scholarly journals Reduced visual and frontal cortex activation during visual working memory in grapheme-colour synaesthetes relative to young and older adults

2018 ◽  
Author(s):  
Gaby Pfeifer ◽  
Jamie Ward ◽  
Natasha Sigala
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Visual Cortex ◽  
Visual Working Memory ◽  
Temporal Cortex ◽  
Region Of Interest ◽  
Inferior Temporal Cortex ◽  
Long Term Memory ◽  
Sensory Recruitment ◽  
Recruitment Model

AbstractThe sensory recruitment model envisages visual working memory (VWM) as an emergent property that is encoded and maintained in sensory (visual) regions. The model implies that enhanced sensory-perceptual functions, as in synaesthesia, entail a dedicated VWM-system, showing reduced visual cortex activity as a result of neural specificity. By contrast, sensory-perceptual decline, as in old age, is expected to show enhanced visual cortex activity as a result of neural broadening. To test this model, young grapheme-colour synaesthetes, older adults and young controls engaged in a delayed pair-associative retrieval and a delayed matching-to-sample task, consisting of achromatic fractal stimuli that do not induce synaesthesia. While a previous analysis of this dataset (Pfeifer et al., 2016) has focused on cued retrieval and recognition of pair-associates (i.e. long-term memory), the current study focuses on visual working memory and considers, for the first time, the crucial delay period in which no visual stimuli are present, but working memory processes are engaged. Participants were trained to criterion and demonstrated comparable behavioural performance on VWM tasks. Whole-brain and region-of-interest-analyses revealed significantly lower activity in synaesthetes’ middle frontal gyrus and visual regions (cuneus, inferior temporal cortex) respectively, suggesting greater neural efficiency relative to young and older adults in both tasks. The results support the sensory recruitment model and can explain age and individual WM-differences based on neural specificity in visual cortex.

051 Is Working Memory Associated with Ag- related Emotional Memory Bias?

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A21-A22
Author(s):  
Negin Sattari ◽  
Lauren Whitehurst ◽  
Sara Mednick
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Emotional Reactivity ◽  
Emotional Memory ◽  
Negative Word ◽  
Memory Bias ◽  
Long Term Memory ◽  
Sleep Condition ◽  
Valence And Arousal ◽  
Positive Memories

Abstract Introduction Aging is accompanied by deterioration in both working memory (WM) and long-term memory (LTM), though the reason is not well understood. Sleep may play a role in young adults, but the findings in older adults are not as clear. In addition, older adults show better memory for positive memories, whereas youngers tend to hold on to negative memories. The prefrontal cortex has been implicated in this emotional memory bias. The current study investigated the role of working memory (a prefrontal task) on emotional memory consolidation across sleep and wake in young and older adults. Methods In the morning, 93 younger (18–39) and 121 older (60–85) adults took a WM task and encoded neutral or negative word pairs, and gave valence and arousal ratings for each pair. After a wake or polysomnography-recorded sleep condition, memory for the word pairs was tested plus valence and arousal ratings. Results Youngers had better overall memory (p<.001), with older adults showing better memory for neutral compared to negative word pairs (p=.04), as well as increased positivity (p=.02), which was correlated with LTM performance (p=.009). In contrast, youngers performed better on the negative word pairs (p=.01), but no change in ratings and no association between emotional reactivity and LTM. Further, WM was positively related to memory in youngers (r=.38, p=.02), but not in older adults. Lastly, no role for sleep likely due to the lack of an immediate test. Conclusion we found that the positivity bias in aging in both memory and valence, with increasing positivity associated with better memory. We found a robust relation between WM and LTM in youngers but not older adults. Our findings are consistent with the socioemotional-selectivity theory that posits that aging is associated with a relative suppression of negative information while WM may play a role. Support (if any):

scholarly journals Anatomy of early visual cortex predicts visual working memory capacity

2013 ◽  
Vol 13 (9) ◽  
pp. 1349-1349
Author(s):  
J. Bergmann ◽  
E. Genc ◽  
A. Kohler ◽  
W. Singer ◽  
J. Pearson
Keyword(s):  
Working Memory ◽  
Visual Cortex ◽  
Visual Working Memory ◽  
Working Memory Capacity ◽  
Memory Capacity ◽  
Early Visual Cortex

scholarly journals The Neural Codes Underlying Internally Generated Representations in Visual Working Memory

