TRACX: a recognition-based connectionist framework for sequence segmentation and chunk extraction

Individuals of all ages extract structure from the sequences of patterns they encounter in their environment, an ability that is at the very heart of cognition. Exactly what underlies this ability has been the subject of much debate over the years. A novel mechanism, implicit chunk recognition (ICR), is proposed for sequence segmentation and chunk extraction. The mechanism relies on the recognition of previously encountered subsequences (chunks) in the input rather than on the prediction of upcoming items in the input sequence. A connectionist autoassociator model of ICR, truncated recursive autoassociative chunk extractor (TRACX), is presented in which chunks are extracted by means of truncated recursion. The performance and robustness of the model is demonstrated in a series of 9 simulations of empirical data, covering a wide range of phenomena from the infant statistical learning and adult implicit learning literatures, as well as 2 simulations demonstrating the model's ability to generalize to new input and to develop internal representations whose structure reflects that of the items in the input sequence. TRACX outperforms PARSER (Perruchet & Vintner, 1998) and the simple recurrent network (SRN, Cleeremans & McClelland, 1991) in matching human sequence segmentation on existing data. A new study is presented exploring 8-month-olds' use of backward transitional probabilities to segment auditory sequences.     

X-rated material and perpetration of sexually aggressive behavior among children and adolescents: is there a link?

Longitudinal linkages between intentional exposure to x-rated material and sexually aggressive behavior were examined among youth 10-15 year olds surveyed nationally in the United States. At Wave 1 in 2006, participants (n = 1,588) were queried about these exposures and outcomes in the preceding 12 months. Wave 2 data (n = 1,206) were collected approximately 12 months after Wave 1 and Wave 3 data (n = 1,159) were collected approximately 24 months after Wave 1. Thus, data for this project represent a 36-month time frame. A marginal model with generalized estimating equations was used to represent the population-average odds of sexually aggressive behavior over the 36 months as a function of exposure to x-rated material over the same time and to account for clustering in the data within person over time. An average of 5% of youth reported perpetrating sexually aggressive behavior and 23% of youth reported intentional exposure to x-rated material. After adjusting for other potentially influential proximal (i.e., sexual aggression victimization) and distal characteristics (e.g., substance use), we found that intentional exposure to violent x-rated material over time predicted an almost 6-fold increase in the odds of self-reported sexually aggressive behavior (aOR: 5.8, 95% CI: 3.2, 10.5), whereas exposure to nonviolent x-rated material was not statistically significantly related (aOR: 1.7, 95% CI: 0.94, 2.9). Associations were similar for boys and girls (boys nonviolent x-rated material aOR = 2.0, 95% CI: 0.8, 4.7; violent x-rated material aOR = 6.5, 95% CI: 2.7, 15.3; girls nonviolent x-rated material aOR = 1.2, 95% CI: 0.5, 3.2; violet x-rated material aOR = 6.1, 95% CI: 2.5, 14.8).     

Integration of visual information for saccade production

To foveate a visual target, subjects usually execute a primary hypometric saccade (S1) bringing the target in perifoveal vision, followed by a corrective saccade (S2) or by more than one S2. It is still debated to what extent these S2 are pre-programmed or dependent only on post-saccadic retinal error. To answer this question, we used a visually-triggered saccade task in which target position and target visibility were manipulated. In one-third of the trials, the target was slightly displaced at S1 onset (so-called double step paradigm) and was maintained until the end of S1, until the start of the first S2 or until the end of the trial. Experiments took place in two visual environments: in the dark and in a dimly lit room with a visible random square background. The results showed that S2 were less accurate for shortest target durations. The duration of post-saccadic visual integration thus appears as the main factor responsible for corrective saccade accuracy. We also found that the visual context modulates primary saccade accuracy, especially for the most hypometric subjects. These findings suggest that the saccadic system is sensitive to the visual properties of the environment and uses different strategies to maintain final gaze accuracy.     

