scholarly journals Massive Effects of Saliency on Information Processing in Visual Working Memory

2021 ◽  
pp. 095679762097578
Author(s):  
Martin Constant ◽  
Heinrich R. Liesefeld
Keyword(s):  
Working Memory ◽  
Information Processing ◽  
Computational Model ◽  
Visual Working Memory ◽  
Visual Cognition ◽  
Weighted Sum ◽  
Direct Control ◽  
Top Down ◽  
Bottom Up

Limitations in the ability to temporarily represent information in visual working memory (VWM) are crucial for visual cognition. Whether VWM processing is dependent on an object’s saliency (i.e., how much it stands out) has been neglected in VWM research. Therefore, we developed a novel VWM task that allows direct control over saliency. In three experiments with this task (on 10, 31, and 60 adults, respectively), we consistently found that VWM performance is strongly and parametrically influenced by saliency and that both an object’s relative saliency (compared with concurrently presented objects) and absolute saliency influence VWM processing. We also demonstrated that this effect is indeed due to bottom-up saliency rather than differential fit between each object and the top-down attentional template. A simple computational model assuming that VWM performance is determined by the weighted sum of absolute and relative saliency accounts well for the observed data patterns.

scholarly journals Massive Effects of Saliency on Information Processing in Visual Working Memory

2019 ◽  
Author(s):  
Martin Constant ◽  
Heinrich René Liesefeld
Keyword(s):  
Working Memory ◽  
Information Processing ◽  
Computational Model ◽  
Visual Working Memory ◽  
Visual Cognition ◽  
Task Design ◽  
Weighted Sum ◽  
Direct Control ◽  
Top Down ◽  
Attentional Set

Limitations in the ability to temporarily represent information in visual working memory (VWM) are crucial for (visual) cognition. Whether VWM processing is dependent on an object’s saliency (i.e., how much it stands out) has been neglected in VWM research. Therefore, we developed a novel VWM task design that allows direct control over saliency. In three experiments with this task (on 10, 31, and 60 healthy adults, respectively), we consistently find that VWM performance is strongly and parametrically influenced by saliency and that both an object’s relative (to concurrently presented objects) and absolute saliency influence VWM processing. We also demonstrate that this effect is indeed due to bottom-up saliency, rather than differential fit between each object and the top-down attentional set. A simple computational model assuming that VWM performance is determined by the weighted sum of absolute and relative saliency accounts well for the observed data patterns.

scholarly journals Impaired and Intact Aspects of Attentional Competition and Prioritization during Visual Working Memory Encoding in Schizophrenia

2021 ◽  
Author(s):  
Catherine V Barnes ◽  
Lara Roesler ◽  
Michael Schaum ◽  
Carmen Schiweck ◽  
Benjamin Peters ◽  
...  
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Information ◽  
Information Needs ◽  
Detection Task ◽  
Memory Encoding ◽  
Change Detection Task ◽  
Top Down ◽  
Bottom Up ◽  
Irrelevant Distractors

Objective: People with schizophrenia (PSZ) are impaired in the attentional prioritization of non-salient but relevant stimuli over salient but irrelevant distractors during visual working memory (VWM) encoding. Conversely, the guidance of top-down attention by external predictive cues is intact. Yet, it is unknown whether this preserved ability can help PSZ overcome impaired attentional prioritization in the presence of salient distractors. Methods: We employed a visuospatial change-detection task using four Gabor Patches with differing orientations in 69 PSZ and 74 healthy controls (HCS). Two patches flickered to reflect saliency and either a predictive or a non-predictive cue was displayed resulting in four conditions. Results: Across all conditions, PSZ stored significantly less information in VWM than HCS (all p < 0.001). With a non-predictive cue, PSZ stored significantly more salient than non-salient information (t140 = 5.66, p < 0.001, dt = 0.5). With a predictive cue, PSZ stored significantly more non-salient information (t140 = 5.70, p < 0.001, dt = 0.5). Conclusion: Our findings support a bottom-up bias in schizophrenia with performance significantly better for visually salient information in the absence of a predictive cue. These results indicate that bottom-up attentional prioritization is disrupted in schizophrenia, but the top-down utilization of cues is intact. We conclude that additional top-down information significantly improves performance in PSZ when non-salient visual information needs to be encoded in working memory.

