Ostracism arouses negative affect. However, little is known about variables that influence the intensity of these negative affective responses. Two studies seek to fill this void by incorporating work on approach- and withdrawal-related emotional states and their associated cortical activations. Study 1 found that following ostracism, anger related directly to relative left frontal cortical activation. Study 2 used unilateral hand contractions to manipulate frontal cortical activity prior to an ostracizing event. Righthand contractions, compared to left-hand contractions, caused greater relative left frontal cortical activation during the hand contractions as well as during ostracism. Also, righthand contractions caused more self-reported anger in response to being ostracized. Within-condition correlations revealed patterns of associations between ostracisminduced frontal asymmetry and emotive responses to ostracism consistent with Study 1. Taken together, these results suggest that asymmetrical frontal cortical activity affects angry responses to ostracism, with greater relative left frontal cortical activity being associated with increased anger.

Frontal electroencephalographic (EEG) alpha (α) asymmetry may index the activation of lateralized affect and motivation systems in humans. Resting EEG activation was measured and its relationship to Iowa gambling task (IGT) performance was evaluated. No effects were found for α power asymmetry. However, beta (β) power asymmetry, an alternative measure of resting EEG activation, was associated with the number of risky decisions made in the early portion of the task. Additionally, IGT deck selection patterns suggest there are at least three distinct performance styles in healthy individuals. Interestingly, β power asymmetry contradicts performance predictions based on accepted frontal asymmetry affect and motivation models.

Frontal electroencephalographic (EEG) alpha (α) asymmetry may index the activation of lateralized affect and motivation systems in humans. Resting EEG activation was measured and its relationship to Iowa gambling task (IGT) performance was evaluated. No effects were found for α power asymmetry. However, beta (β) power asymmetry, an alternative measure of resting EEG activation, was associated with the number of risky decisions made in the early portion of the task. Additionally, IGT deck selection patterns suggest there are at least three distinct performance styles in healthy individuals. Interestingly, β power asymmetry contradicts performance predictions based on accepted frontal asymmetry affect and motivation models.

Trots den omfattande forskning som utförts om både priming och emotioner, och relationen dem emellan, finns det ännu idag anledning att fortsätta söka fördjupa förståelsen av hur emotionell priming processeras i hjärnan. Den aktuella studien har ämnat utgöra en liten men relevant del av neuropsykologins kontinuerliga arbete med att underbygga fortsatta framsteg och fördjupad förståelse om hur människans hjärna arbetar. Experiment med emotionell priming har genomförts, för att med EEG-mätningar undersöka hjärnans reaktioner. Studiens resultat uppvisar en neurologisk skillnad mellan hur hjärnan reagerar på leende ansikten jämfört med neutrala ansikten. Däremot kunde ingen primingeffekt påvisas vid upprepade tester, vilket skulle kunna tyda på att priming inte sker på neurologisk nivå utan kräver någon form av medveten eller omedveten kognitiv aktivering för att ha någon effekt. / Despite the extensive research conducted on both priming and emotions, and the relationship between them, there is still reason to further seek to deepen our understanding of how emotional priming is processed in the brain. The current study aimed to be a small but relevant part of neuropsychology's ongoing work in supporting continued progress and in-depth understanding of how the human brain works. Experiments with emotional priming have been carried out to examine the brain's reactions with EEG measurements. The results of the study show a neurological difference between how the brain reacts to smiling faces versus neutral faces. However, no priming effect could be detected in repeated tests, which could indicate that priming does not occur at the neurological level but requires some form of conscious or unconscious cognitive activation to have an effect.

Lo scopo della presenta ricerca è analizzare il ruolo del sistema di ricompensa in relazione al costrutto BIS/BAS (Behavioural Inhibition System/ Behavioural Activation System) in un contesto sano e di dipendenza da sostanza. Il lavoro ha inoltre esplorato l'asimmetria cerebrale frontale nelle scelte decisionali che implicano stimoli di ricompensa e condizioni punizione. I risultati hanno confermato l'ipotesi di un anomalia del sistema di ricompensa in individui con alto BAS e in pazienti con dipendenza da sostanza, che sovrastimavano la ricompensa immediata a scapito di quella a lungo termine durante l’Iowa Gambling Task. Un’altra componente cruciale emersa da questo progetto è una iper-attivazione del lobo frontale di sinistra rispetto a quello di destra in risposta alle opzioni più rischiose. Questo "effetto di sbilanciamento inter-emisferico” potrebbe essere considerato come un indicatore critico del comportamento decisionale disfunzionale nella dipendenza o come fattore di vulnerabilità allo sviluppo di dipendenze. Infine, questo "modello di squilibrio corticale" è stato applicato ad altre forme di dipendenza comportamentale, misurate con l’Internet Addiction Test (IAT). In effetti, un aumento dell'attività frontale di sinistra è stata osservata per gli individui ad alto IAT in risposta a stimoli premianti. In particolare, i risultati ottenuti sottolineano l'importanza di un modello integrato di dipendenza che tiene conto del sistema motivazionale (BIS/BAS) correlato alla lateralizzazione dell'attività corticale. / The aim of this PhD research was intended to analyze the role of the reward system by the BIS/BAS (Behavioural Inhibition System/ Behavioural Activation System) construct in healthy and addiction context. It explored the frontal brain asymmetry in decisional choices implying reward stimuli and punishment conditions. Results confirmed the hypothesis of a “reward bias” induced by high-BAS individuals and patients suffering from Substance Use Disorder (SUD) to overestimate the immediate reward to the detriment of the delayed reward during the Iowa Gambling Task. Another critical component is the frontal left-hyper activation of the brain in response to more risky options. This "inter-hemisphere" unbalancing effect can be considered as a critical indicator of the dysfunctional decision behavior in dependence or as a vulnerability factor to the development of addiction. Finally, this “cortical imbalance model” was applied to other forms of behavioural addiction, measured by the Internet Addiction Test (IAT). Indeed, an increased left frontal activity was observed for high-IAT individuals in response to rewarding stimuli. In particular, the results underlined the importance of an integrated model of addiction that takes into account the motivational system (BIS / BAS) related to the lateralization of cortical activity.