2.1 Participants
Thirty right-handed Chinese (L1)-English (L2) bilingual university
students with normal or corrected-to-normal vision were recruited in the
experiment. All participants were born in China and had no immigration
or study abroad experience. On average, the participants began learning
English in traditional classroom settings at the age of 8.40 years
(SD = 2.18, range: 6-13). No participant reported neurological,
cognitive, or motor impairments. Research ethics approval was obtained
from the Committee of Protection of Participants at Beijing Normal
University and all participants provided written informed consent before
beginning the experiment. One participant was excluded because of
excessive EEG artifacts. The final sample consisted of 29 participants
(10 males, 19 females, mean age: 22.66, range: 19-27).
To gather information about the participants’ language proficiency, we
administered the Oxford Quick Placement test (OPT; Geranpayeh, 2003) and
asked participants to provide self-ratings of their language abilities
on a 6-point scale (1 = no knowledge; 6 = perfect knowledge) (Liu et
al., 2021; Liu et al., 2023a; 2023b). The mean score from the OPT was
36.63 (SD = 5.52), which falls within the A2 level of the Common
European Framework of Reference. The average self-ratings of L1
proficiency were: listening (M = 5.62, SD = .49), speaking
(M = 5.17, SD = .54), reading (M = 4.59, SD = .78), and writing (M = 5.1, SD = .77). For L2
proficiency, the self-ratings were: listening (M = 3.62,SD = 1.05), speaking (M = 3.45, SD = .74), reading
(M = 3.03, SD = .98), and writing (M = 3.31,SD = 1.2). Paired-sample t -tests revealed that the
participants’ L1 was significantly stronger than L2 in all four domains:
listening (t = 10.41, p < .001), speaking
(t = 11.65, p < .001), reading (t = 8.81,p < .001), and writing (t = 7.81, p < .001). These self-ratings and OPT scores are similar to
those reported on intermediate Chinese-English bilinguals in prior
research (Kang et al., 2017; Liu et al., 2016; Liu et al., 2021; Liu et
al., 2023b; Yuan et al., 2021; Wu et al., 2019), suggesting unequal
proficiency between their two languages.