Childhood multiple sclerosis: a review

Multiple sclerosis (MS) is an autoimmune demyelinating disorder of the central nervous system (CNS) that is increasingly recognized as a disease that affects children. Similar to adult-onset MS, children present with visual and sensory complaints, as well as weakness, spasticity, and ataxia. A lumbar puncture can be helpful in diagnosing MS when CSF immunoglobulins and oligoclonal bands are present. White matter demyelinating lesions on MRI are required for the diagnosis; however, children typically have fewer lesions than adults. Many criteria have been proposed to diagnose MS that have been applied to children, mostly above 10 years of age. The recent revisions to the McDonald criteria allow for earlier diagnosis, such as after a clinically isolated event. However, children are more likely than adults to have monosymptomatic illnesses. None of the approved disease-modifying therapies used in adult-onset MS have been approved for pediatrics; however, a few studies have verified their safety and tolerability in children. Although children and adults with MS have similar neurological symptoms, laboratory (cerebrospinal fluid) data, and neuroimaging findings, the clinical course, pathogenesis, and treatment of childhood onset MS require further investigation.     

Heterogeneity in verbal memory: a marker of preclinical Alzheimer's disease?

Demonstrations of memory changes in those at risk for Alzheimer's disease by the presence of the APOE e4 allele have been inconsistent to date. The present study went beyond traditional analyses of central tendency (i.e., group differences on mean test scores) and also conducted distribution analyses to search for subtle cognitive differences in subgroups of normal-functioning elderly persons with the APOE e4 genotype. The results of the study revealed that (a) the e4 and non-e4 groups failed to differ in terms of their mean scores on tests of memory and verbal skills; and (b) relative to the non-e4 group, the e4 subjects had significantly greater heterogeneity of variance on the memory measures but not on fundamental verbal skills. Logistic regression analyses indicated that the discrepancy in scores on the memory measures was a significant predictor of genotype group membership (82% correct classification rate). Implications of these findings for the detection of a preclinical phase of AD are discussed.     

Attentional fixation in panic disorder

According to Beck's (1988) clinical observations, patients with panic disorder describe a fixation on their distressing physical and psychological symptoms and an inability to access corrective information during panic attacks. The present study sought to evaluate empirically the notion that attentional fixation is characteristic of these patients. A subset of panic patients participating in 3 cognitive therapy clinical trials completed the Attentional Fixation Questionnaire (AFQ) at intake, during treatment and at termination. The AFQ had adequate internal consistency at all time intervals, and it correlated positively with measures of depression, anxiety and distorted cognitive content. At termination, the AFQ total score and nearly all single items decreased significantly, and patients who continued to meet diagnostic criteria for panic disorder scored higher on most items than patients who no longer met diagnostic criteria for panic disorder. These preliminary data suggest that attentional fixation is an important dimension of cognition relevant to panic disorder.     

Infants' use of category knowledge and object attributes when segregating objects at 8.5 months of age

The current research investigates infants' perception of a novel object from a category that is familiar to young infants: key rings. We ask whether experiences obtained outside the lab would allow young infants to parse the visible portions of a partly occluded key ring display into one single unit, presumably as a result of having categorized it as a key ring. This categorization was marked by infants' perception of the keys and ring as a single unit that should move together, despite their attribute differences. We showed infants a novel key ring display in which the keys and ring moved together as one rigid unit (Move-together event) or the ring moved but the keys remained stationary throughout the event (Move-apart event). Our results showed that 8.5-month-old infants perceived the keys and ring as connected despite their attribute differences, and that their perception of object unity was eliminated as the distinctive attributes of the key ring were removed. When all of the distinctive attributes of the key ring were removed, the 8.5-month-old infants perceived the display as two separate units, which is how younger infants (7-month-old) perceived the key ring display with all its distinctive attributes unaltered. These results suggest that on the basis of extensive experience with an object category, infants come to identify novel members of that category and expect them to possess the attributes typical of that category.     

Emotional reminiscing and the development of an autobiographical self

According to autobiographical memory theorists, past event conversations provide children with a framework for evaluating and connecting past events into a coherent autobiography (R. Fivush, 1994; K. Nelson, 1993; M. K. Welch-Ross, 1995). Two studies were conducted to empirically examine the association between past event conversation style and an independent measure of children's self-concept consistency. In Study 1, 50 New Zealand mothers discussed everyday past events with their children at 51 and 65 months of age. In Study 2, 51 New Zealand parents discussed 1 positive and 3 negative past events with their 5- and 6-year-old children. The consistency of children's self-views was assessed in both studies using the Children's Self-View Questionnaire (R. Eder, 1990). Children's self-concept consistency was moderately associated with greater explanation of the causes and consequences of children's negative emotions, resolution through social contact, and evaluation of positive events but not with simple attributions of emotion. These findings implicate parent-child conversations as a medium through which children can begin to understand the personal meaning of past experiences.     

