Comprehension Deficits after Brain Injury

Comprehension Deficits Are the Big Picture Stuff

Newer research and better assessment is informing the connection between brain injury and comprehension deficits.

By Rebecca Martin

Today I would like to explore what we are learning about the comprehension deficits in those with mild brain injury.

“I have read the same page 3 times and still can’t remember what I just read.”

What if those words were not just an occasional incident but an integral part of your daily life? Think of how many times in the course of a week we are reading or hearing directions to perform a task, listening to or reading the plot line in a film or book, or even following directions to get to the right menu when making a phone call. In the age of technology we often find ourselves struggling to follow directions amidst either internal or external distractions. But imagine being unable to comprehend those instructions in a situation in which focus is not compromised.

Spoken and written language is an area of study which is being explored now more than ever. In regard to language and brain injury–we are finding that older ways of measuring deficits do not adequately assess the way problems with comprehension are impacting the brain injury community in a very real way. We are also learning that many types of problems with comprehension were previously unreported to professionals as brain injury survivors struggled to cope with the loss of skills which they had prior to injury. The brain injured student who had to work harder than his classmates to understand lectures or reading was unlikely to understand that brain injury was responsible for this struggle. And previously, even if one suspected that there was a significant connection between comprehension deficits and the brain injury, traditional tests for deficits revealed little correlation between the two.

We are gaining more knowledge about the function of the brain and what areas are involved in the myriad of cognitive functions in the brain.

“According to the American Speech-Language-Hearing Association (ASHA), patients with traumatic brain injury may experience difficulties in finding words to express themselves or in understanding an idea through speech, writing, and/or reading.” https://www.intechopen.com/chapters/45951

For more about brain damage after carbon monoxide poisoning, click here. 

Language itself is our primary way of sharing ideas and information. We use our ability to utilize speech, reading and writing in every aspect of our lives from work and school to leisure activities and relationships. Accompanying the mechanics of language itself is a whole range of other cues that we use to enhance the exchange of language. These can be in the form of gestures, visual cues, intonation, facial expressions and other related cues which we decipher and utilize to understand that which is presented to us. We are able to discern nuances in speech which tell us if the speaker is being literal, joking or sarcastic.

The nuances of communication can be compared to a television show which before the break leaves us hanging with a look at what is coming up. We are given a small snippet of a conversation which promises a shocking plot twist only to come back after the break and realize that the entire conversation was not so spectacular. We merely comprehended the words in one way out of context and in another way in context. However, if we only had a takeaway of the words out of context we would have a very skewed understanding of what actually transpired. Only by understanding the totality of the information presented to us can we properly utilize the information.

The whole area of language (which most of us take for granted) it is a highly complex system. Language itself has rules. Letters have meaning. Sentences are constructed certain ways. Words are affected by time, gender, and even emotional connections which we acquire from the day we are born. Think of the rules one must learn when learning another language. We must learn present, past and future tenses, We must learn which nouns are feminine and masculine. We also learn social rules associated with language; which words are acceptable, what we say in the presence of others, etc.

Human language is amazing. Whether sharing a recipe for banana bread or an idea to end cancer forever, language is the basis for our entire civilization.

The Focal Geography of Comprehension

Understanding comprehension problems after brain injury requires more than a focus on narrow focal parts of the brain but the ways in which the entire brain integrate information in daily life.

The main areas responsible for speech and language in the brain are located in the left hemisphere of the brain. The Broca is located in the frontal lobe and is responsible for language processing. Memories, meaning and motions combine to help us comprehend what we are seeing or hearing. Language is decoded in the Wernicke area located close to the Broca. Through perception, comprehension and other nuances of language this are helps us “translate” the lingual input to the brain. The motor cortex connects the two hemispheres of the brain through neural pathways thus allowing for visual and spatial input to travel to the decoding centers and back to make speech possible. But the brain is more complicated than that. When looking at the comprehension of the spoken word vs the written word and then to the act of communicating through the spoken or written word, the comprehension of language must be broken down into more distinct topics.

