Perceptual learning of contrast discrimination in macaca mulatta

Chen, Xing; Sanayei, Mehdi; Thiele, Alexander

doi:10.1167/13.13.22

Cited by 9 publications

(18 citation statements)

References 56 publications

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“…If the test stimulus was of lower contrast than the sample, the monkey had to saccade to a black target, otherwise it had to saccade to a white target. These basic requirements of the CD task were identical to those used previously during training on the non-roving task (described in Chen et al [1] ).…”

Section: Methodsmentioning

confidence: 99%

“…Unlike in the previous study by Chen et al [1] , the contrast of the sample stimulus was not fixed at 30%, but could take on one of three values (20, 30 or 40%) on a given trial. The test stimulus took on one of 12 possible contrasts, depending on the sample contrast (20% sample: [5, 10, 12, 15, 18, 22, 25, 28, 35, 45, 60, 90% test]; 30% sample: [5, 10, 15, 22, 25, 28, 32, 35, 38, 45, 60, 90% test]; 40% sample: [5, 10, 15, 25, 32, 35, 38, 42, 45, 50, 60, 90% test]), yielding 36 conditions in total.…”

Section: Methodsmentioning

confidence: 99%

“…Gratings were vertically oriented; the SF was 4 cycles per degree (cpd) in both monkeys; and the diameter was 3 dva in monkey 1 and 0.75 dva in monkey 2. Apart from the contrast levels, all stimulus parameters were the same as those used previously during training on the non-roving task described in Chen et al [1] .…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Perceptual learning (PL) refers to a long-lasting improvement in one's perceptual abilities, which occurs with repeated exposure to the relevant stimuli during a period of training on a perceptual task [1] – [6] . Previously, we demonstrated that PL takes place in a contrast discrimination (CD) task in adult macaques [1] , using a non-roving paradigm. Briefly, this involved a comparison of contrast levels between two consecutively presented stimuli per trial, where the contrast of the stimulus presented in the first interval (the ‘sample’) was fixed at 30% across trials, whereas the contrast of the stimulus presented in the second interval (the ‘test’) varied from trial to trial.…”

Section: Introductionmentioning

confidence: 99%

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Stimulus Roving and Flankers Affect Perceptual Learning of Contrast Discrimination in Macaca mulatta

2014

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‘Stimulus roving’ refers to a paradigm in which the properties of the stimuli to be discriminated vary from trial to trial, rather than being kept constant throughout a block of trials. Rhesus monkeys have previously been shown to improve their contrast discrimination performance on a non-roving task, in which they had to report the contrast of a test stimulus relative to that of a fixed-contrast sample stimulus. Human psychophysics studies indicate that roving stimuli yield little or no perceptual learning. Here, we investigate how stimulus roving influences perceptual learning in macaque monkeys and how the addition of flankers alters performance under roving conditions. Animals were initially trained on a contrast discrimination task under non-roving conditions until their performance levels stabilized. The introduction of roving contrast conditions resulted in a pronounced drop in performance, which suggested that subjects initially failed to heed the sample contrast and performed the task using an internal memory reference. With training, significant improvements occurred, demonstrating that learning is possible under roving conditions. To investigate the notion of flanker-induced perceptual learning, flanker stimuli (30% fixed-contrast iso-oriented collinear gratings) were presented jointly with central (roving) stimuli. Presentation of flanker stimuli yielded substantial performance improvements in one subject, but deteriorations in the other. Finally, after the removal of flankers, performance levels returned to their pre-flanker state in both subjects, indicating that the flanker-induced changes were contingent upon the continued presentation of flankers.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Stimulus Roving and Flankers Affect Perceptual Learning of Contrast Discrimination in Macaca mulatta

2014

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Perceptual Learning of Fine Contrast Discrimination Under Non-roving, Roving-Without-Flanker, and Roving-with-Flanker Conditions and its Relation to Neuronal Activity in Macaque V1

Thiele,

Chen,

Sanayei

et al. 2024

J Cogn Enhanc

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Perceptual learning refers to an improvement in perceptual abilities with training. Neural signatures of visual perceptual learning have been demonstrated mostly in mid- and high-level cortical areas, while changes in early sensory cortex were often more limited. We recorded continuously from multiple neuronal clusters in area V1 while macaque monkeys learned a fine contrast categorization task. Monkeys performed the contrast discrimination task initially when a constant-contrast sample stimulus was followed by a test stimulus of variable contrast, whereby they had to indicate whether the test was of lower or higher contrast than the sample. This was followed by sessions where we employed stimulus roving; i.e. the contrast of the sample stimulus varied from trial to trial. Finally, we trained animals, under ‘stimulus roving-with-flanker’ conditions, where the test stimuli to be discriminated were flanked by ‘flanking stimuli’. Perceptual discrimination abilities improved under non-roving conditions and under roving-with-flanker conditions as training progressed. Neuronal discrimination abilities improved with training mostly under non-roving conditions, but the effect was modest and limited to the most difficult contrast. Choice probabilities, quantifying how well neural activity is correlated with choice, equally increased with training during non-roving, but not during either of the roving conditions (with and without flankers). Noise correlations changed with training in both monkeys, but the changes were not consistent between monkeys. In one monkey, noise correlations decreased with training for non-roving and both roving conditions. In the other monkey, noise correlations changed for some conditions, but lacked a systematic pattern. Thus, while perceptual learning occurred under non-roving and roving-with-flanker conditions, the changes in neural activity in V1 were overall modest and were essentially absent under the different roving conditions.

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Tissue-type plasminogen activator induces conditioned receptive field plasticity in the mouse auditory cortex

Smart¹,

Mitchell²,

McCutcheon³

et al. 2023

iScience

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Perceptual learning of contrast discrimination in macaca mulatta

Cited by 9 publications

References 56 publications

Stimulus Roving and Flankers Affect Perceptual Learning of Contrast Discrimination in Macaca mulatta

Stimulus Roving and Flankers Affect Perceptual Learning of Contrast Discrimination in Macaca mulatta

Perceptual Learning of Fine Contrast Discrimination Under Non-roving, Roving-Without-Flanker, and Roving-with-Flanker Conditions and its Relation to Neuronal Activity in Macaque V1

Tissue-type plasminogen activator induces conditioned receptive field plasticity in the mouse auditory cortex

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