Bottom-up perceptual salience and top-down retro-cues concurrently determine state in visual working memory

2020 ◽  
pp. 174702182096626
Author(s):  
Lingxia Fan ◽  
Lin Zhang ◽  
Liuting Diao ◽  
Mengsi Xu ◽  
Ruiyang Chen ◽  
...  
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Visual Working Memory ◽  
Search Task ◽  
Visual Search Task ◽  
Salient Feature ◽  
Active State ◽  
Top Down ◽  
Bottom Up ◽  
Perceptual Salience

Recent studies have demonstrated that in visual working memory (VWM), only items in an active state can guide attention. Further evidence has revealed that items with higher perceptual salience or items prioritised by a valid retro-cue in VWM tend to be in an active state. However, it is unclear which factor (perceptual salience or retro-cues) is more important for influencing the item state in VWM or whether the factors can act concurrently. Experiment 1 examined the role of perceptual salience by asking participants to hold two features with relatively different perceptual salience (colour vs. shape) in VWM while completing a visual search task. Guidance effects were found when either colour or both colour and shape in VWM matched one of the search distractors but not when shape matched. This demonstrated that the more salient feature in VWM can actively guide attention, while the less salient feature cannot. However, when shape in VWM was cued to be more relevant (prioritised) in Experiment 2, we found guidance effects in both colour-match and shape-match conditions. That is, both more salient but non-cued colour and less salient but cued shape could be active in VWM, such that attentional selection was affected by the matching colour or shape in the visual search task. This suggests that bottom-up perceptual salience and top-down retro-cues can jointly determine the active state in VWM.

scholarly journals Signature patterns for top-down and bottom-up information processing via cross-frequency coupling in macaque auditory cortex

2018 ◽  
Author(s):  
Christian D. Márton ◽  
Makoto Fukushima ◽  
Corrie R. Camalier ◽  
Simon R. Schultz ◽  
Bruno B. Averbeck
Keyword(s):  
Information Processing ◽  
Auditory Cortex ◽  
Predictive Coding ◽  
Low Frequency ◽  
Information Need ◽  
Top Down ◽  
Bottom Up ◽  
Low Frequencies ◽  
Frequency Coupling ◽  
Cross Frequency Coupling

AbstractPredictive coding is a theoretical framework that provides a functional interpretation of top-down and bottom up interactions in sensory processing. The theory has suggested that specific frequency bands relay bottom-up and top-down information (e.g. “γ up, β down”). But it remains unclear whether this notion generalizes to cross-frequency interactions. Furthermore, most of the evidence so far comes from visual pathways. Here we examined cross-frequency coupling across four sectors of the auditory hierarchy in the macaque. We computed two measures of cross-frequency coupling, phase-amplitude coupling (PAC) and amplitude-amplitude coupling (AAC). Our findings revealed distinct patterns for bottom-up and top-down information processing among cross-frequency interactions. Both top-down and bottom-up made prominent use of low frequencies: low-to-low frequency (θ, α, β) and low frequency-to-high γ couplings were predominant top-down, while low frequency-to-low γ couplings were predominant bottom-up. These patterns were largely preserved across coupling types (PAC and AAC) and across stimulus types (natural and synthetic auditory stimuli), suggesting they are a general feature of information processing in auditory cortex. Moreover, our findings showed that low-frequency PAC alternated between predominantly top-down or bottom-up over time. Altogether, this suggests sensory information need not be propagated along separate frequencies upwards and downwards. Rather, information can be unmixed by having low frequencies couple to distinct frequency ranges in the target region, and by alternating top-down and bottom-up processing over time.1SignificanceThe brain consists of highly interconnected cortical areas, yet the patterns in directional cortical communication are not fully understood, in particular with regards to interactions between different signal components across frequencies. We employed a a unified, computationally advantageous Granger-causal framework to examine bi-directional cross-frequency interactions across four sectors of the auditory cortical hierarchy in macaques. Our findings extend the view of cross-frequency interactions in auditory cortex, suggesting they also play a prominent role in top-down processing. Our findings also suggest information need not be propagated along separate channels up and down the cortical hierarchy, with important implications for theories of information processing in the brain such as predictive coding.

Hominin Stone Flaking and the Emergence of ‘Top-down’ Design in Human Evolution

2020 ◽  
Vol 30 (4) ◽  
pp. 647-664
Author(s):  
Mark W. Moore
Keyword(s):  
Working Memory ◽  
Simple Algorithm ◽  
Stone Tool ◽  
Current View ◽  
Top Down ◽  
Bottom Up ◽  
Daniel Dennett ◽  
Research Challenge ◽  
Physical Laws ◽  
Recent Experimental Work

The philosopher Daniel Dennett argues that complex structures in the natural and cultural worlds emerge from two types of design. Bottom-up design involves the rote action of a simple algorithm in an environment constrained by physical laws. Top-down design involves deliberation and planning, and is unique to modern humans. Identifying the emergence of top-down design in the hominin lineage is an important research challenge, and the archaeological record of stone technology is our best evidence for it. A current view is that artefact types and flaking methods increased in complexity from 3.3 to c. 0.3 million years ago, reflecting improving capacities at spatial cognition and working memory, culminating in top-down design perhaps as early as 1.75 million years ago. Recent experimental work, however, has shown that a simple ‘remove flake’ algorithm constrained by the laws of fracture mechanics—a form of bottom-up design—can produce stone tool attributes thought to be evidence of top-down design. Here, these models are reviewed and critiqued in light of the new experimental evidence. A revised working memory-based model, focusing on the recursive aspects of stone flaking, is proposed.

