Module 10: Complimentary Cognitive Processes – Sensation (and Perception)

Module Overview

Module 10 is the first of four modules which will cover cognitive processes that work in conjunction with, or are complementary to, learning. Our first topic will be sensation, and we will begin this discussion by covering the communication model of the nervous system, of which sensation is maybe the most important piece. We will also cover the neural impulse, perception and the brain, and sending commands out from the brain to the body via the peripheral nervous system. Do not worry. We will cover these topics at a very basic or introductory level.

Module Outline

• 10.1. Understanding Communication in the Nervous System
• 10.2. Sensation
• 10.3. The Neural Impulse
• 10.4. Perception: Adding Meaning to Raw Sensory Data
• 10.5. Sending Commands Out

Module Learning Outcomes

• Outline how communication occurs in the nervous system.
• Describe how the five sensory systems affect learning.
• Understand how the neural impulse occurs.
• Explain how brain structures and the process of perceptions aids us in learning associations in our environment.
• Clarify the importance of sending commands out to the body for learning. 
  

10.1. Understanding Communication in the Nervous System

Section Learning Objectives

• Revisit the definition of learning.
• Outline how communication in the nervous system occurs.
• Identify the parts of the nervous system.
• Describe the structure of the neuron and all key parts.

To begin our discussion of complimentary cognitive processes to learning, we will take a step back and discuss communication in the nervous system. Why is that? When we use the term learning or any relatively permanent change in behavior due to experience and practice, we must first detect something in our environment to learn about or from it. This is where sensation, the neural impulse, and perception and the brain come in. How so?

10.1.1. Communication in the Nervous System

Figure 10.1 gives us an indication of how the universal process of communication in the nervous system works regardless of race, gender, ethnicity, sexual orientation, religion, SES, or any other variable a person could be categorized into. Of course, there can be differences in how well our senses operate, our nervous system carries messages to and from the brain, and/or in how the brain processes the information. But that discussion is for another class.

Figure 10.1. Communication in the Nervous System

• A. Receptor cells in each of the five sensory systems detect energy. The detection of physical energy emitted or reflected by physical objects is called sensation. The five sensory systems include vision, hearing, smell, taste, and touch. We will discuss each briefly in Section 10.2.
• B. This information is passed to the nervous system via the neural impulse and due to the process of transduction or converting physical energy into electrochemical codes. Sensory or afferent neurons, which are part of the peripheral nervous system, do the work of carrying information to the brain. We will explore this process in Section 10.3.
• C. The information is received by brain structures (central nervous system) and perception occurs. What the brain receives is a lot of raw sensory data and this has to be interpreted, or have meaning added to it, which is where perception comes in. We will discuss the brain and perception in Section 10.4.
• D. Once the information has been interpreted, commands are sent out, telling the body how to respond (Step E), also via the peripheral nervous system and the action of motor or efferent neurons. We will discuss this in Section 10.5.

Just so that we are on the same sheet of music, let us more thoroughly describe the parts of the nervous system, especially since two were mentioned above (central and peripheral).

10.1.2. The Parts of the Nervous System

The nervous system consists of two main parts — the central and peripheral nervous systems.  The central nervous system (CNS) is the control center for the nervous system which receives, processes, interprets, and stores incoming sensory information. It consists of the brain and spinal cord. The peripheral nervous system consists of everything outside the brain and spinal cord. It handles the CNS’s input and output and divides into the somatic and autonomic nervous systems.

The somatic nervous system allows for voluntary movement by controlling the skeletal muscles and carries sensory information to the CNS. The autonomic nervous system regulates the functioning of blood vessels, glands, and internal organs such as the bladder, stomach, and heart. It consists of sympathetic and parasympathetic nervous systems.

The sympathetic nervous system is involved when a person is intensely aroused. It provides the strength to fight back or to flee (fight-or-flight instinct). Eventually, the response brought about by the sympathetic nervous system must end. The parasympathetic nervous system calms the body.