Will you be there for me when things go right? Supportive responses to positive event disclosures

Close relationship partners often share successes and triumphs with one another, but this experience is rarely the focus of empirical study. In this study, 79 dating couples completed measures of relationship well-being and then participated in videotaped interactions in which they took turns discussing recent positive and negative events. Disclosers rated how understood, validated, and cared for they felt in each discussion, and outside observers coded responders' behavior. Both self-report data and observational codes showed that 2 months later, responses to positive event discussions were more closely related to relationship well-being and break-up than were responses to negative event discussions. The results are discussed in terms of the recurrent, but often overlooked, role that positive emotional exchanges play in building relationship resources.     

Viewpoint and orientation influence picture recognition in the blind

In the first three experiments, subjects felt solid geometrical forms and matched raised-line pictures to the objects. Performance was best in experiment 1 for top views, with shorter response latencies than for side views, front views, or 3-D views with foreshortening. In a second experiment with blind participants, matching accuracy was not significantly affected by prior visual experience, but speed advantages were found for top views, with 3-D views also yielding better matching accuracy than side views. There were no performance advantages for pictures of objects with a constant cross section in the vertical axis. The early-blind participants had lower performance for side and frontal views. The objects were rotated to oblique orientations in experiment 3. Early-blind subjects performed worse than the other subjects given object rotation. Visual experience with pictures of objects at many angles could facilitate identification at oblique orientations. In experiment 5 with blindfolded sighted subjects, tangible pictures were used as targets and as choices. The results yielded superior overall performance for 3-D views (mean, M = 74% correct) and much lower matching accuracy for top views as targets (M = 58% correct). Performance was highest when the target and matching viewpoint were identical, but 3-D views (M = 96% correct) were still far better than top views. The accuracy advantage of the top views also disappeared when more complex objects were tested in experiment 6. Alternative theoretical implications of the results are discussed.     

What you want (and do not want) affects what you see (and do not see): avoidance social goals and social events

Two studies examined the influence of approach and avoidance social goals on memory for and evaluation of ambiguous social information. Study 1 found that individual differences in avoidance social goals were associated with greater memory of negative information, negatively biased interpretation of ambiguous social cues, and a more pessimistic evaluation of social actors. Study 2 experimentally manipulated social goals and found that individuals high in avoidance social motivation remembered more negative information and expressed more dislike for a stranger in the avoidance condition than in the approach condition. Results suggest that avoidance social goals are associated with emphasizing potential threats when making sense of the social environment.     

Why walkers slip: shine is not a reliable cue for slippery ground

In a series of four studies, we investigated the visual cues that walkers use to predict slippery ground surfaces and tested whether visual information is reliable for specifying low-friction conditions. In Study 1, 91% of participants surveyed responded that they would use shine to identify upcoming slippery ground. Studies 2-4 confirmed participants' reliance on shine to predict slip. Participants viewed ground surfaces varying in gloss, paint color, and viewing distance under indoor and outdoor lighting conditions. Shine and slip ratings and functional walking judgments were related to surface gloss level and to surface coefficient of friction (COF). However, judgments were strongly affected by surface color, viewing distance, and lighting conditions--extraneous factors that do not change the surface COF. Results suggest that, although walkers rely on shine to predict slippery ground, shine is not a reliable visual cue for friction. Poor visual information for friction may underlie the high prevalence of friction-related slips and falls.     

Ontogeny of the adrenal response to (+)-methamphetamine in neonatal rats: the effect of prior drug exposure

We examined the ontogeny of the corticosterone response to (+)-methamphetamine in neonatal rats. In experiment-1, animals were injected with 10 mg/kg of (+)-methamphetamine or saline and plasma corticosterone levels were examined in separate groups 30 or 105 min later on postnatal day (P) 1, 3, 5, 7, 9, 11, 13, 15, 17, or 19. The adrenal response to methamphetamine was best described by a U-shaped function with the nadir of corticosterone release occurring between P7 and P13. Experiment-2 was similar except that the effect of four consecutive days of exposure to (+)-methamphetamine (four times daily at 2 h intervals with 10 mg/kg) was assessed with a single final dose early on the fifth day (i.e. P1-5, 3-7, 5-9, 7-11, 9-13, 11-15, 13-17, 15-19). The 30 min corticosterone response after multiple methamphetamine doses was augmented compared to single exposures, with the exception of the two earliest dosing intervals ending on P5 and P7, where the responses were lower. In addition, at 105 min, the levels of corticosterone were attenuated relative to a single drug administration. With the exception of animals receiving methamphetamine from P15 to P19, thymus weights were unaffected. The data demonstrate that (+)-methamphetamine is a robust activator of corticosterone release in developing animals and this release is extensively modified by age and previous drug exposure.