Lecture notes for Introduction to psychology at the University of Groningen

Lecture Notes to be used with Introduction to psychology. These notes provide an introduction to the various subjects within the field of psychology, such as the science and history of Psychology, Consciousness, Perception, Learning, Attention and memory and Thinking and Intelligence.

Lecture: The Science of Psychology

This lecture can be reviewed additionally to chapter 1

This lecture describes what it means to be a psychological scientist, a brief history of psychology, as well as current issues in psychology.

What is Psychology?

Psychology branches out far beyond the clinical realm. In fact, what people often forget is that psychologists are scientists. Psychology, therefore, is the study of behaviour, the mechanisms behind it, and, if necessary, how to change it. This includes long-term and short-term behaviours, as well as the physiology behind them, particularly the physiology of the brain.

What is Science?

Science is the process of discovering new things in or about the world around us. Psychologists use the scientific method to form theories about behaviour:

• By observing and researching about the world, psychologists are able to come up questions about behaviour.

• Using these questions, hypotheses are formed.

• These hypotheses are tested through experimentation or field observation

• Conclusions about the hypotheses are drawn

Psychology as a Science

It is important to note that this lecture talks about Western philosophy and science (based on dualism), rather than Eastern (monistic) philosophy and science. Psychology, as a science, is empirical, which means that it is about things that you observe, either directly or indirectly. While many things can be observed directly, a large part of psychology is about things that are only indirectly observed.

Psychology bridges the gap between the natural sciences and the humanities. While it can include many other disciplines, such as law, medicine, theology, mathematics, and physics, psychology is ultimately a subdiscipline of philosophy.

The two major themes studied in psychology today are the mind-body problem, ie. how the mind and the body are related, and the nature vs. nurture debate, ie. whether we are free to control our own fate and change who we are.

Some Important People in Psychology

1875: The first psychology labs were established in 1875 under Wilhelm Wundt (Leipzig) and William James (Harvard), both professors of physiology. James was later appointed chair of psychology in 1880, while Wundt believed that psychology should stay as a subdiscipline of philosophy.

1892: Gerard Heymans established the first experimental psychology lab in Groningen

1894: Carl Stumpf was appointed chair of the Berlin Experimental Psychology lab, where he later trained many influential psychologists.

1896: The first psychological clinic, for the treatment of learning disabilities, was established by Lightner Witmer.

1930's: Burrhus Skinner and John Watson introduced behaviourism and changed psychology significantly.

A Brief Word About Freud

Sigmund Freud (1856 - 1939) is the founding father of psychoanalysis. He began by investigating the treatment of hysteria and formed many theories that had little or nothing to do with Wundt and James' scientifically-grounded theories. Freud is, however, very popular because of his theories on sex and psychoanalysis; however it is important to note that while psychology today acknowledges many Freudian theories, the tenets of psychoanalytical theory cannot be verified by science.

A Brief History of Psychology

Psychology in the early 20th century was firmly rooted in physiology and philosophy. It was experimental in nature and focused on topics such as consciousness, attention, cultural differences, and sensation and perception.

In the 1930's, Watson and Skinner pushed for behaviourism in psychology. Behaviourism is the concept that the only valid topics of study in psychology are those that can be observed through a stimulus and response. The underlying mental processes are not observable, and therefore, not of interest to science. This impacted psychology in several ways. On one hand, it made psychology a credible science, as focus was on empiricism; but it also caused these unobservable topics, such as attention and perception, to become taboo topics.

Between 1950 and 1970, advances in computer sciences helped make reverse-engineering the 'black box,' or the unobservable processes possible. The Cognitive Revolution, which shifted the focus of psychology onto information processing, resulted in the cognitive approach, the predominant theoretical framework in all branches of psychology

Psychology today focuses on those early questions about processes that go beyond stimulus and response. While remaining deeply rooted in philosophy and physiology, the predominant approach is cognitivism, which places the focus of modern-day psychology on information processing.

