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Module 12 - Language and Aphasia

Language is a cornerstone of human experience and communication. Language takes on many forms, it can be verbal, auditory, and visual, and it's used by everyone every single day.

Levels of Language Representation

Language is divided into sections of understanding.

Phoneme - The sound associated with each letter of the alphabet.

Morpheme - The smallest unit of a word that holds meaning. For example, the words "book" and "shelf" are two independent morphemes in the word "bookshelf".

There are 2 types of morphemes. Content morphemes provide the root meaning of a word, while functional morphemes modify the meaning of a word. The words "and" or "but" are functional morphemes.

There are a few language representations that apply to groups of words:

Syntax - The pattern of words, or the relationship between words, that increase understanding.

Discourse - A coherent collection of sentences.

Lexicon

The lexicon is the brain's mental representation of words. Most people assume that the lexicon is simply a dictionary that supplies definitions with words, but it's actually more of a mental map.

Each word in our vocabulary comes with a very thorough collection of associations and connections that work together to represent our knowledge.

These associations can be mental images, our understanding of the physical makeup of the word, memories that are associated, and anything else that our brain might use. The lexicon is personalized to each person based on knowledge, experience, perception, and expectation and it's always changing.

Aphasia

Language is controlled by a number of areas in the brain: Broca's area, Wernicke's area, the primary auditory cortex, and many more.

Damage to any of the relevant areas of the brain can result in aphasia, which is the inability to understand or express speech.

There are many kinds of aphasia:

Broca's Aphasia - Very poor speech production, struggles with short conjunction words and word endings, poor syntax. The meaning of the words is intact.

Wernicke's Aphasia - Speech seems normal, might make up words, struggles with understanding speech and word association tasks.

Aphasia presents differently for everyone. There will be varying levels of impairment in speech and understanding.

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Module 11 - Mental Simulation

Motor cognition is the idea that the motor system and cognitive processes work together to prepare actions and run "what if" scenarios in the mind.

This "what if" scenario is a mental simulation or imagination. It draws upon the brain's model of the world to imagine the result of a certain action.

Bayesian cognition is the idea that the brain perceives sensory information from the world and uses it to make predictions and fill in gaps in perception.

Mental simulation uses the ideas of Bayesian cognition to predict the outcome of events or actions.

An integrated neural system for mental simulation

There are three parts to this system:

The brain transforms the perception of an action into the intention to perform the action.

Action intention is transformed into a motor program, how the action could be performed.

The motor program is transformed into a mental image/simulation.

This system forms a loop of seeing an action, planning the action, and running a mental simulation of the action.

Imitation

The concept of imitation is well-known in the context of babies copying the words and actions that occur around them. Mental simulation plays a role in imitation that is often overlooked.

There are two steps of stimulation in imitation:

Motor planning - The brain simulates the action that will occur based on the actions it perceives.

Movement specification - The brain specifies how the action will be done in the motor system.

Practicing the actions in the mind helps to strengthen the action in the motor system before it occurs. This happens frequently in toddlers, but it also happens when anyone is observing a new skill. For example, if you're mom is teaching you how to make scrambled eggs you probably imagine yourself whisking the eggs before you actually do it.

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Module 10 - Motor Areas

While studying cognition, action is often overlooked in favor of focusing on the aspects of the mind that are more distinctly human. Why think about motion and movement when we could wonder about the more mysterious functions.

The motor system is often seen as an independent function that doesn't utilize cognition. However, that's not necessarily true.

The motor system often uses cognition to predict the actions of others. For example, when you're driving and you see the car in front of you turn on its blinker, you're brain recognizes that means the car will probably make a turn.

The motor system also used cognition to plan actions before doing them. For example, when the Cha Cha Slide comes on, the brain recognizes that a certain set of movements will follow and it prepares those actions before you have to do them.

Many actions are also preceded by mental imagery that "runs" the scenario to see what will happen.

Two Processing Pathways

Visual information is processed in the brain through the dorsal pathway, which recognized the position of something and how to get to it, and the ventral pathway, which recognizes what the information is.

Once that visual information is processed, that perception is transformed into action. For example, I see my coffee is on the windowsill and I can get to it if I lean over and reach out with my left hand. This understanding allows for the action to occur.

