scholarly journals Memory precision of object-location binding is unimpaired in APOE ε4-carriers with spatial navigation deficits

2020 ◽  
Author(s):  
Helena M. Gellersen ◽  
Gillian Coughlan ◽  
Michael Hornberger ◽  
Jon S. Simons
Keyword(s):  
Early Detection ◽  
Visual Memory ◽  
Spatial Navigation ◽  
Memory Task ◽  
Spatial Position ◽  
Feature Binding ◽  
Object Location ◽  
Ε4 Allele ◽  
Location Binding ◽  
Sensitive Marker

AbstractResearch suggests that tests of memory fidelity, feature binding and spatial navigation are promising for early detection of subtle behavioural changes related to Alzheimer’s disease (AD). In the absence of longitudinal data, one way of testing the early detection potential of cognitive tasks is through the comparison of individuals at different genetic risk for AD. Most studies have done so using samples aged 70 years or older. Here, we tested whether memory fidelity of long-term object-location binding may be a sensitive marker even among cognitively healthy individuals in their mid-60s by comparing participants at low and higher risk based on presence of the ε4-allele of the apolipoprotein gene (n=26 ε3ε3 and n=20 ε3ε4 carriers). We used a continuous report paradigm in a visual memory task that required participants to recreate the spatial position of objects in a scene. We employed mixture modelling to estimate the two distinct memory processes that underpin the trial-by-trial variation in localisation errors: retrieval success which indexes the proportion of trials where participants recalled any information about an object’s position and the precision with which participants retrieved this information. Prior work has shown that these memory paradigms that separate retrieval success from precision are capable of detecting subtle differences in mnemonic fidelity even when retrieval success could not. Nonetheless, a Bayesian analysis found good evidence that ε3ε4 carriers did not remember fewer object locations (F(1, 42)=.450, p=.506, BF01=3.02), nor was their precision for the spatial position of objects reduced compared to ε3ε3 carriers (F(1, 42)=.12, p=.726, BF01=3.19). Importantly, ε3ε4-carriers from the same sample have previously been reported to exhibit wayfinding deficits in a spatial navigation task (Coughlan et al. 2019, PNAS, 116(19)). The sensitivity of memory fidelity tasks may therefore not extend to individuals with one ε4-allele in their early to mid-60s. These results provide further support to prior proposals that spatial navigation may be a sensitive marker for the earliest AD-dependent cognitive changes, even before episodic memory. More research in preclinical AD is needed to confirm this hypothesis by direct comparison of memory fidelity and spatial navigation tasks.

scholarly journals Evidence for Object-Place binding in pigeons in a sequence-learning procedure

2019 ◽  
Author(s):  
Aaron Blaisdell
Keyword(s):  
Response Time ◽  
Sequence Learning ◽  
Food Reinforcement ◽  
Regular Sequence ◽  
Feature Binding ◽  
Object Location ◽  
Learning Effects ◽  
Time Costs ◽  
Learning Procedure ◽  
Location Binding

We studied object-location binding in pigeons using a sequence learning procedure. A sequence of four objects was presented, one at a time at one of four locations on a touchscreen. A single peck at the object ended the trial, and food reinforcement was delivered intermittently. In Experiment 1, a between-subjects design was used to present objects, locations, or both in a regular sequence or randomly. Response time costs on nonreinforced probe tests on which object order, location order, or both were disrupted revealed sequence learning effects. Pigeons encoded location order when it was consistent, but not object order when it alone was consistent. When both were consistent, pigeons encoded both, and also showed evidence of object-location binding. In Experiment 2, two groups of pigeons received training on sequences where the same object always appeared at the same location. For some pigeons a consistent sequence was used while for others sequence order was randomized. Only when sequence order was consistent was object-location binding found. These experiments are the first demonstrations of strong and lasting feature binding in pigeons.

scholarly journals Patients with Mild Cognitive Impairment Show Lower Visual Short-Term Memory Performance in Feature Binding Tasks

2017 ◽  
Vol 7 (1) ◽  
pp. 74-86 ◽  
Author(s):  
Raju P. Sapkota ◽  
Ian van der Linde ◽  
Nirmal Lamichhane ◽  
Tirthalal Upadhyaya ◽  
Shahina Pardhan
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Short Term Memory ◽  
Feature Binding ◽  
Object Location ◽  
Short Term ◽  
Cognitive Changes ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Location Binding

