Periodic Reporting for period 1 - PVB-ASD (The Predictive Visual Brain in Autism Spectrum Disorders)
Berichtszeitraum: 2018-09-01 bis 2020-08-31
We have created multiple experimental protocols that assess the effects of expectations and intrinsic learning at multiple levels in the visual processing hierarchy. This way we can assess whether the possible alterations in predictive processing are affecting early, mid or late stages of processing (or are widespread). We developed and applied a battery of tests using a high-density EEG system and an extra experiment using fMRI.
Assessing predictive processing in Autism with methods that allow for the identification and location of possible deficits both in space and time can lead to the refinement of the contemporary predictive processing inspired models of Autism and help clinicians and caregivers. There is also some evidence in the literature that applying a predictive coding framework to ASD could lead to the identification of different ASD subgroups, aiding differential diagnosis.
There have been a few relevant delays in the development of the action given technical problems with equipment and the COVID-related lockdown of 2020 (delaying the finalization of data collection). This has naturally affected the dissemination of the results too. The process of dissemination will happen throughout the year 2021 and reach the goals initially planned.
Overall, participants with ASD are less affected by the hidden contingencies in the tasks (generally consisting of stimuli with higher or lower probabilities of presentation). This means that participants were less affected by presentation probability and therefore also less surprised by unlikely stimulus presentations. This effect was more clear for tasks and stimuli that targeted the early visual cortex. On top of this, we found no overall differences between average confidence measures for participants with ASD and neurotypicals.
At this stage, our results indeed suggest altered predictive processing in participants with ASD. The patients seem to be less efficient in the intrinsic learning of stimulus presentation contingencies. This seems to happen mostly at early visual processing stages. These results will be reassessed when the data collection is finished.