scholarly journals Quickly fading afterimages: hierarchical adaptations in human perception

2019 ◽  
Author(s):  
Madeline E. Klinger ◽  
Christian A. Kell ◽  
Danko Nikolić
Keyword(s):  
Prolonged Exposure ◽  
Visual Stimuli ◽  
Human Perception ◽  
Visual Content ◽  
Blank Screen ◽  
Adaptive Mechanisms ◽  
Fast Removal

AbstractAfterimages result from a prolonged exposure to still visual stimuli. They are best detectable when viewed against uniform backgrounds and can persist for multiple seconds. Consequently, the dynamics of afterimages appears to be slow by their very nature. To the contrary, we report here that about 50% of an afterimage intensity can be erased rapidly—within less than a second. The prerequisite is that subjects view a rich visual content to erase the afterimage; fast erasure of afterimages does not occur if subjects view a blank screen. Moreover, we find evidence that fast removal of afterimages is a skill learned with practice as our subjects were always more effective in cleaning up afterimages in later parts of the experiment. These results can be explained by a tri-level hierarchy of adaptive mechanisms, as has been proposed by the theory of practopoiesis.

The evaluation of Acacia and other tree pods for goats: influence of rumen fluid source and polyethylene glycol addition on in vitro gas production

2002 ◽  
Vol 2002 ◽  
pp. 132-132 ◽  
Author(s):  
V. Mlambo ◽  
F. L. Mould ◽  
T. Smith ◽  
E. Owen ◽  
I. Mueller-Harvey
Keyword(s):  
Polyethylene Glycol ◽  
Prolonged Exposure ◽  
Rumen Fluid ◽  
Gas Production ◽  
Rumen Microorganisms ◽  
Protein Supplements ◽  
In Vitro Gas Production ◽  
Adaptive Mechanisms ◽  
Acacia Pods

After prolonged exposure to tanniniferous diets, it has been reported that some rumen microorganisms acquire defensive mechanisms against tannins (Brooker et al., 2000) or produce tannin-degrading enzymes. Such rumen microorganisms are said to be “tannin resistant” as their fermentation activity is less inhibited by the presence of tannins in the host’s diet. As acacia pods contain tannins their use as protein supplements for goats in the dry season may require that they be first detannified e.g. by using polyethylene glycol (PEG). However, goats with prior exposure to tanniniferous diets may have developed adaptive mechanisms to deal with tannins. This study, therefore, investigated the need for tannin inactivation in feeds given to ‘adapted’ animals by comparing the effect on the in vitro fermentation of tree pods incubated with and without PEG using rumen fluid from adapted and unadapted goats.

scholarly journals Human perception of visual stimuli modulated by direction of linear polarization

2015 ◽  
Vol 115 ◽  
pp. 48-57 ◽  
Author(s):  
Gary P. Misson ◽  
Brenda H. Timmerman ◽  
Peter J. Bryanston-Cross
Keyword(s):  
Linear Polarization ◽  
Visual Stimuli ◽  
Human Perception

Cross-Modal and Non-Sensory Influences on Auditory Streaming

Perception ◽  
10.1068/p5035 ◽  
2003 ◽  
Vol 32 (11) ◽  
pp. 1393-1402 ◽  
Author(s):  
Robert P Carlyon ◽  
Christopher J Plack ◽  
Deborah A Fantini ◽  
Rhodri Cusack
Keyword(s):  
Auditory Stimulus ◽  
Experimental Psychology ◽  
Visual Stimuli ◽  
Human Perception ◽  
Tone Sequence ◽  
Visual Task ◽  
Auditory Streaming ◽  
Visual Targets

Carlyon et al (2001 Journal of Experimental Psychology: Human Perception and Performance27 115–127) have reported that the buildup of auditory streaming is reduced when attention is diverted to a competing auditory stimulus. Here, we demonstrate that a reduction in streaming can also be obtained by attention to a visual task or by the requirement to count backwards in threes. In all conditions participants heard a 13 s sequence of tones, and, during the first 10 s saw a sequence of visual stimuli containing three, four, or five targets. The tone sequence consisted of twenty repeating triplets in an ABA–ABA … order, where A and B represent tones of two different frequencies. In each sequence, three, four, or five tones were amplitude modulated. During the first 10 s of the sequence, participants either counted the number of visual targets, counted the number of (modulated) auditory targets, or counted backwards in threes from a specified number. They then made an auditory-streaming judgment about the last 3 s of the tone sequence: whether one or two streams were heard. The results showed more streaming when participants counted the auditory targets (and hence were attending to the tones throughout) than in either the ‘visual’ or ‘counting-backwards’ conditions.

