Morgan D. Barense's research while affiliated with University of Toronto and other places

Publications (9)

Preprint
Full-text available
Combining information from multiple senses is essential to object recognition. Yet how the mind combines sensory input into coherent multimodal representations, the multimodal binding problem, remains poorly understood. Here, we applied multi-echo fMRI across a four-day paradigm, in which participants learned 3-dimensional multimodal object represe...
Article
Though much progress has been made to understand feature integration, debate remains regarding how objects are represented in mind based on their constituent features. Here, we advance this debate by introducing a novel shape-color “conjunction task” to reconstruct memory resolution for multiple object features simultaneously. In a first experiment...
Article
The modulation of gaze fixations on neural activity in the hippocampus, a region critical for memory, has been shown to be weaker in older adults compared to younger adults. However, as such research has relied on indirect measures of memory, it remains unclear whether the relationship between visual exploration and direct measures of memory is sim...
Article
Significance Our brains draw on memories to predict the future; when our predictions are incorrect, we must update our memories to improve future predictions. Past studies have demonstrated that the hippocampus signals prediction error (i.e., surprise) but have not linked this neural signal to memory updating. Here, we uncover this missing connecti...
Article
The development of dependable screening methods would allow for the early detection of incipient Alzheimer's disease (AD). Alzheimer’s pathology accumulates in the perirhinal cortex (PRC) well before diagnosis. Converging lines of research show the PRC critically contributes to object visual processing, especially when disambiguating between object...
Article
Full-text available
In memory, representations of spatial features are stored in different reference frames; features relative to our position are stored egocentrically and features relative to each other are stored allocentrically. Accessing these representations engages many cognitive and neural resources, and so is susceptible to age-related breakdown. Yet, recent...
Preprint
Full-text available
During navigation, information at multiple scales needs to be integrated. Single-unit recordings in rodents suggest that gradients of temporal dynamics in the hippocampus and entorhinal cortex support this integration. In humans, gradients of representation are observed, such that granularity of information represented increases along the long axis...
Article
Representations of space in mind are crucial for navigation, facilitating processes such as remembering landmark locations, understanding spatial relationships between objects, and integrating routes. A significant problem, however, is the lack of consensus on how these representations are encoded and stored in memory. Specifically, the nature of e...

Citations

... In [25], a memory model is confirmed in which both the features of the object and the object in the form of bound features are presented. Moreover, the features of an object can be bound not only through their common position, but directly with each other. ...
... First, the context-reminder used here (Fig. 1b) contains the parametric structure to trigger memory reconsolidation 22,36 ; known to depend on prediction error between real and expected experiences during the reminder sessions 22,56,60,61 . Although the neural mechanisms that allow prediction error to update memories remain unknown, there has been increasing evidence of the role of hippocampus activation and its neuromodulation by dopamine and acetylcholine 96 . It is possible that the surged Ca 2+ activity we described here after a context-training presentation would signal the labilization of the consolidated memory trace that enters reconsolidation. ...
... This is consistent with a prior study where a deficit in the switching between egocentric and allocentric strategies in older adults was described [34]. Moreover, our results aligned with a recent work [61] that indicated that performance for object location memory could be more impaired when specifically switching from an egocentric framework to an allocentric one. This could indicate a potential difficulty of binding multiple viewpoints in a coherent representation [34,61]. ...
... This modulation was strongest when participants learned in an egocentric frame of reference and were then tested in either an egocentric or allocentric frame of reference. Previous studies among younger adults have demonstrated that relying on an allocentric "mapbased" mental strategy in spatial contexts is more efficient than relying on an egocentric strategy [66], and that a preference for an allocentric strategy when navigating is associated with greater hippocampal volumes [25]. Here, our findings substantially advance this past research to include healthy older adults. ...