Because the RTs are measured only after the sentence is fully presented in the ACE behavioral paradigms, those studies cannot discount the possibility of an epiphenomenal post-comprehension process such as action preparation (instead of a real process of motor-language integration).
N400 and P600 might reflect a second step in lexical, semantic and syntactic information processing, or might, instead, indicate specific linguistic or non-linguistic post-comprehension processes.
fMRI, unfortunately, does not provide the precise temporal resolution necessary to rule out the possibility that such activations reflect a post-comprehension and merely epiphenomenal process, as some researchers have suggested (Mahon and Caramazza 2008).
A range of post-comprehension processes may be relevant here, for example the use of semantic memory in predicting and pre-activating memory circuits of forthcoming words or for building a memory representation for the encountered stimulus (Kutas & Federmeier, 2000).
Still, are the late components reflections of prolonged specifically linguistic processes, in-depth- or re-processing, or would they rather reflect post-comprehension processes (Glenberg & Kaschak, 2002) following completed psycholinguistic information access and context integration?
A different possibility is that comprehension processes terminate early, within 200 ms, and late brain responses reflect post-comprehension processes (Glenberg & Kaschak, 2002) specifically triggered by failure of semantic or syntactic integration of a word or other meaningful stimulus into its context.
But statistical results demonstrate a significant difference between the pre- and post- tests in that the experimental group outperformed the control group in post reading comprehension test.
However, we must acknowledge a limitation of the fMRI technique for distinguishing between immediate and post hoc comprehension processes, both of which may play a role in generating the hemodynamic response to the sentences.
The authors concluded that participants who multitasked on the laptop scored significantly lower in the post-lecture comprehension test than the ones who did not multitask.
A post-lecture comprehension test containing 20 questions to evaluate simple knowledge and a further set of 20 question to evaluate application of knowledge was conducted with the purpose to measure learning.
Our results suggest that ACE is not an epiphenomenal post-sentence comprehension process.