2021 ◽  
pp. 1-16
Author(s):  
Qing Yu ◽  
Bradley R. Postle
Keyword(s):  
Working Memory ◽  
Visual Cortex ◽  
Visual Working Memory ◽  
Subjective Experience ◽  
Neural Representation ◽  
Delayed Recall ◽  
Early Visual Cortex ◽  
Memory Representations ◽  
Internal Sources ◽  
Scaling Analyses

Abstract Humans can construct rich subjective experience even when no information is available in the external world. Here, we investigated the neural representation of purely internally generated stimulus-like information during visual working memory. Participants performed delayed recall of oriented gratings embedded in noise with varying contrast during fMRI scanning. Their trialwise behavioral responses provided an estimate of their mental representation of the to-be-reported orientation. We used multivariate inverted encoding models to reconstruct the neural representations of orientation in reference to the response. We found that response orientation could be successfully reconstructed from activity in early visual cortex, even on 0% contrast trials when no orientation information was actually presented, suggesting the existence of a purely internally generated neural code in early visual cortex. In addition, cross-generalization and multidimensional scaling analyses demonstrated that information derived from internal sources was represented differently from typical working memory representations, which receive influences from both external and internal sources. Similar results were also observed in intraparietal sulcus, with slightly different cross-generalization patterns. These results suggest a potential mechanism for how externally driven and internally generated information is maintained in working memory.

scholarly journals The limited contribution of early visual cortex in visual working memory for surface roughness

2020 ◽  
Author(s):  
Munendo Fujimichi ◽  
Hiroki Yamamoto ◽  
Jun Saiki
Keyword(s):  
Working Memory ◽  
Visual Cortex ◽  
Visual Working Memory ◽  
Brain Activity ◽  
Visual Representations ◽  
Brain Regions ◽  
Daily Lives ◽  
Early Visual Cortex ◽  
Roughness Discrimination ◽  
Visual Properties

Are visual representations in the human early visual cortex necessary for visual working memory (VWM)? Previous studies suggest that VWM is underpinned by distributed representations across several brain regions, including the early visual cortex. Notably, in these studies, participants had to memorize images under consistent visual conditions. However, in our daily lives, we must retain the essential visual properties of objects despite changes in illumination or viewpoint. The role of brain regions—particularly the early visual cortices—in these situations remains unclear. The present study investigated whether the early visual cortex was essential for achieving stable VWM. Focusing on VWM for object surface properties, we conducted fMRI experiments while male and female participants performed a delayed roughness discrimination task in which sample and probe spheres were presented under varying illumination. By applying multi-voxel pattern analysis to brain activity in regions of interest, we found that the ventral visual cortex and intraparietal sulcus were involved in roughness VWM under changing illumination conditions. In contrast, VWM was not supported as robustly by the early visual cortex. These findings show that visual representations in the early visual cortex alone are insufficient for the robust roughness VWM representation required during changes in illumination.

scholarly journals Visual working memory for objects in scenes in younger and older adults: Insights from pupillometry

2021 ◽  
Vol 21 (9) ◽  
pp. 2592
Author(s):  
Giorgia D'Innocenzo ◽  
Anastasiia Mikhailova ◽  
Moreno I. Coco
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Visual Working Memory

Manifold Visual Working Memory

2020 ◽  
pp. 311-332
Author(s):  
Nicole Hakim ◽  
Edward Awh ◽  
Edward K. Vogel
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Neural Activity ◽  
Long Term Memory ◽  
Term Memory ◽  
Memory Representations ◽  
Latent Representations ◽  
Definition Of ◽  
Spatial Locations

Visual working memory allows us to maintain information in mind for use in ongoing cognition. Research on visual working memory often characterizes it within the context of its interaction with long-term memory (LTM). These embedded-processes models describe memory representations as existing in three potential states: inactivated LTM, including all representations stored in LTM; activated LTM, latent representations that can quickly be brought into an active state due to contextual priming or recency; and the focus of attention, an active but sharply limited state in which only a small number of items can be represented simultaneously. This chapter extends the embedded-processes framework of working memory. It proposes that working memory should be defined operationally based on neural activity. By defining working memory in this way, the important theoretical distinction between working memory and LTM is maintained, while still acknowledging that they operate together. It is additionally proposed that active working memory should be further subdivided into at least two subcomponent processes that index item-based storage and currently prioritized spatial locations. This fractionation of working memory is based on recent research that has found that the maintenance of information distinctly relies on item-based representations as well as prioritization of spatial locations. It is hoped that this updated framework of the definition of working memory within the embedded-processes model provides further traction for understanding how we maintain information in mind.

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