Action from the motor system is more complex than simply a machine that moves. It cannot occur without the assistance of mental cognition.

[rebekahhoard]

Cognitive Psychology Class Overview

Throughout this course, we learned about the mind. We learned about how the parts of the brain work together to provide the best possible understanding of the world around us, and about why it sometimes gets things wrong.

In Module 1, we learned about the evolution of the understanding of the mind, pseudoscience, and mental chronometry.

In Module 2, we learned about perception, problems with perception, and how the brain learns the structure of the world.

In Module 3, we learned about how the brain tries to fix the problems of perception.

In Module 4, we learned about attention, engagement and disengagement, and spacial attention.

In Module 5, we learned about the Turing Test, knowledge, and how things are represented.

In Module 6, we learned about the stages of memory, encoding, and memory loss.

In Module 7, we learned about working memory.

In Module 8, we learned about the frontal lobe, executive functions, and executive dysfunction.

In Module 9, we learned about decision-making models and the various logical flaws that can occur.

In Module 10, we learned about motor systems and how they're connected to cognition.

In Module 11, we learned about mental simulation, imitation, and how the two concepts are related.

In Module 12, we learned about language, how language is represented in the brain, and aphasia.

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Module 9 - Decision-Making

Decision-making is a constant part of everyone's life. You can't get through a single day without making a decision. The decisions we make on a daily basis take extremely varied forms, but they all require executive attention.

Models of Decision-making

Sometimes decisions are fairly straightforward, but others require a lot of thought. No matter how simple or complicated, the decisions typically follow a model.

There are two decision-making models:

Normative (The Expected Utility Model) - The choices are weight to compare the costs and benefits of each options, and whichever has the highest utility (most benefits and lowest cost) is chosen.

Descriptive - The choices are characterized and explained rather than reduced to numbers.

The EUM suffers from the fanning effect, which means the idea falls apart as more details about it become known. It isn't as reasonable as it appears to be.

In reality, decisions are typically based on mental representations. We look at the potential gains and losses relative to a point, rather than looking only at the final values.

We end up relying on our mental shortcuts, or heuristics, to guide us to the right decision. Emotions almost always end up being the most important during the decision-making process.

When presented with one option that provides instant gratification and another that offers delayed gratification, it's more common that instant gratification is chosen.

While it seems more reasonable to think that humans should be rational about decision-making, we often rely much more heavily on emotions and gut feelings.

Decision-making Fallacies

A lot of the heuristics we use to speed up the decision-making process contain errors.

There are some common logic flaws that may affect decisions:

Availability Heuristic - Overestimating the likelihood of something because an example comes more quickly to your mind. For example, more people are afraid of flying than driving despite it being more likely for a car to crash than a plane.

Representativeness Heuristic - Overestimating the likelihood of something because you've experienced it before. For example, assuming that a teenage girl is a Taylor Swift fan because her fans are usually shown as teen girls.

Anchoring - The tendency to rely more heavily on the first piece of information provided, which then sets the tone for the rest of the information.

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Module 8 - Executive Dysfunction

The question of what cognition is, and what controls it is as old as the idea of cognition. The numerous ideas have come and gone and it's now clear that cognitive functions are controlled by the frontal lobe of the brain.

But what happens when there's damage to the frontal lobe?

A notable case of frontal lobe damage is Patient W.R. He suffered from a bilateral frontal brain tumor which resulted in executive dysfunction. He claimed that he "doesn't feel grief", he no longer cared about important life events that typically result in strong emotions, and he didn't make any plans for the future.

While frontal lobe damage presents differently for everyone, it is incredibly common for people to display inappropriate anger or socially inappropriate emotions. They tend to lack motivation and be very apathetic. They also tend to have very poor judgment and planning skills.

Clinical neuropsychologists discovered five main deficit areas:

Executive Attention - the ability to keep potentially distracting information from entering short-term memory.

Switching Attention - the ability to unconsciously shift attention between tasks.

Inhibition of Response - the ability to suppress behaviors that may be inappropriate given the context.

Sequencing - the ability to execute a set of actions or assignments in a particular order.

Monitoring - the ability to self-monitor and be aware of one's actions as well as the things happening nearby.

