The effects of incidentally learned temporal and spatial predictability on response times and visual fixations during target detection and discrimination.

Melissa R Beck,Amanda E Van Lamsweerde,S Lee Hong,Justin M Ericson

doi:10.1371/journal.pone.0094539

Melissa R Beck, Amanda E Van Lamsweerde + Show 2 more

Open Access

https://doi.org/10.1371/journal.pone.0094539

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Journal: PloS one	Publication Date: Apr 14, 2014
Citations: 47	License type: CC BY 4.0

Affiliation: Louisiana State University, Ohio University

Abstract

Responses are quicker to predictable stimuli than if the time and place of appearance is uncertain. Studies that manipulate target predictability often involve overt cues to speed up response times. However, less is known about whether individuals will exhibit faster response times when target predictability is embedded within the inter-trial relationships. The current research examined the combined effects of spatial and temporal target predictability on reaction time (RT) and allocation of overt attention in a sustained attention task. Participants responded as quickly as possible to stimuli while their RT and eye movements were measured. Target temporal and spatial predictability were manipulated by altering the number of: 1) different time intervals between a response and the next target; and 2) possible spatial locations of the target. The effects of target predictability on target detection (Experiment 1) and target discrimination (Experiment 2) were tested. For both experiments, shorter RTs as target predictability increased across both space and time were found. In addition, the influences of spatial and temporal target predictability on RT and the overt allocation of attention were task dependent; suggesting that effective orienting of attention relies on both spatial and temporal predictability. These results indicate that stimulus predictability can be increased without overt cues and detected purely through inter-trial relationships over the course of repeated stimulus presentations.

Highlights

Attention can be more efficiently oriented if it is known when and where potential targets will appear (e.g., [1][2])
Temporal and spatial predictability led to faster responses to the target, supporting the hypothesis that participants were capable of determining target predictability based on the inherent pattern of presentation
Spatial predictability allowed participants to visually fixate on the target location prior to its onset

Summary

Introduction

Attention can be more efficiently oriented if it is known when and where potential targets will appear (e.g., [1][2]). The more unpredictable the stimulus, the more information that needs to be processed prior to the response and the slower the reaction times (RT). This general effect has been seen in both RT (cf [4][5]) and movement time (cf.[6]). Overt and explicit cues that increase the predictability of when and where a target will appear decrease the amount of information to be processed and RT. What is less understood is the extent to which temporal and spatial predictability can be incidentally learned through inter-trial relationships

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