Nowadays, there has been a rapid shift from psychology to neuroscience. Emphasis is being put on researching how the brain works and the implications of that in psychological treatment. Additionally, we are beginning to ask ourselves whether our methods have been effective in the past. We have begun to question the significance of our experimentation and are trying more and more often to replicate previous studies, in order to prove the validity of those studies.

Lecture: BANG - Bits, atoms, neurons, genes

This lecture can be reviewed additionally to chapter 3

Studying the Brain

While still controversial, animal research is a large part of studying the brain. Animals are used for many reasons, including:

• They share similar mechanisms of neural transmission to humans

• They allow for easily repeatable and reproducible experiments

• Some experiments are too dangerous to do on humans

• Evolution: studying species that are related to us tells us more about ourselves

The majority of lab animals are rats and mice; however psychological experiments are also done on cats, dogs, hamsters, guinea pigs, and apes.

While on the surface, many of these animal experiments seem cruel or pointless, it is important to remember that each experiment is thoroughly vetted by an ethics board, and that lots of training in animal care is done before experimenters can actually work with animals. This board prevents unnecessary stress, pain, and distress that is put on the animals and strict regulations must be adhered to.

Methods in Brain Research

Animal experimentation allows us to play around with genes that are inserted into animals. Animals that are, for example, genetically predispositioned to develop tumours, can be used in cancer studies. Another method that is made possible by animal experimentation is optogenetics, where genes from algae plants are implanted into the DNA of specific neurons. These genes cause the neuron to be responsive to either blue or yellow light, where the lights work as an on and off switch for the neurons. In this way, it is possible to explore what happens when specific neural pathways are turned on or off

There are also several methods used for brain imaging, that are further described int eh textbook:

• EEG (electro-encephalography)

• MEG

• fMRI (functional Magnetic Resonance Imaging)

• The fMRI works, put simply, on the basis of measuring blood flow in specific parts of the brain during specific activities

• TMS (transcranial magnetic stimulation)

Neurons and Networks

The Central Nervous System (CNS) includes the brain and spinal cord, while the Peripheral Nervous System (PNS) involves every other nerve in the body.

Neurons ('nerve cells') are the key players in information processing in the brain. There are several types of neurons:

• Sensory Neurons transfer information from sensory organs to the CNS

• Motor Neurons transfer information from the CNS to muscles

• Interneurons are responsible for forming networks in the brain and are responsible for complex information processing

So now begs the question - how does it all work?

First, we must examine the anatomy of a neuron. Do a quick google image search so that you can follow along.

The neuron is divided into several parts, each playing their role in neurotransmission:

The dendrites receive action potentials from stimuli. The cell body is connected to the axon, which conducts action potentials away form the cell's body. The axon is surrounded by a myelin sheath, which increases the speed at which action potentials are propagated. The terminal buttons form a connection to the neighbouring neuron's dendrites, and this connection is called the synapse.

The Second Law of Thermodynamics states that in any cyclic process, entropy will either increase or stay the same. The body is constantly trying to find a balance, a homeostasis. This is not the case for neurons. Neurons rest at a potential of -70 mV, and it requires work in order to stay resting in this potential.

The key ions that play a role in maintaining a neuron's resting potential are sodium (Na) and potassium (K). These atoms are both positively charged. The neuron's negative resting potential is maintained by the sodium-potassium pump. This pump sits in the neuron's membrane and uses ATP (adenosine triphosphate) as energy to pump 3 Na out of and 2 K into the cell, causing the cell to be more negative than its surroundings. This allows for a resting potential of -70 mV.

The neural membrane also has ion channels that respond to chemical messages from other neurons (which will be discussed later), which change the membrane potential. There are also voltage-dependent Na and K channels that allow ions in or out of a cell. These open or close when the membrane potential reaches a threshold (around 50 mV). These are the channels that open during an action potential; first the Na channels open, allowing lots of Na to flow into the cell, then the K channels open, allowing K to flow slowly out of the cell.

Depolarization is when the membrane potential becomes more positive, shifting towards 0. This is excitation.

Hyperpolarization is when the membrane potential becomes more negative, shifting below -70 mV.

