Biology subjects

Bertrand, J. K.

Publications and source records attributed to Bertrand, J. K..

4 recordsLinked to original sources

bioRxiv2023

Continuous Measures of Decision-Difficulty Captured Remotely: I. Mouse-tracking sensitivity extends to tablets and smartphones

As decisions require actions to have an effect on the world, measures derived from movements such as using a mouse to control a cursor on a screen provide powerful and dynamic indices of decision-making. In this first of a set of two studies, we replicated classic reach-decision paradigms across computers, tablets, and smartphones, we show that portable touch-devices can sensitively capture decision-difficulty. We see this in pre- and during-movement temporal and motoric measures across diverse decision domains. We found touchscreen interactions to more sensitively reflect decision-difficulty during movement compared to computer interactions, and the latter to be more sensitive before movement initiation. Paired with additional evidence for the flexibility and unique utility of pre- and during-movement measures, this substantiates the use of widely available touch-devices to massively extend the reach of decision science. We build upon this in the second study in this series (Bertrand et al., 2023) with the use of webcam eye-tracking to further elucidate, earlier in time, the decision process. This subsequent work provides additional support for tools that enable remote collection of rich decision data in ecologically-valid environments.

neuroscience↗

bioRxiv2023

Continuous Measures of Decision-Difficulty Captured Remotely: II. Webcam eye-tracking reveals early decision processing

As decisions require the gathering of relevant information, eye-tracking measures that capture the way visual information is typically acquired offer powerful indices of the dynamic decision-making process. This study is the second of a pair of studies that explore continuous measures of decision-making using remote, online tools in naturalistic settings. While cursor-tracking, used in the companion paper (Ouellette Zuk et al., 2023), enabled access to dynamic decision processes expressed during movement, in the present study, we now employ webcam eye-tracking to examine the dynamics of information gathering during decision making prior to movement initiation. Using three previously published binary choice tasks, we explored indices of decision difficulty in the gaze dynamics that would complement the motor measures in our companion paper. We find that harder choices elicit more eye dwells and longer final dwells, reflecting a decision resolution process that Ouellette Zuk et al. index during the final choice movement. Beyond this, we identify distinct gaze patterns uniquely employed in each task, revealing the utility and sensitivity of gaze metrics in illuminating the early difficulty-independent information gathering processes at play. Together, this paper series demonstrates the power of remote, online methods as tools for deeply understanding the complete, dynamic and continuous decision process, from the first glance to the final response.

neuroscience↗

bioRxiv2020

Reaching for known unknowns: Rapid reach decisions accurately reflect the future state of dynamic probabilistic information

Everyday tasks such as catching a ball appear effortless, but in fact require complex interactions and tight temporal coordination between the brains visual and motor systems. What makes such interceptive actions particularly impressive is the capacity of the brain to account for temporal delays in the central nervous system--a limitation that can be mitigated by making predictions about the environment as well as ones own actions. Here, we wanted to assess how well human participants can plan an upcoming movement based on a dynamic, predictable stimulus that is not the target of action. A central stationary or rotating stimulus determined the probability that each of two potential targets would be the eventual target of a rapid reach-to-touch movement. We examined the extent to which reach movement trajectories convey internal predictions about the future state of dynamic probabilistic information conveyed by the rotating stimulus. We show that movement trajectories reflect the target probabilities determined at movement onset, suggesting that humans rapidly and accurately integrate visuospatial predictions and estimates of their own reaction times to effectively guide action.

neuroscience↗

bioRxiv2017

Entrainment of theta, not alpha, oscillations is predictive of the brightness enhancement of a flickering stimulus

Frequency-dependent brightness enhancement, where a flickering light can appear twice as bright as an equiluminant constant light, has been reported to exist within the alpha (8 - 12 Hz) band. Could oscillatory neural activity be driving this perceptual effect? Here, in two experiments, human subjects reported which of two flickering stimuli were brighter. Strikingly, 4 Hz stimuli were reported as brighter more than 80% of the time when compared to all other tested frequencies, even though all stimuli were equiluminant and of equal temporal length. Electroencephalography recordings showed that inter-trial phase coherence (ITC) of theta (4 Hz) was: 1) Significantly greater than alpha, contralateral to the flickering stimulus; 2) Enhanced by the presence of a second ipsilateral 4 Hz flickering stimulus; and 3) Uniquely lateralized, unlike the alpha band. Importantly, on trials with two identical stimuli (i.e. 4 Hz vs 4 Hz), the brightness discrimination judgment could be predicted by the hemispheric balance in the amount of 4 Hz ITC. We speculate that the theta rhythm plays a distinct information transfer role, where its ability to share information between hemispheres via entrainment promotes a better processing of visual information to inform a discrimination decision.

neuroscience↗