Search bioRxiv⌕ Search

bioRxiv · 10.1101/2024.08.27.609883

Dissociating External and Internal Attentional Selection

Abstract

Visual Working Memory (VWM) stores visual information for upcoming actions. Just as attention can shift externally towards relevant objects in the visual environment, attention can shift internally towards (i.e., prioritize) VWM content that is relevant for upcoming tasks. Internal and external attentional selection share a number of key neural and functional characteristics, which include their spatial organization: recent work has shown that spatial attention is directed towards the previous location of a prioritized memory item, similar to how a perceived stimulus is prioritized. Attending stimuli that are physically present is useful, as it enhances processing of the relevant visual input. When prioritizing items in memory, however, attending the prior stimulus location cannot serve this purpose, as there is no visual input to enhance. Here, we address this apparent contradiction which highlights the gaps in our understanding of the mechanisms underlying external and internal visual attention. In two EEG experiments, we compare location-specific sensory enhancement during the attentional selection of external (perceived) as compared to internal (memorized) stimuli. During both internal and external selection we observed a lateralization of alpha oscillations and gaze position bias toward the previous locations of prioritized items, confirming earlier findings that suggested an inherent spatial organization within VWM. Critically, using Rapid Invisible Frequency Tagging (RIFT), we show that sensory enhancement at the attended location is only observed during external attentional selection of (perceived) stimuli. No such location-specific sensory enhancement was observed during attentional selection of items in VWM. Furthermore, we found no clear relationship across trials between alpha lateralization and sensory enhancement (measured through RIFT) during external attention, suggesting that these two metrics indeed reflect distinct cognitive mechanisms. In sum, using a novel combination of EEG and RIFT, we demonstrate a fundamental distinction between the neural mechanisms underlying the selection of perceived and memorized objects. Both types of selection operate within a spatial reference frame, but only external selection modulates early sensory processing. Our findings suggest that the visual system is not vestigially recruiting existing mechanisms of external attention for prioritization in VWM, but is instead using space as an organizational principle to store and select items in VWM.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Arora, K., Gayet, S., Kenemans, J. L., Van der Stigchel, S., Chota, S.. 2024-08-27. Dissociating External and Internal Attentional Selection. https://doi.org/10.1101/2024.08.27.609883

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Same Movements, Different Skills: How Context Shapes Learning in Humans and Neural Networks

What determines whether experiences are integrated into shared representations or split? Motor skill learning offers a revealing test: when two tasks require an identical sequence of movements, both intuition and theory suggest that practice in one should generalize to the other. Yet we find that changing context can make identical movements different skills. In simple recurrent networks trained on the same sequence across contexts, splitting was greatest when strong contextual inputs coincided with a high initial weight scale; neither alone sufficed. Greater representational separation coincided with separate context-specific learning curves. Humans practicing the same finger sequence while alternating between two performance-irrelevant contexts likewise exhibited context-specific curves, rather than the single continuous trajectory observed when practicing in a single context. State-space modeling favored split learning states in humans and very weakly coupled states in the most context-dependent networks. These findings have broader implications for understanding how learning generalizes across contexts.

neuroscience↗

Postpartum resource scarcity reshapes maternal care, offspring prioritization, and the steroid-sensitive medial preoptic area

Parental care requires balancing offspring needs with environmental constraints, yet how resource scarcity alters the organization of maternal responses remains poorly understood. Here, we examined maternal behavior, offspring prioritization, and steroid receptor-associated extracellular matrix organization in postpartum rats exposed to limited bedding and nesting (LBN) or control conditions with ample nesting materials. LBN increased pup-directed and reduced self-directed behaviors but also increased behavioral entropy, a measure of behavioral fragmentation, indicating less predictable caregiving sequences. LBN dams preferentially retrieved male pups first, whereas control dams preferentially retrieved females first. LBN also increased the proportion of pup-investigation time directed toward males compared with controls. In offspring on postnatal day 10, corticosterone was elevated in female but not male LBN pups, a pattern that paralleled the maternal male bias. To identify associated neurobiological changes, we assessed steroid receptors and extracellular matrix organization in the medial preoptic area (mPOA), a key region for maternal behavior. LBN increased numbers of estrogen receptor (ER)- and androgen receptor (AR)-immunoreactive cells, reduced perineuronal net (PNN) abundance, and decreased receptor-positive cell enwrapment. Because PNNs constrain structural plasticity, these findings suggest that the postpartum environment alters the organization of steroid receptor-associated extracellular matrix, potentially modulating experience-dependent plasticity in neurosteroid-sensitive circuits. In sum, LBN increases the levels of maternal engagement while reshaping its temporal organization and allocation, accompanied by selective remodeling of steroid-sensitive preoptic architecture. Therefore, maternal adaptation to adversity may be better understood as changes in caregiving allocation strategies rather than a simple gain or loss of maternal care.

neuroscience↗

The Computational Grammar of Human Behaviour in a Biological Environment

Human behaviour unfolds as an extended stream of spontaneous actions shaped by environmental demands and the agent's goals. The organisation of these actions, situated between setting abstract goals and concrete movement execution, remains poorly characterised. Here, we introduce DynaClade, an unsupervised temporal action segmentation algorithm for human full-body motion capture data, and apply it to freely moving participants navigating ecologically realistic risky foraging environments in virtual reality. DynaClade identifies discrete actions whose kinematic characteristics and spatial distributions correspond to environmental affordances, supporting the validity of the approach. Among these actions, we discovered a hitherto undescribed movement pattern defined by increased body sway without locomotion. Action sequences were highly non-random and showed clear history dependence beyond first-order Markov structure, most of which was explained by a second-order prediction. This higher-order structure was well captured in a hidden Markov model, in which some of the observed actions were associated with more than one latent state. Each of these latent states corresponded to the same action in a distinct action context. These findings suggest that spontaneous human actions are predominantly selected based on the current action and context, rather than following pre-planned or habitually assembled sequences.

neuroscience↗