Masking Effects of Similar and Dissimilar Letters: A Test of the Interactive Channels Model

1977 ◽  
Vol 44 (3_suppl) ◽  
pp. 1219-1228 ◽  
Author(s):  
James T. Townsend ◽  
Joan Gay Snodgrass
Keyword(s):  
Discrimination Task ◽  
Noise Letter ◽  
Target Discrimination ◽  
The Right

Subjects identified which of two target letters was presented when the target was accompanied by a similar or dissimilar noise letter, the target appeared on the right or left of fixation, and the target was central or peripheral to the noise letter. Although performance deteriorated in the presence of noise letters compared to control conditions, masking was no greater with similar than dissimilar noise letters. Rather masking effects were specific to particular target-mask pairs, suggesting facilitation of target perception when mask and target shared features critical to the target-discrimination task. Thus, no evidence for Estes' interactive channels model was obtained. Neither the left vs right position of the target nor its centrality had any effect on accuracy or speed. Correct latencies to a target covaried with its accuracy of detection, but incorrect latencies were more strongly associated with the target identified than with the target presented.

Visual Field Sensitivity on a Two-Choice Discrimination Task

1981 ◽  
Vol 53 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Paul Salmon ◽  
Albert Rodwan
Keyword(s):  
Visual Field ◽  
Signal Detection ◽  
Left Visual Field ◽  
Discrimination Task ◽  
Visual Fields ◽  
Detection Analysis ◽  
Field Sensitivity ◽  
Signal Detection Analysis ◽  
The Right ◽  
Stimulation Of

A signal-detection analysis was used to evaluate visual-field sensitivity on a two-choice (same/different) discrimination task. Pairs of unfamiliar geometrical forms were presented tachistoscopically to the right or left visual fields of 12 subjects. Of 12 subjects 11 obtained left visual-field values which exceeded those of the right. The data suggested that the superiority of stimulation of the left visual field resulted from greater sensitivity to “same” figure pairs.

Event-related potentials during a target discrimination task based on texture cue

2003 ◽  
Vol 34 (14) ◽  
pp. 34-43 ◽  
Author(s):  
Jiuk Jung ◽  
Tetsuo Kobayashi ◽  
Yuwen Li ◽  
Shinya Kuriki
Keyword(s):  
Discrimination Task ◽  
Event Related Potentials ◽  
Target Discrimination ◽  
Related Potentials

scholarly journals Timing of Target Discrimination in Human Frontal Eye Fields

2004 ◽  
Vol 16 (6) ◽  
pp. 1060-1067 ◽  
Author(s):  
Jacinta O'Shea ◽  
Neil G. Muggleton ◽  
Alan Cowey ◽  
Vincent Walsh
Keyword(s):  
Visual Processing ◽  
Time Window ◽  
Time Windows ◽  
Cell Activity ◽  
Correct Rejection ◽  
Frontal Eye Field ◽  
Search Performance ◽  
Target Discrimination ◽  
Eye Field ◽  
The Right

Frontal eye field (FEF) neurons discharge in response to behaviorally relevant stimuli that are potential targets for saccades. Distinct visual and motor processes have been dissociated in the FEF of macaque monkeys, but little is known about the visual processing capacity of FEF in humans. We used double-pulse transcranial magnetic stimulation [(d)TMS] to investigate the timing of target discrimination during visual conjunction search. We applied dual TMS pulses separated by 40 msec over the right FEF and vertex. These were applied in five timing conditions to sample separate time windows within the first 200 msec of visual processing. (d)TMS impaired search performance, reflected in reduced d′ scores. This effect was limited to a time window between 40 and 80 msec after search array onset. These parameters correspond with single-cell activity in FEF that predicts monkeys' behavioral reports on hit, miss, false alarm, and correct rejection trials. Our findings demonstrate a crucial early role for human FEF in visual target discrimination that is independent of saccade programming.

Gamma oscillations in gerbil auditory cortex during a target-discrimination task reflect matches with short-term memory

2008 ◽  
Vol 1220 ◽  
pp. 70-80 ◽  
Author(s):  
Marcus Jeschke ◽  
Daniel Lenz ◽  
Eike Budinger ◽  
Christoph S. Herrmann ◽  
Frank W. Ohl
Keyword(s):  
Auditory Cortex ◽  
Discrimination Task ◽  
Short Term Memory ◽  
Gamma Oscillations ◽  
Short Term ◽  
Term Memory ◽  
Target Discrimination

scholarly journals Cerebro-cerebellar Interactions Underlying Temporal Information Processing

2010 ◽  
Vol 22 (12) ◽  
pp. 2913-2925 ◽  
Author(s):  
Kenji Aso ◽  
Takashi Hanakawa ◽  
Toshihiko Aso ◽  
Hidenao Fukuyama
Keyword(s):  
Information Processing ◽  
Discrimination Task ◽  
Temporal Information ◽  
Generation Task ◽  
Feed Forward ◽  
Time Processing ◽  
Temporal Information Processing ◽  
Time Discrimination ◽  
Forward Computation ◽  
The Right

The neural basis of temporal information processing remains unclear, but it is proposed that the cerebellum plays an important role through its internal clock or feed-forward computation functions. In this study, fMRI was used to investigate the brain networks engaged in perceptual and motor aspects of subsecond temporal processing without accompanying coprocessing of spatial information. Direct comparison between perceptual and motor aspects of time processing was made with a categorical-design analysis. The right lateral cerebellum (lobule VI) was active during a time discrimination task, whereas the left cerebellar lobule VI was activated during a timed movement generation task. These findings were consistent with the idea that the cerebellum contributed to subsecond time processing in both perceptual and motor aspects. The feed-forward computational theory of the cerebellum predicted increased cerebro-cerebellar interactions during time information processing. In fact, a psychophysiological interaction analysis identified the supplementary motor and dorsal premotor areas, which had a significant functional connectivity with the right cerebellar region during a time discrimination task and with the left lateral cerebellum during a timed movement generation task. The involvement of cerebro-cerebellar interactions may provide supportive evidence that temporal information processing relies on the simulation of timing information through feed-forward computation in the cerebellum.

scholarly journals Is Right Angular Gyrus Involved in the Metric Component of the Mental Body Representation in Touch and Vision? A tDCS Study

2021 ◽  
Vol 11 (3) ◽  
pp. 284
Author(s):  
Grazia Fernanda Spitoni ◽  
Giorgio Pireddu ◽  
Valerio Zanellati ◽  
Beatrice Dionisi ◽  
Gaspare Galati ◽  
...  
Keyword(s):  
Discrimination Task ◽  
Sensory Modality ◽  
Body Representation ◽  
The Body ◽  
Angular Gyrus ◽  
Visual Modality ◽  
Order Function ◽  
The Right ◽  
Sense Of Touch

Several studies have found in the sense of touch a good sensory modality by which to study body representation. Here, we address the “metric component of body representation”, a specific function developed to process the discrimination of tactile distances on the body. The literature suggests the involvement of the right angular gyrus (rAG) in processing the tactile metricity on the body. The question of this study is the following: is the rAG also responsible for the visual metric component of body representation? We used tDCS (anodal and sham) in 20 subjects who were administered an on-body distance discrimination task with both tactile and visual stimuli. They were also asked to perform the same task in a near-body condition. The results allow us to confirm the role of rAG in the estimation of tactile distances. Further, we also showed that rAG might be involved in the discrimination of distances on the body not only in tactile but also in visual modality. Finally, based on the significant effects of anodal stimulation even in a near-body visual discrimination task, we proposed a higher-order function of the AG in terms of a supramodal comparator of quantities.

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