Human Perception Characteristics according to the Arrangement of Visual Stimuli

2020 ◽  
Vol 39 (3) ◽  
pp. 257-266
Author(s):  
Yejin Lee ◽  
Kwang Tae Jung ◽  
Hyun Chul Lee
Keyword(s):  
Visual Stimuli ◽  
Human Perception

scholarly journals Sensory experience during early sensitive periods shapes cross-modal temporal biases

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Stephanie Badde ◽  
Pia Ley ◽  
Siddhart S Rajendran ◽  
Idris Shareef ◽  
Ramesh Kekunnaya ◽  
...  
Keyword(s):  
Strong Evidence ◽  
Temporal Order ◽  
Visual Stimuli ◽  
Human Perception ◽  
Sensory Experience ◽  
Sensitive Period ◽  
Visual Events ◽  
Sustained Effects ◽  
Transient Loss

Typical human perception features stable biases such as perceiving visual events as later than synchronous auditory events. The origin of such perceptual biases is unknown. To investigate the role of early sensory experience, we tested whether a congenital, transient loss of pattern vision, caused by bilateral dense cataracts, has sustained effects on audio-visual and tactile-visual temporal biases and resolution. Participants judged the temporal order of successively presented, spatially separated events within and across modalities. Individuals with reversed congenital cataracts showed a bias towards perceiving visual stimuli as occurring earlier than auditory (Expt. 1) and tactile (Expt. 2) stimuli. This finding stood in stark contrast to normally sighted controls and sight-recovery individuals who had developed cataracts later in childhood: both groups exhibited the typical bias of perceiving vision as delayed compared to audition. These findings provide strong evidence that cross-modal temporal biases depend on sensory experience during an early sensitive period.

scholarly journals Decision-level adaptation in motion perception

2015 ◽  
Vol 2 (12) ◽  
pp. 150418 ◽  
Author(s):  
George Mather ◽  
Rebecca J. Sharman
Keyword(s):  
Sensory Neurons ◽  
Prolonged Exposure ◽  
Visual Stimuli ◽  
Relative Activity ◽  
Sensory Level ◽  
Decision Factors ◽  
Decision Level ◽  
Implied Motion ◽  
Level Of Processing ◽  
Stimulus Direction

Prolonged exposure to visual stimuli causes a bias in observers' responses to subsequent stimuli. Such adaptation-induced biases are usually explained in terms of changes in the relative activity of sensory neurons in the visual system which respond selectively to the properties of visual stimuli. However, the bias could also be due to a shift in the observer's criterion for selecting one response rather than the alternative; adaptation at the decision level of processing rather than the sensory level. We investigated whether adaptation to implied motion is best attributed to sensory-level or decision-level bias. Three experiments sought to isolate decision factors by changing the nature of the participants' task while keeping the sensory stimulus unchanged. Results showed that adaptation-induced bias in reported stimulus direction only occurred when the participants' task involved a directional judgement, and disappeared when adaptation was measured using a non-directional task (reporting where motion was present in the display, regardless of its direction). We conclude that adaptation to implied motion is due to decision-level bias, and that a propensity towards such biases may be widespread in sensory decision-making.

scholarly journals Visual Adaptation to Goal-directed Hand Actions

2009 ◽  
Vol 21 (9) ◽  
pp. 1805-1819 ◽  
Author(s):  
Nick E. Barraclough ◽  
Rebecca H. Keith ◽  
Dengke Xiao ◽  
Mike W. Oram ◽  
David I. Perrett
Keyword(s):  
Prolonged Exposure ◽  
Visual Stimuli ◽  
Visual Adaptation ◽  
Action Perception ◽  
Cell Responses ◽  
Action Processing ◽  
Opposite Action ◽  
Single Cell Responses ◽  
Adaptation Action ◽  
Processing Mechanisms

Prolonged exposure to visual stimuli, or adaptation, often results in an adaptation “aftereffect” which can profoundly distort our perception of subsequent visual stimuli. This technique has been commonly used to investigate mechanisms underlying our perception of simple visual stimuli, and more recently, of static faces. We tested whether humans would adapt to movies of hands grasping and placing different weight objects. After adapting to hands grasping light or heavy objects, subsequently perceived objects appeared relatively heavier, or lighter, respectively. The aftereffects increased logarithmically with adaptation action repetition and decayed logarithmically with time. Adaptation aftereffects also indicated that perception of actions relies predominantly on view-dependent mechanisms. Adapting to one action significantly influenced the perception of the opposite action. These aftereffects can only be explained by adaptation of mechanisms that take into account the presence/absence of the object in the hand. We tested if evidence on action processing mechanisms obtained using visual adaptation techniques confirms underlying neural processing. We recorded monkey superior temporal sulcus (STS) single-cell responses to hand actions. Cells sensitive to grasping or placing typically responded well to the opposite action; cells also responded during different phases of the actions. Cell responses were sensitive to the view of the action and were dependent upon the presence of the object in the scene. We show here that action processing mechanisms established using visual adaptation parallel the neural mechanisms revealed during recording from monkey STS. Visual adaptation techniques can thus be usefully employed to investigate brain mechanisms underlying action perception.

