In the present study, two typically developing 4-year-old children, Pete and Joe, were trained six conditional discriminations and tested for the formation of three 3-member equivalence classes. Pete and Joe did not establish the AC relation within 600 trials and were given two conditions of preliminary training, including naming of stimuli with…

Most eyewitness identification research simulates single perpetrator crimes, but real-world crimes often transpire at the hands of multiple perpetrators. It is unclear how multiple perpetrators might impact the ability of eyewitnesses to discriminate between the guilty and innocent. To address this issue, we conducted two experiments in which…

According to the Diagnostic Feature-Detection (DFD) hypothesis, the presence of fillers that match the eyewitness's description of the perpetrator will boost discriminability beyond a showup, and very few fillers may suffice to produce the advantage. We tested this hypothesis by comparing showups with simultaneous lineups of size 3, 6, 9, and 12.…

A portion of children diagnosed with autism spectrum disorder (ASD) have difficulty acquiring conditional discrimination. However, previous researchers suggested that the discrimination of nonverbal auditory stimuli may be acquired more efficiently (Eikeseth & Hayward, 2009; Uwer, et al., 2002). For example, a child may learn to touch a…

Often, the evidence we observe is consistent with more than one explanation. How do learners discriminate among candidate causes? The current studies examine whether counterfactuals help 5-year olds (N = 120) select between competing hypotheses and compares the effectiveness of these prompts to a related scaffold. In Experiment 1, counterfactuals…

Eyewitness researchers recommend that "not present" and "don't know" response options should be presented with police lineups. Although it is important that witnesses--most of whom are unlikely to be familiar with the identification task--are fully cognizant of all response options available to them, an understanding of how…

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…

During exploration, young children often show an intuitive sensitivity to uncertainty, despite their strong tendency towards overconfidence in their explicit judgments. Here, we examine the development of children's explicit and implicit recognition of uncertainty using the same stimuli. We presented 4- and 5-year-olds with objects that varied in…

Linguistic category learning has been shown to be highly sensitive to linear order, and depending on the task, differentially sensitive to the information provided by preceding category markers ("premarkers," e.g., gendered articles) or succeeding category markers ("postmarkers," e.g., gendered suffixes). Given that numerous…

Individuals diagnosed with autism spectrum disorder (ASD) who engage in stereotypy may also emit a prior, temporally contiguous, high-risk response to access stereotypic behaviors. For example, the participant in this study who was diagnosed with ASD engaged in a chained response that included elopement, often in unsafe locations, to access light…

The ability to discriminate social signals from faces is a fundamental component of human social interactions whose developmental origins are still debated. In this study, 5-year-old (N = 29) and 7-year-old children (N = 31) and adults (N = 34) made perceptual similarity and trustworthiness judgments on a set of female faces varying in level of…

The current study examined the effects of a brief mindfulness induction on overselectivity. Participants were randomly assigned to a mindfulness, unfocused attention (relaxation), or no-intervention group. Participants experienced their designated intervention for 10 min, and they underwent simultaneous discrimination training (AB+ CD-) followed…

Dyslexia has frequently been related to atypical auditory temporal processing and speech perception. Results of studies emphasizing speech onset cues and reinforcing the temporal structure of the speech envelope, that is, envelope enhancement (EE), demonstrated reduced speech perception deficits in individuals with dyslexia. The use of this…

Learning to categorize perceptually similar stimuli can result in people becoming more sensitive to differences along perceptual dimensions that are relevant to category membership and/or less sensitive to equivalent differences along irrelevant perceptual dimensions. These effects of acquired distinctiveness and acquired equivalence may be caused…

In their seminal study of chess expertise, Simon and Chase (Chase & Simon, 1973; Simon & Chase, 1973) proposed that perceptual learning was a necessary component of skill acquisition. In their view, acquisition of skill results from the strategic use of learning at multiple levels to adaptively overcome inherent limitations. The knowledge…