Subliminal Priming Effects of Masked Social Hierarchies During a Categorization Task: An Event-Related Brain Potentials Study.

Evidence so far shows that status detection increases attentional resources, especially for high hierarchies. However, little is known about the effects of masked social status cues on cognition. Here, we explore the masked priming effects of social status cues during a categorization task. For this purpose, we use Event-Related brain Potentials (ERP) time-locked to the presentation of two types of artworks (Christian, non-Christian) primed by masked social hierarchies sorted into two types (religious, military), and in two ranks (high, low) each. ERP results indicate early attention effects at N1, showing larger amplitudes for the processing of artworks after high and military ranks. Thereafter, the P3a increased for all artworks primed by religious vs. military figures, indicating a relevant role of task demands at this processing stage. Our results remark the automaticity of hierarchy detection and extend previous findings on the effects of social status cues on complex cognitive processes.

Effects of reader's facial expression on syntactic processing: A brain potential study.

Embodied views of language support that facial sensorimotor information can modulate language comprehension. The aim of this study is to test whether the syntactic processing of simple sentences, as measured with event-related brain potentials (ERP), could be affected by reader's facial expressions. Participants performed a correctness decision task using sentences that could be either correct (50%) or contain a morphosyntactic disagreement (either in gender or number), while making one of four facial expressions: participants either (a) posed no facial expression ("control" condition) (b) brought their eyebrows together, making the ends of two golf tees touch ("frown" condition), (c) held a pencil with their teeth ("smile" condition), or (d) held the pencil using their lips ("non-smile" condition). In all conditions the customary left anterior negativities did not appear. In contrast, an N400-like component emerged, which was larger for the "frown" condition and reduced in the "smile" and "non-smile" conditions. These results can be interpreted as the consequence of either an unconscious emotion induction or an interplay between the motor and the language systems subsequent to the effort needed to hold the facial expression.

A new device to present textured stimuli to touch with simultaneous EEG recording.

The study of touch has recently grown, due mainly to the extensive use of several types of actuators that stimulate several subsystems of touch. There is a widespread interest in applying these mechanisms to the study of the neurophysiological correlates of tactual perception. In this article, we present a new device (the tactile spinning wheel [TSW]) for delivering textured surfaces to the finger pad. The TSW allows one to control several parameters of the stimulation (angular speed, texture, etc.) and, connected to an EEG recording system, makes it possible to study neural electrophysiological events. The device consists of a rotating platform on which the tactile stimuli are fixed, a system that synchronizes stimuli onset with the EEG system, and an electronic interface that controls the platform. We present the technical details of the TSW, its calibration, and some experimental results we have obtained with this device.