Action potentials cause neurons to release either excitatory (causes depolarization) or inhibitory (causes hyperpolarisation) neurotransmitters into the synaptic cleft. The amplitude of the AP is determined by the properties of the neurons that conduct the AP and is not dependent on the neural signal. Depending on the neurotransmitter used, the next neuron is affected, and the signal is carried from one neuron to the next. Action potentials happen locally (ie, on one part of the cell membrane.)

Neurotransmitters allow us to play with various 'knobs and buttons.' The net effect of the neurotransmitter depends on the amount of neurotransmitter released, the number of receptors in the post-synaptic membrane, and the neurotransmitter's turnover rate.

Neural Networks

Putting it all together: Neurons form complex networks that are responsible for processing information. They are organised in layers and each individual connection has its own strength, and by adding layers, we are able to refine under which circumstances a neuron will fire.

NOTE: Due to time restrictions the last part of this lecture is not covered in these notes.

Lecture: Consciousness

This lecture can be reviewed additionally to chapter 4

Philosophy and the Nature of Consciousness

One of the main problems in psychology is the mind/body problem - essentially, how can we explain the connection between our mental states (thoughts, beliefs, actions) and our physical bodily processes? The 'hard problem' of consciousness was first proposed by philosopher Dave Chalmers in the 1960's, posing the question, 'why does the feeling which accompanies awareness of sensory information exist at all?'

His reasoning is that qualia (singular quale), individual experiences of subjective, conscious experience, cannot be fully explained by physical properties alone. Instead, Chalmers argues that consciousness is a fundamental property that is ontologically autonomous of any known (or even possible) physical properties

In the past, due to the movement of behaviourism (see lecture 1), the study of consciousness was taboo in the world of psychological research; however, starting from the 1970's, psychologists began looking further into the phenomenon of consciousness.

There are two main fallacies in consciousness research:

1. 'The Hidden Observer' or the fallacy of cryptodualism

This fallacy concerns itself with a philosophical problem: even if we were to come up with a theory of consciousness, would it really explain the phenomenon?

2. 'The Edward Argument' or the fallacy of the operationalisation of consciousness

This fallacy concerns itself with a methodological problem: can we really come up with an appropriate experiment to test consciousness?

Monism vs. Dualism

In the study consciousness, there are two main schools of thought: monism and dualism.

• Dualism is the idea that mind and body are separate things. This was first proposed by philosopher, René Descartes. The problem with dualism is that it evokes the 'hard'problem.' Interestingly though, many modern-day theories of consciousness implicitly assume dualism.

• Monism is the theory that mind and body are one:

• Mentalism means that everything is the mind (Eastern philosophy)

• Materialism means that everything is matter. Scientific psychology uses the theory of materialism because it is measurable and empirically verifiable.

The identity position stipulates that the brain and mind are the same thing, but described in different terms, while supervenience refers to how lower levels of explanation give higher levels their features, but the relation is not completely one-to-one.

Contemporary Models of Consciousness

While there are many different theories on consciousness, researchers have come to some consensus about the nature of consciousness:

• Consciousness is the result of complex brain activity

• An essential component of consciousness is the interaction between different brain areas

• It remains unclear as to exactly what areas of the brain are responsible for consciousness, as well as whether or not attention is required for consciousness to occur.

Operationalisation of Consciousness

One of the major issues in consciousness research is how to go about operationalising consciousness. Some examples of variables that are observed in consciousness experiments include: 1. Verbal report, 2. Detection in a Yes/No task, 3. Object recognition, 4. Eye movements, 5. Pupil dilation.

The problem of operationalising consciousness is still of great debate in psychology today.

Altered States of Consciousness

There are many factors and activities that can lead to one having an altered state of consciousness. These include meditation, hypnosis, and drugs.

Hypnosis

Hypnosis can be defined as an altered state of consciousness, where subjects are particularly receptive to suggestions. It is important to note that while 15% of the population can be considered 'highly hypnotisable,' hypnosis does not necessarily work on everyone. There is currently no clear explanation as to why hypnosis works, but the working theory is that hypnosis works on the basis of increased cognitive flexibility.

