Decisional Difficulty in Pattern Discrimination

1978 ◽  
Vol 47 (3_suppl) ◽  
pp. 1191-1194 ◽  
Author(s):  
Samuel C. Fulkerson ◽  
Paul S. Mann
Keyword(s):  
Task Difficulty ◽  
Discrimination Task ◽  
Critical Factor ◽  
Pattern Discrimination ◽  
Relative Influence ◽  
Response Uncertainty ◽  
Uncertainty Condition ◽  
Black And White ◽  
High Uncertainty

To assess the relative influence of decisional ambiguity and response uncertainty on task difficulty, a pattern discrimination task was presented to 60 college undergraduates. The comparison stimuli were nine 20 × 20 matrices of randomly assigned black and white squares, with percent of black squares varying evenly from 10% to 90%. The standard contained 50% black squares. In a low-response uncertainty condition there were two response categories, and five in a high uncertainty condition. It was hypothesized that decisional ambiguity should be greatest at the boundaries between categories. The results suggested that decisional ambiguity was the critical factor determining judgment difficulty.

Information Transmission in a Pattern Discrimination Task as a Function of Initial Task Difficulty

1965 ◽  
Vol 21 (3) ◽  
pp. 927-939
Author(s):  
John Coules ◽  
Donald L. Avery ◽  
Alan Meskil
Keyword(s):  
Information Transmission ◽  
Task Difficulty ◽  
High Performance ◽  
Discrimination Task ◽  
Pattern Discrimination ◽  
Judgment Task ◽  
Line Of Sight ◽  
Learning Effects ◽  
Stimulus Uncertainty ◽  
Initial Task

Information transmission measures were obtained with the method of absolute judgments and learning effects were evaluated as the nature of the discrimination task varied. Two experiments were conducted using regular and irregular geometric forms which were tilted in various degrees from the line of sight. In Exp. I, the judgment task increased in difficulty from large to fine differences in tilt, whereas in Exp. II the discrimination task was difficult throughout the experiment. In both experiments the task increased in difficulty because stimulus uncertainty increased. Results showed that when the demands of the task are such that early and sustained high performance is required, it is better if the observers are presented with the difficult task from the start rather than gradually increase its difficulty. Geometric forms showed significant differences in the amount of information transmitted.

Pattern Discrimination Learning with Rhesus Monkeys

1966 ◽  
Vol 19 (1) ◽  
pp. 311-324 ◽  
Author(s):  
Sandra R. Blehert
Keyword(s):  
Discrimination Learning ◽  
Mathematical Description ◽  
Rhesus Monkeys ◽  
Stimulus Pattern ◽  
Discrimination Task ◽  
Pattern Discrimination ◽  
Individual Learning ◽  
Group Data

Rhesus monkeys were trained to criterion on a 2-stimulus and a 5-stimulus pattern discrimination task. The probabilities of response to the various stimuli throughout learning are examined for individual Ss, and it is found that Ss exhibit consistency in the order and manner in which incorrect stimuli are eliminated. This suggests a simple mathematical description of the process, which is used to deepen the analysis of the data, permitting estimation of individual learning parameters and construction of more meaningful summaries of the group data.

Training Procedures and Task Difficulty in Brightness and Position Discriminations by Rats

1972 ◽  
Vol 31 (1) ◽  
pp. 71-76 ◽  
Author(s):  
James P. Allison
Keyword(s):  
Single Unit ◽  
Task Difficulty ◽  
Discrimination Task ◽  
Training Procedure ◽  
Position Task ◽  
And Task

This research concerned training procedures (correction vs noncorrection), type of discrimination task (position vs brightness), and task difficulty in two 2 × 3 experiments using rats in single-unit mazes. An interaction was found between type of training procedure and task difficulty for the brightness task, with noncorrection Ss requiring relatively fewer trials to reach a criterion than correction Ss as the task became more difficult. A statistically insignificant interaction was found for the position task.

scholarly journals Effects of expected task difficulty on metacognitive confidence and multitasking

2021 ◽  
Author(s):  
Maxine Tamara Sherman ◽  
Anil Seth
Keyword(s):  
Decision Making ◽  
Self Efficacy ◽  
Secondary Task ◽  
Task Difficulty ◽  
Discrimination Task ◽  
Prior Probability ◽  
Daily Life ◽  
Perceptual Discrimination ◽  
Perceptual Decision Making ◽  
Decision Confidence

In daily life, repeated experiences with a task (e.g. driving) will generally result in the development of a belief about one’s ability (“I am a good driver”). Here we ask how such beliefs, termed self-efficacy, interact with metacognitive confidence judgements. Across three pre-registered experiments, participants performed a perceptual discrimination task and reported their decision confidence. We induced contextual beliefs about performance (our operationalisation of self-efficacy) by manipulating the prior probability of an easy or hard trial occurring in each block. In Experiment 1 easy and hard trials generated the same levels of performance (a “subjective difficulty” manipulation), whereas in Experiments 2 and 3 performance differed across difficulty conditions (an “objective difficulty” manipulation). Results showed that context (self-efficacy) and difficulty interacted multiplicatively, consistent with the notion that confidence judgements combine decision evidence with a prior (contextual) belief on being correct. This occurred despite context having no corresponding effect on performance. We reasoned that performing tasks in easy contexts may reduce cognitive “load”, and tested this, in Experiment 3, by instructing participants to perform two tasks concurrently. Consistent with a reduction in load, the effects of context transferred from influencing confidence on our primary task to improving performance on the secondary task. Taken together, these studies reveal that contextual beliefs about performance facilitate multitasking, potentially by reducing the load of tasks believed to be easy, and they extend psychophysical investigations of perceptual decision-making by incorporating ‘higher-order’ beliefs about difficulty context, corresponding to intuitive notions of self-efficacy.

