scholarly journals The reverse motion illusion in random dot motion displays and implications for understanding development

2022 ◽  
Vol 3 ◽  
Author(s):  
Catherine Manning ◽  
Kimberly Meier ◽  
Deborah Giaschi
Keyword(s):  
Visual Development ◽  
Motion Direction ◽  
Reverse Motion ◽  
Open Questions ◽  
Adult Participants ◽  
Dot Motion ◽  
The Individual ◽  
Perceived Motion ◽  
Collaborative Efforts ◽  
Random Dot Motion

Across two independent developmental labs, we have been puzzled by the observation that a small proportion of our child and adult participants consistently report perceiving motion in the direction opposite to that presented in random dot motion displays, sometimes even when the motion is at 100% coherence. In this review, we first draw together existing reports of misperceptions of motion direction in random dot displays across observers in a small percentage of trials, before reporting evidence of consistent reverse motion perception in a minority of observers, including previously unreported observations from our own studies of visual development. We consider possible explanations for this reverse motion illusion, including motion induction, motion energy, correspondence noise and spatial undersampling. However, more work is required to understand the individual differences relating to this percept. We suggest that errors in perceived motion direction are likely to be more widespread than can be currently gleaned from the literature and explain why systematic study is needed, especially in children. Finally, we list some remaining open questions and call for collaborative efforts to document this phenomenon and stimulate future investigation.

scholarly journals A Hierarchical Attractor Network Model of perceptual versus intentional decision updates

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anne Löffler ◽  
Anastasia Sylaidi ◽  
Zafeirios Fountas ◽  
Patrick Haggard
Keyword(s):  
Network Model ◽  
Higher Order ◽  
Motion Direction ◽  
Attractor Network ◽  
Movement Trajectories ◽  
Internal Action ◽  
Perceptual Evidence ◽  
Dot Motion ◽  
Action Tendencies ◽  
Random Dot Motion

AbstractChanges of Mind are a striking example of our ability to flexibly reverse decisions and change our own actions. Previous studies largely focused on Changes of Mind in decisions about perceptual information. Here we report reversals of decisions that require integrating multiple classes of information: 1) Perceptual evidence, 2) higher-order, voluntary intentions, and 3) motor costs. In an adapted version of the random-dot motion task, participants moved to a target that matched both the external (exogenous) evidence about dot-motion direction and a preceding internally-generated (endogenous) intention about which colour to paint the dots. Movement trajectories revealed whether and when participants changed their mind about the dot-motion direction, or additionally changed their mind about which colour to choose. Our results show that decision reversals about colour intentions are less frequent in participants with stronger intentions (Exp. 1) and when motor costs of intention pursuit are lower (Exp. 2). We further show that these findings can be explained by a hierarchical, multimodal Attractor Network Model that continuously integrates higher-order voluntary intentions with perceptual evidence and motor costs. Our model thus provides a unifying framework in which voluntary actions emerge from a dynamic combination of internal action tendencies and external environmental factors, each of which can be subject to Change of Mind.

scholarly journals Detaching from influence in decision-making: objective and subjective freedom of choice

2020 ◽  
Author(s):  
Gwydion Williams ◽  
Patrick Haggard ◽  
Lucie Charles
Keyword(s):  
Decision Making ◽  
Irrelevant Information ◽  
Freedom Of Choice ◽  
Motion Direction ◽  
Dot Motion ◽  
Trial Participants ◽  
Random Dot Motion

How much can people resist influence in choice? In this study, we explored participants’ abilities to voluntarily detach from irrelevant information to make free choices. Participants saw random-dot-motion stimuli and a colour-cue indicating whether their response should be congruent or incongruent with the direction of dot-motion. Importantly, in a third condition, the colour-cue instructed participants to detach from dot-motion direction and to freely choose how to respond. After each trial, participants rated how much they felt their decision was influenced by the stimulus. Our results showed that participants conflated opposition and independence: responses incongruent with the stimulus were systematically associated with a greater sense of freedom and detachment, whether these responses were instructed or made freely. Further, this effect seemed stronger in participants who tended to oppose the stimulus more frequently. Taken together, these results suggest that feelings of freedom rely on opposing suggestion and breaking from our habits.

scholarly journals Recent progress understanding pathophysiology and genesis of brain AVM—a narrative review

2021 ◽  
Author(s):  
Hans-Jakob Steiger
Keyword(s):  
Large Degree ◽  
Advanced Imaging ◽  
Genetic Origin ◽  
The Past ◽  
Open Questions ◽  
Brain Avm ◽  
Pubmed Search ◽  
Substantial Progress ◽  
The Individual ◽  
Arterial Aneurysms

AbstractConsiderable progress has been made over the past years to better understand the genetic nature and pathophysiology of brain AVM. For the actual review, a PubMed search was carried out regarding the embryology, inflammation, advanced imaging, and fluid dynamical modeling of brain AVM. Whole-genome sequencing clarified the genetic origin of sporadic and familial AVM to a large degree, although some open questions remain. Advanced MRI and DSA techniques allow for better segmentation of feeding arteries, nidus, and draining veins, as well as the deduction of hemodynamic parameters such as flow and pressure in the individual AVM compartments. Nonetheless, complete modeling of the intranidal flow structure by computed fluid dynamics (CFD) is not possible so far. Substantial progress has been made towards understanding the embryology of brain AVM. In contrast to arterial aneurysms, complete modeling of the intranidal flow and a thorough understanding of the mechanical properties of the AVM nidus are still lacking at the present time.

scholarly journals How Can Psychological Science Help Counter the Spread of Fake News?

