Biology subjects

Ridderinkhof, K. R.

Publications and source records attributed to Ridderinkhof, K. R..

3 recordsLinked to original sources

bioRxiv2018

Creative Minds Are Out of Control: Mid Frontal Theta and Creative Thinking

Creativity is considered to be the driving force behind innovation and progress, yet the mechanisms supporting creative thought remain elusive. In the current study, we investigated whether fluctuations in top-down control are related to creative thinking. Here, participants performed a caption this task in which they had to provide an original and apt caption to accompany a presented picture, while EEG signals were recorded. To assess changing levels of top-down control, we made use of the strong relationship between mid frontal oscillatory activity in the theta range (4-7 HZ) and top-down control. Results demonstrate that specifically during the process of optimization and implementation of creative solutions, lower levels of mid frontal theta resulted in higher levels of creativity. In addition, increased creativity related to enhanced functional connectivity between occipital and mid frontal cortex. Together, our findings indicate that creativity benefits from a top-down induced shift towards an internally-oriented state during idea optimization and evaluation.

animal behavior and cognition↗

bioRxiv2018

No evidence that frontal eye field tDCS affects latency or accuracy of prosaccades

Transcranial direct current stimulation (tDCS) may be used to directly affect neural activity from outside of the skull. However, its exact physiological mechanisms remain elusive, particularly when applied to new brain areas. The frontal eye field (FEF) has rarely been targeted with tDCS, even though it plays a crucial role in control of overt and covert spatial attention. Here we investigate whether tDCS over the FEF can affect the latency and accuracy of saccadic eye movements. 26 participants performed a prosaccade task in which they made eye movements to a sudden-onset eccentric visual target (lateral saccades). After each lateral saccade, they made an eye movement back to the center (center saccades). The task was administered before, during and after anodal or cathodal tDCS over the FEF, in a randomized, double-blind, within-subject design. One previous study (Kanai et al., 2012) found that anodal tDCS over the FEF decreased the latency of saccades contralateral to the stimulated hemisphere. We did not find the same effect: neither anodal nor cathodal tDCS influenced the latency of lateral saccades. tDCS also did not affect accuracy of lateral saccades (saccade endpoint deviation and saccade endpoint variability). For center saccades, we found some differences between the anodal and cathodal sessions, but these were not consistent across analyses (latency, endpoint variability), or were already present before tDCS onset (endpoint deviation). We tried to improve on the design of Kanai et al. (2012) in several ways, including the tDCS duration and electrode montage, which could explain the discrepant results. Our findings add to a growing number of null results, which have sparked concerns that tDCS outcomes are highly variable. Future studies should aim to establish the boundary conditions for frontal eye field tDCS to be effective, in addition to increasing sample size and adding additional controls such as a sham condition. At present, we conclude that it is unclear whether eye movements or other aspects of spatial attention can be affected through tDCS of the frontal eye fields.

neuroscience↗

bioRxiv2017

Cross-task contributions of fronto-basal ganglia circuitry in response inhibition and conflict-induced slowing

Why are we so slow in choosing the lesser of two evils? We considered whether such slowing relates to uncertainty about the value of these options, which arises from the tendency to avoid them during learning, and whether such slowing relates to fronto-subthalamic inhibitory control mechanisms. 49 participants performed a reinforcement-learning task and a stop-signal task while fMRI was recorded. A reinforcement-learning model was used to quantify learning strategies. Individual differences in lose-lose slowing related to information uncertainty due to sampling, and independently, to less efficient response inhibition in the stop-signal task. Neuroimaging analysis revealed an analogous dissociation: subthalamic nucleus (STN) BOLD activity related to variability in stopping latencies, whereas weaker fronto-subthalamic connectivity related to slowing and information sampling. Across tasks, fast inhibitors increased STN activity for successfully cancelled responses in the stop task, but decreased activity for lose-lose choices. These data support the notion that fronto-STN communication implements a rapid but transient brake on response execution, and that slowing due to decision uncertainty could result from an inefficient release of this \"hold your horses\" mechanism.

neuroscience↗