Comprehension Begins Before Birth

We begin learning language before we are born. Studies have shown that babies will mimic in their cry patterns the melodical nuances of the dialect they are being born into. (Mampe, B., Friederici, A. D., Christophe, A., and Wermke, K. 2009.) The cries of German babies were compared to the cries of French babies and distinct differences were found. Babies also develop the Fusiform Gyrus portion of the brain very early on in a direct response to facial recognition cues. The Fusiform Gyrus is the facial recognition center of the brain but it also plays a role in our comprehension of the written language. Written language co-opts this area as we learn to recognize words like a visual dictionary where they are stored as shapes and sounds basically. A study at the Georgetown University Medical Center revealed that whether we speak a word out loud or silently, the same neurons are fired indicating that we do not separate the audio of a word from the word itself. If we are given a nonsense word, different neurons are fired but once we are familiarized with the nonsense word, it falls into the same category as previously learned words. https://www.scientificamerican.com/article/when-we-read-we-recognize-words-as-pictures-and-hear-them-spoken-aloud/

So, rather than acquiring language in terms of a complicated system for deciphering the alphabet, we are storing the actual visual appearance and sound of each word, individually. And to make it more complicated, we are storing words that appear and sound the same separately based on meaning. A word such as ‘shell’ can apply to a snail, a bomb, or the act of peeling peas. In this instance we are identifying the context and application of the word as well. Our brains are actually shuffling through the list of possibilities to capture the nuance of the word and its intended meaning. When a brain injury effects our ability to comprehend language in any form it can have far-reaching implications. It does not impact just the ability to follow directions or understand language in the written or spoken form, it can impact other areas of daily functioning. It might affect the ability to drive or perform other tasks. This is one kind of comprehension deficit.

Research into Comprehension Deficits

One study revealed that those post-MTBI had problems with high-level language and general language performance which could potentially affect their performance in higher level jobs. https://pubmed.ncbi.nlm.nih.gov/23611468/

Another study looked at comprehension deficits in the criminal justice system. It found that those with TBI underperformed in both accuracy and speed when presented with legal language. This appears to indicate that those with a previous moderate to severe TBI might be less able to navigate the legal system effectively. https://pubmed.ncbi.nlm.nih.gov/30169438/

A look into social-legal functioning of adults with a former moderate to severe brain injury revealed that TBI survivors underperformed in comprehending precautionary rules as well as social-exchange rules. https://pubmed.ncbi.nlm.nih.gov/31192655/ Because there is a high incidence of a former TBI in the prison population, the inability to completely understand precautionary rules and the inability to comprehend the legal verbiage could possibly explain a link to higher incarceration.

Visual problems after brain injury can cause comprehension deficits. The inability to focus correctly or change focus from near to far, eyes not working together and creating double vision, and problems with eye movements may impact one’s ability to read.  Other comprehension deficits may stem from a partial or full loss of vision, headaches, motion sensitivity and light sensitivity. Individuals with Post Trauma Vision Syndrome (PTVS) may perceive the words on a page as individual letters. For many types of vision problems after brain injury orthoptic therapy is beneficial.

Aphasia – Language Comprehension Deficits

Damage to the language centers of the brain leads to a condition called aphasia. The main two forms of aphasia are receptive aphasia and expressive aphasia.

Receptive aphasia is an impairment of the understanding of language. It is the result of damage to Wernicke’s area of the brain.

In its most severe form, the person will not recognize spoken and/or written words. They will not be able to understand sentences or follow conversations. However, usually people will retain some understanding. For example, the person may recognize some but not all words, or simple but not complex sentences. It may be that familiar words still have meaning (e.g. pill), but that less frequently used words are no longer understood (e.g. medication). https://www.headway.org.uk/about-brain-injury/individuals/effects-of-brain-injury/communication-problems/language-impairment-aphasia/

Damage to the Wernicke’s area may also affect the speech output. Sentences may not make sense, words may be misused or made up. The person thus affected may be unaware that what they are saying is not making sense and be confused by the response they receive.

