View-Independent Working Memory Representations of Artificial Shapes in Prefrontal and Posterior Regions of the Human Brain

@article{Christophel2018ViewIndependentWM,
  title={View-Independent Working Memory Representations of Artificial Shapes in Prefrontal and Posterior Regions of the Human Brain},
  author={Thomas B. Christophel and Carsten Allefeld and Christian Endisch and John-Dylan Haynes},
  journal={Cerebral Cortex},
  year={2018},
  volume={28},
  pages={2146–2161}
}
Traditional views of visual working memory postulate that memorized contents are stored in dorsolateral prefrontal cortex using an adaptive and flexible code. In contrast, recent studies proposed that contents are maintained by posterior brain areas using codes akin to perceptual representations. An important question is whether this reflects a difference in the level of abstraction between posterior and prefrontal representations. Here, we investigated whether neural representations of visual… 

Figures from this paper

Reevaluating the Sensory Account of Visual Working Memory Storage
  • Yaoda Xu
  • Psychology, Biology
    Trends in Cognitive Sciences
  • 2017
Persistent Activity During Working Memory From Front to Back
TLDR
A comprehensive theory of WM will require a unification of these two major ‘arcs’ of research, which evolved over the last decade from sophisticated computational neuroimaging approaches enabling researchers to decode the contents of WM from the patterns of neural activity in many parts of the brain including early visual cortex.
Eye Movement-Related Confounds in Neural Decoding of Visual Working Memory Representations
TLDR
A potential remedy is demonstrated, whereby the decoders are trained on a functional localizer that was specifically designed to target bottom-up sensory signals and as such avoids eye movements, and argued for more awareness of the potentially pervasive and ubiquitous effects of eye movement-related confounds.
Revisit once more the sensory storage account of visual working memory
TLDR
Converging evidence suggests that early visual areas may contribute to the decision stage of a VWM task by facilitating target and probe comparison and that behavioural interactions between VWM and perception tasks do not necessarily support the involvement of sensory regions in VWM storage.
The dynamics of visual representations under top-down modulation
TLDR
A decoding approach was adopted to empirically assess the dissociation of sensory from decision processes in human magnetoencephalography recordings, and found that the sensory processing accurately refl ected the physical stimulus, irrespective of the eventual decision.
Parametric Representation of Tactile Numerosity in Working Memory
TLDR
A delayed match-to-numerosity paradigm to test what brain regions retain approximate numerosity memoranda found numerosity-specific WM representations in the right LPFC as well as in the supplementary motor area and the left premotor cortex extending into the superior frontal gyrus, thus bridging the gap in abstract quantity WM literature.
Cortical specialization for attended versus unattended working memory
TLDR
It is demonstrated here that encoding unattended contents involves a division of labor, since visual cortex only maintains attended items, intraparietal areas and the frontal eye fields represent both attended and unattended items.
...
...

References

SHOWING 1-10 OF 110 REFERENCES
Parietal and early visual cortices encode working memory content across mental transformations
Decoding the Contents of Visual Short-Term Memory from Human Visual and Parietal Cortex
TLDR
The results demonstrate that storage in VSTM extends beyond visual areas, but no frontal regions were found, and indicates that maintenance of content in the frontoparietal network might be limited to parietal cortex.
Stimulus Selectivity in Dorsal and Ventral Prefrontal Cortex after Training in Working Memory Tasks
TLDR
The results indicate that regional specialization for stimulus selectivity is present in the primate prefrontal cortex regardless of training.
Spatially Global Representations in Human Primary Visual Cortex during Working Memory Maintenance
TLDR
The results suggest that visual details are held in WM through a spatially global recruitment of early sensory cortex, which may enhance memory precision by facilitating robust population coding of the stored information.
The Distributed Nature of Working Memory
Decoding the content of visual short-term memory under distraction in occipital and parietal areas
TLDR
Overall, consistent with previous univariate findings, the results indicate that superior IPS, but not occipital cortex, has a central role in VSTM storage.
...
...