Toward rational use of cognitive training in those with mild cognitive impairment.

The term cognitive training includes a range of techniques that hold potential for treating cognitive impairment caused by neurologic injury and disease. Our central premise is that these techniques differ in their mechanisms of action and therefore engage distinct brain regions (or neural networks). We support this premise using data from a single-blind randomized-controlled trial in which patients with mild cognitive impairment were randomized to either mnemonic strategy training (MST) or spaced retrieval training (SRT) as they learned ecologically relevant object-location associations. Both training approaches were highly effective in the short term, but MST demonstrated a clear advantage after days to weeks. MST also increased activation in and functional connectivity between frontal, temporal, and parietal regions as well as the hippocampus. In contrast, patterns of reduced activation and functional connectivity were evident following SRT. These findings support the rational development of cognitive training techniques.

The Reliability of the African Neuropsychology Battery in Persons of African Descent.

OBJECTIVE: The African Neuropsychology Battery (ANB) includes eight culturally appropriate cognitive tests developed for use in the Congo and other sub-Saharan African populations. The current study examines the reliability of the ANB in three samples of participants of African descent. METHODS: Subjects were recruited in the United States and the Congo to participate in three studies of ANB internal consistency reliability (Study 1), test-retest reliability (Study 2), and interrater reliability for the two ANB measures (i.e., Visuospatial Memory and Proverb Tests) requiring examiner ratings of response adequacy (Study 3). Subjects were administered ANB tests of visuospatial perception, language, memory, abstract reasoning, and problem solving. We calculated Cronbach's alpha, corrected item-total correlations and mean inter-item correlations for internal consistency, Pearson product-moment correlations and intraclass correlation coefficients for test-retest reliability, and intraclass correlation coefficients for interrater reliability. RESULTS: The ANB tests had acceptable internal consistency (Cronbach's alphas ranging from .37 to .93). Across subtests, test-retest reliability coefficients ranged from .39 to .91, and intraclass correlation stability coefficients (ICCs) ranged from .39 to .82. Of the two ANB tests requiring interrater reliability, only the Proverb Test had a low ICC of .13, (confidence intervals: -.29 to .52). CONCLUSION: The present study demonstrated that most ANB tests show adequate reliability in participants of African descent. However, the scoring criteria of the African Proverb Test require revision in order to improve the interrater reliability of the measure.

Mnemonic strategy training increases neocortical activation in healthy older adults and patients with mild cognitive impairment.

Learning and memory deficits characterize the diagnosis of amnestic mild cognitive impairment (aMCI), which is widely viewed as a clinical precursor to Alzheimer's type dementia. There is a growing interest in non-pharmacologic interventions, such as mnemonic strategies, for improving learning and memory in patients with aMCI as well as for maintaining functioning in healthy older adults. Using an ecologically relevant object-location association paradigm, we conducted a randomized, controlled, single-blind study in which healthy older adults and patients with aMCI were randomized to either mnemonic strategy training or a control group that was matched for stimulus exposure. We previously reported that mnemonic strategy training resulted in significantly greater learning and memory improvements compared to the matched exposure condition, in both aMCI patients and healthy controls. The current study examined changes in neocortical activation during encoding in a subset of participants who underwent functional magnetic resonance imaging (fMRI) scanning both before and after training. To minimize potential confounds in between-group comparisons, we employed non-linear cortex based alignment and included only correctly encoded stimuli in our analyses. When re-encoding stimuli learned during training (i.e., trained stimuli), we found a general enhancement of activation in right prefrontal and parietal regions, possibly reflecting practice-related improvement in coordinate spatial processing in all but the aMCI exposure group. Left hemisphere activation was typically only evident in the mnemonic strategy trained participants, regardless of diagnostic status, with the ventrolateral prefrontal cortex appearing especially important for strategy use. While encoding relatively novel stimuli, both mnemonic strategy groups (aMCI patients and healthy controls) demonstrated increased activation in a subset of regions showing change for the trained stimuli, indicating a mnemonic strategy-induced change in the processing of new information. These findings could not be explained by repeated exposure since there was little to no activation overlap in the respective exposure control groups. The current results reinforce the potential benefits of cognitive interventions in these growing populations and indicate that neuroplastic change in key rostral and lateral prefrontal regions mediate this behavioral change.

