Are Episodic Buffer Processes Intact in ADHD? Experimental Evidence and Linkage with Hyperactive Behavior

Working memory deficits are present in a substantial proportion of children with ADHD, and converging evidence links these deficits with ADHD-related behavioral and functional impairments. At the same time, working memory is not a unitary construct, and evidence is lacking regarding the role of several components of this system in ADHD. Preclinical behavioral studies are needed to fractionate the multicomponent working memory system, determine which specific subcomponent(s) are impaired in ADHD, and more importantly link these subcomponent(s) with specific ADHD-related behavioral symptoms/functional impairments. The current study reflects one piece of that puzzle, and focuses on the episodic buffer component of working memory. Across multiple testing days, a well-characterized sample of 86 children ages 8–13 (M=10.52, SD=1.54; 34 girls; 64% Caucasian/Non-Hispanic) with ADHD (n=49) and without ADHD (n=37) completed three counterbalanced working memory tests that were identical in all aspects except the key subcomponent process (phonological, visuospatial, episodic buffer). Gross motor movement during these and control tasks were measured using 4 high-precision actigraphs. There was no evidence of group differences in gender, age, SES, or IQ. Bayesian mixed-model ANOVAs indicated that the ADHD group performed significantly worse on all three working memory tests (d=1.17–1.44) and was significantly more hyperactive than controls (d=0.66–1.05) during the visuospatial and episodic buffer tests. In contrast, the ADHD and Non-ADHD groups were equivalent with regard to effects of episodic buffer demands on performance and hyperactive behavior. The most parsimonious conclusion is that the episodic buffer is likely intact in ADHD, and unrelated to ADHD hyperactivity symptoms.     

Response of colony mice to intruders with different fighting experience

Six male mice placed in a large, moderately complex enclosure formed a stable dominance hierarchy in which two mice defended adjacent floor areas and the remaining four mice were subordinate and did not form territories. Intruder mice with winning or losing experience in prior paired encounters, or those with no fighting experience, were introduced individually into the colony for 30 minute periods. These intruders were attacked by the dominant members of the colony, and the fighting outcomes were strongly dependent upon the fighting experience of the intruder. Intruders with losing or no fighting experience engaged in little mutual fighting with residents, were easily defeated, and terminated attacks by engaging in subordinate behaviors. Intruders with winning experience fought vigorously with residents, attacked and, in many cases, defeated residents. These results suggest that relatively little winning experience gained in earlier paired encounters may be sufficient to overcome the various fighting advantages enjoyed by a dominant territorial holding member of a colony.     

Self-Healing Aspects of EMDR: The Therapeutic Change Process and Perspectives of Integrated Psychotherapies

Eye Movement Desensitization and Reprocessing (EMDR) (Shapiro 1989a, 1989b, 1995) is an innovative, comprehensive approach to psychotherapy. While EMDR's use of eye movements has attracted a great deal of attention, the efficacy of the EMDR method can be explained parsimoniously in terms of many different types of therapy. Lang's (1985) information processing networks provide a way to understand the Accelerated Information Processing model proposed by Shapiro to explain EMDR. A representative EMDR session is presented to illustrate the integrative components of EMDR's procedural elements and the range of clinical effects. Therapeutic changes seen as a result of self-healing using EMDR are discussed from the perspectives of other psychotherapeutic approaches in order to understand the contribution of EMDR to the psychotherapy integration movement.     

Male Leadership in an Addicted Women's Group: An Empirical Approach

This study examined the premise that women's addiction groups should be facilitated by female leaders. Results from pretest‐posttest comparisons indicated that attitudes toward men of participants in groups facilitated by men were more positive than were those of participants in groups facilitated by women.     

Adults’ strategy choices for simple addition: Effects of retrieval interference

Simple addition (e.g., 3 + 2, 7 + 9) may be performed by direct memory retrieval or by such procedures as counting or transformation. The distribution of associations (DOA) model of strategy choice (Siegler, 1988) predicts that procedure use should increase as retrieval interference increases. To test this, 100 undergraduates performed simple addition problems, either after blocks of simple multiplication (high-interference context) or after blocks of simple division problems (low-interference context). Addition took longer and was more error prone after multiplication; in particular, there were more multiplication confusion errors on the relatively easy, small-number addition problems (e.g., 3 + 2 = 6, 4 + 3 = 12), but not on the more difficult, large-number additions. Consistent with the DOA, participants reported greater use of procedures for addition after multiplication, but more so for small addition problems. The findings demonstrate that adults’ use of procedural strategies for simple addition is substantially influenced by retrieval interference.     