Meditation

Meditation is the practice of the focus of attention. Meditative states are associated with an increase in alpha and beta brain waves, causing feelings of relaxation and engagement in meditators. The story behind an increase in these waves is yet to be scientifically explored; however several studies have indicated a correlation between meditation and improved physical health.

Drugs

Psychoactive drugs are substances that alter normal brain function. Each drug has a specific mechanism that depends on the specific neurotransmitter system targeted. Legal drugs include caffeine, nicotine, and alcohol, while less legal and illegal drugs include cannabis, cocaine, LSD, Ecstasy, and Heroin. The specific mechanisms by which these drugs work go beyond the scope of this course.   

Lecture: Perception

This lecture can be reviewed additionally to chapter 5

Overview

We perceive with our senses, sight, hearing, touch, taste, and smell. Perception is a key process in understanding how people interact with the world. Perception is part of the aforementioned cognitive model.

Not all senses are represented equally in psychology. Because we know more about vision than the other senses, it makes sense that it would be the main focus of perception studies. Additionally, studies in vision are easier to organise and humans are very visual beings.

From Sensation to Perception

Perception is a construction - our brains make a construction of what our sensory organs pick up, and in some cases, our brains make up a construction that is not congruent with reality. For example, it is quite common to feel phantom vibrations from mobile phones if you are expecting a call, when in reality, you may not even have the phone with you.

Why is this the case? Essentially, the brain fills in the gaps based on prior knowledge, the information it has and what it's expecting. There's a lot of noise in the environment, and the brain must fill in or filter parts of the sensory input you receive, in order to come up with a valid representation of the world.

There are two main systems at work, when dealing with perception:

Top Down Stream - information from memory flowing back to perceptual systems

Bottom Up Stream - Information from your sensory organs to perceptual systems

What's interesting about this is that some psychological patients who have hallucinations are thought to have an imbalance of the two streams, where the top down stream is more prominent than the bottom up stream.

Psychophysics

Psychophysics is the study of how physical stimuli results in sensations, and how strong a stimulus must be in order to be perceived. The two key players in this field were Ernst Weber and Gustav Fechner.

These areas of study are often investigated using a two alternative forced choice (2AFC) test.

• In this test, study participants are presented with a stimulus in 50% of the trials. They are then asked to answer 'yes or 'no' as to whether or not they detected a stimulus. By running such an experiment, it is possible to predict, for example, how long a stimulus needs to be present in order for it to be perceived.

The point at which 50% of the stimuli are detected is called the detection threshold.

Another factor that can be measured with psychophysics is the just noticeable difference (JND). This is the amount two stimuli have to differ in order to trigger a response that the two stimuli are different, 50% of the time.

What's tricky here is that the JND is not based on absolute values. According to Weber's law, the JND is based on the proportion of the original stimulus, not on absolute values.

For example, if you had a 1 kg weight in one hand and a 2 kg weight in the other hand, it is very easy to tell the difference; however if you had a 10 kg weight in one hand and 11 kg weight in the other hand, it would not be as easy to tell the difference.

Signal Detection Theory

In one type of testing, study participants are presented with situations where they have to decide whether or not a signal is present, by simply answering 'yes' or 'no.' The stimulus is presented to the study participants in 50% of all instances.

Each instance can be coded as one of the four following options:

• Hit: Stimulus is present and participant answers 'yes'

• Miss: Stimulus is present and the participant answers 'no'

• False Alarm: Stimulus is not present and the participant answers 'yes'

• Correct Rejection: Stimulus is not present and the participant answers 'no'

By doing these kinds of studies, it is possible to determine detection curves for when the signal is present and when the signal is absent, and using these curves, it is possible to calculate the probability of making a decision in an uncertain situation.

These types of experiments are used in memory experiments and when a researcher wants to test how decisions are mare in uncertain situations. For example, this type of test would be used to determine how we perceive distance in foggy conditions.

