Social approach and avoidance in language: N400-like ERP negativity indexes congruency and theta rhythms the conflict.

Motivational congruency has been examined using tasks where participants perform approach or avoidance movements towards socially positive or negative faces. Language is tightly intertwined with interpersonal cognition. Thus, similar situations could be represented by means of language in interpersonal contexts: adjectives furnish valence to people (e.g. someone is cordial or arrogant), and attitudinal verbs define direction to relationship-actions: approach-avoidance (e.g. accept vs. reject). In an Electroencephalography (EEG) study, 40 participants were presented with sentences where a character was valenced (e.g. "Arthur is cordial/arrogant") before being the target of a relationship-actions ("Grisela welcomed/ignored Arthur at the party"). We analyzed both Event-related potential (ERP) amplitude and time-frequency power in response to the attitudinal verb. For ERP amplitudes, we found a significant cluster between 280 and 370 ms, covering part of the development of a N400-like ERP component. This cluster reflects an interaction driven by congruency between motivational direction and target valence. Likewise, time-frequency power analysis revealed an enhancement of theta rhythms under incongruent conditions, most likely indexing conflict processing. Results support that relationship-actions are represented as approach and avoidance and thus involve conflict processing and resolution of incongruent situations. Implications for the interweaving of affective language and social cognition within Embodiment Simulation Theory are discussed.

Negation interacts with motivational direction in understanding action sentences.

Linguistic negation acts by inhibiting the representation of information under its scope, often leading to the representation of positive alternative states of affairs. Motivational direction refers to approach/avoidance intentionality in our interactions with environmental stimuli expressed by means of verbs (e.g., "accept" vs "reject"). We consider it plausible that negation interacts with direction to represent the true motivation of the protagonist in sentence understanding (e.g., if an approach action is negated it is represented as avoidance). In the first study, we examine this interaction offline by asking participants to judge approach or avoidance meaning of affirmative (e.g., "he/she included/excluded meat") and negative sentences ("he/she did not include/exclude meat"). Results support that negation reversed participants' interpretation of sentence motivational direction. In a further study, we carried out two probe recognition experiments to examine the interaction during sentence comprehension; in both, the critical probe was the word referring to the target of the action (e.g., "meat"). In the first experiment, participants had to recognize the probe word presented 1500 milliseconds after sentence offset, while for the second one, the delay was 500 milliseconds. Results showed that at 1500 ms, target recognition took significantly more time for negated avoidance sentences than for the other conditions. Therefore, representing negated avoidance sentences seems to imply more complex processing, as avoidance verbs would be implicitly negative. By contrast, at the 500 ms delay, negation impaired target recognition for both approach and avoidance sentences, suggesting an unspecific inhibitory effect of negation at that sentence processing stage. Implication of these results for both research on negation and in action understanding are discussed.

Enhancing Memory for Relationship Actions by Transcranial Direct Current Stimulation of the Superior Temporal Sulcus.

We examine the effect of transcranial direct current stimulation (tDCS) of right superior temporal sulcus (rSTS) in memorization of approach/avoidance relationship-action sentences; for example, "Alejandro accepted/rejected Marta in his group." Sixty-five university students participated in a tDCS study, in which a between-subjects design was adopted. Sixty-four participants were also given the behavioral approach system (BAS) and behavioral inhibition system (BIS) scales. Participants were subjected to 20 min of stimulation: anodal (N = 24), cathodal (N = 21), or sham (N = 20); subsequently, they were given a list of 40 sentences (half approach and half avoidance) and told to try to memorize them. Finally, they performed a changed/same memory task (half the sentences were the "same" and half were "changed"). Previously, we had examined performance in the memory task without tDCS with another group of participants (N = 20). We found that anodal stimulation improved d' index of discriminability (hits-false alarms) compared to sham and cathodal conditions for both approach and avoidance sentences. Moreover, the comparison between anodal and task-alone performance showed that stimulation improved d' index of approach sentences more, as task-alone performance showed better discrimination for avoidance than for approach. Likewise, we explored a potential modulation of tDCS effect by (BAS) and (BIS) traits. We found that d' index improvement in anodal stimulation condition only benefited low BAS and low BIS participants. Implications of these results are discussed in the context of rSTS function in encoding and memorizing verbally described intentional relationship-actions and the role of individual differences on modulating tDCS effect.