scholarly journals Stereoscopic information disrupts the closure grouping effect in discrimination task but not in detection task

2016 ◽  
Vol 16 (12) ◽  
pp. 801
Author(s):  
Junjun Zhang
Keyword(s):  
Discrimination Task ◽  
Detection Task ◽  
Grouping Effect

scholarly journals Using a More Intuitive Cue in a Temporal Attention Discrimination Task to Compare Endogenous and Exogenous Mechanisms

2021 ◽  
Author(s):  
Colin R McCormick ◽  
Ralph S. Redden ◽  
Raymond M Klein
Keyword(s):  
Reaction Time ◽  
Discrimination Task ◽  
Detection Task ◽  
Temporal Attention ◽  
Cognitive Mechanism ◽  
Speed And Accuracy

Temporal attention is a cognitive mechanism that allows individuals to prepare to respond to ananticipated event. Lawrence and Klein (2013) distinguished two forms of temporal attention: oneelicited by purely endogenous alerting mechanisms, and one elicited through exogenous alertingmechanisms. Recently, McCormick et al. displayed that these mechanisms generate additiveeffects on reaction time, however more informative speed and accuracy comparisons were notpossible due to them being measured during a detection task. The current pair of experimentslooks to compare these two forms of temporal attention in a discrimination task while measuringboth speed and accuracy, by inducing methodological modifications that lower task demand.These manipulations were successful, as temporal cueing effects were observed for both thecombined form and the less-studied purely endogenous form. However, speed-accuracyperformance for these two forms of temporal attention did not align with our predictions basedon Lawrence and Klein (2013), leading us to speculate on the generalizability of their results.

Off on the Wrong Foot: Local Features in Biological Motion

Perception ◽  
10.1068/p6140 ◽  
2009 ◽  
Vol 38 (4) ◽  
pp. 522-532 ◽  
Author(s):  
Daniel R Saunders ◽  
Julia Suchan ◽  
Nikolaus F Troje
Keyword(s):  
Motion Perception ◽  
Discrimination Task ◽  
Biological Motion ◽  
Large Body ◽  
Detection Task ◽  
Observer Performance ◽  
Local Motion ◽  
Motion Patterns ◽  
Direction Discrimination ◽  
Biological Motion Perception

Biological-motion perception consists of a number of different phenomena. They include global mechanisms that support the retrieval of the coherent shape of a walker, but also mechanisms which derive information from the local motion of its parts about facing direction and animacy, independent of the particular shape of the display. A large body of the literature on biological-motion perception is based on a synthetic stimulus generated by an algorithm published by James Cutting in 1978 ( Perception7 393–405). Here we show that this particular stimulus lacks a visual invariant inherent to the local motion of the feet of a natural walker, which in more realistic motion patterns indicates the facing direction of a walker independent of its shape. Comparing Cutting's walker to a walker derived from motion-captured data of real human walkers, we find no difference between the two displays in a detection task designed such that observers had to rely on global shape. In a direction discrimination task, however, in which only local motion was accessible to the observer, performance on Cutting's walker was at chance, while direction could still be retrieved from the stimuli derived from the real walker.

Discrimination and Detection of Changes in the Velocity of Visual Motion: Effect of Aperture Size

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 239-239
Author(s):  
L Likova ◽  
G Dimitrov ◽  
S Mateeff ◽  
J Hohnsbein
Keyword(s):  
Change Detection ◽  
Discrimination Task ◽  
Critical Frequency ◽  
Visual Motion ◽  
Critical Factor ◽  
Detection Task ◽  
Viewing Distance ◽  
Aperture Size ◽  
Mean Velocity ◽  
The Subject

Recently Mateeff and Hohnsbein (1996 Vision Research36 2873 – 2882) showed that the critical frequency for detection of modulated velocity of motion was invariant with respect to the viewing distance. The critical frequency was a function of the ratio between the mean velocity and the size of the aperture through which the motion was observed. In the present study we examined whether the velocity/aperture ratio affects velocity discrimination and detection of single velocity changes. Six subjects observed a random-dot pattern that could move within an invisible square aperture. In the discrimination task, two motions of 250 ms duration with slightly different velocities were presented with a 1 s interval between them. The subject had to report which of the motions was faster. In the change-detection task the same two motions were presented without an interval between them and the subject had to report whether the change was from a low to a high velocity or vice versa. Mean velocities of 8 and 64 deg s−1 and aperture sizes of 10 and 40 deg were employed in both tasks. Weber fractions were determined by the method of constant stimuli. The discrimination accuracy was not affected by aperture size at either mean velocity. The detection task was also unaffected by aperture size at 8 deg s−1. However, at 64 deg s−1 decreasing aperture size impaired the Weber fractions by a factor of about three. We suggest that the decrease of the lifetime of the dots of the pattern at high velocities and small apertures may be the critical factor for the impairment of the change detection. This factor is of less importance for the velocity discrimination task.