2021 ◽  
Vol 24 ◽  
Author(s):  
Sander van der Linden ◽  
Jon Roozenbeek ◽  
Rakoen Maertens ◽  
Melisa Basol ◽  
Ondřej Kácha ◽  
...  
Keyword(s):  
Research Agenda ◽  
Source Credibility ◽  
Fake News ◽  
Intervention Effectiveness ◽  
Motivated Cognition ◽  
Individual Level ◽  
Psychological Science ◽  
Open Questions ◽  
The Individual

Abstract In recent years, interest in the psychology of fake news has rapidly increased. We outline the various interventions within psychological science aimed at countering the spread of fake news and misinformation online, focusing primarily on corrective (debunking) and pre-emptive (prebunking) approaches. We also offer a research agenda of open questions within the field of psychological science that relate to how and why fake news spreads and how best to counter it: the longevity of intervention effectiveness; the role of sources and source credibility; whether the sharing of fake news is best explained by the motivated cognition or the inattention accounts; and the complexities of developing psychometrically validated instruments to measure how interventions affect susceptibility to fake news at the individual level.

scholarly journals The basis of area and dot number effects in random dot motion perception

1982 ◽  
Vol 22 (10) ◽  
pp. 1253-1259 ◽  
Author(s):  
Curtis L. Baker ◽  
Oliver J. Braddick
Keyword(s):  
Motion Perception ◽  
Dot Motion ◽  
Random Dot Motion

scholarly journals A new variant of the barberpole effect: Psychophysical data and computer simulations

Psihologija ◽  
2002 ◽  
Vol 35 (3-4) ◽  
pp. 209-223
Author(s):  
Dejan Todorovic
Keyword(s):  
Receptive Fields ◽  
Vertical Component ◽  
Parallel Line ◽  
Random Fluctuation ◽  
Final State ◽  
Motion Direction ◽  
Weak Preference ◽  
New Variant ◽  
Direction Sensitivity ◽  
Perceived Motion

The classic barberpole effect shows that perceived direction of motion of parallel line segments depends on the orientation of the frame defined by segment end points. A stimulus configuration was created by crossing two oblique barberpoles. Perceived motion in the crossed portion of the configuration is bi-stable, alternating between two oblique directions defined by the two component barberpoles. Ratings of dominance of perceived motion direction in the crossed portion of two barberpoles of different width and orientation revealed a strong preference for the wider component barberpole and a weak preference for the nearer-to-vertical component barberpole. A network model is presented in which each unit inhibits units with different direction sensitivity and co-extensive receptive fields, and excites units with equal direction sensitivity and neighboring receptive fields. Simulations of the temporal evolution of the spatial activity profile exhibit the effect of barberpole width and the bi-stability of percepts. Fatigue of highly adapted units enables the gradual emergence of non-adapted units. Small initial variations can lead to profound differences in the final state of the system, explaining the quasi-random fluctuation between the two perceptual variants.

scholarly journals Sensitivity of Neurons in the Middle Temporal Area of Marmoset Monkeys to Random Dot Motion

2017 ◽  
Author(s):  
Tristan A. Chaplin ◽  
Benjamin J. Allitt ◽  
Maureen A. Hagan ◽  
Nicholas S. Price ◽  
Ramesh Rajan ◽  
...  
Keyword(s):  
Primate Species ◽  
Neural Basis ◽  
Temporal Area ◽  
Middle Temporal ◽  
Mt Neurons ◽  
Wide Range ◽  
Middle Temporal Area ◽  
Dot Motion ◽  
Marmoset Monkeys ◽  
Random Dot Motion

AbstractNeurons in the Middle Temporal area (MT) of the primate cerebral cortex respond to moving visual stimuli. The sensitivity of MT neurons to motion signals can be characterized by using random-dot stimuli, in which the strength of the motion signal is manipulated by adding different levels of noise (elements that move in random directions). In macaques, this has allowed the calculation of “neurometric” thresholds. We characterized the responses of MT neurons in sufentanil/nitrous oxide anesthetized marmoset monkeys, a species which has attracted considerable recent interest as an animal model for vision research. We found that MT neurons show a wide range of neurometric thresholds, and that the responses of the most sensitive neurons could account for the behavioral performance of macaques and humans. We also investigated factors that contributed to the wide range of observed thresholds. The difference in firing rate between responses to motion in the preferred and null directions was the most effective predictor of neurometric threshold, whereas the direction tuning bandwidth had no correlation with the threshold. We also showed that it is possible to obtain reliable estimates of neurometric thresholds using stimuli that were not highly optimized for each neuron, as is often necessary when recording from large populations of neurons with different receptive field concurrently, as was the case in this study. These results demonstrate that marmoset MT shows an essential physiological similarity to macaque MT, and suggest that its neurons are capable of representing motion signals that allow for comparable motion-in-noise judgments.New and NoteworthyWe report the activity of neurons in marmoset MT in response to random-dot motion stimuli of varying coherence. The information carried by individual MT neurons was comparable to that of the macaque, and that the maximum firing rates were a strong predictor of sensitivity. Our study provides key information regarding the neural basis of motion perception in the marmoset, a small primate species that is becoming increasingly popular as an experimental model.

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