Varieties of grapheme-colour synaesthesia: a new theory of phenomenological and behavioural differences

Recent research has suggested that not all grapheme-colour synaesthetes are alike. One suggestion is that they can be divided, phenomenologically, in terms of whether the colours are experienced in external or internal space (projector–associator distinction). Another suggestion is that they can be divided according to whether it is the perceptual or conceptual attributes of a stimulus that is critical (higher–lower distinction). This study compares the behavioural performance of 7 projector and 7 associator synaesthetes. We demonstrate that this distinction does not map on to behavioural traits expected from the higher–lower distinction. We replicate previous research showing that projectors are faster at naming their synaesthetic colours than veridical colours, and that associators show the reverse profile. Synaesthetes who project colours into external space but not on to the surface of the grapheme behave like associators on this task. In a second task, graphemes presented briefly in the periphery are more likely to elicit reports of colour in projectors than associators, but the colours only tend to be accurate when the grapheme itself is also accurately identified. We propose an alternative model of individual differences in grapheme-colour synaesthesia that emphasises the role of different spatial reference frames in synaesthetic perception. In doing so, we attempt to bring the synaesthesia literature closer to current models of non-synaesthetic perception, attention and binding.     

Dialectical behavior therapy skills use as a mediator and outcome of treatment for borderline personality disorder

A central component of Dialectical Behavior Therapy (DBT) is the teaching of specific behavioral skills with the aim of helping individuals with Borderline Personality Disorder (BPD) replace maladaptive behaviors with skillful behavior. Although existing evidence indirectly supports this proposed mechanism of action, no study to date has directly tested it. Therefore, we examined the skills use of 108 women with BPD participating in one of three randomized control trials throughout one year of treatment and four months of follow-up. Using a hierarchical linear modeling approach we found that although all participants reported using some DBT skills before treatment started, participants treated with DBT reported using three times more skills at the end of treatment than participants treated with a control treatment. Significant mediation effects also indicated that DBT skills use fully mediated the decrease in suicide attempts and depression and the increase in control of anger over time. DBT skills use also partially mediated the decrease of nonsuicidal self-injury over time. Anger suppression and expression were not mediated. This study is the first to clearly support the skills deficit model for BPD by indicating that increasing skills use is a mechanism of change for suicidal behavior, depression, and anger control.