scholarly journals Blocking of Stimulus Control in Children with Autism

Author(s):  
Heidi Skorge Olaff ◽  
Monica Vandbakk ◽  
Per Holth

AbstractThe present study aimed to investigate the blocking of stimulus control in three children with autism. We used a go/no-go procedure in a standard blocking paradigm. In Phase 1, we established one of two sounds or colored squares as a discriminative stimulus for touching a tablet screen. In Phase 2, a colored square was added to the sound or a sound was added to the colored square in a stimulus compound. The discrimination training continued as in Phase 1. We subsequently tested discriminative control by each of the single stimuli separately and by the compounds. Finally, after testing with no programmed consequences, we reestablished the original discrimination and replicated the test of stimulus control. The results support previous experiments by demonstrating that the establishment of discriminative control by a second stimulus by adding it to a previously established discriminative stimulus in a compound was blocked by the earlier discrimination training in all three participants. We discuss procedural details that may be critical to avoid the blocking of stimulus control in the applied field, particularly with respect to the acquisition of skills that involve multiple stimuli, such as joint attention, social referencing, and bidirectional naming.

2021 ◽  
Author(s):  
◽  
Lynne Whitney

<p>In the present thesis, the intradimensional-extradimensional shift effect was treated as a problem of two-dimensional stimulus control. Factors determining stimulus control in the ID-ED shift were explored over six experiments. In Experiment 1 adult students were trained to discriminate between successively presented stimuli that differed in both line length and orientation. For half the subjects the length dimension was relevant (ie: different stimuli on that dimension were correlated with different outcomes) and for half the subjects orientation was relevant (phase 1). All subjects were then shifted to a second discrimination between new line lengths and orientations (Phase 2). For half, this constituted an intradimensional (ID) shift in that the previously relevant dimension remained relevant; for the remaining subjects the previously irrelevant dimension was made relevant in an extradimensional (ED) shift. The ID shift required significantly fewer trials to establish strong stimulus control by the relevant dimension in Phase 2 than did the ED shift. Experiments 1 and 2 further established that such differences were not attributable to a dominance relationship between dimensions or to specific cue values. Experiment 3 examined the development of stimulus control by the two dimensions over trials in Phase 2. In the ED shift, two-dimensional generalisation gradients showed a systematic weakening and strengthening of control by the Phase 1 relevant and Phase 2 relevant dimensions respectively. In the ID shift there was no change in stimulus control by either dimension. Experiment 4 established that transfer to the orientation dimension following differential training on length (ED shift) was superior to orientation following non-differential training on length (PD shift). Learning that differences on an extradimensional dimension were relevant in Phase I therefore had a facilitatory effect on control by orientation. Experiments 5 and 6 investigated the effects of manipulating the number of cues on the irrelevant Phase 1 dimension (orientation) and/or the irrelevant phase 2 dimension (length), in an ED shift where orientation was relevant in Phase 2. Both orientation and length (Experiment 5) or orientation alone (Experiment 6) were varied in the generalisation test. The ED shift in Phase 2 was retarded by the irrelevant dimension in Phase 1. It was concluded that in general the phase I relevant dimension must lose control in Phase 2, and the phase 1 irrelevant dimension must gain control in Phase 2 (Experiment 3). However, the inverse relation between loss of control by one dimension and gaining of control by the other does not occur in a way consistent with the Inverse Hypothesis of some selective attention theories. In addition, the previously relevant dimension in an ED shift facilitates control by the new relevant dimension in phase 2 re1ative to non-differential training, consistent with attentional enhancement. The major factor found to be slowing down the development of control by the new relevant dimension in an ED shift is the presence of the irrelevant dimension in Phase 1, (Experiment 5). This is probably a 'learned irrelevance' effect.</p>


