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African Americans experience higher incidence and prevalence of Alzheimer's disease (AD). Yet, they continue to be underrepresented in AD research, limiting the ability to generalize findings to the increasingly diverse US population. To reduce AD disparities, targeted efforts are needed to increase the representation of African Americans in AD research. This mini review identified evidence-based strategies that increased research participation among older African Americans. Four recruitment strategies emerged from eight published peer-reviewed studies that directly evaluated the effectiveness of strategies aimed at increasing the number of African American participants in Alzheimer's research. The strategies include community outreach and education, face-to-face discussions, remote access, and referral and partnership with local organizations. Across different locations, these strategies increased the number of African Americans enrolled into AD research, the number of people that signed up to donate their brains for AD research upon death, and the knowledge and perception of AD in the communities. Targeted efforts are effective in increasing AD research participation among older African Americans, especially when combined with approaches that emphasize transparency and mutual trust and involve the community as stakeholders in the research process., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Despite their high risks for Alzheimer's disease, older Black men are minimally represented in Alzheimer's research and clinical trials. The absence of older Black men in Alzheimer's research limits our ability to characterize the changes associated with cognitive impairments in older Black men-a key health disparity concern., Methods: Drawing on lessons we learned from years of community-based participatory research in Newark, NJ, we highlight recruitment strategies developed alongside community partners to guide our enrollment and retention efforts for Black men., Results: We identified seven recruitment strategies: provide indirect health education through social programming, target older men through the younger men in their lives, go beyond Black churches, use older Black men as trained community ambassadors, enlist the women in Black men's lives, frame research participation as a legacy to leave their sons, and use past and current Black men participants as role models., Conclusions: These recruitment strategies help us address many barriers to recruiting older Black men. They can be easily implemented by researchers conducting aging and brain health research or interested in working with older Black men and under-represented populations.

Introduction: African Americans are two to three times more likely to be diagnosed with Alzheimer's disease (AD) compared to White Americans. Exercise is a lifestyle behavior associated with neuroprotection and decreased AD risk, although most African Americans, especially older adults, perform less than the recommended 150 min/week of moderate-to-vigorous intensity exercise. This article describes the protocol for a Phase III randomized controlled trial that will examine the effects of cardio-dance aerobic exercise on novel AD cognitive and neural markers of hippocampal-dependent function (Aims #1 and #2) and whether exercise-induced neuroprotective benefits may be modulated by an AD genetic risk factor, ABCA7 rs3764650 (Aim #3). We will also explore the effects of exercise on blood-based biomarkers for AD., Methods and Analysis: This 6-month trial will include 280 African Americans (≥ 60 years), who will be randomly assigned to 3 days/week of either: (1) a moderate-to-vigorous cardio-dance fitness condition or (2) a low-intensity strength, flexibility, and balance condition for 60 min/session. Participants will complete health and behavioral surveys, neuropsychological testing, saliva and venipuncture, aerobic fitness, anthropometrics and resting-state structural and functional neuroimaging at study entry and 6 months., Discussion: Results from this investigation will inform future exercise trials and the development of prescribed interventions that aim to reduce the risk of AD in African Americans., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2023 Gluck, Gills, Fausto, Malin, Duberstein, Erickson and Hu.)

Introduction: Excess body weight and Alzheimer's disease (AD) disproportionately affect older African Americans. While mid-life obesity increases risk for AD, few data exist on the relationship between late-life obesity and AD, or how obesity-based and genetic risk for AD interact. Although the APOE-ε4 allele confers a strong genetic risk for AD, it is unclear if late-life obesity poses a greater risk for APOE-ε4 carriers compared to non-carriers. Here we assessed: (1) the influence of body mass index (BMI) (normal; overweight; class 1 obese; ≥ class 2 obese) on cognitive and structural MRI measures of AD risk; and (2) the interaction between BMI and APOE-ε4 in older African Americans., Methods: Seventy cognitively normal older African American participants (M age = 69.50 years; M BMI = 31.01 kg/m 2 ; 39% APOE-ε4 allele carriers; 86% female) completed anthropometric measurements, physical assessments, saliva collection for APOE-ε4 genotyping, cognitive testing, health and lifestyle questionnaires, and structural neuroimaging [volume/surface area (SA) for medial temporal lobe subregions and hippocampal subfields]. Covariates included age, sex, education, literacy, depressive symptomology, and estimated aerobic fitness., Results: Using ANCOVAs, we observed that individuals who were overweight demonstrated better hippocampal cognitive function (generalization of learning: a sensitive marker of preclinical AD) than individuals with normal BMI, p = 0.016, η p 2 = 0.18. However, individuals in the obese categories who were APOE-ε4 non-carriers had larger hippocampal subfield cornu Ammonis region 1 (CA1) volumes, while those who were APOE-ε4 carriers had smaller CA1 volumes, p = 0.003, η p 2 = 0.23., Discussion: Thus, being overweight by BMI standards may preserve hippocampal function, but obesity reduces hippocampal structure and function in older African Americans with the APOE-ε4 Alzheimer's disease risk allele., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Osiecka, Fausto, Gills, Sinha, Malin and Gluck.)