Deep Hypothermia With Retrograde Cerebral Perfusion Versus Moderate Hypothermia With Antegrade Cerebral Perfusion for Arch Surgery.

BACKGROUND: Patients undergoing aortic arch replacement are at high risk for neurologic injury. This study compared two different established neuroprotective strategies in patients undergoing elective transverse hemiarch replacement. METHODS: Twenty patients undergoing hemiarch replacement were prospectively randomized to receive deep hypothermic circulatory arrest with retrograde cerebral perfusion (DHCA+RCP) or moderate hypothermic circulatory arrest with antegrade cerebral perfusion (MHCA+ACP). All patients received neurologist-adjudicated examinations and magnetic resonance imaging before discharge. The primary end point was a composite of stroke, transient ischemic attack, and magnetic resonance imaging-adjudicated injury. Secondary end points were transient neurologic dysfunction, and the National Institutes of Health Stroke Scale, and neurocognitive scores. RESULTS: Randomization resulted in 11 DHCA+RCP patients and 9 MHCA+ACP patients. There was no difference in cardiopulmonary bypass, cross-clamp, or circulatory arrest times. MHCA+ACP patients underwent circulatory arrest at significantly warmer temperatures (26.3° ± 1.8°C) than DHCA+RCP patients (19.9° ± 0.1°C, p < 0.0001). There were no deaths or renal failure in either group. There was 1 stroke in each group. National Institute of Health stroke scale scores and neurocognitive test results were equivalent. Diffusion-weighted magnetic resonance imaging demonstrated lesions in 100% (9 of 9) of MHCA+ACP patients compared with 45% (5 of 11) of DHCA+RCP patients (p < 0.01). MHCA+ACP patients had a significantly higher number of lesions than DHCA+RCP patients (p < 0.01). The primary end point was achieved in 100% of MHCA+ACP patients compared with 45% of DHCA+RCP patients (p < 0.01). CONCLUSIONS: Although there was no significant difference in clinically evident neurologic injury, this pilot study suggests that MHCA+ACP may be associated with a higher incidence of radiographic neurologic injury than DHCA+RCP in patients undergoing elective hemiarch replacement.

Neurocognition and Cerebral Lesion Burden in High-Risk Patients Before Undergoing Transcatheter Aortic Valve Replacement: Insights From the SENTINEL Trial.

OBJECTIVES: The authors sought to determine baseline neurocognition before transcatheter aortic valve replacement (TAVR) and its correlations with pre-TAVR brain imaging. BACKGROUND: TAVR studies have not shown a correlation between diffusion-weighted image changes and neurocognition. The authors wanted to determine the extent to which there was already impairment at baseline that correlated with cerebrovascular disease. METHODS: SENTINEL (Cerebral Protection in Transcatheter Aortic Valve Replacement) trial patients had cognitive assessments of attention, processing speed, executive function, and verbal and visual memory. Z-scores were based on normative means and SDs, combined into a primary composite z-score. Brain magnetic resonance images were obtained pre-TAVR on 3-T scanners with a T2 fluid-attenuated inversion recovery (FLAIR) sequence. Scores ≤-1.5 SD below the normative mean (7th percentile) were considered impairment. Paired t tests compared within-subject scores, and chi-square goodness-of-fit compared the percentage of subjects below -1.5 SD. Correlation and regression analyses assessed the relationship between neurocognitive z-scores and T2 lesion volume. RESULTS: Among 234 patients tested, the mean composite z-score was -0.65 SD below the normative mean. Domain scores ranged from -0.15 SD for attention to -1.32 SD for executive function. On the basis of the ≥1.5 SD normative reference, there were significantly greater percentages of impaired scores in the composite z-score (13.2%; p = 0.019), executive function (41.9%; p < 0.001), verbal memory (p < 0.001), and visual memory (p < 0.001). The regression model between FLAIR lesion volume and baseline cognition showed statistically significant negative correlations. CONCLUSIONS: There was a significant proportion of aortic stenosis patients with impaired cognition before TAVR, with a relationship between baseline cognitive function and lesion burden likely attributable to longstanding cerebrovascular disease. These findings underscore the importance of pre-interventional testing and magnetic resonance imaging in any research investigating post-surgical cognitive outcomes in patients with cardiovascular disease.