For a visual breakdown of the nervous system, please see Figure 10.2 below.

Figure 10.2.  The Structure of the Nervous System

10.1.3. The Neuron

The fundamental unit of the nervous system is the neuron, or nerve cell. It has several structures in common with all cells in the body. The nucleus is the control center of the body and the soma is the cell body. In terms of structures that make it different, these focus on the ability of a neuron to send and receive information. The axon sends signals/information to neighboring neurons while the dendrites receive information from neighboring neurons and look like little trees. Notice the s on the end of dendrite and that axon has no such letter. In other words, there are lots of dendrites but only one axon. Also, of importance to the neuron is the myelin sheath or the white, fatty covering which: 1) provides insulation so that signals from adjacent neurons do not affect one another and, 2) increases the speed at which signals are transmitted. The axon terminals are the end of the axon where the electrical impulse becomes a chemical message and is passed to an adjacent neuron.

Though not neurons, glial cells play an important part in helping the nervous system to be the efficient machine that it is. Glial cells are support cells in the nervous system that serve five main functions:

1. Acting as a glue to hold the neuron in place.
2. Forming the myelin sheath.
3. Providing nourishment for the cell.
4. Removing waste products.
5. Protecting the neuron from harmful substances.

Finally, nerves are a group of axons bundled together like wires in an electrical cable. We will talk about a few of them in Section 10.2.

Figure 10.3. The Neuron

10.2. Sensation

Section Learning Objectives

• Define sensation.
• Identify the two thresholds related to the detection of a stimulus.
• Describe the importance of vision for learning.
• Describe the importance of hearing for learning.
• Describe the importance of taste for learning.
• Describe the importance of smell for learning.
• Describe the importance of touch for learning.

10.2.1. What is Sensation?

Simply, sensation is the detection of physical energy that is emitted or reflected by physical objects. We sense the world around us all day, every day. If you are sitting in a lecture you see the slides on the screen and hear the words coming from the professor’s mouth. As you sit there, you are likely smelling scents from your classmates (hopefully pleasant ones). You might be chewing gum and tasting its flavors. And your clothes brush up against your skin as you move in your seat. These events are detected using our eyes, ears, mouth, nose, and skin and as you will see in Module 11 are sent to sensory memory first.

Once physical energy is detected by any of the 5 sensory systems, the receptor cells (or transducers) convert that energy into neural energy. Afferent (sensory) neurons or nerve cells in the Somatic Nervous System send the information off to the brain to be interpreted (discussed in subsequent sections in this module).

Sensory thresholds indicate the least amount of energy needed to detect a stimulus to begin with, or a change in a stimulus, at least half (50%) of the time. First, the least amount of energy needed to produce a sensation 50% of the time is called the absolute threshold. How far away does a car have to be before you hear it? If you hear it at a half mile away at least 5 of 10 trials, that is the absolute threshold for hearing (at least as this car and the sound it creates is concerned). Second, the smallest change in stimulation that a person can detect 50% of the time is called the difference threshold. If you are adding salt to your food, at what point do you notice that it has become saltier? It had some amount of salt in it before, and the addition of salt makes the taste/sensation stronger. You can measure how much is being added and if at the same amount of additional salt you say it is saltier at least 5 of 10 times, this would be your difference threshold for taste (and as salt is concerned). Please note that for both examples, I chose to use 10 times or trials, but this could have been at least 2 of 4 or 10 of 20, etc. The point is that for a threshold to be established, you must identify the stimulus or change in a stimulus at least half of those times. Ten was just an easy number to work with.

