The roles of topicalization, parallel function and verb semantics in the interpretation of pronouns

Three experiments examined the interactive effects of implicit causality, parallel function and/or topicalization in pronoun comprehension. In all three experiments subjects saw sentences containing a pronoun and the names of two people. Subjects were required to name the item preferential with the pronoun. Reaction times and pronoun assignments were recorded. The sentences employed were originally of the format, John scolded Bill because he was annoying/annoyed. Experiment Ipreposed the subordinate clause. This manipulation did not result in a complete attenuation of the effect of implicit causality as a determinant of pronoun assignment. Experiment II retained the main clause in its initial position but in the passive voice. Subjects' responses indicated a significant preference for assigning the pronoun coreferential with the grammatical subject. Experiment HI combined the manipulations of Experiments I and II. Results paralleled those of Experiment II. Findings from the three experiments suggest that parallel function does not attenuate semantic criteria such as implicit causality. Rather, topicalization appears to be an influence capable of counteracting opposing semantic forces. Sentence comprehension requires the integration of surface structure information. This requirement is exemplified by the interpretation of those anaphoric relations which call for an antecedent in the linguistic structure of the sentence. One class of such anaphoric processes that has received some attention in the psychological literature is pronoun comprehension (Caramazza, Grober, Garvey and Yates, 1977; Grober, Beardsley and Caramazza, 1978; Maratsos, 1973; Springston, Note 1). The major finding of these studies has been that semantic factors such as the Experiencer Constraint (Springston, 1975) and Implicit Causality (Caramazza, et al., 1977) often play what Springston terms a 'directive' Linguistics 17 (1979), 497-518. © Mouton Publishers. 498 Alfonso Caramazza and Shalini Gupta role in pronoun comprehension. In other words, the semantic properties of certain classes of verbs ensure the pronominalization of a particular noun phrase (NP) in a sentence even though surface constraints alone permit other candidate noun phrases. These findings suggest that the role of semantic analysis must be included in any model of pronoun resolution. Although syntactic constraints may suffice to restrict the set of permissible antecedents, the problem of choosing among this set of entities often requires nonsyntactic processes. For instance, the syntactically derived Precede-Command-Rule (Langacker, 1969; Ross, 1969) states that an anaphoric pronoun may only precede its antecedent if it is in a sentence subordinate to (commanded by) the sentence containing the antecedent; the Rule can be considered to function merely as an 'interpretation filter' (Hankamer and Sag, 1976), specifying as ungrammatical any interpretation that violates this surface structure constraint. However, the Precede-Command-Rule by itself is insufficient to capture the whole range of anaphoric phenomena. Consider the following sentences: (1) Sanij lied to Henry2 because hcj could not reveal the truth. (2) Sanij scolded Henry2 because he2 was annoying. In these sentences the main clauses both precede and command the subordinate clauses. Thus by the Precede-Command-Rule Sam and Henry are structurally acceptable referents of the pronoun in both sentences. However, the fact that Sam (NPX) is the plausible referent in sentence (1) while Henry (NP2) is the plausible referent in sentence (2) requires the consideration of semantic factors in determining pronoun assignments. Garvey and Caramazza (1974) have suggested that when sentences describe causal relationships, pronoun assignment is largely influenced by implicit causality, a property of the main verb. For instance in sentence fragments of the form NPl past V NP2 because Pro. where the only varying information is the verb, and the causal connective because is the fixed variable, the causal agent suggested by the main verb usually serves as the antecedent for the following anaphoric expression. Garvey, Caramazza and Yates (1976) found that under these conditions, completions provided by subjects to such sentence fragments were not random. Rather, some verbs consistently led to completions favoring NPt as the pronoun antecedent whereas others consistently led to completions favoring NP2 as the pronoun antecedent. Other verbs did not strongly constrain assignments in one direction or the other. These empirically derived ratings provide support for the biasing influence of implicit causality in sentence production, especially since the combination of the verb and causal connective does not necessarily preclude the alternate noun phrase (see sentences (3) and (4)) from serving as the referent, for example: Interpretation of pronouns 499 (3) Sanij lied to Henry2 because he2 