scholarly journals Mugs and Plants: Object Semantic Knowledge Alters Perceptual Processing with Behavioral Ramifications

2021 ◽  
Author(s):  
Dick Dubbelde ◽  
Sarah Shomstein
Keyword(s):  
Spatial Resolution ◽  
Discrimination Task ◽  
Temporal Discrimination ◽  
Red Light ◽  
Semantic Knowledge ◽  
Detection Task ◽  
Perceptual Processing ◽  
Gap Detection ◽  
Behavioral Differences ◽  
Manipulable Object

Abstract Neural processing of objects with action associations is thought to recruit dorsal visual regions more than objects without such associations. We hypothesized that because the dorsal and ventral visual pathways have differing proportions of magno- and parvo-cellular input, there should be behavioral differences in perceptual tasks between manipulable and non-manipulable objects. This hypothesis was tested using gap detection task, suited to the spatial resolution of the ventral parvocellular processing, and object flicker discrimination task, suited to the temporal resolution of the dorsal magnocellular processing. Directly predicted from the cellular composition of each pathway, a non-manipulable object advantage was observed in tasks relying on spatial resolution, and a manipulable object advantage in temporal discrimination. We also show that these relative advantages are modulated by either reducing object recognition through inversion or by suppressing magnocellular processing using red light. These results establish perceptual differences between objects dependent on prior knowledge and experience.

scholarly journals Top–down task-specific determinants of multisensory motor reaction time enhancements and sensory switch costs

2021 ◽  
Author(s):  
Ayla Barutchu ◽  
Charles Spence
Keyword(s):  
Discrimination Task ◽  
Multisensory Processing ◽  
Detection Task ◽  
Auditory Signal ◽  
Motor Reaction ◽  
Top Down ◽  
Complex Interplay ◽  
Task Instructions ◽  
Switch Costs ◽  
Dual Target

AbstractThis study was designed to investigate the complex interplay between multisensory processing, top–down processes related to the task relevance of sensory signals, and sensory switching. Thirty-five adults completed either a speeded detection or a discrimination task using the same auditory and visual stimuli and experimental setup. The stimuli consisted of unisensory and multisensory presentations of the letters ‘b’ and ‘d’. The multisensory stimuli were either congruent (e.g., the grapheme ‘b’ with the phoneme /b/) or incongruent (e.g., the grapheme ‘b’ with the phoneme /d/). In the detection task, the participants had to respond to all of the stimuli as rapidly as possible while, in the discrimination task, they only responded on those trials where one prespecified letter (either ‘b’ or ‘d’) was present. Incongruent multisensory stimuli resulted in faster responses as compared to unisensory stimuli in the detection task. In the discrimination task, only the dual-target congruent stimuli resulted in faster RTs, while the incongruent multisensory stimuli led to slower RTs than to unisensory stimuli; RTs were the slowest when the visual (rather than the auditory) signal was irrelevant, thus suggesting visual dominance. Switch costs were also observed when switching between unisensory target stimuli, while dual-target multisensory stimuli were less likely to be affected by sensory switching. Taken together, these findings suggest that multisensory motor enhancements and sensory switch costs are influenced by top–down modulations determined by task instructions, which can override the influence of prior learnt associations.

scholarly journals Trained-feature specific offline learning in an orientation detection task

2018 ◽  
Author(s):  
Masako Tamaki ◽  
Zhiyan Wang ◽  
Takeo Watanabe ◽  
Yuka Sasaki
Keyword(s):  
Discrimination Task ◽  
Nrem Sleep ◽  
Detection Task ◽  
Visual Perceptual Learning ◽  
Offline Learning ◽  
Visual Areas ◽  
Visual Tasks ◽  
Standard Task ◽  
Orientation Detection ◽  
Performance Gains

AbstractIt has been suggested that sleep provides additional enhancement of visual perceptual learning (VPL) acquired before sleep, termed offline performance gains. A majority of the studies that found offline performance gains of VPL used discrimination tasks including the texture discrimination task (TDT). This makes it questionable whether offline performance gains on VPL are generalized to other visual tasks. The present study examined whether a Gabor orientation detection task, which is a standard task in VPL, shows offline performance gains. In Experiment 1, we investigated whether sleep leads to offline performance gains on the task. Subjects were trained with the Gabor orientation detection task, and re-tested it after a 12-hr interval that included either nightly sleep or only wakefulness. We found that performance on the task improved to a significantly greater degree after the interval that included sleep and wakefulness than the interval including wakefulness alone. In addition, offline performance gains were specific to the trained orientation. In Experiment 2, we tested whether offline performance gains occur by a nap. Also, we tested whether spontaneous sigma activity in early visual areas during non-rapid eye movement (NREM) sleep, previously implicated in offline performance gains of TDT, was associated with offline performance gains of the task. A different group of subjects had a nap with polysomnography. The subjects were trained with the task before the nap and re-tested after the nap. The performance of the task improved significantly after the nap only on the trained orientation. Sigma activity in the trained region of early visual areas during NREM sleep was significantly larger than in the untrained region, in correlation with offline performance gains. These aspects were also found with VPL of TDT. The results of the present study demonstrate that offline performance gains are not specific to a discrimination task such as TDT, and can be generalized to other forms of VPL tasks, along with trained-feature specificity. Moreover, the present results also suggest that sigma activity in the trained region of early visual areas plays an important role in offline performance gains of VPL of detection as well as discrimination tasks.