Background: Early cognitive changes in people at risk of developing dementia may be detected using behavioral tests that examine the performance of typically affected brain areas, such as the hippocampi. An important cognitive function supported by the hippocampi is memory binding, in which object features are associated to create a unified percept. Aim: To compare visual short-term memory (VSTM) binding performance for object names, locations, and identities between a participant group known to be at higher risk of developing dementia (mild cognitive impairment [MCI]) and healthily aging controls. Methods: Ten MCI and 10 control participants completed five VSTM tests that differed in their requirement of remembering bound or unbound object names, locations, and identities, along with a standard neuropsychological test (Addenbrooke’s Cognitive Examination [ACE]-III). Results: The performance of the MCI participants was selectively and significantly lower than that of the healthily aging controls for memory tasks that required object-location or name-location binding. Conclusion: Tasks that measure unimodal (object-location) and crossmodal (name-location) binding performance appear to be particularly effective for the detection of early cognitive changes in those at higher risk of developing dementia due to Alzheimer’s disease.

Neuropsychology and Psychology of MCS

1994 ◽  
Vol 10 (4-5) ◽  
pp. 545-554
Author(s):  
Nancy Fiedler ◽  
Howard Kipen ◽  
John Deluca ◽  
Kathie Kelly-Mcneil ◽  
Benjamin Natelson
Keyword(s):  
Visual Memory ◽  
Memory Task ◽  
Chronic Fatigue ◽  
Psychological Research ◽  
Emotional Symptoms ◽  
Attentional Processes ◽  
Multiple Chemical Sensitivities ◽  
Fatigue Syndrome ◽  
Axis I ◽  
Normal Controls

Neurological symptoms are frequently reported by patients with multiple chemical sensitivities (MCS). Methods to compare the psychiatric, personality, and neuropsychological function of patients with MCS, chronic fatigue syndrome (CFS), and normal controls are described. Increased rates of Axis I psychiatric diagnoses are observed in the literature for MCS and CFS subjects relative to controls. Findings on the MMPI-2 and the Toronto Alexithymia Scale reveal prof iles consistent with the tendency to report somatic rather than emotional symptoms in response to stress. However, many of the reported somatic symptoms also coincide with those found in neurologic disorders. The overall neuropsychological prof ile for MCS subjects does not reflect cognitive impairment. Relative to normal controls, the only difference in neuropsychological performance observed is reduced recognition of nontarget designs on a visual memory task. More fruitful areas for future psychological research will include measurement of the interaction between behavioral response styles and attentional processes in cognition, as well as observations under controlled challenge conditions.

scholarly journals Are visual working memory and episodic memory distinct processes? Insight from stroke patients by lesion-symptom mapping

2021 ◽  
Author(s):  
Selma Lugtmeijer ◽  
◽  
Linda Geerligs ◽  
Frank Erik de Leeuw ◽  
Edward H. F. de Haan ◽  
...  
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Visual Working Memory ◽  
Visual Memory ◽  
Right Hemisphere ◽  
Memory Task ◽  
Stroke Patients ◽  
Lesion Symptom Mapping ◽  
Criterion Setting ◽  
The Right

AbstractWorking memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, 81 adults with sub-acute ischemic stroke and 29 elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes.

scholarly journals Concurrent feature-specific reactivation within the hippocampus and neocortex facilitates episodic memory retrieval

2021 ◽  
Author(s):  
Michael B. Bone ◽  
Bradley R. Buchsbaum
Keyword(s):  
Visual Cortex ◽  
Memory Retrieval ◽  
Visual Memory ◽  
Recognition Accuracy ◽  
Memory Task ◽  
Large Individual ◽  
Storage And Retrieval ◽  
Specific Index ◽  
Early Visual Cortex ◽  
Episodic Memories

AbstractThe hippocampus is a key brain region for the storage and retrieval of episodic memories, but how it performs this function is unresolved. According to the hippocampal indexing theory, the hippocampus stores an event-specific index of the pattern of neocortical activity that occurred during perception. During retrieval, reactivation of the index by a partial cue facilitates the reactivation of the associated neocortical pattern. Therefore, event-specific retrieval requires joint reactivation of the hippocampal index and the associated neocortical networks. To test this theory, we examine the relation between performance on a recognition memory task requiring retrieval of image-specific visual details and feature-specific reactivation within the hippocampus and neocortex. We show that trial-by-trial recognition accuracy correlates with neural reactivation of low-level features (e.g. luminosity and edges) within the posterior hippocampus and early visual cortex for participants with high recognition lure accuracy. As predicted, the two regions interact, such that recognition accuracy correlates with hippocampal reactivation only when reactivation co-occurs within the early visual cortex (and vice-versa). In addition to supporting the hippocampal indexing theory, our findings show large individual differences in the features underlying visual memory and suggest that the anterior and posterior hippocampus represents gist-like and detailed features, respectively.