scholarly journals F78. OVERCOMING A BOTTOM-UP ATTENTIONAL BIAS BY PROVIDING TOP-DOWN INFORMATION DURING WORKING MEMORY ENCODING IN SCHIZOPHRENIA

2018 ◽  
Vol 44 (suppl_1) ◽  
pp. S250-S250
Author(s):  
Catherine Barnes ◽  
Lara Rösler ◽  
Michael Schaum ◽  
Deliah Macht ◽  
Benjamin Peters ◽  
...  
Keyword(s):  
Working Memory ◽  
Attentional Bias ◽  
Memory Encoding ◽  
Top Down ◽  
Bottom Up

scholarly journals Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals

2015 ◽  
Vol 112 (43) ◽  
pp. 13401-13406 ◽  
Author(s):  
Christoph Teufel ◽  
Naresh Subramaniam ◽  
Veronika Dobler ◽  
Jesus Perez ◽  
Johanna Finnemann ◽  
...  
Keyword(s):  
Information Processing ◽  
Prior Knowledge ◽  
Early Psychosis ◽  
Psychotic Symptoms ◽  
Psychotic Experiences ◽  
Healthy Individuals ◽  
Top Down ◽  
Bottom Up ◽  
Psychosis Proneness ◽  
Sensory Evidence

Many neuropsychiatric illnesses are associated with psychosis, i.e., hallucinations (perceptions in the absence of causative stimuli) and delusions (irrational, often bizarre beliefs). Current models of brain function view perception as a combination of two distinct sources of information: bottom-up sensory input and top-down influences from prior knowledge. This framework may explain hallucinations and delusions. Here, we characterized the balance between visual bottom-up and top-down processing in people with early psychosis (study 1) and in psychosis-prone, healthy individuals (study 2) to elucidate the mechanisms that might contribute to the emergence of psychotic experiences. Through a specialized mental-health service, we identified unmedicated individuals who experience early psychotic symptoms but fall below the threshold for a categorical diagnosis. We observed that, in early psychosis, there was a shift in information processing favoring prior knowledge over incoming sensory evidence. In the complementary study, we capitalized on subtle variations in perception and belief in the general population that exhibit graded similarity with psychotic experiences (schizotypy). We observed that the degree of psychosis proneness in healthy individuals, and, specifically, the presence of subtle perceptual alterations, is also associated with stronger reliance on prior knowledge. Although, in the current experimental studies, this shift conferred a performance benefit, under most natural viewing situations, it may provoke anomalous perceptual experiences. Overall, we show that early psychosis and psychosis proneness both entail a basic shift in visual information processing, favoring prior knowledge over incoming sensory evidence. The studies provide complementary insights to a mechanism by which psychotic symptoms may emerge.

Voluntary and Stimulus-Induced Attention Detected as Motion Sensation

Perception ◽  
1993 ◽  
Vol 22 (5) ◽  
pp. 517-526 ◽  
Author(s):  
Okihide Hikosaka ◽  
Satoru Miyauchi ◽  
Shinsuke Shimojo
Keyword(s):  
Information Processing ◽  
Response Bias ◽  
Visual Information ◽  
Stimulus Change ◽  
Early Stage ◽  
Visual Information Processing ◽  
Salient Object ◽  
Voluntary Attention ◽  
Top Down ◽  
Bottom Up

Attention may be drawn passively to a visually salient object. We may also actively direct attention to an object of interest. Do the two kinds of attention, passive and active, interact and jointly influence visual information processing at some neural level? What happens if the passive and active attentions come into conflict? These questions were addressed with the aid of a novel psychophysical technique which reveals an attentional gradient as a sensation of motion in a line which is presented instantaneously. The subjects were asked to direct attention with voluntary effort: to the side opposite to a stimulus change, to an object with a predetermined colour, and to an object moving smoothly. In every case the same motion sensation was induced in the line from the attended side to the unattended side. This voluntary attention, however, can easily and quickly be distracted by a change in the periphery, though it can be regained within a period of 200 to 500 ms. The results suggest that the line motion can be induced in voluntary (top-down) as well as stimulus-driven (bottom-up) situations, thus indicating the truly attentional nature of the effect, rather than it being some kind of retinotopic sensory artifact or response bias. The results also suggest that these two kinds of attention have facilitatory effects acting together on a relatively early stage of visual information processing.

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