10.2.2. Vision

The receptor cells for vision, the rods and cones, are located in the retina and fovea of the eye. What exactly distinguishes them from each other? First, there are about 120 million rods in the eye but only 8 million cones. Second, rods are needed for night vision while cones are needed for color vision and seeing in the daylight. Third, cones can be found in the fovea, a depressed spot on the retina and objects falling here are in sharpest focus, and retina, the light-sensitive inner portion of the eye containing the receptor cells for vision. Rods, on the other hand, are found only in the retina (there are none in the fovea). The information gathered by these receptor cells is carried to the brain by the optic nerve. How so? Rods and cones connect to bipolar cells, which in turn connect to ganglion cells. It is the axons of the ganglion cells that come together to form the optic nerve. After nerve fibers making up the optic nerve leave the eye, they separate and some cross to the other side of the head at the optic chiasm. Ultimately, this sensory information ends up in the visual cortex. Please note that the exact process for vision (i.e. the structure and function of the eye) is beyond the scope of this textbook.

As for a connection to learning, consider that observational learning is based upon observing others and then repeating what you see (or hear). In respondent conditioning, the stimulus, whether NS/CS or US must be detected. The visual system is used if we see the Golden Arches (CS) and being to salivate (CR) or see a bee flying around a trash can and remember when we were stung in the past (an example of higher-order conditioning). In the case of operant conditioning, we make a response for which there is a consequence. Though we may hear verbal praise from our parents, we may also see them give us money (holding it is tactile). Consider that vicarious reinforcement and punishment involve seeing or hearing another person receive a consequence for their actions. This, in turn, influences our future action though we had no firsthand experience ourselves.

10.2.3. Hearing

Hearing, also called audition, is all about the detection of sound, or a type of energy arising from vibrations. These vibrations cause air particles to move, bump into other particles close by, and then bump into more particles and so on until they run out of energy. If we are nearby, then our ears may be able to gather up these sound waves.

The actual hearing of a sound starts in the outer ear with the sound waves being collected by the structure we commonly call the ear, but it is more properly termed the pinna.  The waves travel down the auditory canal to the eardrum, or tympanic membrane, which then vibrates itself. Three little bones called the hammer (malleus), anvil (incus), and stirrup (stapes) hit each other in succession and amplify the wave. This action occurs in the middle ear. The last bone is attached to the oval window and when the stirrup vibrates, it causes the oval window to move, thereby causing the fluid in the cochlea to move, part of the inner ear. This movement causes vibrations on the basilar membrane, which divides the cochlea lengthwise and has on the top of it the organ of Corti. Embedded within the organ of Corti are hair cells, the sensory receptors for hearing. These cells bend and transduce the energy into electrochemical codes. This message moves along the auditory nerve. Information is then passed to the brain and specifically the thalamus.

This sequence of steps is very important to learning. As noted above, we may repeat racist comments because we heard our parents utter them. This exemplifies observational learning. In respondent conditioning, a dog may hear a bell and then salivate (CS-CR). In terms of operant conditioning, the consequence of our action could be a tirade by our parents or praise by our boss, both delivered verbally and detected through audition.

10.2.4. Taste

Taste, or gustation, occurs when chemicals stimulate thousands of receptors in the mouth. When we eat something, chemical substances in the food dissolve in saliva and move into the crevices between the papillae. There they come into contact with the taste receptors. Papillae are bumps you see if you look at your tongue in the mirror. Taste buds are embedded in the tongue’s papillae. The chemical interaction between food substances and taste cells causes adjacent neurons to fire, sending a nerve impulse to the parietal lobe of the brain and to the limbic system.

Of course, you know there are five basic taste qualities — sweet, salty, bitter, sour, and savory. Sweet helps us identify foods that are healthful or rich in calories. Salty is necessary for all bodily functions. Bitter and sour help us identify foods that are rancid or poisonous. Savory can help us identify protein-rich foods and is best described as the taste of monosodium glutamate (MSG).

As an aside, the experience of flavor results from the combination of taste plus smell, discussed in Section 10.2.5. What happens when you have a cold? How does food taste? Think about the answer for a bit………………… You likely said not as good as it usually does. Why is this? Simply, to detect flavor, we need taste and smell. If your nose is clogged, you cannot effectively use one of the two senses needed to detect flavor and so foods do not taste as good or taste bland.

