Syntactic Distance

In language production, the syntactic distance between distractor and controller affects the incidence of attraction errors (cf. chapter 3 and references there). The error rate is the higher the closer the distractor is to the controller. Nicol et al.

(1997) found comparable results for language comprehension whereas (Kaan, 2002) found no distance effect for attraction. Pearlmutter (2000) found a distance effect for singular attraction but not for plural attraction. Part of the discrepancy

7In alphabetic languages, readers can typically extract information 12-15 characters to the right of the current fixation (McConkie and Rayner, 1975; Rayner, 1975; Rayner et al., 1982).

across studies can be explained in terms of distractor type: Nicol et al. (1997) and Pearlmutter (2000) examined modifier attraction whereas (Kaan, 2002) inves-tigated object attraction. The difference between the results of Nicol et al. (1997) and Pearlmutter (2000) might have to do with the different tasks used in the two studies, though more research is needed to clarify this issue.

Nicol et al. (1997) used a sentence classification task. The stimulus sentences had a complex subject containing a PP-modifier and a relative clause (cf. (4)).

(4) a. The owner of [the house [who charmed the REALTOR(S)]] was no longer willing to sell.

b. The owner of [the house [which charmed the REALTOR(S)]] was no longer willing to sell.

The relative clause either modified the complex NP preceding it (the owner of the house) (high attachment) or the NP inside the PP (the house) (low attachment).

The head nouns of the two construals—owner and house—varied with respect to animacy. Since the relative pronoun was compatible with either an animate antecedent (who) or an inanimate antecedent (which), it signaled the intended at-tachment site.

The linear distance between the controller and the distractor as well as the linear distance between distractor and verb is the same in (4a) and (4b); the syn-tactic distance, however, differs: High attachment brings the distractor closer to the controller than low attachment.⁸ For high attachments like (4a), Nicol et al.

(1997) found a disadvantage of the mismatch condition visible in an increase of the error rate (6.8% vs. 5.6%) and a slowdown in response times (2562 ms vs.

2495 ms). For low attachments like (4b), mismatch and match conditions did not differ (error rates of 6.0% vs. 5.8%; response times of 2536 ms vs. 2585 ms).

Pearlmutter (2000) found a somewhat less conclusive pattern. Using a self-paced reading procedure, Pearlmutter tested complex subject phrases with stacked PP-modifiers as exemplified in in (5) and (6).

(5) a. The lamp [near the painting [of the house]] was damaged in the flood.

b. The lamp [near the PAINTINGS [of the house]] was damaged in the flood.

c. The lamp [near the painting [of the HOUSES]] was damaged in the flood.

d. The lamp [near thePAINTINGS[of theHOUSES]] was damaged in the flood.

8The details of this distance difference depend on the exact analysis of NPs and DPs respec-tively, and on the analysis of adjunction. Note further, that the distance to the head noun might not be the crucial measure but rather the distance to the maximal projection of the entire NP. High attachment, however, decreases the distance also under this perspective.

(6) a. The lamps [near the paintings [of the houses]] were damaged in the flood.

b. The lamps [near thePAINTING [of the houses]] were damaged in the flood.

c. The lamps [near the paintings [of the HOUSE]] were damaged in the flood.

d. The lamps [near thePAINTING [of theHOUSE]] were damaged in the flood.

As indicated by capitalization, N2 and N3 varied in their number specifications:

N2 or N3 or both or none of them mismatched N1 number. Pearlmutter’s first experiment investigated sentences like (5) with a singular subject. Reading times in the verb region were enhanced whenever the subject contained a plural NP.

The increase was identical for sentences with plural N2 and sentences with plural N3. Having both modifiers specified for plural did not increase the processing difficulty any further. Numerically, the attraction penalty was even smaller in sentences with two plural modifiers. Statistically, however, the three conditions with a plural modifier did not differ from each other but differed from the faster match condition. In summary, the experiment shows a distance independent and non-additive attraction effect.

Pearlmutter’s second experiment attested attraction in sentences like (6) with a plural subject. This is an interesting finding in itself since production studies found virtually no attraction for plural subjects in English. In contrast to plural attraction examined in the first experiment, singular attraction was distance depen-dent. When N2 was singular as in (6b) and (6d), reading times in the verb region were longer than in the match condition (6a). The number specification of N3, in contrast, did not affect reading times. Furthermore, the attraction penalty was reduced in comparison to the first experiment. Pearlmutter attributes the reduced attraction effect in the second experiment to the markedness of plural which makes a plural head noun less prone to interference. This asymmetry in susceptibility to attraction corresponds to the asymmetry found in language production where at-traction occurs almost exclusively with singular subjects. An obvious question is then why plural subjects are vulnerable to attraction in the first place. Pearlmutter concludes that intervening material weakens the subject’s number marking. He argues further that the strength of the number marking is determined by some complexity metric. The exact nature of that metric as well as potential differences between language production and comprehension are left to future research. The distance effect found in the second experiment is argued to be a joint effect of the markedness of plural and the hierarchical nature of the feature tracking mech-anism. The plural marking of the head noun is relatively strong and N3 is too deeply embedded and therefore too weak to produce noticeable interference. This

argumentation is pretty much in the spirit of the Marking and Morphing Model (Bock et al., 2001; Eberhard et al., 2005), but it leaves open why attraction was distance independent in the first experiment. Implicitly, Pearlmutter seems to at-tribute the discrepancy to a kind of ceiling effect.⁹ The higher susceptibility to interference makes singular subjects vulnerable to attraction even from the deeper embedded N3.

Finally, investigating object attraction in Dutch sentence comprehension, Kaan (2002) found distance effects in her judgment data but not in the ERP data which were obtained in parallel. Participants produced more judgment errors when sub-ject and verb were separated by two phrases as in (7a) compared to (7b). The ERP waveforms, in contrast, showed no effect of subject–verb distance.

(7) a. Hoewel

‘Although according to the rumor the emperor will go ban the dissident there is a lot of opposition.’

Kaan interprets the distance effect in judgment accuracy as evidence for a lin-ear slot model in combination with decay. The number properties of the subject NP are stored in a linear slot in working memory and their activation level decays over time. The longer distance between subject and verb is the more the activation level decreases and the higher is the probability of overlooking an agreement vio-lation and, respectively, of detecting an apparent agreement viovio-lation. Under the assumption of an asymmetric number representation, the distance effect should occur only in sentences with a plural subject. Although Kaan does not report a Number×Distance interaction, the error rates seem to confirm this expectation.

Note that the preceding discussion referred to the subject–verb distance. Although this distance manipulation also affected the distractor–controller distance, the in-cidence of attraction, on the other hand, was distance independent. But note that the distance manipulation in (7) affects linear distance while the syntactic distance increases only slightly at least under the assumption that (7a) and (7b) differ with respect to the attachment site of the PP. Alternatively, one could assume that the difference results from movement of the subject NP. In this case, one would have

9A ceiling effect is explicitly taken into account for the non-additive nature of attraction in this experiment (cf. Pearlmutter, 2000: 94).

to explain what triggers the movement in (7a) and blocks it in (7b). To what ex-tent movement would affect the syntactic subject–verb distance depends on the particular landing site of such a movement operation.