ABSTRACT Objectives: Because African Americans are at elevated risk for cognitive decline and Alzheimer's disease, it is important to understand which health and lifestyle factors are most important for reducing this risk. Obesity and poor sleep quality are common in lower-income, urban African Americans and have been linked to cognitive decline in older age. Fortunately, increasing aerobic fitness via regular exercise can improve cognitive function. This study sought to (1) examine the cross-sectional relationship between aerobic fitness and cognitive function in older African Americans, and (2) determine whether body mass index and sleep quality moderated the relationship between aerobic fitness and cognition. Design: 402 older African Americans, ages 60-90 (84% female, mean education level = 14 years) completed neuropsychological testing, computerized behavioral tasks, physical performance measures, and health and lifestyle questionnaires. Hierarchical linear regressions were performed to determine associations between aerobic fitness and cognition and whether body mass index and sleep quality moderate the fitness-cognition relationship while controlling for age, sex, education, depressive symptoms, and literacy. Results: Higher aerobic fitness levels were significantly associated with better executive function. The relationships between fitness and hippocampal-dependent cognitive functions (learning and memory, generalization) were attenuated in those who are obese (body mass index  ≥  30 kg/m 2 ) or rated their sleep quality as poor, p s < .05. Conclusion: Our results suggest that while exercise and associated improvements in aerobic fitness are key for improved cognition, these benefits are maximized in those who maintain low body weight and get sufficient, high quality sleep. Exercise programs for older African Americans will be most effective if they are integrated with education programs that emphasize healthy eating, weight control, and sleep hygiene and conceptualize individuals as part of their broader social and environmental context.

Evidence suggests that memory consolidation is facilitated by sleep, both through the strengthening of existing memories and by extracting regularities embedded in those memories. We previously observed that one sleep stage, Slow-Wave sleep (SWS), is particularly involved in the extraction of temporal regularities. We suggested that this attribute can naturally stem from the time-compressed memory replay known to occur in the hippocampus during SWS. A prediction coming out of this "temporal scaffolding" hypothesis is that sleep would be especially influential on extraction of temporal regularities when the time gap between the events constituting the regularities is shortish. In this study, we tested this prediction. Eighty-three participants performed a cognitive task in which hidden temporal regularities of varying time gaps were embedded. Detecting these regularities could significantly improve performance. Participants performed the task in two sessions with an interval filled with either wake or sleep in between. We found that sleep improved performance across all time gaps and that the longer the gap had been, the smaller was the improvement across both sleep and wake. No interaction between sleep and gap size was observed; however, unlike sleeping participants, awake participants did not exhibit any further performance improvement for the long gaps following the interval. In addition, across all participants, performance for the long gaps was associated with the development of conscious awareness to the regularities. We discuss these results in light of the temporal scaffolding hypothesis and suggest future directions to further elucidate the mechanisms involved., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Lerner and Gluck.)

The current study sought to determine the influence of initial sleep quality and body mass index on the cognitive and mood outcomes of a community-based cardio-dance exercise program. Thirty-two older African Americans who participated in a 5-month cardio-dance exercise program were propensity-matched to 32 no-contact controls. Participants completed neuropsychological tests of attention, executive function, and memory and a self-reported depression measure at baseline and post-test. Among exercise participants, we observed significant improvements in depression (baseline = 6.16 ± 5.54, post-test = 4.66 ± 4.89, η p 2 = . 12 , p = .009) and attention (baseline = 40.53 ± 14.01, post-test = 36.63 ± 13.29, η p 2 = . 12 , p = .009) relative to controls. Improvements in executive function and attention were most pronounced among exercise participants with poor sleep quality (baseline = 7.71 ± 1.25, post-test = 8.29 ± 2.06, η p 2 = . 41 , p = .04) and with obesity (baseline = 38.05 ± 12.78, post-test = 35.67 ± 13.82, η p 2 = . 30 , p = .001), respectively. This study provides novel evidence that exercise has the potential to improve depression in older African Americans. For those with poor sleep quality or obesity, exercise can also improve some cognitive outcomes.

