Distinguishing between different syntactic roles of identical words in normal reading: an ERP study Lakretz Yair (yair.lakretz@post.tau.ac.il) Tel-Aviv University 69978, Tel-Aviv, Israel Marjanovic Katarina (kmarjano@sissa.it) SISSA, Via Bonomea 265 34136 Trieste, Italy Gu YuQiao (yuqiaogu@sissa.it ) SISSA, Via Bonomea 265 34136 Trieste, Italy Treves Alessandro (ale@sissa.it ) SISSA, Via Bonomea 265 34136 Trieste, Italy Abstract Separating between semantic and syntactic aspects of language processing in the brain is a difficult task. In an attempt to dis- tinguish between the two, many studies so far have measured responses to semantic or syntactic violations in reading com- prehension tasks. However, this methodology may be inac- curate in describing semantic and syntactic processing during normal reading. In this study, we use a novel task, measuring responses to identical target words as they assume different syntactic roles. All sentences presented in the task are syntac- tically correct sentences without lexical-semantic anomalies. We present results from a behavioral experiment, testing the validity of the experimental design, and results from a pilot ERP study, measuring brain responses to the difference in the syntactic role of the target words. We conclude that the pro- posed design is valid and may be used to shed light on seman- tic and syntactic processing during language comprehension, in normal reading. Keywords: Language comprehension; syntactic violation; ERPs; normal reading task; noun-plus-noun constructions. Introduction Semantic and syntactic aspects of language processing are as- sociated with characteristic electrophysiological responses to language stimuli. For example, many studies have shown that the N400 component systematically correlates with lexical- semantic aspects of language processing, and is concluded to reflect lexical-integration processing, e.g. (Kutas & Hillyard, 1980, 1984). Other studies have shown that the syntactic as- pect of language processing correlates with the P600 compo- nent, e.g. (Friederici, Pfeifer, & Hahne, 1993) - See related literature section. Many of these studies use reading comprehension tasks, in- volving stimuli of sentences which contain either a semantic or syntactic violation. The type of violation is used to reveal the syntactic or semantic process in question. However, this methodology offers no insight into how these types of pro- cessing are distinguished in normal reading, that is, without violating the syntactic rules or semantic expectations. In this study, we present a novel task for event-related po- tentials (ERP) studies which enables distinguishing between semantic and syntactic aspects of language processing in nor- mal reading. In the experimental design, participants are pre- sented with target words which differ by their syntactic role but have similar semantic content, and are otherwise (e.g. orthographically) identical. For this, we make use of noun- plus-noun constructions in English, in which the first noun preserves its meaning while changing its position on the syn- tactic tree, moving from the position of the specifier of a head in a noun phrase (NP), to the head of the NP in a simple sen- tence without such construction. For example, compare be- tween the word ’family’ in ’It’s a family discount’ to the same word in ’It’s a family from Sweden’. We conducted two experiments, a behavioral and an ERP experiment. The behavioral experiment was designed to test the validity of the novel task described below, and it is also used to select pertinent stimuli for the task. We then con- ducted an ERP pilot study using the task and the stimuli which were selected according to the behavioral experiment. We present here qualitative results from this pilot study. Related literature ERP signatures of semantic and syntactic aspects of language processing In order to study the first language (L1) syntactic aspect of language processing, many ERP studies adopted violation paradigms where non-grammatical sentences are compared with correct sentences, which are otherwise similar to the violation stimuli. These studies assume that when all other linguistic variables are held constant, the brain response to the target stimulus, compared to the control stimulus, re- flects processes which are related to the grammatical rule in question. The major ERP signatures reported in L1 sentence processing are (for a recent review see (Caffarra, Molinaro, 611