scholarly journals Automated video tracking and flight analysis show how bumblebees solve a pattern discrimination task using active vision

2021 ◽  
Author(s):  
HaDi MaBouDi ◽  
Mark Roper ◽  
Marie Guiraud ◽  
James A.R. Marshall ◽  
Lars Chittka
Keyword(s):  
High Speed ◽  
Discrimination Task ◽  
Active Vision ◽  
Pattern Discrimination ◽  
Relevant Information ◽  
Small Region ◽  
Video Tracking ◽  
Head Movements ◽  
Flight Behaviour ◽  
Automated Video Tracking

AbstractActive vision, the ability of the visual system to actively sample and select relevant information out of a visual scene through eye and head movements, has been explored in a variety of animal species. Small-brained animals such as insects might rely even more on sequential acquisition of pattern features since there might be less parallel processing capacity in their brains than in vertebrates. To investigate how active vision strategies enable bees to solve visual tasks, here, we employed a simple visual discrimination task in which individual bees were presented with a multiplication symbol and a 45° rotated version of the same pattern (“plus sign”). High-speed videography of unrewarded tests and analysis of the bees’ flight paths shows that only a small region of the pattern is inspected before successfully accepting a target or rejecting a distractor. The bees’ scanning behaviour of the stimuli differed for plus signs and multiplication signs, but for each of these, the flight behaviour was consistent irrespective of whether the pattern was rewarding or unrewarding. Bees typically oriented themselves at ~±30° to the patterns such that only one eye had an unobscured view of stimuli. There was a significant preference for initially scanning the left side of the stimuli. Our results suggest that the bees’ movement may be an integral part of a strategy to efficiently analyse and encode their environment.Summary statementAutomated video tracking and flight analysis is proposed as the next milestone in understanding mechanisms underpinning active vision and cognitive visual abilities of bees.

scholarly journals A stimulus artefact undermines the evidence for independent ON and OFF channels in stereopsis

2018 ◽  
Author(s):  
Jenny C. A. Read ◽  
Bruce G. Cumming
Keyword(s):  
Neural Network ◽  
Discrimination Task ◽  
Stereoscopic Vision ◽  
Early Vision ◽  
Linear Filters ◽  
Black And White ◽  
Stimulus Artefact ◽  
Mixed Polarity ◽  
Left And Right ◽  
Random Dot Pattern

AbstractEarly vision proceeds through distinct ON and OFF channels, which encode luminance increments and decrements respectively. It has been argued that these channels also contribute separately to stereoscopic vision. This is based on the fact that observers perform better on a noisy disparity discrimination task when the stimulus is a random-dot pattern consisting of equal numbers of black and white dots (a “mixed-polarity stimulus”, argued to activate both ON and OFF stereo channels), than when it consists of all-white or all-black dots (“same-polarity”, argued to activate only one). However, it is not clear how this theory can be reconciled with our current understanding of disparity encoding. Recently, a binocular convolutional neural network was able to replicate the mixed-polarity advantage shown by human observers, even though it was based on linear filters and contained no mechanisms which would respond separately to black or white dots. Here, we show that the stimuli used in all these experiments contain a subtle artefact. The interocular correlation between left and right images is actually lower for the same-polarity stimuli than for mixed-polarity stimuli with the same amount of disparity noise applied to the dots. Since our current theories suggest stereopsis is based on a correlation-like computation in primary visual cortex, it is then unsurprising that performance was better for the mixed-polarity stimuli. We conclude that there is currently no evidence supporting separate ON and OFF channels in stereopsis.

Seasonal relative influence of food quantity, quality, and feeding behaviour on zooplankton growth regulation in coastal food webs

2009 ◽  
Vol 90 (6) ◽  
pp. 1189-1201 ◽  
Author(s):  
C.A. Vargas ◽  
R.A. Martínez ◽  
R. Escribano ◽  
N.A. Lagos
Keyword(s):  
Food Webs ◽  
Growth Rates ◽  
Feeding Behaviour ◽  
Growth Regulation ◽  
Critical Factor ◽  
Multiple Regression Model ◽  
Trophic Levels ◽  
Relative Influence ◽  
Natural Occurrence ◽  
Food Quantity

In aquatic food webs zooplankton constitutes an important link between primary producers and higher trophic levels. Copepods often dominate the zooplankton in coastal oceans and are the prey of the majority of planktivorous fish. Feeding behaviour, as well as the food quantity and quality are recognized factors that affect copepod growth, and therefore, the energy transfer efficiency throughout food webs. The natural occurrence and magnitude of these growth factors and their combined effects on marine copepods, as keystone grazers in the pelagic marine realm, are poorly understood. Here, we assessed how these different factors vary throughout the year, and then examine their relative influence upon copepods maximal growth rates. A multiple regression model, including all variables previously selected, and the inclusion of the sea temperature allowed us to estimate the pure influence of the studied factors, and the environmental effect on copepod growth rates. The results imply that ingestion of diatoms may induce a positive effect on specific growth rates of copepods, and the quality of this food item (high PUFA and HUFA availability) might explain such effect. Therefore, seasonal variability in diatom abundance, possibly driven by changes in the oceanographic regime, should be considered a critical factor controlling copepod growth in productive coastal ecosystems.

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