Expressive aphasia refers to an impairment in the ability to use and express language. This occurs as a result to damage to the Broca’s area of the brain.

Comprehension deficits on any level can be difficult on those with TBI. Instructions to decrease  distractions, taking time to analyze what has been presented, re-reading material, taking notes, and asking people to repeat themselves is often not possible in real life. The student in the classroom asking for the instructor to repeat himself is not looking at a realistic accommodation to his/her deficits. And ultimately the reactions of those around the person are likely to be impatience and a view that the person is mentally impaired. This response to a diminished comprehension speed will result in self-doubt and possibly depression. In the workforce this inability to immediately understand directions could mean the loss of a job.

It certainly leads to a loss in productivity as more time is spent struggling to understand instructions, especially in a world which cites diminishing attention spans as a reason to speed up. The general public has also had concerns about information overload since the 70s. And now we worry about the proliferation of fake news as the internet magnifies the amount of information available on any topic we can imagine.  This has resulted in the proliferation of simplistic ways of addressing the amount of information we are faced with shortcut devices such as memes. This information is quickly and easily passed along multitudes of times and impact what we think of important issues.

Nowhere was this so evident as during the pandemic when conspiracy theorists propagated information which lead to the unnecessary deaths of thousands. Countless people were impacted by snippets of information denying the pandemic and failed to look any farther. This becomes a very dangerous world for those with diminished comprehension skills who may not understand other preventative measures for safety.

Many of the problems associated with comprehension impairments go unnoticed and untreated. We are all expected to just “keep up”. When we fail to do so, then it is seen as a testimony to our lack of intelligence. But damage to these very small areas in the brain is not a reflection on one’s intelligence. With the advancements in speech and language therapies many of these comprehension deficits can be improved and sometimes overcome.

Pure alexia is the name for a condition which impairs a person’s ability to comprehend the written word. Pure alexia can occur after a brain injury or repeated brain injuries such as those one might experience in sports. One therapy for pure alexia involves a restart in the learning process by going back to basics and repeating the processes learned in childhood. For severe brain injuries, integrating tactile learning can help rebuild neural connections in order to recover the ability to read. Other strategies involve reading out loud daily an assigned text to help the brain recover. This ability to repair neural pathways is referred to as neural plasticity. The ability of the brain to modify itself is what enables us to mature from infant to adult. Many therapies involve steps which retrace our previous development in order to repair or create neural pathways. In cases where such a process is ineffective, there are devices available to render communication into other forms when only one impairment exists. They can translate the written word into the spoken word, for instance.

There is insufficient information about comprehension deficits in those with TBI available. Comprehension deficits are misunderstood subsequent to brain injury, despite it being terribly significant. If one can visualize the student attempting to memorize reading materials that he/she is also having trouble comprehending we can see that it is a very valid and impactful impairment. It is also a dangerous impairment when one fails to comprehend precautionary instructions on the job, resulting in further and perhaps deadly injuries.

It is also impactful on the ability to navigate the daily tasks of living in the modern world where we are more likely to encounter recorded or written instructions. Navigating simple things like automated banking, the new gas pumps at your favorite station or a phone menu which prompts us ever onward to address a concern over an account. In such situations, we are expected to immediately process and comprehend more and more information throughout the day. The inability to navigate life successfully often leads to anxiety and ultimately depression which can further impact the symptoms. The downward spiral of these interacting factors can lead to serious results.

Much of the human experience is based on our ability to exchange information and ideas effectively in order to understand the world in which we live. In order to fully utilize the information we receive every day we must first comprehend that information. It is not enough for the brain to just perceive information; it must integrate that information in a way in which it is comprehended and then utilized. As research begins to focus on the entire process, rather than a discrete narrow injury, we may move towards therapies where a lifetime of recovery from brain injury is possible.