The Role of the Thalamus in Attention, Memory, and Consciousness

The brain is a special organ with nervous tissues that help us feel, move, and think. But did you ever wonder if the nervous tissue could be damaged easily? Actually. we are all made different, but we all have this round-shaped head protected by the skull,  fluid, and other muscles.

Let me put it this way – your central nervous system has two parts. And any science student will know this, they are called the central and the peripheral. If you’re thinking “Well, which part has what?”, here is the answer. CNS includes the brain and spinal cord, while the peripheral has everything else. 

The spinal cord is an important part of the CNS and carries sensory signals from the brain to the rest of the body and relays information. This whole structure has always been very surprising to me. Maybe that’s why I find it equally interesting to explore and study about. In fact, many professors and scientists also marvel at how the spinal cord in the spinal column is safeguarded by bones, meninges, and cerebrospinal fluids. It’s like someone wanted these to be protected – for humans to survive. Here comes the role of Thalasmus.

“The thalamus acts as the grand central station of our brain, directing sensory and motor signals to various cortical destinations. Its pivotal role in attention is like that of a conductor, ensuring that our focus is precise and timely,” states Dr. Alex Rivera, Neuroscientist.

I’ll First Explain the Connection between the Brain and Stimuli

The cortex, in turn, is divided into four parts, or lobes. Yes, if you think that’s too many, it is – and that’s how complex our brains are. In simple words, I would say, they are frontal, parietal, occipital, and temporal. Each lobe has specific jobs. Let me tell you about each one in detail.

• Frontal Lobe- It sits right in front of the brain. And this is what you should be thankful for if you are able to move, solve math problems, or even speak. It has areas like the motor cortex (for moving muscles) and the Broca area (for language).
• Parietal Lobe– It is found towards the back. It helps you process all that important information you keep in your head all day long. The somatosensory cortex is in the parietal lobe. It also helps us understand what we’re touching based on what we’ve felt earlier.
• Occipital Lobe– It’s all about vision. And it helps you understand the context. I’m sure you don’t just want to see it but also to put it in context right? If you ever wondered, “Wait, but this doesn’t seem right”, it’s because of the occipital lobe. It works in a manner that takes information from the eyes. It uses past experiences to understand what we see.
• Temporal Lobe– What if you could see and understand but not hear? Located on the sides, this lobe deals with hearing and processes sound. It also has the Wernicke area, which helps in understanding speech.

“Memory is not just about storage but about the integration of information. The thalamus, by its connectivity with the hippocampus, underlies our ability to not just remember, but to weave memories into our present consciousness,” says Professor Jamie Chen, Cognitive Science in an interview with Icy Whiz.

“The thalamus’s role in attention can be likened to a gatekeeper, determining what information is important enough to enter our conscious awareness. This selective gating is crucial for cognitive functions such as learning and memory.” Dr. Eric Zhang, a Neuropsychologist, corroborates.

So, each lobe has a special job in helping us move, think, see, and hear.

There have even been studies done on mice by MIT researchers. “By understanding how the thalamus controls the cortical output, hopefully, we could find more specific and druggable targets in this area, instead of generally modulating the prefrontal cortex, which has many different functions,” says Guoping Feng, the James W. and Patricia T. Poitras Professor in Brain and Cognitive Sciences at MIT, a member of the Broad Institute of Harvard and MIT, and the associate director of the McGovern Institute for Brain Research at MIT.

Here Is All You Need to Know About Thalamus

If you ever wondered why the human head is so round, I’ll tell you why. The thalamus is a roundish part in the middle of the human brain. It works like a relay station for all the messages about your body’s movement and senses, like hearing, taste, sight, and touch (but not smell). 

Now, before messages go to the outer layer of your brain (called the cerebral cortex), something else happens. For further processing, like more thinking and understanding, it passes through the thalamus. This is like a train passing through a station. Think of it like you’re going to the airport. You need to catch the flight, but you cannot do it without the security check, right?

The thalamus is found in the middle of your brain, right above the brain stem. Even though it may seem like one big part, you have two thalamines on each side of your brain. 

Picture it as the central hub of a bike wheel that you ride on. So, you have these nerve fibers – like spokes on the wheel. It connects to all parts of your brain’s outer layer – the cerebral cortex. The diencephalon consists of the hypothalamus, subthalamus, and epithalamus. And this is the part of the brain that consists of the thalamus. 

Functions of the Thalamus 

Relaying sensory information is one of the primary duties. Relay – that’s the word. And this is kind of all relay races that you have participated in. It takes in nerve signals from all your sensory organs (except smell). It then sends them to specific areas in your brain for processing, like auditory stimuli.

Another process is to relay motor functions (movement) information. Again, what you do know, you need to tell. Or else, you would be like “I know this, but does the person who needs to know this, know it?”. Like sensory info, the thalamus is a hub for movement-related motor pathways.

Also, the thalamus helps you prioritize your attention properly. It helps you decide what to focus on from the many things your senses pick up. It also plays a role in consciousness. It is what helps keep you awake and alert. Finally, it plays a part in your thinking (cognition) and memory. It’s connected to parts of your brain that handle emotions, memories, learning, and more.

In addition, the thalamus contributes to how you perceive things and has a role in your sleep and wakefulness.

Curious to Know How Does Thalasmus Work?

Your thalamus works like a traffic cop for information. Messages, called sensory impulses, travel from your body through nerve fibers to your thalamus.

The thalamus has special areas called nuclei. Each handles a specific type of information—like touch or sight. These nuclei process the messages. It then sends them through more nerve fibers to the right part of your brain’s outer layer (cerebral cortex) for understanding. 

But Have You Ever Thought What Would Happen If the Thalamus is Damaged? 

Your thalamus is like a central hub for information in your brain. It helps with senses and movement. If it gets damaged, it can affect many things. It’s like your car engine. “My car isn’t running without the engine!”. And that’s what will happen if the thalamus stops working as well.

So, if you forget things, don’t feel that interested about things, have trouble speaking or understanding, or even paying attention (not like in class, most of us have trouble with that), or even have trouble moving, you may want to go to a doctor. Interestingly, if you feel sleepy all the time or have chronic pain, it could be a symptom too.

And if you don’t get it checked, you could have sleep issues like insomnia. Or, a rare condition called fatal familial insomnia (which can be deadly). You could also have speech problems with mixed-up or meaningless words (thalamic aphasia). Some of us might even experience vision issues like loss of vision or sensitivity to light. But wait, what causes it? Science says that the main reasons for thalamus damage are strokes and tumors in the thalamus.

What Conditions Affect the Thalamus? 

For one, you have Fatal familial insomnia, which is an inherited disease related to a specific protein (prion). This affects a particular chromosome. People with this condition experience severe insomnia. They can also experience panic attacks, paranoia, phobias, hallucinations, and an inability to sleep. As it progresses, there can be rapid weight loss. Other symptoms include the onset of dementia and loss of the ability to speak.

Then, there is Creutzfeldt-Jacob disease and Fabry disease. These illnesses share a feature called the pulvinar sign. An MRI scan shows a change in density at the back (posterior) of the thalamus that looks like hockey sticks. Korsakoff syndrome, caused by alcohol, can damage a part of your brain. This part is called the mammillothalamic fasciculus, which extends into the thalamus.

Last Updated on May 20, 2024 by Pragya