The case for sensorimotor coding in working memory

The highly influential Baddeley and Hitch model of working memory (Baddeley & Hitch, 1974; see also Baddeley, 1986) posited analogical forms of representation that can be broadly characterized as sensorimotor, both for verbal and for visuospatial material. However, difficulties with the model of verbal working memory in particular have led investigators to develop alternative models that avoid appealing either to sensory coding or to motoric coding, or to both. This paper examines the evidence for sensorimotor coding in working memory, including evidence from neuropsychology and from sign language research, as well as from standard working memory paradigms, and concludes that only a sensorimotor model can accommodate the broad range of effects that characterize verbal working memory. In addition, several findings that have been considered to speak against sensorimotor involvement are reexamined and are argued to be in fact compatible with sensorimotor coding. These conclusions have broad implications, in that they support the emerging theoretical viewpoint of embodied cognition.     

Abnormalities of motor and praxis imagery in children with DCD

In an earlier study using the visually guided pointing task (VGPT) the authors showed that the timing of imagined movement sequences in children with developmental coordination disorder (DCD) does not conform to the conventional speed-for-accuracy trade-off (or Fitts' law [P.M. Fitts, Journal of Experimental Psychology 47 (1954) 381-391]) that occurs when the distance and accuracy requirements of movements are varied [P. Maruff, P.H. Wilson, M. Trebilcock, J. Currie, Neuropsychologia 37 (1999b) 1317-1324]. The present study sought to replicate this earlier finding and to examine (using a weight manipulation) whether this deficit was also attributable to inaccurate programming of relative force. The chronometry of real and imagined movements was investigated in a group of 20 children with DCD aged between 8 and 12 years and a group of controls matched on age and verbal IQ (VIQ). Movement duration was tested for real and imagined movements using the preferred hand, with the VGPT performed under two load conditions: with and without the addition of a weight attached to a pen. Group means of each subjects' mean movement duration were calculated and plotted against target width for each of the four conditions [Movement type (2) x Load (2)] and a logarithmic curve was fitted to the data points. In the control group, the speed-for-accuracy trade-off for both real and imagined performance conformed to Fitts' law under each load condition. In the DCD group only real movements conformed to Fitts' law. Moreover, the effect of load differed between groups--for real movements, movement duration did not differ between load and no-load conditions for either group, while for imagined movements, movement duration increased under the load condition for the control group only. These results replicate and extend the results of our earlier study. This pattern of performance suggests that children with DCD have an impairment in the ability to generate internal representations of volitional movements which may reflect an impaired ability to process efference copy signals. The ability to programme both relative force and timing appears to underly this difficulty. Results have implications for the use of (guided) motor imagery training in order to facilitate the development of motor skill in children with DCD.     

Stressful life events and impulsiveness in failed suicide

The relationship of recent stressful life events with impulsiveness in triggering suicide attempts and how impulsiveness changes from one suicide attempt to another is unclear. This study used structured-interview tools and standardized measurements to examine the relationship between life stress and impulsiveness in a sample of patients who required hospitalization for a medically serious suicide attempt. After controlling for potentially confounding variables, the number of disrupted interpersonal relationships in the preceding year was a significant predictor of the impulsiveness of the suicide attempt, with three or more losses (but not other life stresses) associated with less impulsive attempts (T = 2.4, p = .02). Female gender (T = -1.98, p = .05) and lifetime DMS-III-R diagnoses (T = -2.45, p = .02) were significantly associated with more impulsive attempts. In 55 patients with at least two suicide attempts, impulsiveness, lethal intent, and communication of intent were significantly greater for the present compared to the prior attempt (p = 0.000). Certain stressful life events, gender, and total lifetime DSM-III-R diagnoses are associated with impulsiveness of failed suicide attempts; yet, impulsiveness is not necessarily consistent from one suicide attempt to another. This evidence supports and amplifies a stress-diathesis model of suicide behavior. Accordingly, efforts to increase personal resilience in individuals who have "failed suicide" may be more effective at preventing suicide morbidity than simple stress-reduction measures alone.     

Attachment disorders: review and current status

Developmental research on attachment has flourished in the past 15 years (C. H. Zeanah, 1996). However, there has been relatively scant empirical investigation of disorders in attachment. In this article, the pertinent developmental research on the attachment cycle is delineated and the current status of disordered attachment is examined. A particular focus is given to the conceptualization of the most severe form of disordered attachment, Reactive Attachment Disorder.     

