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Journal of Experimental Psychology.... Jul 2019Animals optimize their behavior to maximize rewards by utilizing cues from the environment. In discrimination learning, cues signal when rewards can and cannot be earned...
Animals optimize their behavior to maximize rewards by utilizing cues from the environment. In discrimination learning, cues signal when rewards can and cannot be earned by making a particular response. In our experiment, we trained male mice to press a lever to receive a reward on a random interval schedule. We then introduced a prolonged tone (20, 40, or 80 sec), during which no rewards could be earned. We sought to test our hypothesis that the duration of the tone and frequency of reward during the inter-tone-intervals affect the informativeness of cues and led to differences in discriminative behavior. Learning was expressed as an increase in lever pressing during the intertrial interval (ITI) and, when the informativeness of the cue was high, animals also reduced their lever pressing during the tone. Additionally, we found that the depth of discriminative learning was linearly related to the informativeness of the cues. Our results show that the time-scale invariant information-theoretic definition of contingency applied to excitatory conditioning can also be applied to inhibitory conditioning. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
Topics: Acoustic Stimulation; Animals; Behavior, Animal; Conditioning, Operant; Cues; Discrimination Learning; Male; Mice; Reward; Time Factors
PubMed: 31021132
DOI: 10.1037/xan0000205 -
Animal Cognition Aug 2022One of the most widely studied abilities in lizards is discrimination learning. The protocols used to test lizards are often novel or adapted from other taxa without...
One of the most widely studied abilities in lizards is discrimination learning. The protocols used to test lizards are often novel or adapted from other taxa without proper validation. We need to ensure that tests of discrimination learning are appropriate and properly applied in lizards so that robust inferences can be made about cognitive ability. Here, we present a new protocol for testing lizard discrimination learning that incorporates a target training procedure, uses many daily trials for efficiency and reinforcement, and has a robust, validated, learning criterion. We trained lizards to touch a cue card using operant conditioning and tested lizards separately on a colour, and pattern discrimination test. Lizards successfully learnt to touch a cue card and to discriminate between light and dark blue but had issues discriminating the patterns. After modifying the test procedure, some lizards reached criterion, revealing possible issues with stimulus processing and interference of generalisation. Here, we describe a protocol for operant conditioning and two-choice discrimination learning in lizards with a robust learning criterion that can help researcher better design future studies on discrimination learning in lizards.
Topics: Animals; Conditioning, Operant; Discrimination Learning; Lizards; Spatial Learning; Visual Perception
PubMed: 35124743
DOI: 10.1007/s10071-022-01603-x -
Cell Reports May 2024Changes in sound-evoked responses in the auditory cortex (ACtx) occur during learning, but how learning alters neural responses in different ACtx subregions and changes...
Changes in sound-evoked responses in the auditory cortex (ACtx) occur during learning, but how learning alters neural responses in different ACtx subregions and changes their interactions is unclear. To address these questions, we developed an automated training and widefield imaging system to longitudinally track the neural activity of all mouse ACtx subregions during a tone discrimination task. We find that responses in primary ACtx are highly informative of learned stimuli and behavioral outcomes throughout training. In contrast, representations of behavioral outcomes in the dorsal posterior auditory field, learned stimuli in the dorsal anterior auditory field, and inter-regional correlations between primary and higher-order areas are enhanced with training. Moreover, ACtx response changes vary between stimuli, and such differences display lag synchronization with the learning rate. These results indicate that learning alters functional connections between ACtx subregions, inducing region-specific modulations by propagating behavioral information from primary to higher-order areas.
Topics: Auditory Cortex; Animals; Discrimination Learning; Mice; Acoustic Stimulation; Auditory Perception; Male; Female; Mice, Inbred C57BL; Evoked Potentials, Auditory
PubMed: 38703366
DOI: 10.1016/j.celrep.2024.114172 -
Scientific Reports Apr 2024Perceptual learning is the improvement of perceptual performance after repeated practice on a perceptual task. Studies on perceptual learning in color vision are...
Perceptual learning is the improvement of perceptual performance after repeated practice on a perceptual task. Studies on perceptual learning in color vision are limited. In this study, we measured the impact of color discrimination repetitions at a specific base color on color perception for entire hues. Participants performed five sessions of color discrimination training (200 or 300 trials per session) over five days, at colors on either the negative or positive direction of the L-M color axis, based on group assignment. We administered three color perception assessments (unique hues, color category boundaries, and color appearance) before and after the sessions to evaluate perceptual changes after training. The results showed declines in color discrimination thresholds after training, as expected. Additionally, the training influenced outcomes across all three assessment types. After the training, the perceived color appearance changed near the trained color along the stimulus hue, and some of the unique hues and the color category boundaries moved significantly toward the trained color. These findings indicate that short-term repetitions of color discrimination training can alter color representations in the visual system, distorting color perception around the trained color.
Topics: Humans; Color Perception; Female; Male; Young Adult; Adult; Photic Stimulation; Color; Learning; Color Vision; Discrimination Learning; Discrimination, Psychological
PubMed: 38671047
DOI: 10.1038/s41598-024-60283-4 -
Experimental Brain Research Nov 2018The zebrafish is a model organism to study olfactory information processing, but efficient behavioral procedures to analyze olfactory discrimination and memory are...
