Effects of Trait Media Multitasking on Dual-Task Performance
 
Student Researchers

Jian Cui (Graduate), Shardé Hardy (Graduate), Dev Minotra (Graduate)

This paper was based on a project as part of the COMM 506 course.

Faculty Supervisor

Dr. S. Shyam Sundar

Introduction

Generation Y is known to exhibit a trend shift in the way work is done and how different media are used. A recent psychological study on breadth bias in media multitasking has revealed that individuals with a stronger inclination to simultaneously consume multiple sources of media are more likely to be distracted while attending to a visual stimulus. Additionally, experiments also revealed that they suffered greater switch costs on an experimental task involving frequent switches in the nature of the task being performed.  These results provide a basis to understand how media multitasking may be associated to distraction susceptibility in real world tasks, however, experiments with better external validity need to be conducted to understand any such real world implications.

RESEARCH QUESTION / HYPOTHESES

Tasks in the real world can be diverse in nature, and different combinations of tasks in dual task settings can make the understanding of implications of an experimental result more complex. Our experiment employs a setting that may relate to operators of emergency response or security surveillance. The effective visual scanning of screen’s (Eg. CCTV or maps) may be a critical component of many such domains. However, the requirement of simultaneously dividing attention with an audio stimulus such as radio-chatter, or task-instructions that demand common and distinct cognitive resources, is important to consider.  Our study employs a setting in which participants (N = 57) perform a visual-search task and an audio listening task. Specifically, the study involves discovering a relationship between how breadth bias in media multitasking impacts one’s ability to operate in a dual task setting involving a listening task and a visual-search task. Hence, our general research question is formulated as follows:

RQ1:  For members of Generation Y, controlling for age and gender, what is the relationship between an individual’s multitasking inclination and performance on concurrent listening comprehension and visual search tasks?

The treatment condition required participants to perform the listening and visual-search tasks simultaneously, while the control condition required participants to perform these tasks sequentially. Although these tasks may demand distinct cognitive resources (auditory and visual working memory), some resources are likely to be in common, such as procedural and declarative memory. Hence, our first hypothesis reflects on the general difference in performance across the two conditions, which has been stated as follows:

H1:  Controlling for age, gender, and sequence of stimuli presentation, there will be a decrease in performance on the listening task in the experimental condition (multitasking), and most of this decrease in performance will be attributed to tests of recall.

A recent study found that for high media multitaskers, exhibit an additional cost associated to switching tasks frequently, due to the susceptibility of being distracted by irrelevant stimuli.  Hence, we formulated our second hypothesis as follows:
 
H2a: Controlling for age, gender and sequence of stimuli presentation, participants with higher media-multitasking traits will have a greater overall drop in performance on both tasks (visual and audio), in the treatment condition.

Also, individuals scoring high on the media-multitasking index may not be as focused as low media multitaskers on single-task settings of the study. This again is attributed to susceptibility towards distractions. Our third hypothesis is accordingly stated as follows:

H2b: Controlling for age, gender and sequence of stimuli presentation, higher media multitaskers will perform worse on the individual tasks in the control condition as compared to lower media multitaskers.

Method

The experiment consisted of 57 participants and they were assigned to two conditions based on how two stimuli are presented i.e. sequential or concurrent. Participants were given a questionnaire from which their media multitasking inclination was obtained, before beginning any task. The same questionnaire consisted of a 14-item polychronicity measure . The first task was a listening task for which participants were measured for their recall and recognition performance. The second task was a visual search task requiring participants to identify differences in juxtaposed pictures, or, searching for a specific item or person in a clutter of objects or a crowd.
Independent Variables Included: 
Media Multitasking Index (Continuous)
Condition (Nominal) – levels are Treatment and Control.
Dependent Variables Included:            
Listening Task Recognition Score (Continuous)
Listening Task Recall Score (Continuous)
Visual Search Task Score (Continuous)

Results

Hypothesis 1 was partially supported: It was expected that performance on all task measures would be worse in the treatment condition in comparison to the control condition, as a result ofcognitive load and interference with common cognitive resources. This was true for the recall and recognition components of the listening task. However, participants in the treatment condition performed significantly better on the visual-search task. One explanation to this finding may be provided by the ‘doodling effect’.

Hypothesis 2a was not supported:  Although we expected a particular interaction effect, our results revealed a different interaction effect supported by a marginal statistical significance. Individuals with high media multitasking scores in the treatment condition appeared to perform better on NPR recall. However, recall scores did not differ across media multitasking index in the control condition. 

Also, there was no significant variation in listening recognition scores across different values of the media multitasking scale, for both conditions - treatment and control.

The visual search task performance revealed a marginal interaction effect with a dichotomous variable obtained from the media multitasking index (high or low). Visual search performance was lower for high media multitaskers compared to low media multitaskers, in the control condition. This was an expectation from hypothesis 2b. Also, low media multitaskers performed nearly as good as high media multitaskers in the treatment condition. This indicates a ‘doodling effect’ where high media multitaskers seem to depend on a secondary task in order to cope up with a primary task.  This result does help explain a trend observed on the visual search task performance in the control condition. In that, higher media multitaskers perform worse on the visual search task, although, a larger sample size may be required to obtain statistical significance.
Hypothesis 2b stated that individuals scoring high on the media multitasking index would perform worse in the control condition on listening and visual search task scores. Hypothesis 2b was not supported, but may be supported partially with a larger sample size, due to an observed trend on the visual search task scores.

Conclusion

Given that the visual-search task performance was higher in the treatment condition, this may suggest that participants preferred the visual search task over the listening task in the treatment condition. An alternative explanation is a ‘doodling effect’ where high media multitaskers may have performed poorly in the control condition, while exhibiting the ability to cope up in the treatment condition in the presence of a secondary task.

Given that, it was observed that the control condition (overall) performed better than treatment on listening task scores, it does support the notion that performing two tasks simultaneously, deteriorates performance on individual tasks, due to higher cognitive load and conflict for common cognitive resources. Given that some resources demanded by each task, are distinct from each other, our results still maintain that, less interference does permit performing these tasks concurrently.

Our results may appear to come in conflict with a previous study on breadth bias in cognitive control. Given that high media multitaskers, are less effective in filtering irrelevant stimuli, and that they exhibit higher switch costs, their performance should have deteriorated in across conditions of the experiment. However, a higher breadth bias in consuming media (high media multitasking) may not always lead to attending to distractors. Given that we had two tasks in the treatment condition – a high breadth bias across the streams of media (the NPR recognition and scenes in visual search) may have led to better performance, where relevant information absorbed as a result of breadth bias may have inhibited a number of distractors, leading to the ability to cope in a dual task setting.  Research on the psychological ‘doodling effect’ may also be informed by the results of this study.

For more details regarding the study contact

Dr. S. Shyam Sundar by e-mail at sss12@psu.edu or by telephone at (814) 865-2173

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Media Effects Research Lab at College of Communications, Penn State University