What aspects of face processing are impaired in developmental prosopagnosia?

Developmental prosopagnosia (DP) is a severe impairment in identifying faces that is present from early in life and that occurs despite no apparent brain damage and intact visual and intellectual function. Here, we investigated what aspects of face processing are impaired/spared in developmental prosopagnosia by examining a relatively large group of individuals with DP (n = 8) using an extensive battery of well-established tasks. The tasks included measures of sensitivity to global motion and to global form, detection that a stimulus is a face, determination of its sex, holistic face processing, processing of face identity based on features, contour, and the spacing of features, and judgments of attractiveness. The DP cases showed normal sensitivity to global motion and global form and performed normally on our tests of face detection and holistic processing. On the other tasks, many DP cases were impaired but there was no systematic pattern. At least half showed deficits in processing of facial identity based on either the outer contour or spacing of the internal features, and/or on judgments of attractiveness. Three of the eight were impaired in processing facial identify based on the shape of internal features. The results show that DP is a heterogeneous condition and that impairment in recognizing faces cannot be predicted by poor performance on any one measure of face processing.     

Microinfusion of the D1 receptor antagonist, SCH23390 into the IL but not the BLA impairs consolidation of extinction of auditory fear conditioning

In auditory fear conditioning, repeated presentation of the tone in the absence of the shock leads to extinction of the acquired fear response. Both the medial prefrontal cortex (mPFC) and the basolateral amygdala (BLA) are involved in extinction. Here we examined this involvement by antagonizing D1 receptors in both regions, in the rat. We microinfused the D1 receptor antagonist, SCH23390, into the infra-limbic part of the mPFC (IL) or BLA at different time points. SCH23390 mircoinfused into the IL either before extinction acquisition or following short extinction training resulted in impairment of extinction consolidation. Microinfusion of SCH23390 into the BLA, prior to acquisition of extinction caused impairment in acquisition of extinction without affecting extinction consolidation. This is supported by the results showing that microinfusion of SCH23390 into the BLA following a short-training session did not affect consolidation. These results further strengthen the role of mPFC in consolidation of extinction while highlighting the role of the D1 receptors in this process.     

Skills Practice in Dialectical Behavior Therapy for Suicidal Women Meeting Criteria for Borderline Personality Disorder

Dialectical Behavior Therapy (DBT) is an evidence-based practice for borderline personality disorder (BPD) and suicidal behavior that has been replicated with a variety of populations. Patients’ practice of behavioral skills taught in the group skills training component of DBT may be partly responsible for the positive treatment outcomes according to the skills deficit model of BPD that underlies DBT. This study was designed to examine the type and frequency of skills practiced by DBT patients. Participants were 49 women, who met criteria for BPD and current and chronic suicidal behavior, receiving 1 year of standard DBT as part of a clinical trial. Skills were recorded on the daily diary cards completed by participants each week and reviewed by their individual therapists. Results indicated that the majority of participants reported practicing skills most days throughout treatment. Crisis survival and mindfulness skills were practiced most frequently in our sample. Hierarchical linear modeling demonstrated that skills practice increased as a function of time in therapy. Directions for future research are discussed.     

The relationship between defenses and symptoms in adolescent psychopathology

The relationship between defense mechanisms and symptoms was assessed in a group of 196 psychiatrically hospitalized adolescents. Defense mechanisms were measured through the use of the Defense Mechanisms Inventory (DMI); symptoms and problem behaviors were measured with the Youth Self-Report. Univariate and multivariate analyses indicated that externalizing symptoms are associated with defenses that locate the conflict outside of the self, whereas internalizing symptoms are associated with defenses that locate the conflict within the self. In contrast to previous reports, no gender differences were found in defense preference, though gender differences were found in the relation of defenses to symptoms. The findings are consistent with clinical theory of defense processes and support the distinction between internalizing/externalizing behaviors and personality dimensions for both symptoms and defenses. The study supports the validity of the adolescent form of the DMI.     

Measuring individual differences in statistical learning: Current pitfalls and possible solutions

Most research in statistical learning (SL) has focused on the mean success rates of participants in detecting statistical contingencies at a group level. In recent years, however, researchers have shown increased interest in individual abilities in SL, either to predict other cognitive capacities or as a tool for understanding the mechanism underlying SL. Most if not all of this research enterprise has employed SL tasks that were originally designed for group-level studies. We argue that from an individual difference perspective, such tasks are psychometrically weak, and sometimes even flawed. In particular, the existing SL tasks have three major shortcomings: (1) the number of trials in the test phase is often too small (or, there is extensive repetition of the same targets throughout the test); (2) a large proportion of the sample performs at chance level, so that most of the data points reflect noise; and (3) the test items following familiarization are all of the same type and an identical level of difficulty. These factors lead to high measurement error, inevitably resulting in low reliability, and thereby doubtful validity. Here we present a novel method specifically designed for the measurement of individual differences in visual SL. The novel task we offer displays substantially superior psychometric properties. We report data regarding the reliability of the task and discuss the importance of the implementation of such tasks in future research.     

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.