Continuous measurement of object location memory is sensitive to effects of age and mild cognitive impairment and related to medial temporal lobe volume.

INTRODUCTION: We present findings of a novel and ecologically relevant associative memory test, the Object Location Touchscreen Test (OLTT), which was posited as sensitive to early medial temporal lobe compromise associated with mild cognitive impairment (MCI). METHODS: A total of 114 participants, including healthy young and older controls and patients with MCI, completed the OLTT and standard neuropsychological testing. The OLTT required participants to recall the location of objects under free and cued recall conditions, with accuracy evaluated using distance measures (i.e., a continuous error score), and a standard recognition format. Correlations between performance and volumetric data were evaluated from a subset of 77 participants. RESULTS: Significant age effects were dwarfed by MCI effects across all test conditions. OLTT Cued Recall was strongly and specifically related to the volume of disease-relevant medial temporal lobe regions, generally more than traditional memory tests. DISCUSSION: The OLTT may be sensitive to early structural compromise in regions affected by Alzheimer's disease.

Combined mnemonic strategy training and high-definition transcranial direct current stimulation for memory deficits in mild cognitive impairment.

INTRODUCTION: Memory deficits characterize Alzheimer's dementia and the clinical precursor stage known as mild cognitive impairment. Nonpharmacologic interventions hold promise for enhancing functioning in these patients, potentially delaying functional impairment that denotes transition to dementia. Previous findings revealed that mnemonic strategy training (MST) enhances long-term retention of trained stimuli and is accompanied by increased blood oxygen level-dependent signal in the lateral frontal and parietal cortices as well as in the hippocampus. The present study was designed to enhance MST generalization, and the range of patients who benefit, via concurrent delivery of transcranial direct current stimulation (tDCS). METHODS: This protocol describes a prospective, randomized controlled, four-arm, double-blind study targeting memory deficits in those with mild cognitive impairment. Once randomized, participants complete five consecutive daily sessions in which they receive either active or sham high definition tDCS over the left lateral prefrontal cortex, a region known to be important for successful memory encoding and that has been engaged by MST. High definition tDCS (active or sham) will be combined with either MST or autobiographical memory recall (comparable to reminiscence therapy). Participants undergo memory testing using ecologically relevant measures and functional magnetic resonance imaging before and after these treatment sessions as well as at a 3-month follow-up. Primary outcome measures include face-name and object-location association tasks. Secondary outcome measures include self-report of memory abilities as well as a spatial navigation task (near transfer) and prose memory (medication instructions; far transfer). Changes in functional magnetic resonance imaging will be evaluated during both task performance and the resting-state using activation and connectivity analyses. DISCUSSION: The results will provide important information about the efficacy of cognitive and neuromodulatory techniques as well as the synergistic interaction between these promising approaches. Exploratory results will examine patient characteristics that affect treatment efficacy, thereby identifying those most appropriate for intervention.

Neurocognitive functioning in adults with congenital heart disease.

