-
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 -
Neuroscience and Biobehavioral Reviews 2008We review neuropsychological and neuroimaging evidence for the existence of three qualitatively different categorization systems. These categorization systems are... (Review)
Review
We review neuropsychological and neuroimaging evidence for the existence of three qualitatively different categorization systems. These categorization systems are themselves based on three distinct memory systems: working memory (WM), explicit long-term memory (explicit LTM), and implicit long-term memory (implicit LTM). We first contrast categorization based on WM with that based on explicit LTM, where the former typically involves applying rules to a test item and the latter involves determining the similarity between stored exemplars or prototypes and a test item. Neuroimaging studies show differences between brain activity in normal participants as a function of whether they are instructed to categorize novel test items by rule or by similarity to known category members. Rule instructions typically lead to more activation in frontal or parietal areas, associated with WM and selective attention, whereas similarity instructions may activate parietal areas associated with the integration of perceptual features. Studies with neurological patients in the same paradigms provide converging evidence, e.g., patients with Alzheimer's disease, who have damage in prefrontal regions, are more impaired with rule than similarity instructions. Our second contrast is between categorization based on explicit LTM with that based on implicit LTM. Neuropsychological studies with patients with medial-temporal lobe damage show that patients are impaired on tasks requiring explicit LTM, but perform relatively normally on an implicit categorization task. Neuroimaging studies provide converging evidence: whereas explicit categorization is mediated by activation in numerous frontal and parietal areas, implicit categorization is mediated by a deactivation in posterior cortex.
Topics: Brain Mapping; Cerebral Cortex; Classification; Concept Formation; Discrimination Learning; Humans; Memory
PubMed: 17904637
DOI: 10.1016/j.neubiorev.2007.07.009 -
Behavioural Brain Research Nov 2013Genetically-modified animal models are a powerful tool for investigating the link between neurological and behavioral changes and for the development of therapeutic...
Genetically-modified animal models are a powerful tool for investigating the link between neurological and behavioral changes and for the development of therapeutic interventions. Executive function deficits are symptomatic of many human clinical disorders but few tasks exist for studying executive functions in mice. To address this need, we describe procedures for establishing Pavlovian contextual and instrumental biconditional discriminations (BCDs) in C57BL/6J mice. In the first experiment, contextual cues disambiguated when two short duration stimulus targets would be followed by food pellets. In the second experiment, discrete visual cues signaled when lever press or nose poke responses would be continuously reinforced with food pellets. Mice learned both BCDs as evidenced by differential responding in each cue during training and, more critically, during extinction testing. The implications of these findings for using BCD tasks to analyze the neural substrates of executive processing in animal models are discussed.
Topics: Animals; Conditioning, Classical; Conditioning, Operant; Cues; Discrimination Learning; Extinction, Psychological; Male; Mice; Mice, Inbred C57BL; Reinforcement, Psychology
PubMed: 24016837
DOI: 10.1016/j.bbr.2013.09.010 -
Journal of Experimental Psychology.... Oct 2017Responding to a related pair of measurements is often expressed as a single discrimination ratio. Authors have used various discrimination ratios; yet, little...
Responding to a related pair of measurements is often expressed as a single discrimination ratio. Authors have used various discrimination ratios; yet, little information exists to guide their choice. A second use of ratios is to correct for the influence of a nuisance variable on the measurement of interest. I examine 4 discrimination ratios using simulated data sets. Three ratios, of the form a/(a + b), b/(a + b), and (a - b)/(a + b), introduced distortions to their raw data. The fourth ratio, (b - a)/b largely avoided such distortions and was the most sensitive at detecting statistical differences. Effect size statistics were also often improved with a correction ratio. Gustatory sensory preconditioning experiments involved measurement of rats' sucrose and saline consumption; these flavors served as either a target flavor or a control flavor and were counterbalanced across rats. However, sensory preconditioning was often masked by a bias for sucrose over saline. Sucrose and saline consumption scores were multiplied by the ratio of the overall consumption to the consumption of that flavor alone, which corrected the bias. The general utility of discrimination and correction ratios for data treatment is discussed. (PsycINFO Database Record
Topics: Animals; Behavior, Animal; Computer Simulation; Conditioning, Classical; Conditioning, Operant; Data Interpretation, Statistical; Discrimination Learning; Rats
PubMed: 28805439
DOI: 10.1037/xan0000143 -
Neuron Aug 2006In this issue of Neuron, Rinberg et al. show that mice use a speed-accuracy tradeoff in odor discrimination. Shorter sampling results in high performance for easy... (Review)
Review
In this issue of Neuron, Rinberg et al. show that mice use a speed-accuracy tradeoff in odor discrimination. Shorter sampling results in high performance for easy problems, and enforced longer sampling results in higher accuracy for difficult problems, but mice freely choose intermediate sampling durations and accuracy varies with difficulty. Reward value and task requirements may determine sampling time choice and performance levels.