Chemical and Mechanical Senses

Taste, which is sensed by receptors called taste buds, prevents us from poisoning ourselves. The taste buds work based on ions found in the things we ingest:

• Salty: Cl ^-- ions

• Sour: H ⁺ ions

• Sweet: specific molecules, such as glucose

• Umami: proteins

Taste is not the same as flavour. Taste refers to one of our 5 senses, while flavour is the specific sensation that is evoked by tasting and smelling something at the same time.

Smell is oldest sense that we have. Odorants are inhaled through the nose and end up in the nasal cavity. In the nasal cavity, there are receptors that respond to specific odorants. . Smell is the only sense that does not enter the brain through the thalamus: Signals are sent from the receptors directly to the olfactory bulb, which is directly connected to the brain.

Touch works through receptors in our skin that fire when they are compressed. The signals then go through the thalamus to the sensory cortex, allowing us to perceive things like heat and pain.

Pain is a very specific and important sense of touch. Without pain receptors, you cannot feel when you damage your body. With regard to pain, there are two main fibres:

Fast fibres have a myelin sheath and are responsible for sharp and fast pain.

Slow fibres do not have a myelin sheath and are responsible for aching dull pain.

Vision

Vision is the detection of electromagnetic radiation, a specific form of energy with specific wavelengths. Humans are only aware of a small subset of these waves - the visual light spectrum. The shortest waves in this spectrum are blue, while the longest waves in this spectrum are red.

What do we see? We see light being reflected by objects around us. Light, itself, is all the wavelengths combined. When they hit objects, the objects absorb some of the waves and reflect specific waves back. For example, if you see a blue object, it's actually the object reflecting blue waves back into your eyes.

Eye Anatomy and Physiology

How does all of this work? Rods and cones - receptors that are sensitive to light, are specific nerve cells that are connected to and send information to the ganglion cells.

Rods are sensitive to light but not sensitive to colour. They fire when it's dark and stop firing when light hits the retina. This works through light-sensitive sodium gates that shut down when they sense light.

We have three types of cones, light sensitive cells that can discriminate between different colours. The three different kinds of cones that we have are sensitive to red, green, and blue light respectively. It is important to note that the perception of colours is about differences, not the absolute input values.

Red and green wavelengths are very close to one another, so how green or red something is depends on the difference between the two. An increase in the firing of both red and green cones accounts for a higher level of brightness. The blue cones allow us to perceive how blue or yellow something is. Blue is perceived by the firing of blue cones, while yellow is the absence of this firing.

Organisation of the Visual System

There are two types of organisation in the visual system:

• A hierarchical organisation, where information is processed in one area and forwarded to the next level, and

• A parallel organisation, where two streams of information are processed at the same time

At the same time, there are two independent, but complementary pathways for visual perception:

• The dorsal pathway is responsible for telling us where something is. This pathway feeds through to the parietal cortex.

• The ventral pathway is responsible for telling us what something is. This pathway feeds through to the temporal cortex.

Gestalt Principles in Vision

The Gestalt Principles, first proposed by German psychologists, Kurt Koffka and Wolfgang Köhler, are principles referring tot he way we perceive things visually. Visual perception is a construction - we perceive many individual parts, and the Gestalt Principles essentially claim that the whole (picture) is more than the sum of its parts. These principles include: closure, proximity, continuation, similarity, and figure-ground articulation.

Lecture: Hearing Perception and Bonus topic Dreaming

The Nature of Sound

The basic components of building sounds are called pure tones, or basic auditory components that can be combined (in the right amounts, frequencies, and at the right times) to produce what we hear, for example speech and music.

Unlike visual stimuli, auditory stimuli overlap with each other, both in time and space and in the frequency components they include. We must, therefore, untangle the mess of auditory input we receive and make something sensible out of it.

The Auditory System

There are 3 distinct parts of the ear:

• The Outer Ear: pinna and ear canal

• The Middle Ear: Eardrum (tympanic membrane,) a tight membrane that responds to vibrations in air. The bones here (malleus, incus, stapes,) amplify the sound waves so that they can be interpreted when they hit the liquid in the inner ear

• The Inner Ear: Cochlea - the inner ear is responsible for converting mechanical signals to electrical signals that can be interpreted by the brain

How Does the Ear Work?

