Periodic Reporting for period 1 - TDoTA (Temporal Dynamics of Transient Attention)
Periodo di rendicontazione: 2021-09-01 al 2023-08-31
A main tool that the perceptual system uses to deal with our inherent limitations is selective attention. When we attend to a specific area in our environment, we are more likely to rapidly detect important events in that location. Our ability to attend to certain events while ignoring others is therefore crucial in guiding goal-directed behaviour. However, our understanding of selective attention is still limited. For example, standard models of attention make neurologically implausible assumptions that result in theoretical incoherence. Specifically, attentional selection is assumed to take place at a specific moment in time, discretely dividing perception to processes that are independent from attention and processes that are dependent on attention. This assumption is neurologically implausible as no process in the brain is entirely discrete or instantaneous, and results in theoretical incoherence in how attention is conceptualized (e.g. whether selection should be regarded as cause or effect). This unfortunately derails the efforts of attention researchers in advancing our collective understanding of attention.
Recently, I suggested an alternative framework that explains how selective attention unfolds over time (the “diachronic” account). At the heart of this model is the assumption that selectivity is strongly modulated by brief periods of amplified perceptual processing. Once a potentially important object is detected, amplification to processing builds up rapidly, reaching a peak after 100-200 ms, and then gradually dissipates (“attentional episodes”). The overall objective of the project was to apply this framework to cognitive research on perception, thereby demonstrating the kind of progress that can be made by adopting a diachronic framework of attention. The studies conducted during the project can therefore hopefully result in a new avenue of research on attention, which can substantially improve our understanding of the limitations of perception.
1. The temporal dynamics of selective attention
We explored selective attention dynamics using rapid serial visual presentation (RSVP). Observers often mistake distractors for targets in RSVP. We found that the speed of attentional engagement influences this error. When engagement is delayed (two streams), more distractors are reported, and when it's faster (single stream), more targets are reported. This reveals the connection between distractor intrusion and the timing of selective attention, supporting the concept of attentional episodes.
Published in Scientific Reports
2.Categorization Templates Modulate Selective Attention
Visual search involves guidance and categorization processes. Standard models of attention assume that categorization occurs only after an object has been selected and encoded in working memory. We predicted the idea that categorization templates can modulate selective attention. We found that electrophysiological markers of attentional engagement and behavioural interference effects from posttarget distractors as a function of whether these distractors matched the categorization template. These finding shows that categorization affect attention, providing new evidence for the continuous nature of evidence accumulation and attentional modulations during perceptual processing.
Published in Journal of Experimental Psychology: Human Perception and Performance.
3. Expectation‑based blindness
We documented a new phenomenon, "expectation-based blindness," where expectations gates access to conscious awareness even for attended objects. When an attended target's category changed unexpectedly, participants were less likely to perceive it, demonstrating that objects that are task relevant and focally attended can fail to get noticed when they are unexpected. This finding is incompatible with standard models of attention, but can be accounted for within a diachronic framework.
Published in Psychonomic Bulletin and Review.
Other than publishing, the project allowed me to present our findings and their relationship to the field of selective attention in many conferences (6) as well as colloquiums and invited talks (31)
4. Attention and Feature Binding in the Temporal Domain
Understanding how features are bound together in perception is crucial for daily functioning. While the role of space in binding has been thoroughly investigated, the role of time has received much less attention. We investigated the impact of attentional processes on correct and incorrect temporal binding. We found that the speed of attentional engagement influences feature binding in the temporal domain: when participants reported the identity of a distractor instead of a target, they were also more likely to report the colour of this distractor. These findings are accounted for within our diachronic framework and suggest that attentional engagement facilitates the binding of temporally co-occurring features, but also that other factors can also contribute to temporal binding errors.
5. Expectation effects on perception are not necessarily mediated by attention
This study further bridges the gap between attention and expectations in cognitive psychology and neuroscience. It addresses the debate regarding whether expectation effects are caused solely due to attentional modulation. Our research provides a new method to demonstrate direct expectation effects on perception independent of attention. This challenges existing assumptions and has implications for theories of selective attention and expectations.
Overall, this project advanced the field of attention by challenges long-held assumptions about the nature of selective attention and considering often overlooked temporal aspects. While there are no immediate wider societal implications to this line of fundamental research, it paves the way for exploring individual and group differences in temporal selectivity, which could impact various everyday tasks, such as reading speed, hazard detection, and multisensory integration. The diachronic framework is also a promising framework for understanding cognitive differences in ADHD and autism and the temporal dynamics of attention changes in old age.