Generalization of learning can arise from 2 distinct sources: failure to discriminate a novel test stimulus from the trained stimulus and active extrapolation from the trained stimulus to the test stimulus despite them being discriminable. We investigated these 2 processes in a predictive learning task by testing stimulus discriminability…

Two experiments tested whether a peak-shifted generalization gradient could be explained by the averaging of distinct gradients displayed in subgroups reporting different generalization rules. Across experiments using a causal judgment task (Experiment 1) and a fear conditioning paradigm (Experiment 2), we found a close concordance between…

Stimulus overselectivity is widely accepted as a stimulus control abnormality in autism spectrum disorders and subsets of other populations. Previous research has demonstrated a link between both chronological and mental age and overselectivity in typical development. However, the age at which children are developmentally ready to respond to…

Extinction and recovery of the discriminative stimulus effects of nicotine (0.3 mg/kg) was investigated with a devalued food reinforcer (rats sated). Sixteen rats were trained in a counterbalanced one manipulandum (nose-poke) drug discrimination procedure with the roles of nicotine and saline counterbalanced as S[superscript D] and S[superscript…

Stimulus over-selectivity refers to behavior being controlled by one element of the environment at the expense of other equally salient aspects of the environment. This is a common problem for many individuals, including those with autism spectrum disorders, and learning difficulties, and presents a considerable problem for information processing…

The learning of the relations between discriminative stimuli, choice actions, and their outcomes can be characterized as conditional discriminative choice learning. Research shows that the technique of presenting unique outcomes for specific cued choices leads to faster and more accurate learning of such relations and has great potential to be…

To test the assumptions of two models of timing, Scalar Expectancy Theory (SET) and Learning to Time (LeT), nine pigeons were exposed to two temporal discriminations, each signaled by a different cue. On half of the trials, pigeons learned to choose a red key after a 1.5-s horizontal bar and a green key after a 6-s horizontal bar; on the other…

Individuals with anxiety disorders often do not respond to safety signals and hence continue to be afraid and anxious. Consequently, it is important to develop paradigms in animals that can directly study brain systems involved in learning about, and responding to, safety signals. We previously developed a discrimination procedure in rats of the…

Learning styles in capuchin monkeys were assessed with a computerized reversal-learning task called the mediational paradigm. First, monkeys were trained to respond with 90% accuracy on a two-choice discrimination (A+B-). Then the authors examined differences in performance on three different types of reversal trials (A-B+, A-C+, B+C-), each of…

Two groups of rats were trained in a symbolic delayed matching-to-sample task with a 0-s delay to discriminate sample stimuli that consisted of sequences of tone bursts. For one group, sequences varied in number with total sequence duration controlled. For the other group, total sequence duration, sum of the tone durations, and sum of the gap…

We compared the ability of auditory, visual, and audiovisual (bimodal) exogenous cues to capture visuo-spatial attention under conditions of no load versus high perceptual load. Participants had to discriminate the elevation (up vs. down) of visual targets preceded by either unimodal or bimodal cues under conditions of high perceptual load (in…

Two experiments investigated baseline reviews as a relevant variable in reorganization of equivalence classes. After formation of three 4-member classes, participants learned reversals of baseline conditional discriminations and expanded the classes to 5 members each. In Experiment 1, 4 students responded on equivalence probes without baseline…

Errorless learning refers to a variety of discrimination learning techniques that eliminate or minimize responding to incorrect choices. This article describes experimental roots of errorless learning and applied errorless strategies. Specifically, previous research on stimulus fading, stimulus shaping, response prevention, delayed prompting,…

Ten autistic children and 10 normal nursery school children, matched for mean developmental age, were presented with figure stimuli and had variable irrelevant cues in two-choice simultaneous discrimination learning. Performance of the autistic group did not vary as a function of irrelevant variability, a result attributed to poor performance of…

Progressively delayed extra-stimulus prompts were used to help kindergarten children discriminate left-right mirror-image stimuli in four experiments. Results showed that most subjects rapidly learned to respond to the orientation prompts; delayed orientation prompting was always successful regardless of how the prompts were eliminated; and the…