2021 ◽  
Author(s):  
◽  
Lynne Whitney

<p>In the present thesis, the intradimensional-extradimensional shift effect was treated as a problem of two-dimensional stimulus control. Factors determining stimulus control in the ID-ED shift were explored over six experiments. In Experiment 1 adult students were trained to discriminate between successively presented stimuli that differed in both line length and orientation. For half the subjects the length dimension was relevant (ie: different stimuli on that dimension were correlated with different outcomes) and for half the subjects orientation was relevant (phase 1). All subjects were then shifted to a second discrimination between new line lengths and orientations (Phase 2). For half, this constituted an intradimensional (ID) shift in that the previously relevant dimension remained relevant; for the remaining subjects the previously irrelevant dimension was made relevant in an extradimensional (ED) shift. The ID shift required significantly fewer trials to establish strong stimulus control by the relevant dimension in Phase 2 than did the ED shift. Experiments 1 and 2 further established that such differences were not attributable to a dominance relationship between dimensions or to specific cue values. Experiment 3 examined the development of stimulus control by the two dimensions over trials in Phase 2. In the ED shift, two-dimensional generalisation gradients showed a systematic weakening and strengthening of control by the Phase 1 relevant and Phase 2 relevant dimensions respectively. In the ID shift there was no change in stimulus control by either dimension. Experiment 4 established that transfer to the orientation dimension following differential training on length (ED shift) was superior to orientation following non-differential training on length (PD shift). Learning that differences on an extradimensional dimension were relevant in Phase I therefore had a facilitatory effect on control by orientation. Experiments 5 and 6 investigated the effects of manipulating the number of cues on the irrelevant Phase 1 dimension (orientation) and/or the irrelevant phase 2 dimension (length), in an ED shift where orientation was relevant in Phase 2. Both orientation and length (Experiment 5) or orientation alone (Experiment 6) were varied in the generalisation test. The ED shift in Phase 2 was retarded by the irrelevant dimension in Phase 1. It was concluded that in general the phase I relevant dimension must lose control in Phase 2, and the phase 1 irrelevant dimension must gain control in Phase 2 (Experiment 3). However, the inverse relation between loss of control by one dimension and gaining of control by the other does not occur in a way consistent with the Inverse Hypothesis of some selective attention theories. In addition, the previously relevant dimension in an ED shift facilitates control by the new relevant dimension in phase 2 re1ative to non-differential training, consistent with attentional enhancement. The major factor found to be slowing down the development of control by the new relevant dimension in an ED shift is the presence of the irrelevant dimension in Phase 1, (Experiment 5). This is probably a 'learned irrelevance' effect.</p>


1977 ◽  
Vol 41 (3) ◽  
pp. 791-794
Author(s):  
Ralph W. Richards

Three pigeons were trained on a “go-no go” discrimination task in which positive trials were preceded by 1.5-sec. access to food and negative trials were preceded by 0-sec. access to food. By the end of training pretrial access to food was exerting strong discriminative control over responding: each subject responded more than eight times more frequently during positive than negative trials. During a subsequent generalization test in which trials were preceded by various amounts of food, an orderly decremental gradient was obtained between 0- and 1.5-sec. access to food. A comparison with the gradients from three other subjects not given discrimination training showed that the training sharpened the generalization gradient between the training stimuli.


2001 ◽  
Vol 60 (4) ◽  
pp. 215-230 ◽  
Author(s):  
Jean-Léon Beauvois

After having been told they were free to accept or refuse, pupils aged 6–7 and 10–11 (tested individually) were led to agree to taste a soup that looked disgusting (phase 1: initial counter-motivational obligation). Before tasting the soup, they had to state what they thought about it. A week later, they were asked whether they wanted to try out some new needles that had supposedly been invented to make vaccinations less painful. Agreement or refusal to try was noted, along with the size of the needle chosen in case of agreement (phase 2: act generalization). The main findings included (1) a strong dissonance reduction effect in phase 1, especially for the younger children (rationalization), (2) a generalization effect in phase 2 (foot-in-the-door effect), and (3) a facilitatory effect on generalization of internal causal explanations about the initial agreement. The results are discussed in relation to the distinction between rationalization and internalization.


2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Abdul Hasan Saragih

This classroom research was conducted on the autocad instructions to the first grade of mechinary class of SMK Negeri 1 Stabat aiming at : (1) improving the student’ archievementon autocad instructional to the student of mechinary architecture class of SMK Negeri 1 Stabat, (2) applying Quantum Learning Model to the students of mechinary class of SMK Negeri 1 Stabat, arising the positive response to autocad subject by applying Quantum Learning Model of the students of mechinary class of SMK Negeri 1 Stabat. The result shows that (1) by applying quantum learning model, the students’ achievement improves significantly. The improvement ofthe achievement of the 34 students is very satisfactory; on the first phase, 27 students passed (70.59%), 10 students failed (29.41%). On the second phase 27 students (79.41%) passed and 7 students (20.59%) failed. On the third phase 30 students (88.24%) passed and 4 students (11.76%) failed. The application of quantum learning model in SMK Negeri 1 Stabat proved satisfying. This was visible from the activeness of the students from phase 1 to 3. The activeness average of the students was 74.31% on phase 1,81.35% on phase 2, and 83.63% on phase 3. (3) The application of the quantum learning model on teaching autocad was very positively welcome by the students of mechinary class of SMK Negeri 1 Stabat. On phase 1 the improvement was 81.53% . It improved to 86.15% on phase 3. Therefore, The improvement ofstudent’ response can be categorized good.


2020 ◽  
Vol 70 (suppl 1) ◽  
pp. bjgp20X711425
Author(s):  
Joanna Lawrence ◽  
Petronelle Eastwick-Field ◽  
Anne Maloney ◽  
Helen Higham