Peer status in an ethnic context: Associations with African American adolescents' ethnic identity

This investigation examined the association between ethnic identity centrality and peer status for African American adolescents who represented a sizable proportion, yet numerical minority within a high school context. Initial analyses indicated that a traditional sociometric nomination procedure did not adequately characterize peer status for African American adolescents. A modified nomination procedure varying the ethnicity of nominators yielded measures of African American adolescents' peer acceptance/rejection and perceived popularity as rated by African American or European American peers. Results suggest that high levels of peer acceptance and popularity as rated by African American peers were associated with high ethnic identity centrality; however, acceptance and popularity as rated by European American peers were unrelated to ethnic identity centrality among African American adolescents. Findings suggest the importance of examining peer status of African American adolescents with consideration given to ethnicity as a relevant context.     

Facial Emotion Processing in Borderline Personality Disorder: A Systematic Review and Meta-Analysis

A body of work has developed over the last 20 years that explores facial emotion perception in Borderline Personality Disorder (BPD). We identified 25 behavioural and functional imaging studies that tested facial emotion processing differences between patients with BPD and healthy controls through a database literature search. Despite methodological differences there is consistent evidence supporting a negative response bias to neutral and ambiguous facial expressions in patients. Findings for negative emotions are mixed with evidence from individual studies of an enhanced sensitivity to fearful expressions and impaired facial emotion recognition of disgust, while meta-analysis revealed no significant recognition impairments between BPD and healthy controls for any negative emotion. Mentalizing studies indicate that BPD patients are accurate at attributing mental states to complex social stimuli. Functional neuroimaging data suggest that the underlying neural substrate involves hyperactivation in the amygdala to affective facial stimuli, and altered activation in the anterior cingulate, inferior frontal gyrus and the superior temporal sulcus particularly during social emotion processing tasks. Future studies must address methodological inconsistencies, particularly variations in patients’ key clinical characteristics and in the testing paradigms deployed.     

Medically Defining,Screening, and Treating Conduct Disorder: A French Controversy

For several decades, the use of psychotropic medication has either been regarded as a medical issue or an example of the medicalization of social problems. As the publication in 2005 of a knowledge synthesis on conduct disorder in children and adolescents and the reply of the «Pas de zéro de conduite» collaboration (literally: No F for Conduct) was a highly important event in the French mental health scene, it deserves a thorough discussion. In the hope of improving the practices and policies targeting children and their families, it is essential to gain a better understanding of the bones of contention between the proponents and opponents of a medical or rather biosocial model. To achieve this, we first analyze how this model assigns a central role to certain disorders defined and diagnosed based on constellations of symptoms. We then identify five dimensions which seem to hold center stage in the controversy: genetic susceptibility, neurocognitive deficits and temperament, the familial and social environment seen as a reservoir of stressors, large-scale screening for disorders using simple instruments and multi-modal treatments, including psychotropic medication. We take an interest in the French debate as this allows us to stand back from the models prevailing in North America. It also underscores the importance of multidisciplinary thinking and social sciences when elaborating clinical or political mental health guidelines.     

Decay uncovered in nonverbal short-term memory

Decay theory posits that memory traces gradually fade away over the passage of time unless they are actively rehearsed. Much recent work exploring verbal short-term memory has challenged this theory, but there does appear to be evidence for trace decay in nonverbal auditory short-term memory. Numerous discrimination studies have reported a performance decline as the interval separating two tones is increased, consistent with a decay process. However, most of this tone comparison research can be explained in other ways, without reference to decay, and these alternative accounts were tested in the present study. In Experiment 1, signals were employed toward the end of extended retention intervals to ensure that listeners were alert to the presence and frequency content of the memoranda. In Experiment 2, a mask stimulus was employed in an attempt to distinguish between a highly detailed sensory trace and a longer-lasting short-term memory, and the distinctiveness of the stimuli was varied. Despite these precautions, slow-acting trace decay was observed. It therefore appears that the mere passage of time can lead to forgetting in some forms of short-term memory.     

Effect of Parenting Interventions on Perinatal Depression and Implications for Infant Developmental Outcomes: A Systematic Review and Meta-Analysis

Clinical Child and Family Psychology Review - Considering the significant impact of perinatal depression on both maternal wellbeing and infant development, it is important to examine the...