The Brain: Special Functions In the text below you will find a summary of how the brain performs select functions. Because you have a step by step outline of each function, I expect you to illustrate each step with your model of the brain. You do not need to make a new model for each step. Simply alter the original model and take a picture of it at each step. You will use pieces of pipe cleaner to represent the traveling signals. If you need assistance consult the website first. If you still need assistance ask one of the teachers and they’ll gladly help you. In your descriptions be sue to verbally identify the necessary parts as there are no physical labels in addition to describing the steps. You also might want to reiterate the primary functions of the parts of the brain mentioned in addition to the lobes (if known). http://www.msnbc.com/modules/brain/ Fear Factor (emotional response): You see a spider. The first thing that happens is the visual stimuli are sent to the thalamus. The thalamus sends emotional stimuli to the amygdala and the frontal cortex. The emotional stimuli is sent to the cortex for processing. This is where the emotion is identified as fear. The emotional stimuli is also sent to the amygdale because it helps produce another signal that will lead to changes in the body. Before processing of the stimuli in the cortex is complete, the amygdale sends a signal through the hypothalamus to the body generating a response to the fear (even though we don’t know that we’re afraid yet). The changes that occur can include an increase in heart rate, perspiration, an adrenaline rush, etc. These effects are fed back through the frontal cortex and are interpreted as a fearful response to the spider. In other words, the signal for the body to respond to the fear is sent before the emotional stimuli is identified as fear. Memory The hippocampus encodes a memorable experience and stores it as a neural pattern in the cortex (at the back of the heard). In other words the experience is replayed in the occipital lobe (visual area). It flows from the hippocampus through the occipital lobe and back to the hippocampus. Replaying the pattern of events or info helps to etch it into the brain more deeply (That’s why they say practice makes perfect). During dream sleep the hippocampus replays the experience or info in unusual orders (patterns).This is part of the imprinting process, which is how the brain puts information into long-term memory. These snippets of information are replayed through the frontal cortex back to the hypothalamus and out to the frontal lobe again. Once info has been encoded/imprinted into long-term memory the frontal cortex can retrieve the memory without using the hippocampus.
Senses A green light stimulates the retina, which sends neural signals to the thalamus. The thalamus sends signals to be processed in the visual cortex (occipital lobe), beginning with perception of simple forms, edges, and corners then finally progressing to an interpretation of the image. Next the signal is sent from the visual cortex to the prefrontal cortex where it registers the object as a green light and the command is given for the foot to press on the car’s accelerator pedal. But first this command is sent to the motor cortex (parietal lobe) for processing. Then it is sent down through the spinal cord to the foot.