OBJECTIVE: Adults with congenital heart disease (CHD) are at increased risk of psychological disorders and cognitive deficiencies due to structural/acquired neurological abnormalities and neurodevelopmental disorders as children. However, limited information is known about the neuropsychological functioning of adults with CHD. This study screened neuropsychological abilities and explored group differences related to cardiac disease severity and neurological risk factors in adults with CHD. DESIGN: Participants completed brief neuropsychological testing. Information about neurobehavioral and psychological symptoms, employment, education, and disability were also collected from the patient and a family member. RESULTS: Forty-eight participants with adult CHD completed neuropsychological testing. Visuospatial skills and working memory were worse than expected compared to the typical population. Frequency of neurological comorbidities (e.g., stroke, seizures) was higher in those with more severe heart disease (e.g., single ventricle or cyanotic disease), and executive functioning was weaker in those with neurological comorbidities. Those with more severe heart disease were more likely to be unemployed and to receive disability benefits, but educational attainment did not differ. Those who received disability performed worse on tasks of executive functioning. CONCLUSIONS: Findings suggest concerns about neuropsychological functioning that need to be more comprehensively assessed in adults with CHD. Understanding the cognitive limitations of this aging population can help guide access to resources, transition of care, and medical care engagement, thus improving quality of care and quality of life.

Remediation of a naming deficit following left temporal lobe epilepsy surgery.

Dysnomia is associated with temporal lobe epilepsy and may include a deficit in recalling the names of familiar people. The deficit can worsen following surgery to relieve refractory seizures. The following is a case report comparing implicit (errorless learning) and explicit (rote rehearsal) approaches to retraining face-name associations in a 52-year-old woman who was status post-amygdalo-hippocampectomy for refractory complex partial seizures. Although both approaches initially improved performance above baseline, only errorless learning resulted in stable gains during a 10-min delay and at 1-week follow-up. Initial improvements in naming with rote rehearsal were not maintained even during the 10-min delay. In patients with severe memory impairment and dysnomia, errorless learning may offer a viable rehabilitation strategy for improving naming performance.

Cognitive rehabilitation of memory for mild cognitive impairment: a methodological review and model for future research.

Several recent reviews have suggested that cognitive rehabilitation may hold promise in the treatment of memory deficits experienced by patients with mild cognitive impairment. In contrast to the previous reviews that mainly focused on outcome, the current review examines key methodological challenges that are critical for designing and interpreting research studies and translating results into clinical practice. Using methodological details from 36 studies, we first examine diagnostic variability and how the use of cutoffs may bias samples toward more severely impaired patients. Second, the strengths and limitations of several common rehabilitative techniques are discussed. Half of the reviewed studies used a multi-technique approach that precludes the causal attribution between any specific technique and subsequent improvement. Third, there is a clear need to examine the dose-response relationship since this information was strikingly absent from most studies. Fourth, outcome measures varied widely and frequently depended on neuropsychological tests with little theoretical justification or ecological relevance. Fifth, we discuss how the variability in each of these other four areas complicates efforts to examine training generalization. Overall, future studies should place greater emphasis on ecologically relevant treatment approaches and outcome measures and we propose a hierarchical model that may aid in this pursuit.

Maple syrup urine disease (MSUD): a case with long-term follow-up after liver transplantation.

Maple syrup urine disease (MSUD) is a rare hereditary metabolic condition where the body is unable to breakdown amino acids causing toxic buildup. Acute and long-term management of MSUD involves a restricted diet and regular monitoring of amino acid levels; however, more recently liver transplants have been shown to be successful in treating this condition. Even with successful management of MSUD there is evidence from pediatric cases that shows a distinct pattern of neurocognitive deficits associated with this condition, including impaired nonverbal skills and psychomotor functioning with relatively intact verbal abilities. In the present paper, we report an adult case of MSUD with associated neurocognitive deficits and functional limitations following liver transplantation. Neuroimaging revealed no structural abnormalities, while the results from the neuropsychological evaluation showed impairment in visual-spatial processing, attention, executive functioning, and psychomotor abilities, with relative strengths in verbal skills. The patient also showed reduced adaptive functioning and mild anxiety. This case demonstrates neurocognitive deficiencies within the context of normal magnetic resonance imaging. The possible underlying mechanism of this neuropsychological profile is discussed in relation to other neurodevelopmental models.

