Flawed stimulus design in additive-area heuristic studies

Studying magnitude perception using visual item arrays is notoriously difficult due to the intricate relationship between various dimensions including number, area, density, etc. When item arrays are constructed with a skewed and unbalanced distribution of their dimensional properties, false conclusions are easily made. This kind of flawed stimulus design was identified in a series of recently published studies that argue for an additive-area heuristic whereby people are more sensitive to the sum of the vertical and horizontal element axes in each item than the sum of the mathematical area of each item. By analyzing the dimensional properties of the stimuli used in the original studies (e.g., Yousif & Keil, 2019) using the mathematical framework for constructing stimulus parameters (DeWind et al., 2015) and by re-analyzing the data from another previous work on area judgment (Tomlinson et al., 2020), this paper demonstrates how skewed and unbalanced stimulus sampling leads to false conclusions.

The role of working memory for bridging the gap between perception and goal-directed actions: Evidence by mu and beta oscillations in sensorimotor cortex

What mechanisms are at work when transferring a visual representation in working memory into a higher-level code for guiding future actions? We investigated the underlying attentional and motor selection processes in working memory by means of oscillatory EEG parameters. Participants stored two, three or four objects in working memory and subsequent retroactive cues indicated one or two items as task-relevant. The oscillatory response in mu (10-14 Hz) and beta (15-25 Hz) frequencies with an estimated source in sensorimotor cortex contralateral to response side was used as a correlate of motor planning. There was a stronger suppression of oscillatory power when only one item was cued. Importantly, this effect appeared although the required response could not be anticipated at this point in time. This suggests that working memory can store multiple item-specific motor plans and the selection of a stored visual item leads to an automatic updating of associated response alternatives.

Top-Down Contributions to Attention Shifting and Disengagement: A Template Model of Visual Attention

Two separate systems are involved in the control of spatial attention; one that is driven by a goal, and the other that is driven by stimuli. While the goal- and stimulus-driven systems follow different general principles, they also interplay with each other. However, the mechanism by which the goal-driven system influences the stimulus-driven system is still debated. The present study examined top-down contributions to two components of attention orienting, shifting and disengagement, with an experimental paradigm in which participants held a visual item in short-term memory and performed a prosaccade task with a manipulation of the gap between fixation offset and target onset. Four experiments showed that the short-term memory content accelerated shifting and impaired disengagement, but the influence on disengagement depended on the utility of short-term memory in guiding attention toward the target. Thus, the use of short-term memory was strategic. Computational models of visual attention were fitted to the experimental data, which suggested that the top-down contributions to shifting was more prominent than those to disengagement. The present study shows that the current modeling framework was particularly useful when examining the contributions of theoretical constructs for the control of visual attention, but it also suggests limitations.

Top-Down Contributions to Attention Shifting and Disengagement: A Template Model of Visual Attention

Two separate systems are involved in the control of spatial attention; one that is driven by a goal, and the other that is driven by stimuli. While the goal- and stimulus-driven systems follow different general principles, they also interplay with each other. However, the mechanism by which the goal-driven system influences the stimulus-driven system is still debated. The present study examined top-down contributions to two components of attention orienting, shifting and disengagement, with an experimental paradigm in which participants held a visual item in short-term memory and performed a prosaccade task with a manipulation of the gap between fixation offset and target onset. Four experiments showed that the short-term memory content accelerated shifting and impaired disengagement, but the influence on disengagement depended on the utility of short-term memory in guiding attention toward the target. Thus, the use of short-term memory was strategic. Computational models of visual attention were fitted to the experimental data, which suggested that the top-down contributions to shifting was more prominent than those to disengagement. The present study indicates that the current modeling framework was particularly useful when examining the contributions of theoretical constructs for the control of visual attention, but it also suggests limitations.

Salience Representation in the Parietal and Frontal Cortex

Some objects in the visual field are more likely to attract attention because they are either intrinsically eye catching or relevant in the context of a particular task. These two factors, known as stimulus-driven and goal-directed factors, respectively, are thought to be integrated into a unique salience map, possibly located in the frontal or the parietal cortex. However, the distinct contribution of these two regions to salience representation is difficult to establish experimentally and remains debated. In an attempt to address this issue, we designed several dual tasks composed of a letter reporting task and a visual search task, allowing us to quantify the salience of each visual item by measuring its probability to be selected by attention. In Experiment 1, the salience of the visual search items depended on a combination of conspicuity and relevance factors, whereas in Experiment 2, stimulus-driven and goal-directed factors were tested separately. Then, we used transcranial magnetic stimulation to interfere transiently with the function of the right angular gyrus (ANG) or right FEFs in healthy subjects performing these dual tasks. We found that interfering with the ANG and the FEF function specifically altered the influence of salience on the letter report rate without affecting the overall letter reporting rate, suggesting that these areas are involved in salience representation. In particular, the present study suggests that ANG is involved in goal-directed salience representation, whereas FEF would rather house a global salience map integrating both goal-directed and stimulus-driven factors.