Uncertainty Compensation in Human Attention: Evidence from Response Times and Fixation Durations

Abstract

BackgroundUncertainty and predictability have remained at the center of the study of human attention. Yet, studies have only examined whether response times (RT) or fixations were longer or shorter under levels of stimulus uncertainty. To date, no study has examined patterns of stimuli and responses through a unifying framework of uncertainty.Methodology/Principal FindingsWe asked 29 college students to generate repeated responses to a continuous series of visual stimuli presented on a computer monitor. Subjects produced these responses by pressing on a keypad as soon a target was detected (regardless of position) while the durations of their visual fixations were recorded. We manipulated the level of stimulus uncertainty in space and time by changing the number of potential stimulus locations and time intervals between stimulus presentations. To allow the analyses to be conducted using uncertainty as common description of stimulus and response we calculated the entropy of the RT and fixation durations. We tested the hypothesis of uncertainty compensation across space and time by fitting the RT and fixation duration entropy values to a quadratic surface. The quadratic surface accounted for 80% of the variance in the entropy values of both RT and fixation durations. RT entropy increased as a function of spatial and temporal uncertainty of the stimulus, alongside a symmetric, compensatory decrease in the entropy of fixation durations as the level of spatial and temporal uncertainty of the stimuli was increased.Conclusions/SignificanceOur results demonstrate that greater uncertainty in the stimulus leads to greater uncertainty in the response, and that the effects of spatial and temporal uncertainties are compensatory. We also observed compensatory relationship across the entropies of fixation duration and RT, suggesting that a more predictable visual search strategy leads to more uncertain response patterns and vice versa.

Action anticipation beyond the action observation network: a functional magnetic resonance imaging study in expert basketball players

“…This result is in line with our previous research (Aglioti et al. , 2008) and with studies showing a relationship between stimulus and response uncertainty (Hong & Beck, 2010). Moreover, expert overall performance in anticipating an action (in the expert’s domain of expertise) is superior to that of novices.…”

Altered Neural and Behavioral Dynamics in Huntington's Disease: An Entropy Conservation Approach

“…Our findings support this single-resource viewpoint of the brain, albeit inferred, based on the patterns of brain and behavior. Our results suggest, however, that behavioral patterns could serve as a proxy measure for altered input-output relationships [8] that are reflective of changes occurring across the entire brain with constant entropy [5] , [6] .…”

Biological sources of inflexibility in brain and behavior with aging and neurodegenerative diseases

“…The combined effects of task and environment systematically alter the unpredictability contained at the level of behavior. As demonstrated both in muscle force control (Hong and Newell, 2008a,b) and visual search and cognitive responses (Hong and Beck, 2010), difficult tasks and unpredictable environments resulted in predictable patterns of behavior. These studies demonstrated that patterns of variability changed systematically with the demands of the task and environment.…”

“…The concept of entropy conservation developed for brain activation (Smotherman et al, 1996; Mandell and Selz, 1997) and behavior (Hong and Newell, 2008a,b; Hong and Beck, 2010) argued that adapting to different behavioral demands or environmental changes was the result of the redistribution of entropy or unpredictability. Our animal LFP data provided evidence of entropy conservation across brain and behavior.…”