by Julia Wynne, MA, CCC-SLP (Speech-Language Pathologist); NWACS Board Member

Adults with severe Traumatic Brain Injury (TBI) often have significant long-term difficulties with functional communication. AAC may be a way to effectively supplement or replace impaired communication skills. It is important that AAC for these individuals is easy to learn, but also can address a wide array of communication needs. Two ways that AAC systems can be presented are explored in this study: grid displays versus visual scene displays. When using a grid display, individuals find and put together a string of words to create a message, which might involve navigating through folders to locate a symbol. Visual scene displays include pictures showing situations, experiences, and events. Learn about what the researchers found out about the differences between the use of these displays for adults with TBI below!

Below you will find definitions of some key terms. Keywords will be bolded throughout the blog. You’ll then find the research questions, the importance of the research and a summary of the findings, followed by the most important takeaways from the research article. Enjoy!

Identification and Expression of Themes Depicted in Visual Scene and Grid Displays by Adults With Traumatic Brain Injury

Cognitive Load: since the brain can only do so many things at once, we should be intentional about what we ask it to do

Contextualized Images: a picture with a background showing a naturalistic event

Decontextualized Images: the picture of an object, person, place with no other information or background

Grid Displays: icons and photos are organized into rows and columns of individual cells each representing a word or concept

Visual Scene Displays: real-life photos or pictures that people can use to communicate messages to others by selecting hot spots on the screen with stored messages

1. Do individuals with TBI better identify the gist of themes using a grid display or visual scene display?

2. What are the patterns of response for producing nouns versus verbs on each of the displays?

The use of decontextualized images in a grid display, as well as navigating through pages of an AAC display can be overwhelming for an individual with a TBI since the brain can only do so many things at once. One way to reduce this cognitive load is to group icons on a grid display based on themes, but it may still be difficult to identify symbols and combine them to make a message. The use of contextualized images allows for the creation of clear messages, which might be easier for an individual with a TBI because it is shown in a naturalistic scene. This study looked more deeply into how individuals with TBI view visual information to figure out what theme a grid display or visual scene display is showing. This information is vital to determine which AAC displays might be most appropriate for an individual with a TBI.

13 individuals with a TBI and 13 individuals without a TBI participated in the study. The grid displays consisted of 12 cells arranged in a 3x4 grid. The pictures showed an object or human figure with no background. The visual scene displays showed a naturalistic photo of human figures looking at and touching relevant objects in the environment. Each grid and picture demonstrated themes with which the participants would have had either direct or indirect experience.

The experiment consisted of three phases: 1. Training and practice, 2. The experimental task, 3. Follow-up questionnaire and discussion. When the participants were shown the grid or the visual scene, they were asked to verbally state the themes shown in the pictures presented. Measures were recorded including accuracy on identifying the theme, total viewing time, elicited response type (i.e., naming/action messages), and a theme likeness rating (i.e., whether the participant agreed with the theme that the researchers used).

Results showed that individuals with and without TBI identified visual scenes with higher accuracy than grids. Both groups took less viewing time to identify visual scenes compared with grid displays. Both groups produced more naming responses when shown with grids, and action responses when shown visual scenes.

It is important that clinicians working with individuals with TBI design AAC displays that reduce the cognitive effort that it takes to use them. The current study demonstrated that the themes depicted in visual scenes were more accurately and more quickly identified than grid displays. Participants responded more frequently with verb phrases to visual scenes and with noun phrases to the grid display. Clinicians should therefore consider using visual scene displays to represent verbs and actions for their clients.

People with TBI often have difficulty determining a gist or theme. When presented with a grid display, it might be more difficult to infer the theme based on separate symbols. The connection between objects in visual scenes may be more obvious since it is shown in context. Reducing the cognitive load of figuring out the gist could also lead to decreases in new learning and memory demands.

One noted limitation was that the simplicity of the scenes used in the study may not match actual conversational topics. Another limitation is that the individuals with TBI that participated in the study did not rely on AAC for communication. The researchers did not want the participants to be exposed to the displays being introduced. Also, part of the study included verbal expression and a discussion about their opinion. However, this research should be replicated with the target population.

Please comment below with any thoughts or questions!  

Full article link:  https://doi.org/10.1044/2018_AJSLP-18-0086

Images include Boardmaker PCS. The Picture Communication Symbols ©1981–2018 by Mayer-Johnson LLC. All Rights Reserved Worldwide. Used with permission.

Reference:

Thiessen, A., Brown, J., Freeland, T., & Brewer, C. H. (2019). Identification and Expression of Themes Depicted in Visual Scene and Grid Displays by Adults With Traumatic Brain Injury. American Journal of Speech-Language Pathology, 28(2), 664-675. doi:10.1044/2018_ajslp-18-0086

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