Biology subjects

Boonstra, E. A.

Publications and source records attributed to Boonstra, E. A..

3 recordsLinked to original sources

bioRxiv2022

Learning to predict based on self- versus externally induced prediction violations: a direct comparison using a Bayesian inference modelling approach

Predictive processing is quickly gaining ground as a theory of perception and attention. From this perspective the brain is cast as an organisms predictive model of how its world works and will continue to work in the future. However, research on the brains predictive capacities remains beholden to traditional research practices in which participants are passively shown stimuli without their active involvement. The current study is an investigation into ways in which self-generated predictions may differ from externally induced predictions. Participants completed a volatile spatial attention task under both conditions on different days. We used the Hierarchical Gaussian Filter, an approximate Bayesian inference model, to determine subject-specific parameters of belief-updating and inferred volatility. We found preliminary evidence in support of self-generated predictions incurring a larger reaction time cost when violated compared to predictions induced by sensory cue, which translated to participants increased sensitivity to changes in environmental volatility. Our results suggest that internally generated predictions may be afforded more weight, but these results are complicated by session order and duration effects, as well as a lack of statistical power. We discuss the limitations of our study preventing us from replicating previous research, and ways to remedy these shortcomings in future studies.

neuroscience↗

bioRxiv2022

Conscious perception and the role of the basal ganglia: preliminary findings from a deep brain stimulation study

Conscious perception is thought to depend on global amplification of sensory input. In recent years, the basal ganglia have been implicated in gating conscious access due to their consistent involvement in thalamocortical loops. However, much of the evidence implicating the basal ganglia in these processes in humans is correlational. The current study is a preliminary investigation in four patients to explore whether deep brain stimulation (DBS) in the basal ganglia might improve conscious perception. In our study, treatment-resistant obsessive-compulsive disorder (OCD) patients with a striatal DBS implant completed two canonical conscious perception tasks: emotion-induced blindness and backward masking. We found preliminary evidence in support of a role played by the basal ganglia in conscious perception at the behavioral level: patients performed better when stimulation was active, but we could not establish neural effects corresponding to these behavioral findings, possibly due to our small sample size. We discuss the potential implications and limitations of our study and delineate avenues for future research.

neuroscience↗

bioRxiv2020

Conscious perception and the modulatory role of dopamine: no effect of the dopamine D2 agonist cabergoline on visual masking, the attentional blink, and probabilistic discrimination

RationaleConscious perception is thought to depend on global amplification of sensory input. In recent years, striatal dopamine has been proposed to be involved in gating information and conscious access, due to its modulatory influence on thalamocortical connectivity. ObjectivesSince much of the evidence that implicates striatal dopamine is correlational, we conducted a double-blind crossover pharmacological study in which we administered cabergoline - a dopamine D2 agonist - and placebo to 30 healthy participants. Under both conditions, we subjected participants to several well-established experimental conscious-perception paradigms, such as backward masking and the attentional blink task. ResultsWe found no evidence in support of an effect of cabergoline on conscious perception: key behavioral and event-related potential (ERP) findings associated with each of these tasks were unaffected by cabergoline. ConclusionsOur results cast doubt on a causal role for dopamine in visual perception. It remains an open possibility that dopamine has causal effects in other tasks, perhaps where perceptual uncertainty is more prominent.

neuroscience↗