scholarly journals Cross-modal temporal biases emerge during early sensitive periods

2019 ◽  
Author(s):  
Stephanie Badde ◽  
Pia Ley ◽  
Siddhart S Rajendran ◽  
Idris Shareef ◽  
Ramesh Kekunnaya ◽  
...  
Keyword(s):  
Strong Evidence ◽  
Visual Stimuli ◽  
Human Perception ◽  
Sensory Experience ◽  
Sensitive Period ◽  
Visual Events ◽  
Sustained Effects ◽  
Sensory Modalities ◽  
Transient Loss

AbstractHuman perception features stable biases, such as perceiving visual events as later than synchronous auditory events. The origin of such perceptual biases is unknown, they could be innate or shaped by sensory experience during a sensitive period. To investigate the role of sensory experience, we tested whether a congenital, transient loss of vision, caused by bilateral dense cataracts, has sustained effects on the ability to order events spatio-temporally within and across sensory modalities. Most strikingly, individuals with reversed congenital cataracts showed a bias towards perceiving visual stimuli as occurring earlier than auditory (Exp. 1) and tactile (Exp. 2) stimuli. In contrast, both normally sighted controls and individuals who could see at birth but developed cataracts during childhood reported the typical bias of perceiving vision as delayed compared to audition. Thus, we provide strong evidence that cross-modal temporal perceptual biases depend on sensory experience and emerge during an early sensitive period.

When style matters: visual exploration is low dimensional and driven by intrinsic dynamics.

2021 ◽  
Author(s):  
Andrea Zangrossi ◽  
Giorgia Cona ◽  
Miriam Celli ◽  
Marco Zorzi ◽  
Maurizio Corbetta
Keyword(s):  
Eye Movements ◽  
Interindividual Variability ◽  
Visual Exploration ◽  
Specific Information ◽  
Power Law Distribution ◽  
Visual Content ◽  
Blank Screen ◽  
High Interindividual Variability ◽  
Low Dimensional ◽  
Degree Of Similarity

Abstract It is often assumed that we look at objects that are salient and behaviorally relevant, and that we pay attention differently depending on individual genetics, development, and experience. This view should imply high interindividual variability in eye movements. Conversely, we show that 60% of eye movements variance of more than a hundred observers looking at hundreds of different visual scenes could be summarized by a few components. The first component was not related to image-specific information and identified two kinds of observers during visual exploration: "static" and "dynamic". These viewing styles were accurately identifiable even when observers looked at a blank screen and were described by the degree of similarity to a power-law distribution of eye movements, which is thought to be a measure of intrinsic dynamics. This suggests that eye movements during visual exploration of real-world scenes are relatively independent of the visual content and may underlie intrinsic dynamics.

scholarly journals Stability and individual variability of social attachment in imprinting

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bastien S. Lemaire ◽  
Daniele Rucco ◽  
Mathilde Josserand ◽  
Giorgio Vallortigara ◽  
Elisabetta Versace
Keyword(s):  
Social Behaviour ◽  
Prolonged Exposure ◽  
Visual Stimuli ◽  
Bird Species ◽  
Individual Variability ◽  
Social Attachment ◽  
Precocial Bird ◽  
Filial Imprinting ◽  
Past Experiences ◽  
Over Time

AbstractFilial imprinting has become a model for understanding memory, learning and social behaviour in neonate animals. This mechanism allows the youngs of precocial bird species to learn the characteristics of conspicuous visual stimuli and display affiliative response to them. Although longer exposures to an object produce stronger preferences for it afterwards, this relation is not linear. Sometimes, chicks even prefer to approach novel rather than familiar objects. To date, little is known about how filial preferences develop across time. This study aimed to investigate filial preferences for familiar and novel imprinting objects over time. After hatching, chicks were individually placed in an arena where stimuli were displayed on two opposite screens. Using an automated setup, the duration of exposure and the type of stimuli were manipulated while the time spent at the imprinting stimulus was monitored across 6 days. We showed that prolonged exposure (3 days vs 1 day) to a stimulus produced robust filial imprinting preferences. Interestingly, with a shorter exposure (1 day), animals re-evaluated their filial preferences in functions of their spontaneous preferences and past experiences. Our study suggests that predispositions influence learning when the imprinting memories are not fully consolidated, driving animal preferences toward more predisposed stimuli.

Sign in / Sign up

Export Citation Format

Share Document