One experiment that illustrates the idea of executive attention is the Wisconsin Card Sorting Test. The object of this is to sort the cards based on the rule set by the experimenter, but the sorting rules change frequently. The test measures the speed it takes to shift and follow the new rules. Patients with frontal lobe damage struggle to change between rules.

Frontal lobe damage affects all of these areas to varying degrees depending on the person. It would be hard to maintain "appropriate" behavior in social situations, as well as functioning in a work setting.

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Module 7 - Working Memory

After the info is encoded into long-term memory, it's important that that info is able to be used when it's needed. Info from the long-term memory is able to be retrieved and it is sent to the working memory when it's needed.

The working memory is like a chalkboard, anything can be drawn on it and held there while it's relevant and it gets erased (sent back to long-term memory) when it's no longer needed.

The capacity of the working memory is the same as short-term memory (7+/-2) and varies slightly depending on the person.

Working memory is an active process, and it works in a loop between the central executive, like a conductor that keeps the process running, and independent buffers, areas where information is stored while the process occurs.

There are two buffers involved in working memory:

Phonological Loop - A loop between the phonological store, where the information is held, and the articulatory rehearsal, a model of the voice. You hear the auditory stimulus and then repeat it out loud in a loop.

Visuospatial Sketchpad - A mental navigation that follows space and time which allows you to see places you're familiar with in your head. One example of this is the ability to close your eyes and visualize the layout of your house.

Because the phonological loop and the visuospatial sketchpad aren't connected, they can both be held together in the working memory at the same time.

The central executive controls when info enters the buffers, which buffer it goes into, and coordination between the buffers. How the central executive controls the buffers is still largely a mystery.

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Module 6 - Encoding and Retrieval

Everything that we perceive and attend to goes into the memory in some capacity. As we perceive the input all around up, that information makes its way through the stages of memory. Memory is the collection of information that is stored in the brain.

The memory is stored in an area of the brain called the medial temporal lobe. Injury to this area of the brain can lead to various memory disorders.

Stages of Memory

Memory gets broken up into three stages:

Sensory Memory - An exact copy of incoming info, either iconic (visual) or echoic (auditory) that lasts for only a second. Echoic info lasts a little longer than visual, but both are only momentary.

Short-Term Memory - Storage of about a small amount (7+/-2) of info for a few minutes. The info will be sent to long-term memory if it's repeated, but the info may be lost if the encoding process is interrupted.

Long-Term Memory - Relatively permanent storage of important or meaningful information. There is no time limit for long-term memory.

Long-term memory is categorized into two more specific groups:

Declarative (Explicit) - Knowledge that you can talk about. This could be episodic, knowledge about events, or semantic, knowledge about facts.

Nondeclarative (Implicit) - Skills that aren't word-based. This could be procedural, like riding a bike or cooking a meal without a recipe. It could also be an automatic association between two things. Implicit memory is not dependent on the medial temporal lobe.

Memory Loss

Loss of short-term memory is known as forgetting. This happens very often, a very small amount of what is stored in the short-term makes it to the long-term memory.

Loss of long-term memory could be the result of a number of things including infantile amnesia(the inability of adults to remember early episodic memories), retrograde amnesia(the loss of memories from before the injury or event occurred), anterograde amnesia(the inability to make long-term memories after the injury or event), etc. Damage to the hippocampus can also cause long-term memory loss.

H.M.

H.M. was a patient who had his medial temporal lobe removed. This resulted in anterograde and retrograde amnesia, but his nondeclarative, or implicit, memory was intact.

This is a very good indicator of the importance of the medial temporal lobe in memory processing.

Improving Encoding

Encoding is a critical aspect of memory. Improving encoding increases the likelihood of information making it into long-term memory. A bulk of the encoding process happens during sleep, so the best way to improve is to get good sleep after study sessions.

Some other good ways to improve encoding:

Attention - give your full attention to the info that you're trying to remember.

Elaboration - Increasing the detail of the information will increase the level of understanding you have and you'll be more likely to remember it.

Distributed Practicing - Spread out your repetitions. Study sessions that are spread out show improved memory rather than mass studying or cramming.