scholarly journals Mugs and Plants: Object Semantic Knowledge Alters Perceptual Processing with Behavioral Ramifications

2021 ◽  
Author(s):  
Dick Dubbelde ◽  
Sarah S Shomstein
Keyword(s):  
Spatial Resolution ◽  
Discrimination Task ◽  
Temporal Discrimination ◽  
Red Light ◽  
Semantic Knowledge ◽  
Detection Task ◽  
Perceptual Processing ◽  
Gap Detection ◽  
Behavioral Differences ◽  
Manipulable Object

Neural processing of objects with action associations is thought to recruit dorsal visual regions more than objects without such associations. We hypothesized that because the dorsal and ventral visual pathways have differing proportions of magno-and parvo-cellular input, there should be behavioral differences in perceptual tasks between manipulable and non-manipulable objects. This hypothesis was tested using gap detection task, suited to the spatial resolution of the ventral parvocellular processing, and object flicker discrimination task, suited to the temporal resolution of the dorsal magnocellular processing. Directly predicted from the cellular composition of each pathway, a non-manipulable object advantage was observed in tasks relying on spatial resolution, and a manipulable object advantage in temporal discrimination. We also show that these relative advantages are modulated by either reducing object recognition through inversion or by suppressing magnocellular processing using red light. These results establish perceptual differences between objects dependent on prior knowledge and experience.

Stimulus Ratio Effects on Speech Discrimination by Children and Adults

1991 ◽  
Vol 34 (3) ◽  
pp. 671-678 ◽  
Author(s):  
Joan E. Sussman
Keyword(s):  
Discrimination Task ◽  
Response Pattern ◽  
Response Patterns ◽  
Speech Discrimination ◽  
Adult Group ◽  
Discrimination Accuracy ◽  
Formant Frequency ◽  
Response Strategies ◽  
Place Of Articulation ◽  
Adults And Children

This investigation examined the response strategies and discrimination accuracy of adults and children aged 5–10 as the ratio of same to different trials was varied across three conditions of a “change/no-change” discrimination task. The conditions varied as follows: (a) a ratio of one-third same to two-thirds different trials (33% same), (b) an equal ratio of same to different trials (50% same), and (c) a ratio of two-thirds same to one-third different trials (67% same). Stimuli were synthetic consonant-vowel syllables that changed along a place of articulation dimension by formant frequency transition. Results showed that all subjects changed their response strategies depending on the ratio of same-to-different trials. The most lax response pattern was observed for the 50% same condition, and the most conservative pattern was observed for the 67% same condition. Adult response patterns were most conservative across condition. Differences in discrimination accuracy as measured by P(C) were found, with the largest difference in the 5- to 6-year-old group and the smallest change in the adult group. These findings suggest that children’s response strategies, like those of adults, can be manipulated by changing the ratio of same-to-different trials. Furthermore, interpretation of sensitivity measures must be referenced to task variables such as the ratio of same-to-different trials.

Vivid Imagers Are Better at Detecting Salient Changes

2006 ◽  
Vol 27 (4) ◽  
pp. 218-228 ◽  
Author(s):  
Paul Rodway ◽  
Karen Gillies ◽  
Astrid Schepman
Keyword(s):  
Individual Differences ◽  
Change Detection ◽  
Visual Imagery ◽  
Detection Task ◽  
Level Of Detail ◽  
Detection Accuracy ◽  
Change Detection Task ◽  
Term Change ◽  
High Level

This study examined whether individual differences in the vividness of visual imagery influenced performance on a novel long-term change detection task. Participants were presented with a sequence of pictures, with each picture and its title displayed for 17  s, and then presented with changed or unchanged versions of those pictures and asked to detect whether the picture had been changed. Cuing the retrieval of the picture's image, by presenting the picture's title before the arrival of the changed picture, facilitated change detection accuracy. This suggests that the retrieval of the picture's representation immunizes it against overwriting by the arrival of the changed picture. The high and low vividness participants did not differ in overall levels of change detection accuracy. However, in replication of Gur and Hilgard (1975) , high vividness participants were significantly more accurate at detecting salient changes to pictures compared to low vividness participants. The results suggest that vivid images are not characterised by a high level of detail and that vivid imagery enhances memory for the salient aspects of a scene but not all of the details of a scene. Possible causes of this difference, and how they may lead to an understanding of individual differences in change detection, are considered.

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