Eye Movements in Reading Syntactically Ambiguous Sentences in Russian Language Victor N. Anisimov, Anna S. Jondot, Olga V. Fedorova, Alexander V. Latanov M.V. Lomonosov State University, Moscow Moscow, 2015

30 min recording, sampling rate of 8 fps First study of eye movements in reading syntactically ambiguous sentences fixation

Syntactic ambiguity in English (a) They gave her dog candies (b) They gave her dog candies They told her cat stories They told her cat stories Two interpretations of the sentence: Number of fixations normalized for 10 participants and reading every sentence with definite interpretation - (a) or (b).

Syntactic ambiguity in English dog candies (b) Number of fixation Number of fixations normalized for 10 participants in reading every sentence with definite interpretation - (a) or (b). Number of fixation her dog (a)

The criminal shot the servant of the actress who was on the balcony the servantthe actress early closure late closure Who was on the balcony? Syntactic ambiguity (early/late closure) ? dominates in Englishdominates in Russian

A priory interpretation complexity during reading structurally (syntactically) ambi- guous sentences slows reading in comparison with reading sentences without any syntactic ambiguity.

Method Monitor for stimuli presentation IR - mirror IR - light Hight-speed digital camera

Top view 45 deg. Eye image, reflected from IR mirror, is projected to camera matrix Eye Monitor IR mirrors

29 subjects, years old; 20 sentences Global (G) and Control (C); originally developed eye tracker based on fast digital camera FV300; sampling rate of 250 fps; matrix resolution 640х480 pixels; angular size of the monitor for text presentation 47 deg.; average angular size of the character 0,6 deg. Method (1 st part)

Example of reading sentence with ambiguity regression 1 s 2 nd str 3 id str 1 st str

Example of stimuli (overall 40)

Eye movements parameters in reading 2 nd string (test and control). Data averaged over all sentences and 30 subjects. Spread presented by standard error of mean, sample size in parenthesis). ParameterGlobal (G)Control (C) Significant level, р Reading time (ms) 1393±20 (1169) 1195±14 (1169) <0,00001 Number of fixations (in one string) 5,29±0,05 (1169) 4,72±0,04 (1169) <0,00001 Regression frequency (in one string) 0,662±0,029 (1169) 0,336±0,019 (1169) <0,00001 Fixation duration (ms) 207±1 (5964) 200±1 (5326) <0,00001 Results. 1 st experiment. Anisimov et. al., 2014

Parameters of eye movements in reading 2 nd string in G and C

Regressive saccades Comparison of regressive saccades in 1 st and 2 nd strings in reading sentence with global ambiguity and control F2(G1/G2)=47,61; p<0,01, n=16 F2(G1/C1)=0,80; p<0,37, n=16 F2(G2/C2)=62,9; p<0,01, n=16 p<0,01 Number of regressive saccades 1 st string2 nd string G1 C1 G2 C2

Types of ambiguity G – global LE – local, early closure LL – local, late closure C – control

Gardener met daughter of the cook who went to school. Садовник встретил дочку кухарки, которая пошла в школу. Girl caught snowflake that melt on the palm. Девочка поймала снежинку, которая растаяла на руке. Sentences with and without ambiguity

Types of syntactic ambiguity

· 31 subjects, years old; · 12 sentences LE, LL, G and C; · originally developed eye tracker based on fast digital camera FV300; · sampling rate of 250 Hz; · matrix resolution 640х480 pixels; · angular size of the monitor for text presentation 47 deg.; · average angular size of the character 0,6 deg. Method (2 nd part)

Example of reading sentence with ambiguity

Results. 2 nd experiment. Eye movement parameters (M±SEM, sample size in parentheses) averaged over all subjects in reading LE, LL, G and С.

In reading LL subjects demonstrate more fixations than in reading LE. Significant differences revealed by Student t-test criterion. Number of fixations in reading sentences with local ambiguity.

In reading LL regression frequency significantly higher than in reading G. Number of fixations is quasi significantly higher than in reading G. Significant differences revealed by Student t-test criterion. Regression frequency in reading sentences with ambiguity.

1.Syntactic ambiguity leads to slowing reading because of language processing complication. 2.LL is more complicated in terms of syntactic interpretation than LE. 3.Higher regression frequency and greater number of fixations in reading LL in comparison with reading G indicate that interpretation of LL is more complicated than interpretation of G. 4.Disambiguation of G in Russian (as well as in English) apparently doesn't provoke additional complexity of syntactic analysis and its interpretation is predetermined by domination of early closure (high attachment) principle in Russian to a considerable extent. The absence of any significant differences between eye movement parameters in reading G and LE proves this point.

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