scholarly journals Conceptual distinctiveness does not improve visual working memory for objects but aids object-location binding

2021 ◽  
Author(s):  
Yuri Markov ◽  
Igor Utochkin
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Competitive Interactions ◽  
Object Location ◽  
Location Information ◽  
Limited Capacity ◽  
Common Features ◽  
Categorical Information ◽  
Location Binding ◽  
Different Sources

Visual working memory (VWM) is prone to interference from stored items competing for its limited capacity. These competitive interactions can arise from different sources. For example, one such source is poor item distinctiveness causing a failure to discriminate between items sharing common features. Another source of interference is imperfect binding, a problem of determining which of the remembered features belonged to which object or which item was in which location. In two experiments, we studied how the conceptual distinctiveness of real-world objects (i.e., whether the objects belong to the same or different basic categories) affects VWM for objects and object-location binding. In Experiment 1, we found that distinctiveness did not affect memory for object identities or for locations, but low-distinctive objects were more frequently reported at “swapped” locations that originally went with different objects. In Experiment 2 we found evidence that the effect of distinctiveness on the object-location swaps was due to the use of categorical information for binding. In particular, we found that observers swapped the location of a tested object with another object from the same category more frequently than with any of the objects from another category. This suggests that observers can use some coarse category-location information when objects are conceptually distinct. Taken together, our findings suggest that object distinction and object-location binding act upon different components of VWM.

055 Novel sleep-dependent spatial memory and navigation task using Minecraft

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A23-A23
Author(s):  
Katharine Simon ◽  
Gregory Clemenson ◽  
Brandon Clayton ◽  
Jing Zhang ◽  
Elisabet Alzueta ◽  
...  
Keyword(s):  
Spatial Memory ◽  
Test Performance ◽  
Target Location ◽  
Spatial Navigation ◽  
Memory Task ◽  
Spatial Location ◽  
Delay Test ◽  
Location Accuracy ◽  
Median Split ◽  
Dependent Learning

Abstract Introduction Spatial navigation and memory are hippocampally-dependent and decrease with age, yet, ecologically-valid methods remain elusive. We developed an engaging and inherently flexible spatial navigation/memory task using the Minecraft platform to test sleep-dependent memory. We validated baseline performance and learning rates across two separate Minecraft environments. Methods Using a within-subjects design, twenty-two subjects experienced two conditions (wake/sleep) and two Minecraft environments, counterbalanced across subjects. At encoding, subjects learned the locations of 12 objects. Memory for object location accuracy and navigation route (distance between start and target; vector: angle of direction towards target location from start) was tested immediately and following 12-hours of wake or sleep. Post-hoc analyses were conducted using a median split on subjects’ Immediate test performance. Results There were no significant differences across conditions for the Immediate test performance (t(22) = .567, p = .576) across the two environments. Delayed test showed greater improvement in accuracy after sleep compared to wake (t(18) = 2.795, p=.012), no differences in distance or vector. Median split by Immediate test performance revealed that initially lower performance showed the greatest improvement after delay in the sleep group (t(18) = 2.818, p =.011), but not the wake group (t(18) = -1.051, p =.308). Additionally, these same subjects’ vector direction was initially worse at Immediate Test (t(18) = -2.9, p = .01), and improved with sleep, becoming equivalent to the better performers at Delay test (t(18) = -.336, p = .74). Conclusion We demonstrate a novel spatial navigation/memory tasks using Minecraft that shows sleep-dependent learning across two distinct environments. We showed enhancement of spatial location accuracy after a night of sleep compared to wake. We further demonstrate that with sleep, those with worse initial performance show the greatest memory and navigation improvement, consistent with other findings that sleep supports enhancement of weaker memories and extended to the spatial-domain. This novel platform can be used to evaluate spatial memory across the lifespan and within special clinical populations. Support (if any) NIH R01 AG061355

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