BackgroundGP practices have limited access to medical emergency training and basic life support is often taught out of context as a skills-based event.AimTo develop and evaluate a whole team integrated simulation-based education, to enhance learning, change behaviours and provide safer care.MethodPhase 1: 10 practices piloted a 3-hour programme delivering 40 minutes BLS and AED skills and 2-hour deteriorating patient simulation. Three scenarios where developed: adult chest pain, child anaphylaxis and baby bronchiolitis. An adult simulation patient and relative were used and a child and baby manikin. Two facilitators trained in coaching and debriefing used the 3D debriefing model. Phase 2: 12 new practices undertook identical training derived from Phase 1, with pre- and post-course questionnaires. Teams were scored on: team working, communication, early recognition and systematic approach. The team developed action plans derived from their learning to inform future response. Ten of the 12 practices from Phase 2 received an emergency drill within 6 months of the original session. Three to four members of the whole team integrated training, attended the drill, but were unaware of the nature of the scenario before. Scoring was repeated and action plans were revisited to determine behaviour changes.ResultsEvery emergency drill demonstrated improved scoring in skills and behaviour.ConclusionA combination of: in situ GP simulation, appropriately qualified facilitators in simulation and debriefing, and action plans developed by the whole team suggests safer care for patients experiencing a medical emergency.


2010 ◽  
Vol 9 (4) ◽  
pp. 214-219
Author(s):  
Robyn J. Barst

Drug development is the entire process of introducing a new drug to the market. It involves drug discovery, screening, preclinical testing, an Investigational New Drug (IND) application in the US or a Clinical Trial Application (CTA) in the EU, phase 1–3 clinical trials, a New Drug Application (NDA), Food and Drug Administration (FDA) review and approval, and postapproval studies required for continuing safety evaluation. Preclinical testing assesses safety and biologic activity, phase 1 determines safety and dosage, phase 2 evaluates efficacy and side effects, and phase 3 confirms efficacy and monitors adverse effects in a larger number of patients. Postapproval studies provide additional postmarketing data. On average, it takes 15 years from preclinical studies to regulatory approval by the FDA: about 3.5–6.5 years for preclinical, 1–1.5 years for phase 1, 2 years for phase 2, 3–3.5 years for phase 3, and 1.5–2.5 years for filing the NDA and completing the FDA review process. Of approximately 5000 compounds evaluated in preclinical studies, about 5 compounds enter clinical trials, and 1 compound is approved (Tufts Center for the Study of Drug Development, 2011). Most drug development programs include approximately 35–40 phase 1 studies, 15 phase 2 studies, and 3–5 pivotal trials with more than 5000 patients enrolled. Thus, to produce safe and effective drugs in a regulated environment is a highly complex process. Against this backdrop, what is the best way to develop drugs for pulmonary arterial hypertension (PAH), an orphan disease often rapidly fatal within several years of diagnosis and in which spontaneous regression does not occur?


Cancer ◽  
2019 ◽  
Vol 125 (14) ◽  
pp. 2445-2454 ◽  
Author(s):  
Robin L. Jones ◽  
Sant P. Chawla ◽  
Steven Attia ◽  
Patrick Schöffski ◽  
Hans Gelderblom ◽  
...  

2021 ◽  
Vol 5 (1) ◽  
pp. e000700
Author(s):  
Carrie Allison ◽  
Fiona E Matthews ◽  
Liliana Ruta ◽  
Greg Pasco ◽  
Renee Soufer ◽  
...  

ObjectiveThis is a prospective population screening study for autism in toddlers aged 18–30 months old using the Quantitative Checklist for Autism in Toddlers (Q-CHAT), with follow-up at age 4.DesignObservational study.SettingLuton, Bedfordshire and Cambridgeshire in the UK.Participants13 070 toddlers registered on the Child Health Surveillance Database between March 2008 and April 2009, with follow-up at age 4; 3770 (29%) were screened for autism at 18–30 months using the Q-CHAT and the Childhood Autism Spectrum Test (CAST) at follow-up at age 4.InterventionsA stratified sample across the Q-CHAT score distribution was invited for diagnostic assessment (phase 1). The 4-year follow-up included the CAST and the Checklist for Referral (CFR). All with CAST ≥15, phase 1 diagnostic assessment or with developmental concerns on the CFR were invited for diagnostic assessment (phase 2). Standardised diagnostic assessment at both time-points was conducted to establish the test accuracy of the Q-CHAT.Main outcome measuresConsensus diagnostic outcome at phase 1 and phase 2.ResultsAt phase 1, 3770 Q-CHATs were returned (29% response) and 121 undertook diagnostic assessment, of whom 11 met the criteria for autism. All 11 screened positive on the Q-CHAT. The positive predictive value (PPV) at a cut-point of 39 was 17% (95% CI 8% to 31%). At phase 2, 2005 of 3472 CASTs and CFRs were returned (58% response). 159 underwent diagnostic assessment, including 82 assessed in phase 1. All children meeting the criteria for autism identified via the Q-CHAT at phase 1 also met the criteria at phase 2. The PPV was 28% (95% CI 15% to 46%) after phase 1 and phase 2.ConclusionsThe Q-CHAT can be used at 18–30 months to identify autism and enable accelerated referral for diagnostic assessment. The low PPV suggests that for every true positive there would, however, be ~4–5 false positives. At follow-up, new cases were identified, illustrating the need for continued surveillance and rescreening at multiple time-points using developmentally sensitive instruments. Not all children who later receive a diagnosis of autism are detectable during the toddler period.


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