Biological and social determinants of responsiveness to infants in 10-to-15-year-old girls

Subjects filled out questionnaires and were individually observed interacting with an 8-to-12-month-old infant in a waiting room. Hidden observers recorded the frequency of ignoring, responsiveness to infant bids, and of social bids to the infant. Analyses revealed that older girls ignored more, made fewer bids, and responded less than younger girls did. However, chronological age was highly correlated with measures of biological and social maturity. Multiple regression analyses were used to determine which of these factors best predicted the developmental decline in baby responsiveness. Multiple regressions showed that social maturity was the best predictor of the number of bids to the infant, followed by the development of secondary sex characteristics and menarcheal status (R=.44). Social maturity, babysitting experience, and menarcheal status were the significant predictors of ignoring (R=.48), while menarcheal status, development of secondary sex characteristics, and babysitting experience predicted responsiveness (R=.49). Possible reasons for the decreased interest in infants are discussed, as are the implications for research using baby responsiveness as a measure of sex-role-related changes in adolescence.This research was supported by grants from the Riksbankens Jubileumsfond and the Humanistisk-Samhällsvetenskapliga Forskiningsradet of Sweden to Ann M. Frodi. The authors are grateful to Sharon Bienstock for her assistance.     

An ecological analysis of knowing by wielding.

The ecological approach to perception, as developed by James Gibson, is described and applied to how one knows, by means of the haptic perceptual system, various properties of hand-held objects. Four sets of experiments are reviewed in which subjects reported on the extent, orientation, shape, and fractional components of unseen objects wielded freely. For each task, an invariant specific to the object property in question is identified in the structured arrays of rotational moments and strains produced by the act of wielding. Results are discussed in relation to the concepts of attention and stimulation, as reformulated by the ecological approach, and the general theory of perception as information pickup.     

Sex differences in the lateralized processing of facial emotion

Two reaction time tasks were administered to male and female normal subjects, involving judgments of facial emotion. In the Word-Face task, judgments of similarity or difference of a centrally presented emotion word and an emotional face presented in the left or right visual field were required, and in the Face-Face task, comparisons of a centrally presented and a laterally presented emotional face were required. Results were significant for the matching trials only. Reaction times to negative emotions were faster overall than to positive emotions, and an Emotional Valence by Visual Field interaction was found such that reaction times were faster for negative emotions in the left visual field and for positive emotions in the right visual field. This interaction was significant for the female but not the male subjects, although similar patterns were observed in both sexes. Further, an interaction of Gender, Task, and Emotional Valence was found, such that the two tasks had opposite effects for the two sexes. The Face-Face task appeared to inhibit the performance of the male subjects and facilitate the performance of the female subjects in terms of reaction time. It was suggested that specifying the target emotion by an emotional face elicits a greater emotional response on the part of the subject than specification by a word, and that this emotional elicitation may result in a reactive inhibition in the male subjects and in an elaboration of the emotional response in the female subjects.     

The importance of ‘mass’ in line drawings of faces

Previous research (Davies, Ellis and Shepherd, 1978; Rhodes, Brennan and Carey, 1987) has shown that accurate line drawings of familiar faces are identified rather poorly. However, artists can produce lifelike portraits with pen and ink, and Pearson and Robinson (1985) described an automatic method for producing computer-drawn sketches (‘cartoons’) of faces which appear very similar to those produced by a human artist. In this paper we show that subjects can identify famous faces depicted in such computer-drawn ‘cartoons’ almost as well as full grey-scale images. The cartoon algorithm comprises two components. One component draws lines at the locations of intensity changes corresponding to luminance valleys and edges (the ‘valledge’ detector). The other component applies a ‘threshold’ to the original intensity distribution, and replaces any area darker than threshold with black. Thus the full cartoon contains both ‘line’ and ‘mass’. Neither the valledges nor the threshold components alone were as well identified as full cartoons containing both components. The results suggest that the addition of the threshold component adds significantly to the identifiability of line drawings of faces.