The zebrafish is a model organism to study olfactory information processing, but efficient behavioral procedures to analyze olfactory discrimination and memory are lacking. We devised an automated odor discrimination task for adult zebrafish based on olfactory conditioning of feeding behavior. Presentation of a conditioned odor (CS+), but not a neutral odor (CS-) was followed by food delivery at a specific location. Fish developed differential behavioral responses to CS+ and CS- within a few trials. The behavioral response to the CS+ was complex and included components reminiscent of food search such as increased swimming speed and water surface sampling. Appetitive behavior was therefore quantified by a composite score that combined measurements of multiple behavioral parameters. Robust discrimination behavior was observed in different strains, even when odors were chemically similar, and learned preferences could overcome innate odor preferences. These results confirm that zebrafish can rapidly learn to make fine odor discriminations. The procedure is efficient and provides novel opportunities to dissect the neural mechanisms underlying olfactory discrimination and memory.
Topics: Animals; Conditioning, Classical; Discrimination Learning; Feeding Behavior; Female; Male; Odorants; Olfactory Perception; Smell; Zebrafish
PubMed: 30088022
DOI: 10.1007/s00221-018-5352-x -
Neurobiology of Aging May 2017Emerging evidence suggests that aging is associated with a reduced ability to distinguish perceptually similar stimuli in one's environment. As the ability to accurately...
Emerging evidence suggests that aging is associated with a reduced ability to distinguish perceptually similar stimuli in one's environment. As the ability to accurately perceive and encode sensory information is foundational for explicit memory, understanding the neurobiological underpinnings of discrimination impairments that emerge with advancing age could help elucidate the mechanisms of mnemonic decline. To this end, there is a need for preclinical approaches that robustly and reliably model age-associated perceptual discrimination deficits. Taking advantage of rodents' exceptional olfactory abilities, the present study applied rigorous psychophysical techniques to the evaluation of discrimination learning in young and aged F344 rats. Aging did not influence odor detection thresholds or the ability to discriminate between perceptually distinct odorants. In contrast, aged rats were disproportionately impaired relative to young on problems that required discriminations between perceptually similar olfactory stimuli. Importantly, these disproportionate impairments in discrimination learning did not simply reflect a global learning impairment in aged rats, as they performed other types of difficult discriminations on par with young rats. Among aged rats, discrimination deficits were strongly associated with spatial learning deficits. These findings reveal a new, sensitive behavioral approach for elucidating the neural mechanisms of cognitive decline associated with normal aging.
Topics: Aging; Animals; Discrimination Learning; Maze Learning; Models, Animal; Olfactory Perception; Rats, Inbred F344; Smell; Spatial Learning
PubMed: 28259065
DOI: 10.1016/j.neurobiolaging.2017.01.023 -
The Journal of Neuroscience : the... May 2021Theoretical and modeling studies demonstrate that heterosynaptic plasticity-changes at synapses inactive during induction-facilitates fine-grained discriminative...
Theoretical and modeling studies demonstrate that heterosynaptic plasticity-changes at synapses inactive during induction-facilitates fine-grained discriminative learning in Hebbian-type systems, and helps to achieve a robust ability for repetitive learning. A dearth of tools for selective manipulation has hindered experimental analysis of the proposed role of heterosynaptic plasticity in behavior. Here we circumvent this obstacle by testing specific predictions about the behavioral consequences of the impairment of heterosynaptic plasticity by experimental manipulations to adenosine A1 receptors (A1Rs). Our prior work demonstrated that the blockade of adenosine A1 receptors impairs heterosynaptic plasticity in brain slices and, when implemented in computer models, selectively impairs repetitive learning on sequential tasks. Based on this work, we predict that A1R knock-out (KO) mice will express (1) impairment of heterosynaptic plasticity and (2) behavioral deficits in learning on sequential tasks. Using electrophysiological experiments in slices and behavioral testing of animals of both sexes, we show that, compared with wild-type controls, A1R KO mice have impaired synaptic plasticity in visual cortex neurons, coupled with significant deficits in visual discrimination learning. Deficits in A1R knockouts were seen specifically during relearning, becoming progressively more apparent with learning on sequential visual discrimination tasks of increasing complexity. These behavioral results confirm our model predictions and provide the first experimental evidence for a proposed role of heterosynaptic plasticity in organism-level learning. Moreover, these results identify heterosynaptic plasticity as a new potential target for interventions that may help to enhance new learning on a background of existing memories. Understanding how interacting forms of synaptic plasticity mediate learning is fundamental for neuroscience. Theory and modeling revealed that, in addition to Hebbian-type associative plasticity, heterosynaptic changes at synapses that were not active during induction are necessary for stable system operation and fine-grained discrimination learning. However, lacking tools for selective manipulation prevented behavioral analysis of heterosynaptic plasticity. Here we circumvent this barrier: from our prior experimental and computational work we predict differential behavioral consequences of the impairment of Hebbian-type versus heterosynaptic plasticity. We show that, in adenosine A1 receptor knock-out mice, impaired synaptic plasticity in visual cortex neurons is coupled with specific deficits in learning sequential, increasingly complex visual discrimination tasks. This provides the first evidence linking heterosynaptic plasticity to organism-level learning.