Topics: Animals; Discrimination Learning; Mice; Reaction Time; Smell
PubMed: 16880120
DOI: 10.1016/j.neuron.2006.07.015 -
The Journal of Neuroscience : the... Jul 2017A fundamental property of visual cortex is to enhance the representation of those stimuli that are relevant for behavior, but it remains poorly understood how such...
A fundamental property of visual cortex is to enhance the representation of those stimuli that are relevant for behavior, but it remains poorly understood how such enhanced representations arise during learning. Using classical conditioning in adult mice of either sex, we show that orientation discrimination is learned in a sequence of distinct behavioral stages, in which animals first rely on stimulus appearance before exploiting its orientation to guide behavior. After confirming that orientation discrimination under classical conditioning requires primary visual cortex (V1), we measured, during learning, response properties of V1 neurons. Learning improved neural discriminability, sharpened orientation tuning, and led to higher contrast sensitivity. Remarkably, these learning-related improvements in the V1 representation were fully expressed before successful orientation discrimination was evident in the animals' behavior. We propose that V1 plays a key role early in discrimination learning to enhance behaviorally relevant sensory information. Decades of research have documented that responses of neurons in visual cortex can reflect the behavioral relevance of visual information. The behavioral relevance of any stimulus needs to be learned, though, and little is known how visual sensory processing changes, as the significance of a stimulus becomes clear. Here, we trained mice to discriminate two visual stimuli, precisely quantified when learning happened, and measured, during learning, the neural representation of these stimuli in V1. We observed learning-related improvements in V1 processing, which were fully expressed before discrimination was evident in the animals' behavior. These findings indicate that sensory and behavioral improvements can follow different time courses and point toward a key role of V1 at early stages in discrimination learning.
Topics: Animals; Behavior, Animal; Discrimination Learning; Female; Male; Mice; Mice, Inbred C57BL; Nerve Net; Neurons; Orientation; Task Performance and Analysis; Visual Cortex; Visual Perception
PubMed: 28559381
DOI: 10.1523/JNEUROSCI.3485-16.2017 -
Journal of the Experimental Analysis of... Mar 1980Carter and Werner recently reviewed the literature on conditional discrimination learning by pigeons, which consists of studies of matching-to-sample and...
Carter and Werner recently reviewed the literature on conditional discrimination learning by pigeons, which consists of studies of matching-to-sample and oddity-from-sample. They also discussed three models of such learning: the "multiple-rule" model (learning of stimulus-specific relations), the "configuration" model, and the "single-rule" model (concept learning). Although their treatment of the multiple-rule model, which seems most applicable to the pigeon data, is generally excellent, their discussion of the other two models is incomplete and sometimes inaccurate. Potential problems of terminology are discussed in the present paper, as are additional lines of research that deserve consideration by those interested in further work in this area. The issue of response versus stimulus selection (configuration versus compound-cue learning) is discussed in connection with the configuration model. Particular attention is given to Carter and Werner's criticism of the application, in studies with other species, of the learning set procedure in testing for single-rule learning. Some of the important related issues are: the bias for improvement on new problems in a series, the adequacy of a multiple-rule model to explain learning set formation, and evidence in favor of the single-rule model, at least in primates. Consideration of these additional contributions to the study of conditional discrimination learning emphasizes the usefulness of this task in the comparative study of cognitive processes.
Topics: Animals; Columbidae; Conditioning, Psychological; Discrimination Learning; Problem Solving; Visual Perception
PubMed: 7365410
DOI: 10.1901/jeab.1980.33-291 -
Psychopharmacology Dec 2015Global tobacco-related mortality dwarfs that of all other drugs. Nicotine is believed to be the primary agent responsible for tobacco use and addiction. However,...
RATIONALE
Global tobacco-related mortality dwarfs that of all other drugs. Nicotine is believed to be the primary agent responsible for tobacco use and addiction. However, nicotine is a relatively weak and inconsistent reinforcer in nonhumans and nicotine reinforcement has not been demonstrated in never-smokers.
OBJECTIVES
This study investigated the discriminative, subjective, and reinforcing effects of nicotine in never-smokers.
METHODS
Eighteen never-smokers (< 50 lifetime nicotine exposures) participated in a double-blind study. During a drug discrimination phase, volunteers ingested oral nicotine and placebo capsules (quasi-random order) at least 2 h apart and rated subjective effects repeatedly for 2 h after ingestion in daily sessions. Blocks of 10 sessions were continued until significant discrimination was achieved (p ≤ 0.05, binomial test; ≥ 8 of 10). Following discrimination, nicotine choice was tested by having volunteers choose which capsule set to ingest on each daily session. Successive blocks of 10 sessions were conducted until choice for nicotine or placebo met significance within each volunteer (≥ 8 of 10 sessions).