Testing Effect - Practicing retrieval of information by testing yourself on the knowledge will increase memory. The more tests, the better.

Modal Model of Memory

There are many models that exist to help us understand the memory more clearly. One of the most popular models is the Modal Model.

This model of memory shows the stages of memory as sequential steps on a ladder. Input enters the sensory memory, then moves into the short-term memory, and finally graduates to the long-term memory.

This shows that short-term memory is merely a stepping stone to get to long-term.

The problems with the modal model are:

Memory is about more than simply acquiring knowledge. Memory is also for predicting and pattern-building in the brain.

Memory isn't linear, patients can lose long-term memory without losing short-term.

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Module 5 - Knowledge and Representations

Knowledge is information about the world that is stored in our memories.

Knowledge is something that we gain and use every day. We often don't think about how it's represented. Externally, you could draw a picture, use language, make a list, or make a mind map. Internally, knowledge is represented by our perception, attention, and behaviors.

Turing Test

A question that's been asked since the creation of the computer and AI is, do computers have knowledge?

The creation of chatterbots, which use pre-programmed responses to "converse" with people, and clever bots, which uses previous conversations to "learn" to respond to people, have made this an important question.

The Turing Test was developed to determine if a machine can think. If Turing can't differentiate between a computer and a human, then the machine is declared capable of thought.

Representation

Representation is the physical state that stands for an object, event, or concept that carries information.

Some examples of this could be an album cover, a baseball scorecard, or a map.

There are three formats of representation:

Mental Imagery - a "map" organized by space and time in the visual cortex that shows or remembers what something looks or feels like. This is the most commonly recognized format of representation.

Feature Records - info stored in specific areas of the brain based on characteristics. When the specific group of characteristics all appear together it triggers the memory of that info. For example, a basketball is orange, bumpy, spherical, and rubbery. When that combination of characteristics appears together, the brain will connect it to a basketball.

Amodal Symbols - Abstract symbols that are not tied to experience and aren't connected to anything specific in the brain.

These three formats often work together to form a more complete representation.

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Module 4 - Attention: Engagement and Disengagement

Attention is the act of narrowing our focus to something more specific than general sensory information.

Modes of Control

Attention can be drawn exogenously, which means something external forcefully pulls attention away. An example of this could be a police siren or hearing your name called.

Attention can also be controlled endogenously, which means you willingly give your attention with internal control. An example of this could be choosing to reach down and pet your dog at your feet or choosing to watch a movie.

An aspect of endogenous control is covert attention. It is possible to give your attention to something without actively looking at it. For example, I can focus my attention on my roommate right now without looking at her.

Engagement and Disengagement

Giving something attention requires two separate steps:

Disengagement - Withdrawing attention from any unrelated stimuli

Engagement - Focusing on the chosen stimulus

While the engagement aspect of attention is clear, the disengagement aspect is often overlooked. Someone with attention difficulties might struggle with withdrawing their attention or maintaining their attention.

Bottleneck Problem

One of the problems with attention is the bottleneck that happens. There is so much input to take in, and only some of it is detected. The input that is detected is filtered and only some of it is recognized and attended to, which creates a bottleneck.

Some things skip over the filter.

The cocktail effect is when you're in a crowded area and you're able to pick out someone calling your name despite paying attention to something else.

This effect also occurs when people hear a baby crying or a child calling for their parent. You're brain will hear that and your attention will turn to it despite being focused on something else.

Spatial Attention

Spatial attention is how attention is divided over a scene. If you're looking at a painting, where will your attention linger?

The spatial cueing paradigm is the idea that priming your attention in a certain direction allows your attention to be drawn in that direction more quickly.

Spatial attention hops around something, not usually pausing for long periods.

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Module 3 - Predictive Coding Theory

The problems of perception cause the brain's version of the world to be unreliable, which can be dangerous to ourselves and others.

When these inaccuracies become apparent, the brain attempts to correct the mistakes.

Bayesian Cognition

A possible solution to incorrect or incomplete perceptions is Bayesian Cognition. This is the idea that as someone lives and perceives, the brain begins to predict the world. As those predictions inevitably get something wrong, the brain adjusts its prediction.

The brain learns from its mistakes and continually becomes a better predictor.