In terms of learning, consider the case of conditioned taste aversion or learning that a food substance has made us sick in the past and so we stay away from it in the future. Foods that are bitter or sour are most likely to cause such a reaction. Respondent conditioning helps us learn this type of association which is critical for survival. In terms of operant conditioning, our parents may give us a special treat like ice cream after earning an ‘A’ on a test. We love the taste of ice cream and are indulging in Rocky Road, our favorite flavor by far. Hence the reinforcer delivered by our parents is even more reinforcing, or an establishing operation, because we love the taste of this flavor. We will work hard to get an A on the next test and more Rocky Road.

10.2.5. Smell

The sense of smell is also referred to as olfaction. Receptor cells for smell are specialized neurons embedded in a tiny patch of mucous membranes in the upper part of the nasal passage, just beneath the eye. Signals from the receptors are carried to the brain’s olfactory bulb by the olfactory nerve which is made up of the receptor’s axons. From the olfactory bulb, they travel up to a higher region of the brain.

Do smells affect us? The answer is yes, and they have a definite psychological effect on us. Consider the purchase of perfumes and colognes and that we like to sniff flowers. Also, olfactory centers in the brain are linked with areas that process memories and emotion. This is why we might not just remember the song that was playing when we kissed that special someone for the first time, but also remember the way he or she smelled.

What are some other ways smells affect us? The smell of food induces us to eat even if not physically hungry. As the dogs in Pavlov’s study showed, we salivate at the sight (vision) or smell (olfaction) of food (both US). And this unlearned response to a stimulus can even be linked with something neutral in our environment like a bell or metronome.

10.2.6. Touch

The skin is our largest sense organ. It protects us from the environment, holds in body fluids, regulates our internal temperature, and contains receptors for our sense of touch.  You might say it acts as a boundary between ourselves and everything else and gives a sense that we are distinct from our environment.  The notions that skin is a boundary and makes us distinct are interesting concepts and likely facts we do not give much thought to on a regular basis. Basic senses include touch, warmth, cold, and pain.

Mechanoreceptors are the receptor cells in the skin that are sensitive to different tactile qualities such as shape, vibration, grooves, and movement. Our skin helps us detect temperature, hot or cold, through thermoreceptors and we detect pain through nociceptors. Pain differs from other senses in one important way. When the stimulus that produces it is removed, the sensation may continue — sometimes for years. The skin is remarkably sensitive with the face and fingertips being the most sensitive body parts and our legs, feet, and back being much less so.

Our skin senses are influenced by our expectations such that when tickled by another person, we respond with excitement. The idea of expectations is an interesting one and links to respondent conditioning. How so? The act of being tickled and it making us laugh is a US-UR relationship, or one that does not need to be learned. We come into the world pre-wired to respond in this way. Consider the Tickle Monster. Do kids enter the world knowing what it is? No, so it represents an NS which causes no response. If every time the father or mother says Tickle Monster (NS) when he/she tickles their child (US) making her laugh (UR), eventually the parent merely saying “Here comes the Tickle Monster” will make the child laugh. Therefore, Tickle Monster has become a CS for which a CR occurs, or the relationship has been learned. What is the essence of respondent conditioning? An expectation that every time an NS occurs the US follows which leads to the response. Hence the relationship is learned.

In terms of operant conditioning, a swift crack on the behind is a punishment (PP) for misbehaving and so a child will be less likely to act out again. If we bring our wife flowers for no other reason than we think she is wonderful, and she gives us a kiss, we will be more likely to bring home flowers again. The kiss is a tactile stimulus, detected via mechanoreceptors, and reinforcement (PR) for a desirable behavior.

10.3. The Neural Impulse

Section Learning Objectives

• Outline how neural transmission occurs, outlining the three “parts.”
• Identify and define important neurotransmitters.

