Insights into spared memory capacity in amnestic MCI and Alzheimer's Disease via minimal interference

Impairment on standard tests of delayed recall is often already maximal in the aMCI stage of Alzheimer's Disease. Neuropathological work shows that the neural substrates of memory function continue to deteriorate throughout the progression of the disease, hinting that further changes in memory performance could be tracked by a more sensitive test of delayed recall. Recent work shows that retention in aMCI patients can be raised well above floor when the delay period is devoid of further material - 'Minimal Interference'. This memory enhancement is thought to be the result of improved memory consolidation. Here we used the minimal interference/interference paradigm (word list retention following 10 min of quiet resting vs. picture naming) in a group of 17 AD patients, 25 aMCI patients and 25 controls. We found (1) that retention can be improved significantly by minimal interference in patients with aMCI and patients with mild to moderate AD; (2) that the minimal interference paradigm is sensitive to decline in memory function with disease severity, even when performance on standard tests has reached floor; and (3) that this paradigm can differentiate well (80% sensitivity and 100% specificity) between aMCI patients who progress and do not progress to AD within 2 years. Our findings support the notion that the early memory dysfunction in AD is associated with an increased susceptibility to memory interference and are suggestive of a gradual decline in consolidation capacity with disease progression.     

The cost of action miscues: hemispheric asymmetries

Adaptive behaviors require preparation and when necessary inhibition or alteration of actions. The right hemisphere has been posited to be dominant for preparatory motor activation. This experiment was designed to learn if there are hemispheric asymmetries in the control of altered plans of actions. Cues, both valid and invalid, which indicate the hand most likely to be called onto respond, as well as the imperative stimuli that indicate the actual response hand, were presented to either the right or left visual fields of 14 normal right handed participants. The delay after a miscue is dependent on the time taken to inhibit the premotor and motor systems of the incorrectly activated hemisphere, as well as to activate the motor systems of the opposite hemisphere, which might have been interhemispherically inhibited by this miscue. Analyses of reaction times revealed that miscues presented in left hemispace (right hemisphere) cost more time than those miscues presented in right hemispace (left hemisphere), suggesting that activation of the preparatory systems controlled by the right hemisphere may take longer to reverse than those controlled by the left hemisphere. This asymmetry may be related to asymmetries in the strength of hemispheric activation with contralateral inhibition.     

Mixing metaphors in the cerebral hemispheres: what happens when careers collide?

Are processes of figurative comparison and figurative categorization different? An experiment combining alternative-sense and matched-sense metaphor priming with a divided visual field assessment technique sought to isolate processes of comparison and categorization in the 2 cerebral hemispheres. For target metaphors presented in the right visual field/left cerebral hemisphere (RVF/LH), only matched-sense primes were facilitative. Literal primes and alternative-sense primes had no effect on comprehension time compared to the unprimed baseline. The effects of matched-sense primes were additive with the rated conventionality of the targets. For target metaphors presented to the left visual field/right cerebral hemisphere (LVF/RH), matched-sense primes were again additively facilitative. However, alternative-sense primes, though facilitative overall, seemed to eliminate the preexisting advantages of conventional target metaphor senses in the LVF/RH in favor of metaphoric senses similar to those of the primes. These findings are consistent with tightly controlled categorical coding in the LH and coarse, flexible, context-dependent coding in the RH.     

Grief and trauma intervention for children after disaster: exploring coping skills versus trauma narration

This study evaluated the differential effects of the Grief and Trauma Intervention (GTI) with coping skills and trauma narrative processing (CN) and coping skills only (C). Seventy African American children (6-12 years old) were randomly assigned to GTI-CN or GTI-C. Both treatments consisted of a manualized 11-session intervention and a parent meeting. Measures of trauma exposure, posttraumatic stress symptoms, depression, traumatic grief, global distress, social support, and parent reported behavioral problems were administered at pre, post, 3 and 12 months post intervention. In general, children in both treatment groups demonstrated significant improvements in distress related symptoms and social support, which, with the exception of externalizing symptoms for GTI-C, were maintained up to 12 months post intervention. Results suggest that building coping skills without the structured trauma narrative may be a viable intervention to achieve symptom relief in children experiencing trauma-related distress. However, it may be that highly distressed children experience more symptom relief with coping skills plus narrative processing than with coping skills alone. More research on the differential effects of coping skills and trauma narration on child distress and adaptive functioning outcomes is needed.     

Toward making progress feedback an effective common factor in couple therapy

Systematic monitoring of individual therapy progress, coupled with feedback to the therapist, reliably enhances therapy outcome by alerting therapists to individual clients who are off track to benefit by the end of therapy. The current paper reviews the possibility of using similar systematic monitoring and feedback of therapy progress as a means to enhance couple therapy outcome, including what measures of therapy progress are most likely to be useful, how to structure feedback to be most useful to therapists, and the likely mediators of the effects of therapy progress feedback. One implicit assumption of therapy progress feedback is that clients unlikely to benefit from therapy can be detected early enough in the course of therapy for corrective action to be taken. As a test of this assumption, midtherapy progress was examined as a predictor of final couple therapy outcome in a sample of 134 distressed couples. Either a brief 7- or 32-item assessment of couple therapy progress at midtherapy detected a substantial proportion (46%) of couples who failed to benefit by the end of therapy. Given that failure to benefit from couple therapy is somewhat predictable across the course of therapy, future research should test whether systematic monitoring and feedback of progress could enhance therapy outcome.