would not understand the truth. (4) Sanij scolded Henry2 because het was annoyed. Caramazza et al. (1977) have examined the role of implicit causality in pronoun comprehension. If the semantics of the main verb enter the comprehension process then implicit causality should interact with the information contained in the subordinate clause making sentence types (3) and (4) more difficult to comprehend (as measured by reaction time) than sentence types (1) and (2) respectively. Data reported by Caramazza et al. was found to be consistent with this hypothesis, i.e. subjects were significantly faster at correctly naming the referent of a pronoun when sentences contained subordinate clauses consistent with the main verb's empirically determined bias compared to sentences in which the subordinate clauses contained information inconsistent with the main verb's empirically determined bias. The strength of this implicit causality feature carried over into control sentence where gender cues ought to have been sufficient to lead to rapid pronoun interpretation, i.e. subjects took longer to name the referent in sentences such as (6) than in sentences such as (5): (5) Artj confided in Nancy2 because hQ1 was frightened. (6) Maryx confided in Bernard2 because he2 was understanding. A different mechanism for attributing coreferentiality may arise from the adoption of a parallel function strategy (Sheldon, 1974). Such a strategy simply dictates that a noun phrase having the same grammatical function as the pronoun will be chosen as the preferred referent. Grober et al. (1978) have proposed that parallel function (PF) is employed when the semantic content of a sentence does not lead to an unambiguous assignment of pronouns. Parallel function as a factor influencing pronoun comprehension is closely related to the factor of role-inertia which is a semantically based strategy of matching agent-agent and object-object relations (Maratsos, 1973). Weber (1978) has listed a host of other devices for resolving anaphoric expressions and she has pointed out that very little has been done to demonstrate how these factors might interact in anaphor processing. For instance, the experiments cited above have studied pronoun comprehension primarily in active sentences. Secondly, they were limited to the extent that they were only concerned with the phenomenon of forward pronominalization. It is possible that the influences of implicit causality, parallel function, and role-inertia are sensitive to the surface position of the anaphor in relation to its referent. One strategy for assessing how these factors interact is to subject a specific sentence construction to a number of structural changes without altering the intrinsic semantic relationships, e.g. proposing the subordinate clause, or transforming the main clause into the passive voice. 500 Alfonso Caramazza and Shalini Gupta The study by Caramazza et al. (1977) indirectly showed that parallel function and role-inertia did not play a significant role in forward pronominalization. Rather, it was the semantic force of the main verb that strongly biased pronoun assignment. However, the strength of the implicit causality effect in backward pronominalization remains to be tested. According to the Precede-Command-Rule preposing the subordinate clauses in sentences (l)-(6) would result in grammatically acceptable backward pronominalization. The question of interest is whether such a clause movement allows the implicit causality effect of the verb in the main clause to play a directive role. Grober et al (1978) predicted that in backward pronominalization the directive influence of implicit causality would be blocked by the adoption of a parallel function strategy, although the reasons why this should happen were not explicitly stated. Presumably, the initially-appearing subordinate clause does not provide an adequate semantic context for pronoun comprehension. In such cases the listener is compelled to use syntactically based devices such as grammatical role matching. This analysis assumes that the semantic cues provided by the verb in the later-appearing main clause are insufficient (or appear too late) to impede the adoption of a PF strategy. Furthermore, parallel function and role-inertia need not always be compatible with each other. Conversion from the active voice to the passive voice leads to a reversal of grammatical function of the logical agent and the logical object. If, as Maratsos (1973) suggests, adults try to match logical relations within a sentence (in the absence of stress cues), then their performance on passive sentences should be no different from their performance on the corresponding active sentences since the same logical relations are preserved in the two types of surface structures. However, if parallel function is a 'last resort' syntactic strategy for interpreting potentially ambiguous pronouns, then passivization should lead to very different decisions about coreferential relations because of the changes in grammati