Recall that the cells that do the detecting in the sensory organs are called receptor cells and the physical energy from objects outside of us is converted to neural information in the form of electrochemical codes in the process called transduction. This is then sent to the brain. How so? We will cover this process in three parts.

10.3.1. Part 1: The Axon and Neural Impulse

The neural impulse occurs as follows:

• Step 1 – Neurons waiting to fire are said to be in resting potential and polarized, or having a negative charge inside the neuron and a positive charge outside.
• Step 2 – If adequately stimulated, the neuron experiences an action potential and becomes depolarized. When this occurs, voltage-gated ion channels open, allowing positively charged sodium ions (Na+) to enter. This shifts the polarity to positive on the inside and negative outside. Note that ions are charged particles found both inside and outside the neuron.
• Step 3 – Once the action potential passes from one segment of the axon to the next, the previous segment begins to repolarize. This occurs because the Na channels close and potassium (K) channels open. K+ has a positive charge, so the neuron becomes negative again on the inside and positive on the outside.
• Step 4 – After the neuron fires, it will not fire again no matter how much stimulation it receives. This is called the absolute refractory period. Think of it as the neuron ABSOLUTELY will not fire, no matter what.
• Step 5 – After a short time, the neuron can fire again, but needs greater than normal levels of stimulation to do so. This is called the relative refractory period.
• Step 6 – Please note that this process is cyclical. We started at resting potential in Step 1 and end at resting potential in Step 6.

10.3.2. Part 2: The Action Potential

Let’s look at the electrical portion of the process in another way and add some detail.

Figure 10.4. The Action Potential

• Recall that a neuron is normally at resting potential and polarized. The charge inside is -70mV at rest.
• If it receives sufficient stimulation meaning that the polarity inside the neuron rises from -70 mV to -55mV defined as the threshold of excitation, the neuron will fire or send an electrical impulse down the length of the axon (the action potential or depolarization). It should be noted that it either hits -55mV and fires or it does not. This is the all-or-nothing principle. The threshold must be reached just like in our earlier discussion of absolute and difference thresholds.
• Once the electrical impulse has passed from one segment of the axon to the next, the neuron begins the process of resetting called repolarization.
• During repolarization, the neuron will not fire no matter how much stimulation it receives. This is called the absolute refractory period.
• The neuron next moves into the relative refractory period, meaning it can fire but needs greater than normal levels of stimulation. Notice how the line has dropped below -70mV. Hence, to reach -55mV and fire, it will need more than the normal gain of +15mV (-70 to -55 mV).
• And then we return to resting potential.

Ions are charged particles found both inside and outside the neuron. It is positively charged sodium (Na) ions that cause the neuron to depolarize and fire and positively charged potassium (K) ions that exit and return the neuron to a polarized state.

10.3.3. Part 3: The Synapse

The electrical portion of the neural impulse is just the start. The actual code passes from one neuron to another in a chemical form called a neurotransmitter. The point where this occurs is called the synapse. The synapse consists of three parts — the axon of the sending neuron; the space in between called the synaptic space, gap, or cleft; and the dendrite of the receiving neuron. Once the electrical impulse reaches the end of the axon, called the axon terminal, it stimulates synaptic vesicles or neurotransmitter sacs to release the neurotransmitter. Neurotransmitters will only bind to their specific receptor sites, much like a key will only fit into the lock it was designed for. You might say neurotransmitters are part of a lock-and-key system.

What happens to the neurotransmitters that do not bind to a receptor site? They might go through reuptake which is the process of the presynaptic neuron taking up excess neurotransmitters in the synaptic space for future use or enzymatic degradation when enzymes are used to destroy excess neurotransmitters in the synaptic space.

What exactly are some of the neurotransmitters which are so critical for neural transmission? See Table 10.1 for details.

10.4. Perception: Adding Meaning to Raw Sensory Data

Section Learning Objectives

• List the major structures of the brain.
• Define perception and perceptual set.
• Outline Gestalt principles of perceptual organization.

