Cognitive-load residual is found in Chinese EFL readers’ word comprehension

Although brain functions surrounding the prefrontal cortex (PFC) has been widely acknowledged as a signature of the instant cognitive load (CL) induced by task demands, inconsistent results of the existing studies imply that the hemodynamic changes in the PFC may not serve as a stable direct indicator of second-language (L2) readers’ instant CL. This study employed 61 Chinese university students to comprehend the identical English words in three different groups to reveal the nature of CL. By observing both the PFC-centred brain functions and the comprehension performance of the participants in the three groups, the following conclusions were reached: 1) The PFC can serve only as an individualised signature of the instant CL that afforded by L2 readers; 2) The unsteadiness of the instant CL is due to residual load carried over from previous tasks; and 3) The residual CL cannot be linearly modelled.