Sounds waves enter the outer ear and travel through to the middle ear, to the eardrum. The bones in the middle ear act to amplify the sound waves. These waves continue into the inner ear, where they meet the cochlea, a spiral-shaped cavity filled with liquid, lined with the basilar membrane. Specific areas of the basilar membrane react to specific sound waves, and it is in this way that the mechanical signals of sounds (sound waves) are converted into electrical signals in the brain. These signals then continue on to the auditory cortex.

Impaired Hearing

There are two different types of hearing loss:

1. Congenital hearing loss is hearing loss that you are born with; there are both genetic and non-genetic factors that play a role. This type of hearing loss is not very common.

2. Acquired hearing loss is when you start with normal hearing and then lose it over time. This can be caused by various factors, such as infections, injuries, noise exposure, and ototoxic drugs. However the most common cause of hearing loss is simply aging.

Under extreme noise exposure, the stereo cilia are pushed very aggressively into the tectorial membrane, causing them to break off. This physical damage is responsible for hearing loss.

Characteristics of Hearing Loss

Characterising hearing loss is done by frequencies and levels. An audiogram can be done in order to assess which levels are required to hear each frequency. The challenge is, therefore, not just making everything louder; but compensating for the frequencies that cannot be heard. The two main methods of treating hearing loss are hearing aids, which amplify the sound waves that enter the ear, and cochlear implants, which replace the mechanical actions of the sound waves directly with chemical mechanisms.

Bonus Topic: Dreaming

Regulation of Sleep

Why do organisms need to sleep? We don't really know. What we do know is that sleep is very highly regulated. Sleep is regulated by the hypothalamus, the pineal gland, and the superchiasmatic nucleus.

Each stage of sleep expresses its own specific brain activity. During the normal or awake state, the brain exhibits beta waves. As you start to slow down and relax, in preparation for sleep, the brain waves get slower and slightly higher in amplitude. These are called alpha waves. As you fall asleep, the waves get even larger in amplitude, becoming theta waves; and when you are finally in deep sleep, your brain exhibits larger, slower waves called delta waves.

We go through several iterations of the sleep cycle every night. A part of each cycle is the REM (rapid eye movement) phase. As the night continues, the REM periods become slightly longer and we no longer dip into slow wave sleep. What's interesting about REM sleep is that the EEG activity looks exactly like what you would expect in someone who is awake. Typically, we have 4 periods of REM sleep per night, where we dream.

What Are Dreams (and Sleep) Good For?

Scientists have not yet uncovered the reason behind dreaming. One theory, the Activation Synthesis Hypothesis, proposes that the brain builds a story and incorporates recent events from memory into them. Thus, everything that happens in a dream is internally generated and not influenced by external factors. The current model of dream consciousness is the AIM Model. This model classifies different activities during sleep on three different axes: Activation, Input-Output Gating, and Modulation

Another theory is that sleep is for waste-removal. Our lymphatic systems project directly into our brains. As we sleep, our brains shrink, allowing more space between cells. Since there is more space between cells, the flow of cerebral spinal fluid (CSF) is nor restricted and is able to wash out the waste products produced by our brains.

Finally, while there has not been enough research in this feel, preliminary studies show that sleep may have a cognitive function. In these studies, it was shown that participants who had a good nights' sleep were able to complete a boring task and improve on their results more effectively than participants who stayed up the whole night. Additionally, the participants who stayed up for a whole night were not able to improve on their ability to complete this task until they had had a full night's sleep.

In conclusion, the function of sleeping and dreaming is not yet known, but there are many ongoing studies investigating the effect of sleep (and dreaming) on cognition.

Lecture: Learning

This lecture can be reviewed additionally to chapter 6

Types of Learning

Studying the mechanisms behind learning is an important part of psychology. There are three main types of learning that will be covered in this lecture. Non-associative learning is a more or less permanent change in a response to a stimulus without association to positive or negative reinforcement. This type of learning can be divided into habituation - when the strength or probability of getting a response diminishes as the response is repeated, and sensitization - where a response is increased or amplified as a stimulus is repeatedly introduced.