Correlates of persistent sleep complaints after traumatic brain injury.

The objective of the study was to examine factors associated with persistent sleep complaint (SC) after traumatic brain injury. The study design consisted of a retrospective chart review case series, with longitudinal follow-up data. Subjects were identified from Georgia Model Brain Injury System with sleep data post-injury. Twenty three (47.9%) had no sleep complaint at either 6 or 12 months post-injury or resolved sleep complaint at 12 months (Without Persistent SC group); 25 (52.1%) maintained a sleep complaint from 6 to 12 months or reported a sleep complaint at 12 months post-injury (With Persistent SC group). Demographic, premorbid and peri-injury characteristics and The Neurobehavioral Functioning Inventory (NFI) scores did not differentiate the two groups. The Without Persistent SC group had a slight improvement from 6 to 12 months post-injury in post-traumatic stress (PTS) symptoms and depression. Significant psychological patterns were identified in those with persistent SC at both 6 and 12 months post-injury, i.e., worse depression and worse PTS symptoms. This trend was apparent at 6 months and became significant at 12 months post-injury. However, subjects with newly emerging sleep complaints at 12 months had similar characteristics as the Without Persistent SC group. The observed psychological patterns associated with persistent sleep complaint in a specific time course after brain injury have important research and clinical implications that merit further study.

Mnemonic strategy training improves memory for object location associations in both healthy elderly and patients with amnestic mild cognitive impairment: a randomized, single-blind study.

OBJECTIVE: To evaluate the efficacy of mnemonic strategy training versus a matched-exposure control condition and to examine the relationship between training-related gains, neuropsychological abilities, and medial temporal lobe volumetrics in patients with amnestic mild cognitive impairment (aMCI) and age-matched healthy controls. METHOD: Twenty-three of 45 screened healthy controls and 29 of 42 screened patients with aMCI were randomized to mnemonic strategy or matched-exposure groups. Groups were run in parallel, with participants blind to the other intervention. All participants completed five sessions within 2 weeks. Memory testing for object-location associations (OLAs) was performed during sessions one and five and at a 1-month follow-up. During Sessions 2-4, participants received either mnemonic strategy training or a matched number of exposures with corrective feedback for a total of 45 OLAs. Structural magnetic resonance imaging was performed in most participants, and medial temporal lobe volumetrics were acquired. RESULTS: Twenty-one healthy controls and 28 patients with aMCI were included in data analysis. Mnemonic strategy training was significantly more beneficial than matched exposure immediately after training, p = .006, partial η2 = .16, and at 1 month, p < .001, partial η2 = .35, regardless of diagnostic group (healthy group or aMCI group). Although patients with aMCI demonstrated gains comparable to the healthy control groups, their overall performance generally remained reduced. Mnemonic strategy-related improvement was correlated positively with baseline memory and executive functioning and negatively with inferior lateral ventricle volume in patients with aMCI; no significant relationships were evident in matched-exposure patients. CONCLUSION: Mnemonic strategies effectively improve memory for specific content for at least 1 month in patients with aMCI.

Mnemonic strategy training partially restores hippocampal activity in patients with mild cognitive impairment.

Learning and memory deficits typify patients with mild cognitive impairment (MCI) and are generally attributed to medial temporal lobe dysfunction. Although the hippocampus is perhaps the most commonly studied neuroanatomical structure in these patients, there have been few attempts to identify rehabilitative interventions that facilitate its functioning. Here, we present results from a randomized, controlled, single-blind study in which patients with MCI and healthy elderly controls (HEC) were randomized to either three sessions of mnemonic strategy training (MS) or a matched-exposure control group (XP). All participants underwent pre- and posttraining fMRI scanning as they encoded and retrieved object-location associations. For the current report, fMRI analyses were restricted to the hippocampus, as defined anatomically. Before training, MCI patients showed reduced hippocampal activity during both encoding and retrieval, relative to HEC. Following training, the MCI MS group demonstrated increased activity during both encoding and retrieval. There were significant differences between the MCI MS and MCI XP groups during retrieval, especially within the right hippocampus. Thus, MS facilitated hippocampal functioning in a partially restorative manner. We conclude that cognitive rehabilitation techniques may help mitigate hippocampal dysfunction in MCI patients.

