Pigeons in Control of their Actions: Learning and Performance in Stop-Signal and Change-Signal Tasks

This is the author accepted manuscript. The final version is available from the American Psychological Association via the DOI in this record.In human participants, two paradigms commonly assumed to measure the executive-control processes involved in response inhibition are the Stop-Signal and Change-Signal tasks. There is, however, also considerable evidence that performance in these tasks can be mediated by associative processes. To assess which components of inhibitory response control might be associative, we developed analogues of these two tasks for pigeons. We trained pigeons to peck quickly at one of two keys of different colours to obtain a food reward. On some trials, the rewarded key was replaced (after a varying interval) by a signal of a different colour. For some birds, this was a Change Signal: pecking the signal had no effect, but pecking the usually unrewarded alternative key led to a reward, so the response had to be changed. For other birds, the change in colour was a Stop Signal: pecking the alternative key remained ineffective, but pecking the signal now led to a timeout instead of the usual reward, so responses had to be withheld. Pigeons succeeded in both tasks, but performance declined with increasing signal delay. The details of performance in both tasks were consistent with the independent horse-race model of inhibitory control often applied to studies of human participants. This outcome further suggests that stop-signal tasks of the kind used here might not be suitable for assessing top-down executive-control processes in humans

Legal Challenges for IT Service Providers in Pharmacogenomics

IT providers offering services based on genetic data face serious challenges in managing health data in compliance with the General Data Protection Regulation (GDPR). Based on a literature research and our experiences, an overview of GDPR compliant processing of sensitive data is given. The GDPR requirements for processing sensitive data were specified for a use case concerning a service provider of a pharmacogenomic decision support system. Start-ups who want to enter into the health market also have to comply with the Medical Device Regulation (MDR). The associated efforts for legal compliance constitute an impediment for many start-ups. We created a comprehensive overview, which aligned the requirements of the GDPR with the life-cycle of a medical device. This overview shall help start-ups to grasp and overcome the regulatory hurdles faster

A stimulus-location effect in contingency-governed, but not rule-based, discrimination learning

This is the author accepted manuscript. The final version is available from APA via the DOI in this recordWe tested pigeons' acquisition of a conditional discrimination task between coloured grating stimuli that included choosing one of two response keys, which either appeared as white keys to the left and right of the discriminative stimulus, or were replicas of the stimulus. Pigeons failed to acquire the discrimination when the response keys were white disks but succeeded when directly responding to a replica of the stimulus. These results highlight how conditioning processes shape learning in pigeons: the results can be accounted for by supposing that, when pigeons were allowed to respond directly towards the stimulus, learning was guided by classical conditioning; responding to white keys demanded instrumental learning, which impaired task acquisition for pigeons. In contrast, humans completing the same paradigm showed no differential learning success depending on whether figure or position indicated the correct key. However, only participants who could state the underlying discrimination rule acquired the task, which implies that human performance in this situation relied on the deduction and application of task rules instead of associative processes

Task-Switching in Pigeons: Associative Learning or Executive Control?

This is the author accepted manuscript. The final version is available from the American Psychological Association via the DOI in this record.Human performance in task-switching paradigms is seen as a hallmark of executive-control processes: switching between tasks induces switch costs (such that performance when changing from Task A to Task B is worse than on trials where the task repeats), which is generally attributed to executive control suppressing one task-set and activating the other. However, even in cases where task-sets are not employed, as well as in computational modelling of task switching, switch costs can still be found. This observation has led to the hypothesis that associative-learning processes might be responsible for all or part of the switch cost in task-switching paradigms. To test which cognitive processes contribute to the presence of task-switch costs, pigeons performed two different tasks on the same set of stimuli in rapid alternation. The pigeons showed no sign of switch costs, even though performance on trial N was influenced by trial N-1, showing that they were sensitive to sequential effects. Using Pearce's (1987) model for stimulus generalisation, we conclude that they learned the task associatively - in particular, a form of Pavlovian-conditioned approach was involved - and that this was responsible for the lack of any detectable switch costs. Pearce's model also allows us to make interferences about the common occurrence of switch costs in the absence of task-sets in human participants and in computational models, in that they are likely due to instrumental learning and the establishment of an equivalence between cues signalling the same task

Comparative Evidence for Associative Learning in Task Switching.

