Second Wave Positive Psychology: Exploring the Positive–Negative Dialectics of Wellbeing

Positive psychology has tended to be defined in terms of a concern with ‘positive’ psychological qualities and states. However, critics of the field have highlighted various problems inherent in classifying phenomena as either ‘positive’ or ‘negative.’ For instance, ostensibly positive qualities (e.g., optimism) can sometimes be detrimental to wellbeing, whereas apparently negative processes (like anxiety) may at times be conducive to it. As such, over recent years, a more nuanced ‘second wave’ of positive psychology has been germinating, which explores the philosophical and conceptual complexities of the very idea of the ‘positive.’ The current paper introduces this emergent second wave by examining the ways in which the field is developing a more subtle understanding of the ‘dialectical’ nature of flourishing (i.e., involving a complex and dynamic interplay of positive and negative experiences). The paper does so by problematizing the notions of positive and negative through seven case studies, including five salient dichotomies (such as optimism versus pessimism) and two complex processes (posttraumatic growth and love). These case studies serve to highlight the type of critical, dialectical thinking that characterises this second wave, thereby outlining the contours of the evolving field.

Using the interaural time difference and cross-correlation to localise short-term complex noises

The mammalian binaural cue of interaural time difference (ITD) and cross-correlation have long been used to determine the point of origin of a sound source. The ITD can be defined as the different points in time at which a sound from a single location arrives at each individual ear [1]. From this time difference, the brain can calculate the angle of the sound source in relation to the head [2]. Cross-correlation compares the similarity of each channel of a binaural waveform producing the time lag or offset required for both channels to be in phase with one another. This offset corresponds to the maximum value produced by the cross-correlation function and can be used to determine the ITD and thus the azimuthal angle θ of the original sound source. However, in indoor environments, cross-correlation has been known to have problems with both sound reflections and reverberations. Additionally, cross-correlation has difficulties with localising short-term complex noises when they occur during a longer duration waveform, i.e. in the presence of background noise. The crosscorrelation algorithm processes the entire waveform and the short-term complex noise can be ignored. This paper presents a technique using thresholding which enables higher-localisation abilities for short-term complex sounds in the midst of background noise. To determine the success of this thresholding technique, twenty-five sounds were recorded in a dynamic and echoic environment. The twenty-five sounds consist of hand-claps, finger-clicks and speech. The proposed technique was compared to the regular cross-correlation function for the same waveforms, and an average of the azimuthal angles determined for each individual sample. The sound localisation ability for all twenty-five sound samples is as follows: average of the sampled angles using cross-correlation: 44%; cross-correlation technique with thresholding: 84%. From these results, it is clear that this proposed technique is very successful for the localisation of short-term complex sounds in the midst of background noise and in a dynamic and echoic indoor environment.