Long-term neurocognitive and neuroimaging outcomes in posterior reversible encephalopathy syndrome: two case reports and implications.

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic and neurometabolic state associated with a distinct appearance on computed tomography and magnetic resonance imaging, as well as particular clinical features. While PRES is defined as a reversible condition, instances of irreversible or persisting cytotoxic edema have been reported and appear to be associated with poor outcomes. Studies addressing the post-acute neurocognitive findings in persisting/irreversible PRES are lacking. We report two cases of persisting PRES with associated neurocognitive deficits and functional limitations following acute presentation. Neuroimaging revealed abnormalities within the posterior parietal lobes, along with bilateral involvement of the occipital and frontal lobes. The results from the neuropsychological examination revealed a pattern of impairment generally affecting spatial-perceptual and related functions and aspects of executive function. These cases document instances of irreversible/persisting PRES with associated neurocognitive deficits and functional limitations generally corresponding with the areas implicated on neuroimaging. Studies addressing the post-acute neurocognitive presentation and functional outcomes of PRES are needed.

Where did I put that? Patients with amnestic mild cognitive impairment demonstrate widespread reductions in activity during the encoding of ecologically relevant object-location associations.

Remembering the location of objects in the environment is both important in everyday life and difficult for patients with amnestic mild cognitive impairment (aMCI), a clinical precursor to Alzheimer's disease. To test the hypothesis that memory impairment for object location in aMCI reflects hippocampal dysfunction, we used an event-related functional magnetic resonance imaging paradigm to compare patients with aMCI and healthy elderly controls (HEC) as they encoded 90 ecologically relevant object-location associations (OLAs). Two additional OLAs, repeated a total of 45 times, served as control stimuli. Memory for these OLAs was assessed following a 1-h delay. The groups were well matched on demographics and brain volumetrics. Behaviorally, HEC remembered significantly more OLAs than did aMCI patients. Activity differences were assessed by contrasting activation for successfully encoded Novel stimuli vs. Repeated stimuli. The HEC demonstrated activity within object-related (ventral visual stream), spatial location-related (dorsal visual stream), and feature binding-related cortical regions (hippocampus and other memory-related regions) as well as in frontal cortex and associated subcortical structures. Activity in most of these regions correlated with memory test performance. Although the aMCI patients demonstrated a similar activation pattern, the HEC showed significantly greater activity within each of these regions. Memory test performance in aMCI patients, in contrast to the HEC, was correlated with activity in regions involved in sensorimotor processing. We conclude that aMCI patients demonstrate widespread cerebral dysfunction, not limited to the hippocampus, and rely on encoding-related mechanisms that differ substantially from healthy individuals.

Ecologically-oriented neurorehabilitation of memory: robustness of outcome across diagnosis and severity.

PRIMARY OBJECTIVE: The current study looked for a differential response to memory rehabilitation, testing the hypotheses that outcome would vary significantly as a function of patient diagnosis and severity of memory impairment. RESEARCH DESIGN: Unblinded, open-label, pre/post-treatment comparison of memory rehabilitation in patients stratified by diagnosis (brain injury, n = 15; stroke, n = 12; other neurological condition, n = 6) and memory impairment severity. METHODS AND PROCEDURES: Patients underwent an ecologically-oriented, strategy-based intervention for memory impairment and were evaluated pre- and post-treatment on seven simulations (four with alternate forms, randomized to the pre- or post-test) of everyday declarative or prospective memory tasks. MAIN OUTCOMES AND RESULTS: Patients at all levels of severity and in all three diagnostic groups showed equivalent, statistically significant improvement in memory performance. Neither practice effects from repeat test administration nor spontaneous recovery accounted for the improvement in memory performance. CONCLUSIONS: The current study provided evidence of improved performance in everyday memory content domains with compensatory-based cognitive rehabilitation. Comparable improvement was seen across diagnostic groups and severity ranges. Additional case series and randomized clinical trials are needed to evaluate further the efficacy of compensation-based approaches to cognitive rehabilitation.

