Event-related Potential Correlates of Negation in a Sentence–Picture Verification Paradigm

Abstract

In a sentence-picture verification paradigm, participants were presented in a rapid-serial-visual-presentation paradigm with affirmative or negative sentences (e.g., "In the front of the tower there is a/no ghost") followed by a matching or mismatching picture. Response latencies and event-related potentials (ERPs) were measured during reading and verification. An enhanced negative shift in the ERPs for the subject noun (i.e., "ghost") in negative, compared to affirmative sentences, was found during reading. We relate this ERP deflection to enhanced processing demands required by the negative particle no. Although this effect suggests a direct impact of negation on language processing, results for picture processing reveal that negation is not immediately integrated into sentence meaning. When the delay of picture presentation was short (250 msec), verification latencies and ERPs evoked by the picture showed a priming effect independent of whether the sentence contained a negation. Unprimed pictures (foreground object not mentioned in the sentence) led to longer latencies and higher N400 amplitudes than primed pictures (foreground object mentioned in the sentence). Main effects of negation showed up only in a late positive-going ERP effect. In contrast, when the delay was long (1500 msec), we observed main effects of truth value and negation in addition to the priming effect already in the N400 time window, that is, negation is fully integrated into sentence meaning only at a later point in the comprehension process. When negation has not yet been integrated, verification decisions appear to be modulated by additional time-consuming reanalysis processes.

Can the meaning of multiple words be integrated unconsciously?

“…As our previous research in this domain has typically shown more robust and larger neural than behavioural effects [5], we speculate that EEG was more sensitive than behaviour in elucidating the underlying integrative (subliminal) language mechanisms because of its continuous high-resolution temporal sampling. Further, it has been shown that it takes time to integrate negation into the meaning representation of sentences and it has been suggested that this might happen just shortly before response preparation [31]. Therefore, EEG might reveal subtle effects which extend beyond the time of the response and cannot be detected by behaviour alone.…”

“…In EEG, incongruent prime-target pairs elicit a larger N400 event-related potential (ERP) component than congruent word pairs [19,[23][24][25][26]. The N400 is a negative ERP deflection around 200-500 ms after the onset of the critical word and is typically associated with automatic semantic and syntactic violations [26][27][28][29][30][31][32]. Although it has been assumed for a long time that such unconscious processes are rather automatic and inflexible, recent studies show they are not [1,33,34].…”

“…To zoom in on these specific effects, two regions of interest (ROI) were defined: a frontal ROI (FCz, FC1, FC2, FC3, FC4, Fz, F1, F2, F3, F4, AFz, AF3, AF4, FPz, see inset figure 2a) and an occipito-parietal ROI (Oz, POz, PO3, PO4, Pz, P1, P2, P3, P4, P5, P6, CPz, CP1, CP2, see inset figure 3a). Both ROIs consisted of 14 electrode channels, which increase the signal-to-noise ratio [31] (see e.g. [19,24,36] for similar electrode selection procedures).…”

Syntactic base positions for adjuncts? Psycholinguistic studies on frame and sentence adverbials

“…In our materials the non-referential frame adverbials contained negated phrases like auf keiner Insel ('on no island') but referential frame adverbials like auf Mallorca ('on Majorca') did not. Processing negation is more costly for the sentence processor (see, e.g., Lüdtke, Friedrich, De Filippis and Kaup, 2008), which presumably led to slower reading times and lower ratings for the sentences with non-referential frame adverbials.…”

The pragmatics of descriptive and metalinguistic negation: experimental data from French

“…This doesn't seem to be the case for the beautiful/ugly pair of antonyms. the corresponding POS representation of the utterance (Lüdtke et al 2008). This means thatPOSisintheconversationalrecord.ForMoeschler,thecognitiveeffectofDNisthe suppression of POS from the conversational record.…”