RESULTS
All 18 volunteers significantly discriminated nicotine from placebo; the lowest dose discriminated ranged from 1.0 to 4.0 mg/70 kg. Nine volunteers significantly chose nicotine (choosers) and nine significantly chose placebo (nicotine avoiders). The choosers reported predominately positive nicotine subjective effects (e.g., alert/attentive, good effects, liking), while avoiders tended to report negative effects (e.g., dizzy, upset stomach, disliking). Both choosers and avoiders attributed their choice to the qualitative nature of drug effects.
CONCLUSIONS
These results provide the first evidence that nicotine can function as a reinforcer in some never-smokers.
Topics: Administration, Oral; Adult; Choice Behavior; Discrimination Learning; Double-Blind Method; Female; Humans; Male; Middle Aged; Nicotine; Reinforcement, Psychology; Smoking; Surveys and Questionnaires; Young Adult
PubMed: 26345343
DOI: 10.1007/s00213-015-4053-4 -
PloS One 2015While studies of the gustatory cortex (GC) mostly focus on its role in taste aversion learning and memory, the necessity of GC for other fundamental taste-guided...
While studies of the gustatory cortex (GC) mostly focus on its role in taste aversion learning and memory, the necessity of GC for other fundamental taste-guided behaviors remains largely untested. Here, rats with either excitotoxic lesions targeting GC (n = 26) or sham lesions (n = 14) were assessed for postsurgical retention of a presurgically LiCl-induced conditioned taste aversion (CTA) to 0.1M sucrose using a brief-access taste generalization test in a gustometer. The same animals were then trained in a two-response operant taste detection task and psychophysically tested for their salt (NaCl or KCl) sensitivity. Next, the rats were trained and tested in a NaCl vs. KCl taste discrimination task with concentrations varied. Rats meeting our histological inclusion criterion had large lesions (resulting in a group averaging 80% damage to GC and involving surrounding regions) and showed impaired postsurgical expression of the presurgical CTA (LiCl-injected, n = 9), demonstrated rightward shifts in the NaCl (0.54 log10 shift) and KCl (0.35 log10 shift) psychometric functions, and displayed retarded salt discrimination acquisition (n = 18), but eventually learned and performed the discrimination comparable to sham-operated animals. Interestingly, the degree of deficit between tasks correlated only modestly, if at all, suggesting that idiosyncratic differences in insular cortex lesion topography were the root of the individual differences in the behavioral effects demonstrated here. This latter finding hints at some degree of interanimal variation in the functional topography of insular cortex. Overall, GC appears to be necessary to maintain normal taste sensitivity to NaCl and KCl and for salt discrimination learning. However, higher salt concentrations can be detected and discriminated by rats with extensive damage to GC suggesting that the other resources of the gustatory system are sufficient to maintain partial competence in these tasks, supporting the view that such basic sensory-discriminative taste functions involve distributed processes among central gustatory structures.
Topics: Animals; Avoidance Learning; Cerebral Cortex; Discrimination Learning; Ibotenic Acid; Male; Potassium Chloride; Rats; Rats, Sprague-Dawley; Sodium Chloride; Taste; Taste Perception
PubMed: 25658323
DOI: 10.1371/journal.pone.0117515 -
Behavioural Brain Research Mar 2009The capacity to seek and obtain rewards is essential for survival. Pavlovian conditioning is one mechanism by which organisms develop predictions about rewards and such... (Review)
Review
The capacity to seek and obtain rewards is essential for survival. Pavlovian conditioning is one mechanism by which organisms develop predictions about rewards and such anticipatory or expectancy states enable successful behavioral adaptations to environmental demands. Reward expectancies have both affective/motivational and discriminative properties that allow for the modulation of instrumental goal-directed behavior. Recent data provide evidence that different cognitive strategies (cue-outcome associations) and neural systems (amygdala) are used when subjects are trained under conditions that allow Pavlovian-induced reward expectancies to guide instrumental behavioral choices. Furthermore, it has been demonstrated that impairments typically observed in a number of brain-damaged models are alleviated or eliminated by embedding unique reward expectancies into learning/memory tasks. These results suggest that Pavlovian-induced reward expectancies can change both behavioral and brain processes.
Topics: Amygdala; Animals; Appetitive Behavior; Conditioning, Classical; Discrimination Learning; Learning; Memory; Motivation; Psychomotor Performance; Reward
PubMed: 19022299
DOI: 10.1016/j.bbr.2008.10.028