Two experiments examined whether over-selectivity is the product of a post-acquisition performance deficit, rather than an attention problem. In both experiments, children with Autistic Spectrum Disorder were presented with a trial-and-error discrimination task using two, two-element stimuli and over-selected in both studies. After behavioral control by the previously over-selected stimulus was extinguished, behavioral control by the previously under-selected cue emerged without direct training. However, this effect was only found in higher-functioning children, and not with more severely impaired children. These findings suggest that over-selectivity is not simply due to a failure to attend to all of the stimuli presented. They also suggest that extinction of over-selected stimuli may be a fruitful line of intervention for clinical intervention for some individuals.
Stimulus overselectivity occurs when only one of potentially many aspects of the environment controls behavior. Adult participants were trained and tested on a trial-and-error discrimination learning task while engaging in a concurrent load task, and overselectivity emerged. When responding to the overselected stimulus was reduced by reinforcing a novel stimulus in the presence of the previously overselected stimulus in a second trial-and-error discrimination task, behavioral control by the underselected stimulus became stronger. However, this result was only found under certain circumstances: when there was substantial overselectivity in the first training phase; when control by the underselected stimulus in the first phase was particularly low; and when there was effective reduction in the behavioral control exerted by the previously overselected stimuli. The emergence of behavioral control by the underselected stimulus suggests that overselectivity is not simply due to an attention deficit, because for the emergence to occur, the stimuli must have been attended to and learned about in the training phase; but that a range of additional learning factors may play a role.
Stimulus overselectivity occurs when one aspect of the environment controls behavior at the expense of other equally salient aspects. Stimulus overselectivity can be reduced for some individuals with learning disabilities, if they engage in an observing response in which they point to, touch, or name each of the stimuli prior to selecting the one requested. To see whether this would apply to another population, a total of 55 participants with autism spectrum disorders (ASD) were trained on match-to-sample (MTS), or simple discrimination tasks, to determine whether overselectivity could be eliminated by using an observing response. MTS tasks were presented in a table-top format as well as on a computer. The observing-response procedure did not eliminate overselectivity for any of the participants, regardless of age, task, or format of presentation. These results are interpreted to call to question the effectiveness of this procedure in this context for individuals with ASD.
Background/Objectives
Obesity in pregnancy has been associated with increased childhood cardiometabolic risk and reduced life expectancy. The UK UPBEAT multicentre randomised control trial was a lifestyle intervention of diet and physical activity in pregnant women with obesity. We hypothesised that the 3-year-old children of women with obesity would have heightened cardiovascular risk compared to children of normal BMI women, and that the UPBEAT intervention would mitigate this risk.
Subjects/Methods
Children were recruited from one UPBEAT trial centre. Cardiovascular measures included blood pressure, echocardiographic assessment of cardiac function and dimensions, carotid intima-media thickness and heart rate variability (HRV) by electrocardiogram.
Results
Compared to offspring of normal BMI women (n = 51), children of women with obesity from the trial standard care arm (n = 39) had evidence of cardiac remodelling including increased interventricular septum (IVS; mean difference 0.04 cm; 95% CI: 0.018 to 0.067), posterior wall (PW; 0.03 cm; 0.006 to 0.062) and relative wall thicknesses (RWT; 0.03 cm; 0.01 to 0.05) following adjustment. Randomisation of women with obesity to the intervention arm (n = 31) prevented this cardiac remodelling (intervention effect; mean difference IVS −0.03 cm (−0.05 to −0.008); PW −0.03 cm (−0.05 to −0.01); RWT −0.02 cm (−0.04 to −0.005)). Children of women with obesity (standard care arm) compared to women of normal BMI also had elevated minimum heart rate (7 bpm; 1.41 to 13.34) evidence of early diastolic dysfunction (e prime) and increased sympathetic nerve activity index by HRV analysis.
Conclusions
Maternal obesity was associated with left ventricular concentric remodelling in 3-year-old offspring. Absence of remodelling following the maternal intervention infers in utero origins of cardiac remodelling.
Clinical trial registry name and registration number
The UPBEAT trial is registered with Current Controlled Trials, ISRCTN89971375.
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