Biology subjects

Ten Brink, A. F.

Publications and source records attributed to Ten Brink, A. F..

2 recordsLinked to original sources

bioRxiv2020

No evidence of impaired sensorimotor adaptation in Complex Regional Pain Syndrome

Sensorimotor conflict is theorised to contribute to the maintenance of some pathological pain conditions, such as Complex Regional Pain Syndrome (CRPS). We therefore tested whether sensorimotor adaptation is impaired in people with CRPS by characterising their adaption to lateral prismatic shifts in vision. People with unilateral upper limb CRPS Type I (n = 17), and pain-free individuals (n = 18; matched for age, sex, and handedness) completed prism adaptation with their affected/non-dominant and non-affected/dominant arm, in a counterbalanced order. We examined 1) the rate at which participants compensated for the optical shift during prism exposure (i.e. strategic recalibration), 2) endpoint errors made directly after prism adaptation (sensorimotor realignment) and their retention, and 3) kinematic markers associated with feedforward motor control and sensorimotor realignment. We found no evidence that strategic recalibration was different between people with CRPS and controls, including no evidence for differences in a kinematic marker associated with trial-by-trial changes in movement plans. Participants made significant endpoint errors in the prism adaptation after-effect phase, which are indicative of sensorimotor realignment. Overall, the magnitude of this realignment was not found to differ between people with CRPS and pain-free controls. However, people with CRPS made greater endpoint errors when using their affected hand than their non-affected hand, whereas no such difference was seen in controls. Taken together, these findings suggest that strategic control and sensorimotor realignment were not impaired for either arm in people with CRPS. In contrast, they provide some evidence that there is a greater propensity for sensorimotor realignment in CRPS, consistent with more flexible representations of the body and peripersonal space. Our study challenges the theory that sensorimotor conflict might underlie pathological pain that is maintained in the absence of tissue pathology.

neuroscience↗

bioRxiv2018

Multi-target visual search organisation across the lifespan: Cancellation task performance in a large and demographically stratified sample of healthy adults

Highlights- Cancellation tasks are useful clinical tools that probe many cognitive modules\n- We used cancellation tests on 523 participants of different ages, sex, and education\n- We provide cancellation task norm scores for indices computed from a big sample\n- Cancellation indices include attention bias, processing speed and search organisation\n- About a quarter of the healthy population shows relatively disorganised search\n\n\nAbstractIt is important that accurate tests exist to assess cognition in various groups of individuals. One popular test of attention and executive functioning is the cancellation task, in which participants perform multi-target visual search to find and cancel targets among distractors. Although cancellation tasks have been used extensively with neurological patients, it is only partly clear whether performance is affected by demographic variables such as age and education, which can vary wildly among patients. Here, we describe performance in a sample of 523 healthy participants who participated in a web-based cancellation task. Specifically, we examined indices of spatial bias, processing speed, perseveration and revisiting behaviour, and search organisation. In this sample, age, sex, and level of education did not affect cancellation performance. A cluster analysis identified four cognitive profiles: Participants who make many omissions (N=18), who make many revisits (N=18), who have relatively poor search organisation (N=125), and who have relatively good search organisation (N=362). We advise neurologists and neuropsychologists to exercise caution when interpreting scores pertaining to search organisation in patients: Given the large proportion of healthy individuals with poor search organisation, disorganised search in patients might be pre-existing rather than disorder-related. Finally, we include norm scores for indices of spatial bias, perseverations and revisits, processing speed, and search organisation for a popular cancellation task.

neuroscience↗