At only three millimeters in thickness it is amazing what researchers and we as a society have found that the cerebral cortex can do, especially when it comes to cognitive functions and processing. The occipital lobe, temporal lobes, parietal lobe, and frontal lobes compose the cerebral cortex and how they come together through localization of function and bottom-up processing is profound in such a way that it’s crazy to think that it controls everything I am doing while writing this blog post. Without it we’d be lost, literally. Let’s take a look inside of these lobes and make the connection between the cerebral cortex and bottom-up processing.
While there are four different lobes of the cerebral cortex researchers have found that each has their own significant contribution to cognitive function and this is what we call localization of function. Our textbook Cognitive Psychology: Connecting Mind, Research, and Everyday Experience explains these lobes in depth. The occipital lobe is the first area that processes vision, its main job is to receive information through our eyes and send signals (action potentials) to our brain. The temporal lobes are responsible for taking in audition and also for recognizing faces and different objects. The parietal lobe has the job of processing sensory information like touch, heat, cold, and pain. The frontal lobes have three different areas called the motor cortex, premotor cortex, and the prefrontal cortex. All three of these areas work together to plan, coordinate, and execute our voluntary movements and fine motor control (Goldstein, 2011). Together the different lobes of the prefrontal cortex work together to take in and perceive through different receptors leading me up to my next topic, bottom-up processing.
The term bottom-up processing is used when we discuss perception. The brain has two ways of processing and perceiving information and that is bottom-up and top-down processing. Although top-up processing is very interesting and important I would like to make the connection to the different lobes of the cerebral cortex and bottom-up processing since they are directly connected. The occipital lobe is the area that processes vision and in bottom-up processing that is the very first stage. Bottom-up processing starts with information, or energy, from our environment and converting it into action potentials that transmit to the brain, this is called transduction. Our eyes take in this environmental energy and our occipital lobe is responsible for building a visual map or representation of our surroundings before the environmental energy can be converted to action potential in order for our brain to remember. From the minute we wake up to the minute we go to sleep our cerebral cortex is working hard to help create the signals that go to our brain to help us perceive and remember information and that brings me to this amazing article I read on the cerebral cortex that was published in Neuroinformatics, a cognitive psychology/scientific journal.
The article titled The Small World of the Cerebral Cortex was very interesting and it opened up my eyes to this whole world that really controls almost everything we do from seeing, to sleeping, to eating, to remembering familiar faces, and even how we navigate from place to place whether we are walking, driving, or riding a bike. In the article they talked about cortical neurons in the cerebral cortex and how they create these maps and pathways and help in two different functions, one of them being the integration of various sources of information to include environmental energy, into “coherent behavioral and cognitive states” (Sporns and Zwi, 2004). This specifically relates to perception and bottom-up processing starting in our occipital lobe using vision to take in the information in our surroundings and using these neurons to create the action potential like we talked about earlier that helps us recognize and store information into groups so that we have a way of shaping our views and perceptions. It’s amazing to think that all of this occurs without a voluntary notion every nanosecond of our existence.
The cerebral cortex is an amazing machine composed of the various lobes discussed earlier and without them we wouldn’t be able to perceive and store the information necessary to do things like our daily activities or remembering how we get from home to work without using a map every time. This is just scratching the surface of what we are capable of doing and how the localization of function separates the responsibilities into the different areas of the brain. Think about the last time you thought about telling your brain to convert environmental energy into action potentials.
References
Goldstein, B. E. (2011) Cognitive psychology: Connecting Mind, Research, and Everyday Experience. Belmont, CA: Wadsworth-Cenage.
Sporns, O., & Zwi, J. D. (2004). The small world of the cerebral cortex. Neuroinformatics, 2(2), 145-162. doi:10.1385/NI:2:2:145