errors

on sentences containing reflexives than they do on sentences containing

pronouns.

These results are at odds with previous off-line findings but are in

line with the on-line findings of Love et al. It is not likely that our

results arise because of slow activation of syntactic representation or

because pronominal reference demands greater processing resources.

Only the CPC sentences clearly demand more processing because they

involve a complex structure with two predicates, a main and an em-

bedded one. It is these extra processing demands on top of any syn-

tactic deficit that cause the poor performance on both the match and

mis-match CPC conditions. We argue that the pattern observed in our

data regarding the interpretation of reflexives and pronouns with

quantificational antecedents is another manifestation of the reported

Brain and Language 87 (2003) 21–22

www.elsevier.com/locate/b&l

*Corresponding author. Fax: +11-89-753-365.

E-mail address: s.i.edwards@reading.ac.uk (S. Edwards).

0093-934X/$ – see front matter � 2003 Elsevier Science (USA). All rights reserved.

doi:10.1016/S0093-934X(03)00177-9

deficit that agrammatic individuals have with long-distance syntactic

dependencies, in particular with structures containing moved elements.

Agrammatic subjects have been found to have difficulties in estab-

lishing syntactic dependencies between moved elements and their gaps

(in passives, object clefts, and relatives) and thus in assigning a the-

matic role to the moved element. We propose that the poor perfor-

mance of agrammatic individuals on reflexives and pronouns with a

quantificational antecedent is due to the same difficulty, in particular

failure/inability to link positions via co-indexation. Sentences with

pronouns and referential antecedents, on the other hand, have been

proposed not to involve this kind of syntactic dependency but to fall

within the domain of the pragmatic Rule I. Our account does not

exclude the possibility that individuals with Broca’s aphasia suffer

difficulties in more than one domain of their linguistic abilities and that

the pattern observed in our study is the result of two independent

deficits, one related to the establishment of syntactic dependencies and

the other to processing difficulties of a pragmatic rule regulating

co-reference.

References

Grodzinsky, Y., & Reinhart, T. (1993). The innateness of binding and

coreference: A reply to Grimshaw and Rosen. Linguistic Inquiry,

24, 69–102.

Grodzinsky, Y., Wexler, K., Chien, Y.-C., Marakovitz, S., & Solomon,

J. (1993). The breakdown of binding relations. Brain and Language,

45, 371–395.

Love, T., Nicol, J., Swinney, D., Hickok, G., & Zurif, E. (1998).

The nature of aberrant understanding and processing of pro-forms

by brain-damaged populations. Brain and Language, 65,

59–62.

Varlokosta, S., & Edwards, S. (2003). A preliminary investigation

into binding and coreference in aphasia. Studies in Greek

Linguistics, 23.

Table 1

Distribution of scores for the 10 subjects on the 5 sentence types

Sentence Mis-match correct Match correct

Raw

score

% Raw

score

%

Pronoun 37/60 62 55/60 92

Quantified pronoun 34/60 57 51/60 85

Reflexive 36/60 60 50/60 83

Quantified reflexive 23/60 38 50/60 83

CPC 14/40 35 26/40 65

22 Abstract / Brain and Language 87 (2003) 21–22