Revisiting Persistent Neuronal Activity During Covert Spatial Attention

Abstract

Persistent activity has been observed in the prefrontal cortex (PFC), in particular during the delay periods of visual attention tasks. Classical approaches based on the average activity over multiple trials have revealed that such an activity encodes the information about the attentional instruction provided in such tasks. However, single-trial approaches have shown that activity in this area is rather sparse than persistent and highly heterogeneous not only within the trials but also between the different trials. Thus, this observation raised the question of how persistent the actually persistent attention-related prefrontal activity is and how it contributes to spatial attention. In this paper, we review recent evidence of precisely deconstructing the persistence of the neural activity in the PFC in the context of attention orienting. The inclusion of machine-learning methods for decoding the information reveals that attention orienting is a highly dynamic process, possessing intrinsic oscillatory dynamics working at multiple timescales spanning from milliseconds to minutes. Dimensionality reduction methods further show that this persistent activity dynamically incorporates multiple sources of information. This novel framework reflects a high complexity in the neural representation of the attention-related information in the PFC, and how its computational organization predicts behavior.

Distractibility and impulsivity neural states are distinct from selective attention and modulate the implementation of spatial attention

“…These results indicate that the demixed components identified based on behavioral outcome can be identified irrespective of specific task-related processes and describe a neuronal process that extends across trials. This nicely dovetails with previous findings suggesting a low-frequency dynamics of the activity of a state linked to sensory processing efficiency, encompassing multiple trials over temporal scales of several minutes 12 , 45 . Likewise, none of the results reported in this section changed when performed on hit, miss and false alarm trials that were equalized for TA metrics on the session level (Supplementary Fig.…”

Cognitive Networks (Cognits) Process and Maintain Working Memory

“…But those cells that do, usually exhibit considerable variability from trial to trial, consistent with temporal variability in the synaptic associative inputs and outputs related to the task. That is also consistent with the expected fluctuations in the perceptual and executive attention (Amengual and Ben Hamed, 2021 ) devoted by the animal to components of the delay-task habit, which in the trained animal can be safely assumed to be part of long-term memory.…”

Prefrontal Control of Proactive and Reactive Mechanisms of Visual Suppression

“…In the specific context of our task, one could further predict that only the attentional spotlight that is not anchored at the cued landmark is dynamic as described in Gaillard et al. (2020) , see also Gaillard and Hamed 2020 and Amengual and Hamed 2021 ), while the attentional spotlight placed at the cued landmark is stable and would represent what we call here the priority map defined by task structure. This is actually a very appealing possibility in the sense that not only does it allow for the possibility of multiple attentional spotlights but also for multiple type of priority maps defined either by top-down cognitive contingencies or by bottom-up contingencies implemented through learning.…”