Associative learning, on the other hand, is when an association between two stimuli is learned. This type of learning can be divided into operant conditioning and classical conditioning, which will both be discussed later in the lecture.

Observational Learning is simply learning that occurs from observing the behaviours of others.

Classical Conditioning

Classical conditioning occurs in three stages:

• Before conditioning, the unconditioned stimulus (UCS) produces an unconditioned response (UCR). This stage also includes a neutral stimulus (NS) that does not independently invoke a response in the subject being conditioned. In the example of Pavlov's Dog, Food is the UCS, salivation is the UCR, and the bell is the NS.

• During conditioning, the NS is associated with the UCS and becomes the conditioned stimulus (CS). In our example, this is done by presenting the dog with food and simultaneously ringing the bell. The bell goes from being the NS to the CS.

• After conditioning, the CS will have been associated to the UCR, turning the UCR into a conditioned response (CR). Going back to the example, we end up with the bell as the CS and salivation as a CR.

Operant Conditioning

Operant conditioning, coined by Burrhus Skinner, is where learning results from reinforcement. Operant conditioning deals with operants - intentional actions that have an effect on the surrounding environment. By reinforcing a subject's behaviour using an operant, you can change the probability that the subject will repeat a behaviour.

There are three types of operants:

1. Neutral operants are responses from the environment that do not affect the probability that a behaviour will be repeated.

2. Reinforcers are responses from the environment that increase the probability of a behavior being repeated. These can be positive (where something is given) or negative (where something is removed.)

3. Punishers are responses from the environment that decrease the likelihood of a behaviour being repeated.

Operant conditioning is influenced by the frequency of reinforcement. The different schedule types are:

• Fixed Interval Schedule: reinforcement is provided after a specific amount of time has passed.

• Variable Interval Schedule: reinforcement is provided after some time, but the amount of time is not regular or specific.

• Fixed Ratio Schedule: reinforcement is provided after a specific number of responses are given.

• Variable Ratio Schedule: reinforcement is provided after an unpredictable number of responses.

Observational Learning

Observational learning is simply changing your behaviour based on what you see. By observing others, it is only natural to imitate the behaviours of others and form models of how a particular behaviour should be. One example is if you watch football and try to imitate the actions of professional football players in your own game of football.

This type of learning occurs because when we learn through observation, our mirror neurons are activated. This activation occurs when we watch someone perform an action and when we then try to perform a similar action.

Dopamine

While the exact biological mechanisms behind learning are still unknown, many researchers believe that dopamine is a key component to learning in humans. Dopamine is a neurotransmitter that is important in reinforcement. In operant conditioning, the value of a reinforcer is determined by dopamine release. Some studies have also found that blocking the effects of dopamine with drugs impairs operant conditioning.

Lecture: Attention and Memory

This lecture can be reviewed additionally to chapter 7

Henry Molaison

Henry Molaison, or H.M., as he's called in the textbook, was one of the most famous cases in memory research. He suffered from severe epilepsy, and as an experimental treatment, his doctors removed the part of his brain that was thought to be causing his seizures. This was a significant part of his temporal lobe, including both hippocampi. It was interesting to researchers because while H.M. was still able to hold a conversation, he was unable to remember new things over the long run. For example, his doctors and psychologists would have to re-introduce themselves to him each time they treated him, and he was generally unable to remember new information. What was surprising about his case was that he was still able to learn new motor tasks and improve on those tasks, while not being aware that he had learned the task. This gave psychologists their first insight into the mechanisms behind memory.

What is Memory?

We have several memory systems that can be thought of as computer components.

• Sensory memory is a brief type of memory tied to our sensory systems. This information is often left unstored, as it is constantly changing, being updated every time we get a new input from our sensory systems. In a computer, this type of memory is best compared to BIOS buffers.

