The neurophysiology of electroencephalogram gamma oscillations and their role in brain function, cognitive processes and of altered states of consciousness are described in the opening chapter of Advances in Psychology Research. Volume 137.The second chapter aims to further the understanding of the trauma spectrum disorder conceptualization by examining the content, construct, and criterion validity of this concept, with use of mixed literature reviews and secondary data analyses.The authors go on to provide guidance for the assessment of obsessive-compulsive disorder, addressing the special challenges within long-term care settings and with the increasing geriatric population such as their unwillingness to discuss symptoms because of shame and stigma.Additionally, this compilation reviews the literature on the potential beneficial role of errors, and specifically on students' adaptive reactions and attitudes towards errors, error climate in classrooms, and on teachers' adaptive and/or maladaptive strategies in handling students' errors.The authors continue to reviews literature on youths' cyberbullying involvement by explaining what cyberbullying is, risk factors associated with cyberbullying, and the negative psychological and academic outcomes of cyberbullying involvement.The three main theoretical perspectives which are used to explain role modelling are examined, and furthermore, how media influences this process. The final chapter examines patient preferences for dentists. The sample was composed of 169 Portuguese adults, and participants were asked to indicate their preference for eight dentists who were stratified by gender, age, and training country.