As part of its role in memory consolidation, sleep has been repeatedly identified as critical for the extraction of regularities from wake experiences. However, many null results have been published as well, with no clear consensus emerging regarding the conditions that yield this sleep effect. Here, we systematically review the role of sleep in the extraction of hidden regularities, specifically those involving associative relations embedded in newly learned information. We found that the specific behavioral task used in a study had far more impact on whether a sleep effect was discovered than either the category of the cognitive processes targeted, or the particular experimental design employed. One emerging pattern, however, was that the explicit detection of hidden rules is more likely to happen when the rules are of a temporal nature (i.e., event A at time t predicts a later event B) than when they are non-temporal. We discuss this temporal rule sensitivity in reference to the compressed memory replay occurring in the hippocampus during slow-wave-sleep, and compare this effect to what happens when the extraction of regularities depends on prior knowledge and relies on structures other than the hippocampus., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objective: This study examined learning functions in short-term cocaine users and control participants., Method: Seventeen active cocaine users (reporting 3.5 mean years of cocaine use) and seventeen non-cocaine-using controls (with similar reported levels of alcohol and marijuana use) were compared on tasks measuring different aspects of learning., Results: The cocaine users performed more poorly on the Weather Prediction and List-Learning tasks, as well as supplementary executive and psychomotor function tasks, than controls., Conclusions: Individuals with a relatively short duration of cocaine use exhibited moderate weaknesses in probabilistic category learning, verbal learning and psychomotor functions, relative to controls. These weaknesses may underpin difficulty in learning from the probabilistic consequences of behavior and hinder the ability to respond to cognitive-behavioral treatments.

The African-American Brain Health Initiative at Rutgers University-Newark is a university-community partnership combining community engagement, education and training, and brain health research. Partnering with community-based organizations, it promotes brain health literacy, Alzheimer's awareness, brain-healthy lifestyle choices, and participation in brain research for older African Americans in Greater Newark, New Jersey. Our approach to recruitment relies on building trust through long-term relationships; communicating health knowledge through trusted community leaders; recruiting subjects through targeted efforts; and cultivating research participants as ambassadors.

Aspects of stimulus-response (S-R) learning, mediated by striatal dopamine signaling, have been found to be altered in cocaine users relative to healthy controls. However, the influence of cocaine users' marijuana and alcohol use has not been accounted for. This study evaluated S-R learning and other neurocognitive functions in cocaine users while controlling for the relative influences of marijuana and alcohol use. Twenty-five long-term cocaine users and 2 control groups (25 moderate marijuana and alcohol users and 23 healthy controls) completed a computerized assessment of probabilistic category learning (the Weather Prediction task), as well as measures of equivalence learning, declarative learning, and executive, attentional, and motor function. Cocaine users exhibited decreased performance on the Weather Prediction task, as well as measures of declarative learning, attention, and motor function (p < 0.05), relative to both control groups. Cocaine users exhibited decrements in probabilistic category learning, declarative recall, and attentional and motor function, compared with both marijuana and alcohol users and nondrug users. Therefore, these decrements appear to be specifically related to the cocaine use, but not the moderate marijuana and alcohol use, of long-term cocaine users.