Predictive Coding Theory

Another possible solution to the perception problems is predictive coding theory. Similar to Bayesian Cognition, the predictive coding theory supposes that the brain is continuously updating the model it's creating of the world.

Every new perception adds to and changes the model somehow so the model is always improving its assumptions.

While the brain will always make mistakes with its assumptions, the predictive coding theory is a solution that explains how the brain is able to course correct and keep from making the same mistakes repeatedly.

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Module 2 - Perceptions

Perception is a central theme of cognitive psychology. Nothing can be explained or determined without stating that there will always be differences in perception or errors in perception.

Perception is the intake of sensory information around us that informs our view and understanding of the world around us.

Path Through the Brain

Visual perceptions follow a specific path from the eye into the brain: the image appears upside down and mirrored in the back of the retina. That info then travels through the rods and cones collecting activity and sending it to the optic nerve which travels into the brain through the thalamus and into the Primary Visual Cortex (V1). The image gets more detailed as it travels from the simple cells (showing just lines), to the complex cells (direction and orientation of the lines), and finally to the hypercomplex cells (movement and length of the lines).

There are two processing patterns:

Bottom-up processing - driven by sensory info from the physical world

Top-down processing - seeking and extracting from sensory info driven by our knowledge, beliefs, and expectations.

The brain notices patterns in our perceptions and those patterns build a mental version of the world. People make assumptions and miss key information all the time and this often leads to errors in our patterns and perceptions.

Problems in Perception

There are two problems of perception:

Too much input: A person cannot possibly look around a notice every detail about everything they see, feel, or hear all at once.

Not enough input: Everything we perceive is incomplete, so the brain has to fill in the blanks based on our understanding of the world.

These errors are impossible to correct at the moment due to their nature, and they often have strong consequences.

Cognitive Biases

Cognitive biases are systematic inaccuracies in the way we think and they're often caused by the two problems of perception.

For example, authority bias is the assumption that someone who claims or appears to be an authority figure will always be correct. This bias comes from not having enough input. We assume that they know what they're talking about despite not knowing for sure if they have the expertise. We assume because of their appearance or title rather than their knowledge.

An example of a cognitive bias that comes from having too much input is confirmation bias. There is so much input about any given thing that not all of it can get through, so people are more likely to remember or recognize information that supports a belief that already exists.

Inverse Problem

Another problem with perception is the inverse problem, which states that A) It is possible to derive a specific perception from a given stimulus, but B) it is impossible to derive a specific stimulus from a given perception.

This problem means that we can perceive things without realizing what is causing that perception (For example, I have an intense hatred of Ram trucks and I have no idea why).

[rebekahhoard]

Module 1 - Historical Views

Cognition is the most commonly practiced view of psychology today, but it took a long time to get here. The theories and beliefs surrounding the human mind have been changing and expanding throughout history as technology improves our knowledge and understanding.

There have been several theories of cognition:

Ancient Ideas

Introspection

Behaviorism

Cognition

Each theory had its merits and its downfalls, its supporters and its critics, and each has been an important step to building on our understanding of the mind.

Ancient Ideas

The ancient ideas of the mind varied between time and place. Each theory was pulled from the popular religious and scientific beliefs of the culture and time to best estimate how the mind worked.

The ancient Egyptians believed that thoughts originated in the heart, while judgment originated in the kidneys.

The Bicameral Mind theory, first put forth by Julian Jaynes around 1200 BC, was the idea that the mind is not a conscious entity that would think or reason. According to this theory, thoughts, emotions, and opinions were the consequences of actions by Gods outside of the human body.

Aristotle's theory, from 382-322 BC, stated that the body was in charge of physical actions while the psyche (located in the heart) executed mental actions.

Galen, in Rome from 129-199 AD, was the first to theorize that the mind was in the brain.

The birth of Psychology in the mid-1800s brought along a new way of thinking about the mind. The study of psychology combines the physical ideas of physiology with the mental ideas of philosophy.

Early philosophies of the mind include:

Rationalism: The mind is rational and we access the truth through our thoughts. Knowledge is God-given and present in everyone from birth. The physical mind was thought to be separate from the soul. The soul was believed to enter the body through the pineal gland to control the body.

