Effects of adding a stimulus dimension prior to a nonreversal shift

Rats were trained on a single-stimulus, successive discrimination in a free operant situation. An irrelevant stimulus dimension was present at ail times. Following attainment of the acquisition criterion, Ss were shifted immediately or given 4 or 8 days of overtraining before being shifted. Half of Ss were given a reversal shift and half a nonreversal shift. Overtraining did not affect reversal or nonreversal learning. These results were contrasted with those of Mackintosh (1962). Various theoretical issues were discussed in light of the present findings. It was tentatively concluded that the overtraining effect depends upon the role of observing behavior in the formation and overtraining of a discrimination.

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Overtraining Effects on Reversal and Nonreversal Discrimination Shifts with a Continuously Reinforced Free Operant

Perceptual and Motor Skills ◽

10.2466/pms.1967.24.1.75 ◽

1967 ◽

Vol 24 (1) ◽

pp. 75-82 ◽

Cited By ~ 2

Author(s):

Charles N. Uhl ◽

B. Kent Parker ◽

Philip B. Wooton

Keyword(s):

Discrimination Learning ◽

Irrelevant Stimulus ◽

Stimulus Dimension ◽

Single Stimulus ◽

Reversal Shift ◽

Nonreversal Shift ◽

Continuous Reinforcement ◽

Free Operant ◽

Discrimination Criterion ◽

Free Operant Situation

Rats were trained on a single-stimulus, successive discrimination in a free operant situation with continuous reinforcement of responding to S+. Ss were given 0, 4, or 8 days of overtraining (OT) after reaching the discrimination criterion. Half of the Ss were given a reversal shift (RS) and half a nonreversal shift (NRS). An irrelevant stimulus dimension was present at all times in Exp. 1, and it was absent in Exp. 2. OT did not affect RS or NRS learning in either experiment. NRS learning was faster than RS learning. These results were contrasted with other studies which have reported that OT facilitated RS learning and impeded NRS learning. Certain theoretical interpretations of discrimination learning, particularly Sutherland's treatment of centrally mediated attentional mechanisms, were critically discussed in light of the present findings.

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Mediated transfer in reversal and nonreversal shift paired-associate learning.

Journal of Experimental Psychology ◽

10.1037/h0025282 ◽

1968 ◽

Vol 76 (1, Pt.1) ◽

pp. 89-93 ◽

Cited By ~ 8

Author(s):

Barbara W. Marquette ◽

L. R. Goulet

Keyword(s):

Paired Associate ◽

Paired Associate Learning ◽

Nonreversal Shift ◽

Associate Learning

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Differences in Attentional Involvement Underlying the Perception of Distinctive and Typical Faces

Perception ◽

10.1068/p5751 ◽

2007 ◽

Vol 36 (7) ◽

pp. 1057-1065 ◽

Cited By ~ 4

Author(s):

Jae-Jin Ryu ◽

Avi Chaudhuri

Keyword(s):

Visual Presentation ◽

Stimulus Dimension ◽

Change Detection Task ◽

Identification Task ◽

Processing Efficiency ◽

Capacity Limits ◽

Perceptual Salience ◽

Attentional Tasks ◽

Human Faces ◽

Processing Differences

Differences in human faces can be evaluated along a continuum that ranges from ‘distinctive’ to ‘typical.’ We examined processing differences between distinctive and typical faces by two attentional tasks that induce attentional blink (AB). Given that AB is believed to reflect temporal or capacity limits of attention, stimuli that survive AB are believed to be associated with greater processing efficiency. In a change-detection task, participants were required to detect changes in the two pairs of faces that were presented in rapid succession. Changes involving the distinctive face of a pair were more likely to be detected than those involving a typical face. In a face-identification task, distinctive faces embedded in a rapid serial visual presentation (RSVP) stream were identified with a greater accuracy than typical faces. Together, our results suggest that distinctive faces are associated with greater processing efficiency and may be explained in terms of perceptual salience, a stimulus dimension known to attract attention.