Information has been gathered from the world around us by receptor cells/transducers in our sensory organs and sent to the brain via afferent neurons in the Somatic Nervous System in the form of a neural impulse. Now the brain needs to interpret this information. We will first discuss the brain and some of its parts. Then we will discuss the process of perception briefly.

10.4.1. The Brain

The central nervous system consists of the brain and spinal cord. The former we will discuss briefly and in terms of key structures which include:

• Medulla — Regulates breathing, heart rate, and blood pressure.
• Pons — Acts as a bridge connecting the cerebellum and medulla and helps to transfer messages between different parts of the brain and spinal cord.
• Reticular formation — Responsible for alertness and attention.
• Cerebellum — Involved in our sense of balance and for coordinating the body’s muscles so that movement is smooth and precise. It is involved in the learning of certain kinds of simple responses and acquired reflexes.
• Thalamus — The major sensory relay center for all senses but smell.
• Hypothalamus — Involved in drives associated with the survival of both the individual and the species. It regulates temperature by triggering sweating or shivering and controls the complex operations of the autonomic nervous system.
• Amygdala — Responsible for evaluating sensory information and quickly determining its emotional importance.
• Hippocampus — Our “gateway” to memory. It allows us to form spatial memories so that we can accurately navigate through our environment and helps us to form new memories about facts and events. The spatial memories will help a rat learn a maze and run it quicker with each trial and make fewer errors.
• The cerebrum has four distinct regions in each cerebral hemisphere. First, the frontal lobe contains the motor cortex which issues orders to the muscles of the body that produce voluntary movement. The frontal lobe is also involved in emotion and in the ability to make plans, think creatively, and take initiative. The parietal lobe contains the somatosensory cortex and receives information about pressure, pain, touch, and temperature from sense receptors in the skin, muscles, joints, internal organs, and taste buds. The occipital lobe contains the visual cortex and receives and processes visual information. Finally, the temporal lobe is involved in memory, perception, and emotion. It contains the auditory cortex which processes sound.

Of course, this is not an exhaustive list of structures found in the brain but gives you a pretty good idea of function and which structure is responsible for it. This will better help us understand perception and how we learn.

10.4.2. Perception: An Overview

As we have seen in the preceding sections, there is a great deal of sensory information going to the brain via the neural impulse at any given moment. What do we do about it? That is where perception comes in, or the process of adding meaning to raw sensory data. An analogy is appropriate here. When we collect data in a research study we obtain a ton of numbers. This raw data really does not mean much by itself. Statistics are applied to make sense of the numbers. Sorry. I did not mean to use the s-word in this book. Anyway, sensation is the same as the raw data from our study and perception is the use of statistics to add meaning. You might say we are motivated to engage in the process of perception so that we can make sense of things.

Our perception of a stimulus can vary though…. even on the same day. How so? Perceptual set accounts for how our prejudices, beliefs, biases, experiences, and even our mood affect how we interpret sensory events called stimuli. Let’s say we wake up one morning feeling good but by afternoon are coming down with a cold and by the evening feel crappy. Consider how you might deal with your kids differently as the day goes on.

There is quite a lot that can be discussed in relation to perception but I will focus our attention on Gestalt principles of perceptual organization. Gestalt psychology arose in the early 1900s in response to ideas proposed by Wilhelm Wundt in German and Titchener and his system called Structuralism in the United States. They were against the notion that perception occurred simply by adding sensations. They instead asserted that the whole is different than the sum of its parts. Their principles include:

• Figure-ground — States that figure stands out from the rest of the environment such that if you are looking at a field and see a horse run across, the horse would be the figure and the field would be ground.
• Proximity — States that objects that are close together will be perceived together.
• Similarity — States that objects that have the same size, shape, or color will be perceived as part of a pattern.
• Closure — This is our tendency to complete an incomplete object.
• Good continuation — States that items which appear to continue a pattern will be seen as part of a pattern.
• Pragnanz — Also called the law of good figure or simplicity, this is when we see an object as simple as possible.