Empiricism: Observations draw conclusions. Knowledge comes from experience, we're not born with it. Things become associated in the brain when they appear frequently together (ex: peanut butter and jelly).

Introspectionism

This is Wilhelm Wundt's theory that everything is elemental and it would be possible to understand anything if you could break it down far enough.

Edward Thatcher attempted to catalog all of the elements that go into everything. He was unsuccessful because the elemental breakdown is infinite.

The biggest problem with Introspectionism is that it oversimplifies everything. It doesn't account for differences in perception or description, which means that no concrete conclusions could ever be made.

Behaviorism

The theory of behaviorism, born from the frustration and failure of Introspectionism, is the idea that the inside of the mind is unknowable, so we can only observe from the outside. It is the strict study of the relationship between a stimulus, like a bright flash of light, and a response, shutting your eyes.

This theory completely ignores any concept connected to the mind, opting only to predict behaviors that might be resulting from specific events, or stimuli.

The main problem with Behaviorism is that it limits science to only observational data and completely discounts differences in language, perception, and attention.

Cognitivism

This is the idea that we can learn more about the mind by probing it. This is the first theory of the mind to use technology.

Cognitivism views the mind as a computer, believing that within the mind there is hardware and software.

Both Behaviorism and Cognitivism rely heavily on the scientific method. That means that any experiment done to better understand the brain utilizes hypothesis testing, observations, evidence collection, and Empiricism. These principles and guidelines for experimenting allow us to make predictions and draw conclusions that are supported by facts.

Pseudoscience

Pseudoscience is something that claims to be proven using the scientific method but doesn't actually have any scientific evidence.

One historically significant example is Phrenology. Phrenology was the idea that each section of the brain was in control of an aspect of personality, and a person's personality could be read by analyzing the bumps on their head.

The boundaries of each section were entirely made up and its credibility was entirely through personal testimony. There was never any credible scientific backing.

A more current example is Astrology. It uses someone's birthday and the placement of the stars and planets to make claims about personality.

Localization

A common question throughout the historical study of the mind has been the idea of the brain as a unity. In the early 1800s, Pierre Flourens was charged with finding out if it was true.

Flourens systematically destroyed parts of the brain to determine if it all worked as one, or if different sections of the brain were responsible for different actions.

He found that there were 4 major divisions of the brain:

Cerebrum - responsible for all higher mental functions, including speech, planning, emotions, problem-solving, etc.

Cerebellum - responsible for motor coordination, like movement and spatial awareness.

Brainstem - responsible for life-supporting functions, such as sleep, breathing, heart rate, etc.

Spinal Cord - responsible for sending signals between the brain and the body.

While the cerebrum, brainstem, and spinal cord were found to be unities within themselves, the cerebellum is split further.

Localization is the idea that different areas in the cerebellum are responsible for different things.

The first experiment that led to the discovery of the localization within the cerebellum is known as Patient "Tan". He suffered an injury that affected his left frontal lobe and almost all aspects of his mind remained unharmed, but he could only say the word "tan". Dr. Pierre Paul Broca found that Patient "Tan" as well as all other people with language issues had the same abrasions on the left frontal lobe. That area of the left frontal lobe is now known as Broca's Area.

Further experimenting and research led the knowledge that the cerebellum has 4 lobes:

Occipital - controls sight

Frontal - controls language, decision-making, and movement

Temporal - controls memory and auditory processing

Parietal - controls sensory processing and spatial awareness

The Motor Cortices are specialized areas in the frontal lobe that control parts of movement; the Primary Motor Cortex controls body movement, while the Somatosensory Motor Cortex received signals from the body to direct movement.

Movement was assumed to be instantaneous until Herman Von Helmholtz conducted an experiment and discovered that the velocity of the nerve impulses which cause movement is 50 to 100 meters per second. This means that there is a delay between the signal for movement and the actual movement that follows.

This brought the first study of cognitive psychology.

Mental Chronometry

Mental Chronometry uses time to measure the mind. The aim of the study was to measure the speed of "pure choice". The participant would come into the lab and were told to press the button when they felt a shock. The second task was to push the button that correlated with the foot that felt the shock. They then subtracted the first result from the second result to find how long the choice took.