Changes in food cue reactivity through affective and nonaffective touch: An event-related potential study.

Affective touch (gentle/slow brushing of the skin) can facilitate the allocation of processing resources to simultaneously present stimuli from different modalities. The present event-related potential (ERP) study investigated whether affective touch can enhance attention to visual cues of healthy food. Female participants (n = 117) were randomly assigned to three different groups that either received affective touch, nonaffective touch (fast brushing of the skin), or no touch during the presentation of pictures of healthy food (fruits and vegetables) and non-food. Electrocortical markers of motivated attention (frontal/parietal P300, late positive potential: LPP) and reported appetite for the depicted food items were compared between the three groups. Nonaffective touch was associated with reduced amplitudes of the frontal P300/LPP (300-1000 ms) for food pictures indexing reduced motivated attention. Affective touch did not influence food cue reactivity (P300/LPP, appetite). Effects of affective touch may be restricted to specific stimuli, e.g. those with social relevance.

Affective touch during the processing of angry facial expressions: an event-related potential study.

It has been shown that affective touch can have stress-buffering effects. The current event-related potential (ERP) study investigated whether affective touch can reduce emotional distress and associated late positivity while viewing angry facial expressions. A total of 122 females (mean age = 23 years) were randomly assigned to one of three groups to either receive slow/soft brushing of their forearm (affective touch), fast brushing (nonaffective touch), or no touch while viewing images depicting angry and neutral facial expressions. The participants rated their affective state (valence, arousal) before and after the experiment. They also rated the perceived intensity of the angry facial expressions and the pleasantness of touch during the experiment. Components of the Late Positive Potential (LPP) in response to the images that are associated with stimulus significance, attention allocation, and emotion regulation (early LPP: 400-1000 ms; late LPP: 1000-3000 ms) were extracted for a frontal and a centroparietal cluster. Affective touch was associated with reduced amplitudes of the late LPP in the frontal cluster but did not affect centroparietal LPPs (early, late). Affective touch was rated as more pleasant than nonaffective touch but did not change reported valence, arousal, and perceived anger intensity. In conclusion, affective touch modulated a neural indicator of stimulus significance but did not influence self-report measures. More naturalistic touch settings might enhance the effects.

Oscillatory electroencephalographic patterns of arithmetic problem solving in fourth graders.

Numerous studies have identified neurophysiological correlates of performing arithmetic in adults. For example, oscillatory electroencephalographic (EEG) patterns associated with retrieval and procedural strategies are well established. Whereas fact retrieval has been linked to enhanced left-hemispheric theta ERS (event-related synchronization), procedural strategies are accompanied by increased bilateral alpha ERD (event-related desynchronization). It is currently not clear if these findings generalize to children. Our study is the first to investigate oscillatory EEG activity related to strategy use and arithmetic operations in children. We assessed ERD/ERS correlates of 31 children in fourth grade (aged between nine and ten years) during arithmetic problem solving. We presented multiplication and subtraction problems, which children solved with fact retrieval or a procedure. We analyzed these four problem categories (retrieved multiplications, retrieved subtractions, procedural multiplications, and procedural subtractions) in our study. In summary, we found similar strategy-related patterns to those reported in previous studies with adults. That is, retrieval problems elicited stronger left-hemispheric theta ERS and weaker alpha ERD as compared to procedural problems. Interestingly, we observed neurophysiological differences between multiplications and subtractions within retrieval problems. Although there were no response time or accuracy differences, retrieved multiplications were accompanied by larger theta ERS than retrieved subtractions. This finding could indicate that retrieval of multiplication and subtraction facts are distinct processes, and/or that multiplications are more frequently retrieved than subtractions in this age group.