Feedback-based associative learning (e.g., acquiring new associations from positive or negative outcomes) and generalization (e.g., applying past learning to new settings) are important cognitive skills that enable people to make economic decisions or social judgments. This ability to acquire new skills based on feedback and transfer those experiences to predict positive outcomes in novel situations is essential at all ages, but especially among older adults who must continually adapt to new people, environments, and technologies. Ample evidence from animal work, clinical research, and computational modeling has demonstrated that feedback-based associative learning is sensitive to basal ganglia dysfunction and generalization to medial temporal lobe dysfunction. This dissociation is relevant because of recent evidence that has suggested healthy aging compromises the basal ganglia system earlier than the medial temporal lobes. However, few studies have investigated how healthy aging influences these cognitive processes. Here, we examined both feedback-based associative learning and generalization in younger, middle-aged, and older adults using a computerized acquired equivalence task. Results revealed a significant effect of age group on feedback-based associative learning, consistent with evidence of persistent age-related declines in the basal ganglia. In contrast, generalization was spared in all but the oldest adult group, likely reflecting preserved medial temporal lobe function until advanced old age. Our findings add behavioral evidence to the emerging view that healthy aging affects the striatal system before the medial temporal lobes. Although further evidence is needed, this finding may shed light on the possible time course of neural system dysfunction in healthy aging., (PsycINFO Database Record (c) 2013 APA, all rights reserved.)

Background/aims: Levodopa and dopamine agonists have different effects on the motor, cognitive, and psychiatric aspects of Parkinson's disease (PD)., Methods: Using a computational model of basal ganglia (BG) and prefrontal cortex (PFC) dopamine, we provide a theoretical synthesis of the dissociable effects of these dopaminergic medications on brain and cognition. Our model incorporates the findings that levodopa is converted by dopamine cells into dopamine, and thus activates prefrontal and striatal D(1) and D(2) dopamine receptors, whereas antiparkinsonian dopamine agonists directly stimulate D(2) receptors in the BG and PFC (although some have weak affinity to D(1) receptors)., Results: In agreement with prior neuropsychological studies, our model explains how levodopa enhances, but dopamine agonists impair or have no effect on, stimulus-response learning and working memory., Conclusion: Our model explains how levodopa and dopamine agonists have differential effects on motor and cognitive processes in PD., (Copyright © 2012 S. Karger AG, Basel.)

Objective: Drawing on two different populations, Israeli police and Hungarian civilians, the present study assessed the ability of individuals with posttraumatic stress disorder (PTSD) to generalize previous learning to novel situations. Past neuroimaging studies have demonstrated diminished medial temporal lobe (MTL) activation and/or reduced hippocampal volume in individuals with PTSD. Our earlier computational models of cortico-hippocampal function and subsequent experimental tests of these models in MTL-impaired clinical populations argue that even mild hippocampal dysfunction may result in subtle impairments in generalization. Therefore, we predicted that individuals with PTSD would show impaired generalization., Method: We compared the performance of five groups from two countries, including 19 Israeli police with PTSD and 22 trauma-exposed police without PTSD, and 22 Hungarian civilians with PTSD, 25 trauma-exposed civilians without PTSD, and 25 individuals without PTSD unexposed to the same trauma. Participants were tested on a two-phase learning paradigm, the Acquired Equivalence Task, which measures the ability to generalize past learning to novel situations., Results: We found that both PTSD and non-PTSD participants were capable of learning the initial stimulus-outcome associations, F(4, 108) = 1.79, p = .14. However, as predicted, only individuals with PTSD showed a selective deficit in generalization of this learning to novel situations (F(4, 108) = 8.35, p < .001, Partial η2 = 0.26)., Conclusions: Individuals with PTSD show a selective impairment in generalization of past learning similar to other clinical populations with MTL/hippocampal dysfunction. This is consistent with an emerging view of PTSD as being not only an anxiety disorder but also a learning disorder., ((c) 2012 APA, all rights reserved.)

Most existing models of dopamine and learning in Parkinson disease (PD) focus on simulating the role of basal ganglia dopamine in reinforcement learning. Much data argue, however, for a critical role for prefrontal cortex (PFC) dopamine in stimulus selection in attentional learning. Here, we present a new computational model that simulates performance in multicue category learning, such as the "weather prediction" task. The model addresses how PD and dopamine medications affect stimulus selection processes, which mediate reinforcement learning. In this model, PFC dopamine is key for attentional learning, whereas basal ganglia dopamine, consistent with other models, is key for reinforcement and motor learning. The model assumes that competitive dynamics among PFC neurons is the neural mechanism underlying stimulus selection with limited attentional resources, whereas competitive dynamics among striatal neurons is the neural mechanism underlying action selection. According to our model, PD is associated with decreased phasic and tonic dopamine levels in both PFC and basal ganglia. We assume that dopamine medications increase dopamine levels in both the basal ganglia and PFC, which, in turn, increase tonic dopamine levels but decrease the magnitude of phasic dopamine signaling in these brain structures. Increase of tonic dopamine levels in the simulated PFC enhances attentional shifting performance. The model provides a mechanistic account for several phenomena, including (a) medicated PD patients are more impaired at multicue probabilistic category learning than unmedicated patients and (b) medicated PD patients opt out of reversal when there are alternative and redundant cue dimensions.

