
2 Related Work
Multilingual eye-tracking
Brysbaert (2019)
found differences in word per minute rates during
reading across different languages and proficiency
levels. That eye-tracking data contains language-
specific information is also concluded by Berzak
et al. (2017), who showed that eye-tracking fea-
tures can be used to determine a reader’s native
language based on English text.
Individual differences
The neglection of indi-
vidual differences is a well-known issue in cogni-
tive science, which leads to theories that support
a misleading picture of an idealised human cog-
nition that is largely invariant across individuals
(Levinson,2012). Kidd et al. (2018) pointed out
that the extent to which human sentence processing
is affected by individual differences is most likely
underestimated since psycholinguistic experiments
almost exclusively focus on a homogeneous sub-
sample of the human population (Henrich et al.,
2010).
Along the same lines, when using cognitive sig-
nals in NLP, most often the data is aggregated
across all participants (Hollenstein et al.,2020;
Klerke and Plank,2019). While there is some evi-
dence showing that this leads to more robust results
regarding model performance, it also disregards
differences between subgroups of readers.
Eye-tracking prediction and correlation in
NLP
State-of-the-art word embeddings are
highly correlated with eye-tracking metrics (Hol-
lenstein et al.,2019;Salicchi et al.,2021). Hollen-
stein et al. (2021) showed that multilingual mod-
els can predict a range of eye-tracking features
across different languages. This implies that Trans-
former language models are able to extract cogni-
tive processing information from human signals
in a supervised way. Moreover, relative impor-
tance metrics in neural language models correlate
strongly with human attention, i.e., fixation dura-
tions extracted from eye-tracking recordings during
reading (Morger et al.,2022;Eberle et al.,2022;
Bensemann et al.,2022;Hollenstein and Beinborn,
2021;Sood et al.,2020).
3 Method
We analyse the Spearman correlation coefficients
between first layer attention in a multilingual lan-
guage model and relative fixation durations ex-
tracted from a large multilingual eye-tracking cor-
pus, including 13 languages (Siegelman et al.,
2022;Kuperman et al.,2022) as described below.
Total fixation time (TRT) per word is divided by
the sum over all TRTs in the respective sentence
to compute relative fixation duration for individual
participants, similar to Hollenstein and Beinborn
(2021).
We extract first layer attention for each word
from mBERT
1
, XLM-R
2
and mT5
3
, all three are
multilingual pre-trained language models. We then
average across heads. We also test gradient-based
saliency and attention flow, which show similar
correlations but require substantially higher com-
putational cost. This is in line with findings in
Morger et al. (2022).
Eye-tracking Data
The L1 part of the MECO
corpus contains data from native speakers read-
ing 12 short encyclopedic-style texts (89-120 sen-
tences) in their own languages
4
(parallel texts and
similar texts of the same topics in all languages),
while the L2 part contains data from the same
participants of different native languages reading
12 English texts (91 sentences, also encyclopedic-
style). For each part, the complete texts were
shown on multiple line on a single screen and
the participants read naturally without any time
limit. Furthermore, language-specific LexTALE
tests have been carried out for several languages in
the L1 experiments and the English version for all
participants in the L2 experiment. LexTALE is a
fast and efficient test of vocabulary knowledge for
medium to highly proficient speakers (Lemhöfer
and Broersma,2012).
For comparison, we also run the experiments on
the GECO corpus (Cop et al.,2017), which con-
tains eye-tracking data from English and Dutch na-
tive speakers reading an entire novel in their native
language (L1, 4921/4285 sentences, respectively),
as well as a part where the Dutch speakers read
English text (L2, 4521 sentences). The text was
presented on the screen in paragraphs for natural
unpaced reading.
1https://huggingface.co/
bert-base-multilingual-cased
2https://huggingface.co/
xlm-roberta-base
3https://huggingface.co/google/
mt5-base
4
The languages in MECO L1 include: Dutch (nl), English
(en), Estonian (et), Finnish (fi), German (de), Greek (el), He-
brew (he), Italian (it), Korean (ko), Norwegian (no), Russian
(ru), Spanish (es) and Turkish (tr).