Activation and effective connectivity changes following explicit-memory training for face-name pairs in patients with mild cognitive impairment: a pilot study.

BACKGROUND: Mild cognitive impairment (MCI) is often a precursor to Alzheimer disease. Little research has examined the efficacy of cognitive rehabilitation in patients with MCI, and the relevant neural mechanisms have not been explored. The authors previously showed the behavioral efficacy of cognitive rehabilitation using mnemonic strategies for face-name associations in patients with MCI. Here, the authors used functional magnetic resonance imaging (fMRI) to test whether there were training-specific changes in activation and connectivity within memory-related areas. METHODS: A total of 6 patients with amnestic, multidomain MCI underwent pretraining and posttraining fMRI scans, during which they encoded 90 novel face-name pairs and completed a 4-choice recognition memory test immediately after scanning. Patients were taught mnemonic strategies for half the face-name pairs during 3 intervening training sessions. RESULTS: Training-specific effects comprised significantly increased activation within a widespread cerebral cortical network involving medial frontal, parietal, and occipital regions; the left frontal operculum and angular gyrus; and regions in the left lateral temporal cortex. Increased activation common to trained and untrained stimuli was found in a separate network involving inferior frontal, lateral parietal, and occipital cortical regions. Effective connectivity analysis using multivariate, correlation-purged Granger causality analysis revealed generally increased connectivity after training, particularly involving the middle temporal gyrus and foci in the occipital cortex and the precuneus. CONCLUSION: The authors' findings suggest that the effectiveness of explicit-memory training in patients with MCI is associated with training-specific increases in activation and connectivity in a distributed neural system that includes areas involved in explicit memory.

Use of complex three-dimensional objects to assess visuospatial memory in healthy individuals and patients with unilateral amygdalohippocampectomy.

Because many visuospatial memory tests do not reliably detect right medial temporal lobe (MTL) dysfunction, we developed a novel object recognition test using complex three-dimensional stimuli. To influence encoding strategy, half the stimuli were multicolored (color towers) and accompanied by verbally based instructions, and half were gray (gray towers) and accompanied by visuospatially based instructions. In Experiment 1, healthy subjects completed the test while performing verbal or visuospatial interference tasks or without interference. In Experiment 2, patients with unilateral amygdalohippocampectomies for intractable epilepsy completed the test without interference. Results suggest that color tower recognition was partially dependent on verbal processing and sensitive to MTL lesions in general. Recognition of gray towers was reliant on visuospatial processing, and the decay in accuracy after a delay was sensitive and specific to right MTL lesions. These findings suggest that test stimuli such as three-dimensional objects can be useful in assessing right MTL dysfunction.

Explicit memory training leads to improved memory for face-name pairs in patients with mild cognitive impairment: results of a pilot investigation.

Relatively few studies have examined the use of cognitive rehabilitation in patients with mild cognitive impairment (MCI), largely due to the assumption that training will not improve functioning in patients with progressive conditions. Face-name association, an ecologically valid task, is both dependent on the explicit memory system and difficult for MCI patients. During three hour-long sessions, eight patients diagnosed with MCI were trained in the use of explicit memory strategies with 45 face-name pairs. For each pair, they were taught to visually identify a facial feature, link a phonological cue to that feature, and recall the associated name. There was significant improvement in recognition accuracy, along with faster reaction times, for trained face-name pairs. Improved accuracy persisted when tested one month after training. Significant, but less, improvement was also found on untrained stimuli, raising the possibility of generalization of training strategies. Preliminary results suggest strategy-based cognitive rehabilitation may be beneficial in patients with MCI, though these results must be replicated with a control group to rule out practice effects.