Copyright © 2013 Cognitive Science SocietyHumans can perform several different tasks on the same set of stimuli in rapid alternation. Each task, signaled by a distinct task cue, may require the classification of stimuli using a different stimulus attribute. However, such "task switching" performance comes at a cost, as expressed by weaker performance when switching rather than repeating tasks. This cost is often claimed to be the consequence of a mental reorientation away from the previous task and towards the new task, requiring executive control of behavior. Alternatively, task switching could simply be based on the retrieval of different cue-stimulus-response associations. In this experiment, pigeons learned go-left/go-right discriminations between grating patterns according to either their spatial frequency or their orientation, depending on the color of the pattern (the task cue). When humans solved the same tasks on the basis of verbalizable rules, they responded more slowly and made more errors on trials where they had to switch between tasks than when repeating the same task. Pigeons did not show this "switch cost"; but like humans, their performance was significantly worse when the response (left or right) to a given stimulus varied between tasks than when it stayed the same (the “congruency effect”). Larger effects of both switch costs and congruency were observed in humans learning the tasks by trial and error. We discuss the potential driving factors behind these very different patterns of performance for both humans and pigeons

Information Capturing in Pre-Hospital Emergency Medical Settings (EMS)

Emergency medical situations are characterized by high physical, cognitive and mental demands on the paramedics on the ground. Studies suggest that crucial information such as treatments administered to patients is often documented retrospectively, during patient transport or once a patient is handed over to an emergency department. Information access may also be surprisingly difficult (e.g. patient medical history). In this paper, we focus on supporting in situ information capturing and report on a realistic laboratory-based study involving experienced paramedics that we used to explore the specific requirements and constraints of supporting in situ information capturing. Specifically, we focused on ways to use audio and visual data capture methods and how they need to be designed to better support paramedics without interfering with their work. We then use the resulting information centric perspective to argue for a roadmap towards smart emergency medical services

Pigeons’ performance in a tracking change-signal procedure is consistent with the independent horse-race mode

This is the author accepted manuscript. The final version is available from the American Psychological Association via the DOI in this record.In many cognitive tasks where humans are thought to rely on executive functioning, pigeons’ behavior can be explained by associative processes. A key form of executive functioning is inhibiting prepotent responses, often investigated in humans by means of “Stop-signal” or “Change-signal” procedures. In these procedures, execution of a wellpractised (“Go”) response to a stimulus is occasionally interrupted by a signal to withhold or alter the practised response. Performance in such tasks is usually described by the “independent horse horse-race model” model. This model assumes that the processes that cause the Go and inhibitory responses occur independently; the process that finishes first determines the response observed. We further tested this model by training pigeons to track the circular movement of a colored patch around a touchscreen by pecking it; the spot occasionally deviated from its normal path (the Change signal). The pigeons had to inhibit the habitual movement of their heads in order to land a peck on the spot in its unexpected position. The key predictions of the independent horse-race model were confirmed in the pigeons’ latency data. Thus, the independent race model can also successfully describe Stop-change performance of subjects that do not rely on executive control

Development of a timing chip prototype in 110 nm CMOS technology

We present a readout chip prototype for future pixel detectors with timing capabilities. The prototype is intended for characterizing 4D pixel arrays with a pixel size of $100\times100~\mu \text{m}^2$, where the sensors are Low Gain Avalanche Diodes (LGADs). The long-term focus is towards a possible replacement of disks in the extended forward pixel system (TEPX) of the CMS experiment during the High Luminosity LHC (HL-LHC). The requirements for this ASIC are the incorporation of a Time to Digital Converter (TDC) within each pixel, low power consumption, and radiation tolerance up to $5\times10^{15}~n_\text{eq}\text{~cm}^{-2}$ to withstand the radiation levels in the innermost detector modules for $3000 \text{fb}^{-1}$ of the HL-LHC (in the TEPX). A prototype has been designed and produced in 110~nm CMOS technology at LFoundry and UMC with different versions of TDC structures, together with a front end circuitry to interface with the sensors. The design of the TDC will be discussed, with the test set-up for the measurements, and the first results comparing the performance of the different structures