Attitudes toward parenting strategies, potential for child abuse, and parental satisfaction of ethnically diverse low-income U.S. mothers

Among a sample of 176 low-income mothers from 3 ethnic groups in the United States, the authors investigated ethnic differences in attitudes toward preferred parenting strategies, or styles; ethnic differences in the potential for child abuse; and the relationship between parenting strategies, the potential for child abuse, and parental satisfaction. They distributed the Maternal Reactions to Child's Deviant Behavior subscale (K. M. Rickard, W. Graziano, & R. Forehand, 1984), a shortened version of the Child Abuse Potential Inventory (CAPI; J. S. Milner & R. C. Wimberley, 1979), and a Parental Satisfaction Scale (N. P Medora, S. M. Wilson, & J. Larson, 1996) to the participants. The results indicated no significant ethnic differences in preferred parenting styles. Mothers from all 3 ethnic groups ranked praise and reasoning as the 1st and 2nd preferred parenting strategies. There were no ethnic differences in the perceived potential for child abuse. Parental satisfaction was negatively related to 2 of the CAPI subscales--Loneliness and Problems. The parenting strategy reasoning was positively correlated with parental satisfaction.     

Adolescent substance use disorders: findings from a 14-year follow-up of speech/language-impaired and control children.

Intervening on the development of adolescent addiction requires an understanding of the role of precursors. In a community sample of youth with and without early childhood speech/language (S/L) impairments, 12.7% of participants had a substance use disorder (SUD). Among these participants, 42.0% met criteria for more than 1 SUD. Interestingly, rates of SUDs did not differ by S/L status. However, S/L-impaired participants did show greater psychiatric comorbidity and poorer functioning. A total of 80% of S/L participants with SUDs had a concurrent diagnosis of antisocial personality disorder, compared with 43.8% of SUDs controls. In a logistic regression analysis, we found age 5 mother-rated problem behavior scores and an interaction between S/L status and teacher-rated conduct problem scores were predictive of SUDs. High conduct scores were predictive of SUDs development among control participants but not among S/L-impaired participants. First substance use and initial SUDs symptoms suggest that a window of opportunity exists to reach these troubled young people before they spiral into addiction.     

Gender, Somatization, and Psychopathic Traits in a College Sample

The structure of psychopathic traits and their association with somatization symptoms were investigated in a sample of 199 undergraduate college students enrolled in introductory psychology classes. Using multiple measures of psychopathic traits, an iterated principal axis (IPA) analysis revealed two dimensions of psychopathy that were similar to ones typically found in forensic samples. One dimension focused on a cold, callous, and unemotional interpersonal style and the second dimension focused on an impulsive and antisocial lifestyle. These two dimensions emerged for both men and women, although the correlation between the two was somewhat higher for men than women. Also, the callous and unemotional dimension was negatively correlated with somatization symptoms, and the impulsive and antisocial dimension was positively associated with somatization symptoms. This pattern of associations was similar for both men and women and it suggests that somatization symptoms may be one aspect of the high rate of negative affectivity experienced by antisocial individuals.     

Gender Differences in the Relation Between Neighborhood Quality and Cardiovascular Reactivity in African American Adolescents1

Although research on the influence of neighborhoods on the development of youth is growing, few researchers have examined the impact of neighborhood quality on physiological outcomes or across gender. The present experiment examined gender differences in the association of neighborhood quality and cardiovascular reactivity (increased blood pressure, BP, in response to stress) among 77 healthy African American adolescents (46% male; M age = 14 years). Participants took part in a cold-face stimulus task to determine reactivity scores. After controlling for baseline BP, family income, and parental education, poorer neighborhood quality was associated with increases in both systolic and diastolic BP to the cold-face task for females, and decreases in BP for males. Adolescents’ reports of life stress and support from family members did not explain the differential effect of neighborhood quality across gender. Implications for future research are discussed.     

Convergent validity of and bias in maternal reports of child emotion

This study examined the convergent validity of maternal reports of child emotion in a sample of 190 children between the ages of 3 and 6. Children completed a battery of 10 emotion-eliciting laboratory tasks; their mothers and untrained na?ve observers rated child emotions (happiness, surprise, fear, sadness, and anger) following each task, and trained coders rated videotapes of each task for the same emotions. Consistent with studies using other designs, maternal reports demonstrated weak to moderate convergence with the other rating methods. Extending prior research, a number of maternal characteristics (particularly lifetime psychiatric diagnoses and personality traits) were associated with their reports of child emotions in the lab, above and beyond the effects of objective coding and observer reports of child emotions. For some emotions, mothers' mental health and dispositional variables were more strongly related to their reports of the child's emotions than were objective indices of the child's observable emotional behavior.