These principles help us to make sense of a world full of raw sensations. Other ways we make sense of our world, though not covered here, include monocular and binocular cues, which aid with depth perception, perceptual constancy, apparent motion, and optical illusions. Give some thought as to how these principles of perceptual organization affect which stimuli we attend to from our environment. Maybe for the dog in Pavlov’s study, the bell is the figure against all other background noises in the environment, which is ground.

10.5. Sending Commands Out

Section Learning Objectives

• Contrast primary and secondary appraisal.
• Define afferent and efferent neurons.
• Clarify the importance of sending commands back out for learning.

Now that a stimulus has been sensed, information sent to the brain via the neural impulse, and it has been perceived by the brain, what is next? You need to decide on a course of action. This is where primary and secondary appraisal come in. Primary appraisal (PA) is when we assess the emotional importance of an event. If deemed important, we then need to figure out a course of action to deal with it, which is secondary appraisal (SA). Think about this. We sense the world and send that information to the thalamus. We determine its emotional importance (PA) in the amygdala. If deemed emotionally significant, we decide what to do (SA) in the prefrontal cortex of the cerebrum. Once a course of action is decided upon, we need to send commands/messages out to the rest of the body.

Recall that the peripheral nervous system includes all parts of the nervous system outside the brain and spinal cord. It divides into the somatic and autonomic nervous systems. It is the somatic nervous system that handles sensory information. This is accomplished through sensory, or afferent neurons, which carry messages to the brain.  It is also the somatic nervous system that controls voluntary movement via efferent or motor neurons, which send commands out of or away from, the nervous system.

Remember that if we deem an event in our world to be emotionally important, via the action of the amygdala in the CNS we need to activate our fight-or-flight instinct. This is where the sympathetic nervous system comes in. Once the event has passed, we return to normal via activation of the parasympathetic nervous system. Both are part of the autonomic nervous system and have tremendous implications for learning.

How is this process important for learning? As we gain experience with our environment and the stimuli present in it, we update our understanding or knowledge of the world. This represents learning. If say, we know that a neighbor’s dog is quite aggressive because in the past we went up to pet it and were bitten, in the future we will not approach the dog. In the case of our first interaction with the mangy mutt, we pulled our hand back when bitten because the pain information was detected by nociceptors, sent to the brain via the neural impulse. Interneurons in the spinal cord then quickly told our hand to move away from the dog to prevent further damage and through motor neurons, our brain then processed and added meaning to the raw sensory data, and finally determined that we were in danger and to move away from the dog and get help for the bite, all controlled by efferent neurons. Primary and secondary appraisal were at work. We determined that the bite was a positive punisher which affected our future behavior of touching the dog. Withdrawing our hand was escape behavior and not going near the dog in the future is avoidance behavior, both types of negative reinforcement. You might also say that the dog was initially an NS but quickly became a CS with a CR of fear (being bitten is a US). We could also have stimulus generalization occur and become fearful of all dogs (and similar animals like cats) which will necessitate discrimination training to realize that most dogs are nice. Other children may have observed the attack and were vicariously punished and will also avoid the dog in the future. If we are sent into therapy to deal with our new phobia to dogs, the therapist may choose to treat the problem using modeling (observational learning) or flooding (respondent conditioning).

Module Recap

Module 10 presented the first complementary cognitive process of sensation (and perception). A model for communication in the nervous system was presented and then each step in the process was outlined and linked to learning. This included sensation, the neural impulse, perception and the brain, and sending commands back out. Not only is the whole process important to learning, but each step adds its own unique contribution.

We will now turn to the cognitive process possibly most directly related to learning — memory; much in the same way that sensation and perception and intertwined. I hope you enjoyed the discussion we just undertook.

2nd edition