Topics: Animals; Discrimination Learning; Female; Male; Mice; Mice, Knockout; Neuronal Plasticity; Receptor, Adenosine A1; Visual Cortex
PubMed: 33849950
DOI: 10.1523/JNEUROSCI.3073-20.2021 -
Journal of Vision Dec 2011Perceptual learning (PL) and perceptual expertise (PE) are two fields of visual training studies that investigate how practice improves visual performance. However,... (Comparative Study)
Comparative Study
Perceptual learning (PL) and perceptual expertise (PE) are two fields of visual training studies that investigate how practice improves visual performance. However, previous research suggests that PL can be acquired in a task-irrelevant manner while PE cannot and that PL is highly specific to the training objects and conditions while PE generalizes. These differences are difficult to interpret since PL and PE studies tend to differ on multiple dimensions. We designed a training study with novel objects to compare PL and PE while varying only the training task, such that the training objects, visual field, training duration, and type of learning assessment were kept constant. Manipulations of the training task sufficed to produce the standard effects obtained in PE and PL. In contrast to prior studies, we demonstrated that some degree of PE can be acquired in a task-irrelevant manner, similar to PL. Task-irrelevant PE resulted in similar shape matching ability compared to the directly trained PE. In addition, learning in both PE and PL generalizes to different untrained conditions, which does not support the idea that PE generalizes while PL is specific. Degrees of generalization can be explained by considering the psychological space of the stimuli used for training and the test of transfer.
Topics: Adult; Discrimination Learning; Female; Humans; Male; Photic Stimulation; Psychomotor Performance; Visual Perception
PubMed: 22144562
DOI: 10.1167/11.14.3 -
Neurobiology of Learning and Memory Oct 2021Cognitive flexibility is a prefrontal cortex-dependent neurocognitive process that enables behavioral adaptation in response to changes in environmental contingencies....
Cognitive flexibility is a prefrontal cortex-dependent neurocognitive process that enables behavioral adaptation in response to changes in environmental contingencies. Electrical vagus nerve stimulation (VNS) enhances several forms of learning and neuroplasticity, but its effects on cognitive flexibility have not been evaluated. In the current study, a within-subjects design was used to assess the effects of VNS on performance in a novel visual discrimination reversal learning task conducted in touchscreen operant chambers. The task design enabled simultaneous assessment of acute VNS both on reversal learning and on recall of a well-learned discrimination problem. Acute VNS delivered in conjunction with stimuli presentation during reversal learning reliably enhanced learning of new reward contingencies. Enhancement was not observed, however, if VNS was delivered during the session but was not coincident with presentation of to-be-learned stimuli. In addition, whereas VNS delivered at 30 HZ enhanced performance, the same enhancement was not observed using 10 or 50 Hz. Together, these data show that acute VNS facilitates reversal learning and indicate that the timing and frequency of the VNS are critical for these enhancing effects. In separate rats, administration of the norepinephrine reuptake inhibitor atomoxetine also enhanced reversal learning in the same task, consistent with a noradrenergic mechanism through which VNS enhances cognitive flexibility.
Topics: Adrenergic Uptake Inhibitors; Animals; Atomoxetine Hydrochloride; Baclofen; Conditioning, Operant; Discrimination Learning; GABA-B Receptor Agonists; Male; Rats; Rats, Inbred BN; Reversal Learning; Vagus Nerve Stimulation
PubMed: 34332068
DOI: 10.1016/j.nlm.2021.107498 -
PloS One 2016Perceptual training is generally assumed to improve perception by modifying the encoding or decoding of sensory information. However, this assumption is incompatible...
Perceptual training is generally assumed to improve perception by modifying the encoding or decoding of sensory information. However, this assumption is incompatible with recent demonstrations that transfer of learning can be enhanced by across-trial variation of training stimuli or task. Here we present three lines of evidence from healthy adults in support of the idea that the enhanced transfer of auditory discrimination learning is mediated by working memory (WM). First, the ability to discriminate small differences in tone frequency or duration was correlated with WM measured with a tone n-back task. Second, training frequency discrimination around a variable frequency transferred to and from WM learning, but training around a fixed frequency did not. The transfer of learning in both directions was correlated with a reduction of the influence of stimulus variation in the discrimination task, linking WM and its improvement to across-trial stimulus interaction in auditory discrimination. Third, while WM training transferred broadly to other WM and auditory discrimination tasks, variable-frequency training on duration discrimination did not improve WM, indicating that stimulus variation challenges and trains WM only if the task demands stimulus updating in the varied dimension. The results provide empirical evidence as well as a theoretic framework for interactions between cognitive and sensory plasticity during perceptual experience.
Topics: Acoustic Stimulation; Adolescent; Adult; Auditory Perception; Cognition; Discrimination Learning; Female; Humans; Learning; Male; Memory, Short-Term; Young Adult
PubMed: 26799068
DOI: 10.1371/journal.pone.0147320