Expansion of Sidman's theory: The inclusion of prompt stimuli in equivalence classes

Stimulus equivalence is defined as the ability to relate stimuli in novel ways after training in which not all of the stimuli had been directly linked to one another. Sidman (2000) suggested all elements of conditional discrimination training contingencies that result in equivalence potentially become class members. Research has demonstrated the inclusion of samples, comparisons, responses, and reinforcers in equivalence classes. Given the evidence that all elements of a conditional discrimination become part of the class, the purpose of this study was to determine if class-specific prompts would also enter into their relevant equivalence classes. Experiment 1 investigated the inclusion of prompts in an equivalence class using abstract stimuli with neurotypical students enrolled in higher education courses. Experiment 2 systematically replicated Experiment 1 using meaningful stimuli and individuals diagnosed with autism spectrum disorder. The results of both experiments demonstrated that class-specific prompts became part of equivalence classes with the other positive elements of the contingency. The results are discussed in terms of class expansion and the potential impact on equivalence-based instruction.     

‘Language of the past’ – Exploring past tense disruption during autobiographical narration in neurodegenerative disorders

Compromised retrieval of autobiographical memory (ABM) is well established in neurodegenerative disorders. The recounting of autobiographical events is inextricably linked to linguistic knowledge, yet no study to date has investigated whether tense use during autobiographical narration is disrupted in dementia syndromes. This study investigated the incidence of correct past tense use during ABM narration in patients with Alzheimer's disease (AD, n = 10) and semantic dementia (SD, n = 10) in comparison with healthy older Controls (n = 10). Autobiographical narratives were analysed for episodic content (internal/external) and classified according to tense use (past/present). Across both patient groups, use of the past tense was significantly compromised relative to Controls, with increased levels of off‐target present tense verbs observed. Voxel‐based morphometry analyses based on structural MRI revealed differential associations between past tense use and regions of grey matter intensity in the brain. Bilateral temporal cortices were implicated in the SD group, whereas frontal, lateral, and medial temporal regions including the right hippocampus emerged in AD. This preliminary study provides the first demonstration of the disruption of specific linguistic constructs during autobiographical narration in AD and SD. Future studies are warranted to clarify at what point in the disease trajectory such deficits in tense use emerge, and whether these deficits are a product or contributing factor in memory disruption in these syndromes.     

The differential effect of noise on creative task performance

The effect of an arousal manipulation on creativity task performance was investigated. Sixty, 80, and 100dB of noise were used to raise arousal levels in 72 undergraduates while they were individually assessed on creativity tasks. Two hypotheses were tested: The first was that noise would interfere with performance on creativity tasks, and the second was that high scorers would be resistant to this effect. Results supported the latter hypothesis. The noise‐induction appeared to have a differential effect. For highly original subjects, there was a curvilinear relationship between the noise and performance; this relationship was not reflected in the performance of subjects who scored low in originality. The major finding of this study was that research on the relationship between creativity and arousal may be difficult and misleading if the mediating role of individual differences in creativity are not considered.     

Inhibitory control gains from higher-order cognitive strategy training

The present study examined the transfer of higher-order cognitive strategy training to inhibitory control. Middle school students enrolled in a comprehension- and reasoning-focused cognitive strategy training program and passive controls participated. The training program taught students a set of steps for inferring essential gist or themes from materials. Both before and after training or a comparable duration in the case of the passive controls, participants completed a semantically cued Go/No-Go task that was designed to assess the effects of depth of semantic processing on response inhibition and components of event-related potentials (ERP) related to response inhibition. Depth of semantic processing was manipulated by varying the level of semantic categorization required for response selection and inhibition. The SMART-trained group showed inhibitory control gains and changes in fronto-central P3 ERP amplitudes on inhibition trials; whereas, the control group did not. The results provide evidence of the transfer of higher-order cognitive strategy training to inhibitory control and modulation of ERPs associated with semantically cued inhibitory control. The findings are discussed in terms of implications for cognitive strategy training, models of cognitive abilities, and education.