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Summation of perceptual cues in natural visual scenes

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2008.0692 ◽

2008 ◽

Vol 275 (1649) ◽

pp. 2299-2308 ◽

Cited By ~ 16

Author(s):

M To ◽

P.G Lovell ◽

T Troscianko ◽

D.J Tolhurst

Keyword(s):

Visual Processing ◽

Neural System ◽

Stimulus Dimension ◽

Two Dimensions ◽

Natural Scenes ◽

Perceptual Cues ◽

Combination Rules ◽

Threshold Detection ◽

Visual Scenes ◽

Image Pairs

Natural visual scenes are rich in information, and any neural system analysing them must piece together the many messages from large arrays of diverse feature detectors. It is known how threshold detection of compound visual stimuli (sinusoidal gratings) is determined by their components' thresholds. We investigate whether similar combination rules apply to the perception of the complex and suprathreshold visual elements in naturalistic visual images. Observers gave magnitude estimations (ratings) of the perceived differences between pairs of images made from photographs of natural scenes. Images in some pairs differed along one stimulus dimension such as object colour, location, size or blur. But, for other image pairs, there were composite differences along two dimensions (e.g. both colour and object-location might change). We examined whether the ratings for such composite pairs could be predicted from the two ratings for the respective pairs in which only one stimulus dimension had changed. We found a pooling relationship similar to that proposed for simple stimuli: Minkowski summation with exponent 2.84 yielded the best predictive power ( r =0.96), an exponent similar to that generally reported for compound grating detection. This suggests that theories based on detecting simple stimuli can encompass visual processing of complex, suprathreshold stimuli.

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Simplicity/Complexity or Symmetry/Asymmetry? A Re-Analysis of the Barron-Welsh Art Scales

Perceptual and Motor Skills ◽

10.2466/pms.1965.20.3.685 ◽

1965 ◽

Vol 20 (3) ◽

pp. 685-690 ◽

Cited By ~ 10

Author(s):

E. W. Moyles ◽

R. D. Tuddenham ◽

J. Block

Keyword(s):

Stimulus Dimension ◽

The Individual

The Barron-Welsh Art Scale has been interpreted as a measure of Simplicity/Complexity within people. Re-analysis of the test by scaling the individual figures revealed that the stimulus dimension of Simplicity/Complexity (S/C) was highly confounded with the stimulus dimension of Symmetry/Asymmetry (S/A). It proved possible to separate these two stimulus dimensions and evaluate their significance independently. S/C and S/A appeared to be of equivalent and usually small importance in determining figure preferences. These results suggest the need for caution in attributing preferences to the single S/C attribute of the stimulus figures, or by extension, to the psychological simplicity or complexity of test-takers.

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Modelling generalisation gradients as augmented Gaussian functions

Quarterly Journal of Experimental Psychology ◽

10.1177/1747021820949470 ◽

2020 ◽

Vol 74 (1) ◽

pp. 106-121 ◽

Cited By ~ 1

Author(s):

Jessica C Lee ◽

Llewellyn Mills ◽

Brett K Hayes ◽

Evan J Livesey

Keyword(s):

Gaussian Function ◽

Peak Shift ◽

Stimulus Dimension ◽

Group Differences ◽

Hierarchical Bayesian ◽

Group Level ◽

Gaussian Functions ◽

Novel Method ◽

Bayesian Curve Fitting ◽

High Degree

Studying generalisation of associative learning requires analysis of response gradients measured over a continuous stimulus dimension. In human studies, there is often a high degree of individual variation in the gradients, making it difficult to draw conclusions about group-level trends with traditional statistical methods. Here, we demonstrate a novel method of analysing generalisation gradients based on hierarchical Bayesian curve-fitting. This method involves fitting an augmented (asymmetrical) Gaussian function to individual gradients and estimating its parameters in a hierarchical Bayesian framework. We show how the posteriors can be used to characterise group differences in generalisation and how classic generalisation phenomena such as peak shift and area shift can be measured and inferred. Estimation of descriptive parameters can provide a detailed and informative way of analysing human generalisation gradients.

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