ABSTRACT
Advances in computer and communications technology have deeply affected the way we communicate. Social media have emerged as a major means of human communication. However, a major limitation in such media is the lack of non-verbal stimuli, which sometimes hinders the understanding of the message, and in particular the associated emotional content. In an effort to compensate for this, people started to use emoticons, which are combinations of keyboard characters that resemble facial expressions, and more recently their evolution: emojis, namely, small colorful images that resemble faces, actions and daily life objects. This paper presents evidence of the effect of emojis on memory retrieval through a functional Magnetic Resonance Imaging (fMRI) study. A total number of fifteen healthy volunteers were recruited for the experiment, during which successive stimuli were presented, containing words with intense emotional content combined with emojis, either with congruent or incongruent emotional content. Volunteers were asked to recall a memory related to the stimulus. The study of the reaction times showed that emotional incongruity among word+emoji combinations led to longer reaction times in memory retrieval compared to congruent combinations. General Linear Model (GLM) and Blind Source Separation (BSS) methods have been tested in assessing the influence of the emojis on the process of memory retrieval. The analysis of the fMRI data showed that emotional incongruity among word+emoji combinations activated the Broca's area (BA44 and BA45) in both hemispheres, the Supplementary Motor Area (SMA) and the inferior prefrontal cortex (BA47), compared to congruent combinations. Furthermore, compared to pseudowords, word+emoji combinations activated the left Broca's area (BA44 and BA45), the amygdala, the right temporal pole (BA48) and several frontal regions including the SMA and the inferior prefrontal cortex.
Subject(s)
Memory, Episodic , Mental Recall/physiology , Symbolism , Adult , Brain/physiology , Brain Mapping/methods , Communication , Comprehension , Emotions , Facial Expression , Female , Healthy Volunteers , Humans , Magnetic Resonance Imaging/methods , Male , Memory/physiology , Motor Cortex/physiology , Nonverbal Communication/psychology , Prefrontal Cortex/physiology , Reading , Temporal Lobe/physiology , Writing , Young AdultABSTRACT
Task switching was examined under predictable and unpredictable circumstances. In the first two experiments (in predictable conditions), the upcoming task was determined by the trial sequence. In unpredictable conditions, this task was signaled by the stimulus. Under speeded conditions, participants had to judge either the parity of a digit or the vowel/consonant nature of a letter. On bivalent trials, a digit and a letter were presented. On univalent trials, a task-relevant character occurred alongside a task-irrelevant character (e.g., "&"). Task-switching costs were found, and response times were generally slower on bivalent than on univalent trials. This crosstalk effect was reduced when a task repetition was expected. In the final experiment, trial predictability was defined according to whether a task precue was presented prior to or concurrently with the trial stimulus. Contrasting patterns of crosstalk effects were obtained and are discussed in terms of exogenous and endogenous factors that affect task switching.