Human anterograde amnesia can result from a variety of etiologies, including hypoxic brain injury and anterior communicating artery (ACoA) aneurysm rupture. Although each etiology can cause a similarly severe disruption in declarative memory for verbal and visual material, there may be differences in incrementally acquired, feedback-based learning, as well as generalization. Here, 6 individuals who survived hypoxic brain injury, 7 individuals who survived ACoA aneurysm rupture, and 13 matched controls were tested on 2 tasks that included a feedback-based learning phase followed by a transfer phase in which familiar information is presented in new ways. In both tasks, the ACoA group was slow on initial learning, but those patients who completed the learning phase went on to transfer as well as controls. In the hypoxic group, 1 patient failed to complete either task; the remaining hypoxic group did not differ from controls during learning of either task, but was impaired on transfer. These results highlight a difference in feedback-based learning in 2 amnesic etiologies, despite similar levels of declarative memory impairment., (PsycINFO Database Record (c) 2008 APA, all rights reserved.)

This study examines whether behavioral measures obtained in nondemented elderly can predict cognitive status at 2-year follow-up. Prior studies have established that delayed paragraph recall can help predict short-term risk for decline to mild cognitive impairment and Alzheimer disease. It was examined whether prediction accuracy can be improved by adding a discrimination-and-generalization task that has previously been shown to be disrupted in nondemented elderly with hippocampal atrophy, a risk factor for Alzheimer disease. Fifty nondemented, medically healthy elderly patients received baseline clinical diagnosis and cognitive testing; 2 years later, patients received a follow-up clinical diagnosis of normal, mild cognitive impairment, or probable Alzheimer disease. In all, 2 baseline variables, delayed paragraph recall and generalization performance, were predictive of follow-up outcome with sensitivity of 81% and specificity of 91%-better than the classification accuracy based on either of these measures alone. These preliminary results suggest that these behavioral tasks may be useful tools in predicting short-term cognitive outcome in nondemented elderly.

The ability to form associations between choice alternatives and their contingent outcomes is an important aspect of learning that may be sensitive to hippocampal dysfunction in memory disorders of aging such as amnestic mild cognitive impairment (MCIa), or early Alzheimer disease. In this preliminary study we examined brain activation using functional magnetic resonance imaging (fMRI) in 12 healthy elderly participants and nine patients with MCIa during an associative learning task. Using a high-field 3.0-Tesla MRI scanner, we examined the dynamic neural response during associative learning over trials. The slope of signal attenuation associated with learning was analyzed for differences between groups within an a priori defined hippocampal region. Results indicated dynamic signal attenuation associated with learning in the healthy elderly sample, but not in MCIa. The absence of an associative learning effect in the MCIa sample reaffirms an important link between the learning difficulties that are commonly encountered in MCIa and the mesial temporal region.

Aims: Patients with depression show cognitive impairment, including executive function deficit, impairments in attention, declarative memory and psychomotor performance. In addition to classic, widely studied cognitive functions, in depression implicit learning and the interpretation of feedback and its impact on performance can also be impaired compared to healthy individuals. While cognitive functions have been widely studied, much less is known about implicit learning in depression., Methods: The two-phased Kilroy sequence association test examines the basal ganglia-mediated and the temporal lobe and hippocampus-mediated learning processes within one test. We compared the performance of 22 depressed patients (according to DSM-IV) and 20 healthy control subjects using the Kilroy test. In the depressed group, we also compared the performance on each step of the test with the symptom severity measured by the Hamilton D symptom scale., Results: Depressed patients showed impaired performance compared to healthy subjects on the first, learning phase of the test. The degree of deficit on the learning phase correlated with symptom severity. We found no difference between the two groups on the second, context-dependent phase of the test., Conclusion: Our results confirm the presence of a striatal deficit in depressed patients. Results indicate that parallel memory systems are not equally affected in depression, and the character of deficit in depression may be specific to the illness.

The purpose of the present study was to investigate basal ganglia (BG) and medial temporal lobe (MTL) dependent learning in patients with schizophrenia. Acquired equivalence is a phenomenon in which prior training to treat two stimuli as equivalent (if two stimuli are associated with the same response) increases generalization between them. The learning of stimulus-response pairs is related to the BG, whereas the MTL system participates in stimulus generalization. Forty-three patients with DSM-IV schizophrenia and 28 matched healthy controls participated in the study. Volunteers received the acquired equivalence associative learning task (FISHES) during which associations between faces and pet fishes are learned. Results revealed that patients with schizophrenia showed a selective deficit on stimulus generalization, whereas stimulus-response learning was unaffected. The number of errors during stimulus-response learning correlated with the daily chlorpromazine-equivalent dose of antipsychotics. In conclusion, patients with schizophrenia showed deficits during MTL-dependent learning, but not during BG-dependent learning. High-dose first generation antipsychotics may disrupt BG-dependent learning by blocking dopaminergic neurotransmission in the nigro-striatal system.

The classical conditioning task of blocking involves the adding of a novel but redundant stimulus to a previously trained stimulus. Both blocking and novelty detection are thought to involve the hippocampus. Previously, Solomon (1977) found that nonselective aspiration lesions of the hippocampal region eliminated blocking in rabbit eyeblink conditioning. We tested the effects of selective ibotenic acid lesions of the hippocampus on blocking, as well as on novelty detection, when training is switched from a tone conditioned stimulus (CS) to a compound tone-light CS in eyeblink conditioning. Selective hippocampal lesions did not eliminate blocking but did lead to a facilitation of conditioned response (CR) acquisition to the tone and to the light, but not to the tone-light compound. Selective hippocampal lesions disrupted a CR decrement observed in sham surgical controls when transferred from tone training to tone-light training. It appears that although selective hippocampal lesions do not eliminate blocking in eyeblink conditioning, they do disrupt novelty detection and may facilitate learning to a previously blocked cue.

Prior experiments, as well as computational models, have implicated the hippocampal region in mediating the influence of nonreinforced stimulus preexposure on subsequent learning. Learned irrelevance (LIRR) is a preexposure task in which uncorrelated preexposures to the conditioned stimulus (CS) and the unconditioned stimulus (US) produce a retardation of subsequent CS-US conditioning. In the work presented here, we report the results of tests of LIRR in eyeblink conditioning in rabbits with sham lesions, nonselective cortical-hippocampal region lesions, selective hippocampal lesions, and selective entorhinal lesions. Sham-lesioned rabbits that had been preexposed to the CS and the US exhibited slower acquisition of conditioned response, as compared with context-preexposed controls. Nonselective cotical-hippocampal region lesions disrupted LIRR, whereas selective hippocampal lesions had no detrimental effect on LIRR. Selective entorhinal lesions disrupted LIRR. These findings fit other recent empirical findings and theoretical predictions that some classical conditioning tasks previously thought to depend on the hippocampus depend, rather, on the entorhinal cortex.

In humans, anterograde amnesia can result from damage to the medial temporal (MT) lobes (including hippocampus), as well as to other brain areas such as basal forebrain. Results from animal classical conditioning studies suggest that there may be qualitative differences in the memory impairment following MT vs. basal forebrain damage. Specifically, delay eyeblink conditioning is spared after MT damage in animals and humans, but impaired in animals with basal forebrain damage. Recently, we have likewise shown delay eyeblink conditioning impairment in humans with amnesia following anterior communicating artery (ACoA) aneurysm rupture, which damages the basal forebrain. Another associative learning task, a computer-based concurrent visual discrimination, also appears to be spared in MT amnesia while ACoA amnesics are slower to learn the discriminations. Conversely, animal and computational models suggest that, even though MT amnesics may learn quickly, they may learn qualitatively differently from controls, and these differences may result in impaired transfer when familiar information is presented in novel combinations. Our initial data suggests such a two-phase learning and transfer task may provide a double dissociation between MT amnesics (spared initial learning but impaired transfer) and ACoA amnesics (slow initial learning but spared transfer). Together, these emerging data suggest that there are subtle but dissociable differences in the amnesic syndrome following damage to the MT lobes vs. basal forebrain, and that these differences may be most visible in non-declarative tasks such as eyeblink classical conditioning and simple associative learning.