• Short-term memory is similar to a computer's RAM. When we pay attention to something, the information we pay attention to moves past the sensory memory and gets put into short-term memory. Here, information that is left unused or unrehearsed is lost. A more current model calls this type of memory working memory, where many types of information are kept available for current use. We can store approximately 7 +/- 2 things in our working memory, but this can be increased by chunking, or grouping items together so that they are part of a larger picture and are, therefore, easier to remember.

• Long-term memory is like a computer's hard disk. It is our relatively permanent storage. When we repeat or rehearse memories, they become important enough, that is, the neural connections that are responsible for these memories become strong enough, that we hold on to that information. Long-term memory is arranged in neural networks that connect related ideas. For a more detailed description, see Fig. 7.16 in the textbook.

• In addition to sensory, short-term (working), and long-term memory, we also have pre-programmed information, such as reflexes. These are similar to read-only memory in computers.

Memory is our brain's reconstruction of the world around us. It is our brains trying to process and store the information we receive, so that it is able to retrieve it when we need the information later.

Memory operates in three phases:

• The encoding phase happens as we learn new things. Our brains take new information and transform it into a neural code that can be stored

• The storage phase includes a process called consolidation. Consolidation is when the neural connections that are involved in a particular memory get stronger.

• The retrieval phase is when we reach back into our memory storage and pull out previously encoded and stored memories for use.

It is also important to be aware of the primacy and recency effects. Put simply, items at the beginning or end of a list are often better remember than items in the middle. This effect has been tested through various studies, asking participants to memorise lists of words and write down as many as they could remember. As expected, it was found that items near the beginning or end of the lists were more likely to be recalled than those int he middle of the list.

Where is Memory?

The mechanisms behind memory are still largely unknown. We do know, however, that memories are formed and maintained by neural networks, and that particular regions of the brain are responsible for particular kinds of memory (Fig. 7.4 in textbook):

• The amygdala is involved in fear learning.

• The temporal lobe is involved in declarative memory. This is memory that can be consciously recalled, such as knowledge or facts.

• The cerebellum is involved in motor action learning and memory, such as learning a new physical skill

• The hippocampus is involved in spatial memory, or where something is and how to get there.

• The prefrontal cortex is involved in our working memories.

Attention

Attention is an important part in understanding memory. When we pay attention to something, it signifies that that something is important enough to remember. With a constant stream of sensory input, we need to be able to filter out information that is not important, and focus on information that is. One experiment that you can even try at home involves the shadowing technique, where each ear receives a different auditory message. Often times, participants in these studies report hearing the phrase that is more important to them, completely missing the other phrase that is said. This is an example of how attention plays a role in memory - our brains filter out seemingly useless information for us.

When Memory Doesn't Work...

Sometimes, our memories do not work the way we want them to. We may have a difficult time recalling important information, or have trouble forgetting something that isn't important to us. Daniel Schater, an American neurologist, identified what he calls the seven sins of memory:

• Transience is the reduction of memory, or forgetting things over time.

• Blocking is the inability to remember needed information.

• Absentmindedness is the reduction of memory due to not paying attention.

• Persistence is not being able to get rid of an unwanted memory, for example if you keep remembering a social faux pas, or traumatic experience.

• Misattribution is connecting a memory to the wrong source, for example, thinking that someone is famous just because he or she is well-known.

• Bias is taking current knowledge and applying it to memories, or remembering past attitudes or events as similar to current ones, even though they have changed over time.

• Suggestibility is the changing of a memory based on misleading information.

Additionally, interference sometimes prevents us from using our memories the way we want.

• Proactive interference is when old information prevents us from remembering new information, for example, when you change your PIN and can only remember your old PIN.

• Retroactive interference is the opposite, when new information prevents us from remembering old information, for example, when you change phone numbers, learn your new phone number, but can only remember your old phone number.

Amnesia is a deficit in long-term memory. This can occur after trauma, such as a car accident, or brain disease, such as cancer. As with interference, there are two types:

Retrograde amnesia is the loss of long-term memories from the past. This includes many types of long-term memory, such as facts, knowledge, learned skills, events, people, and personal information.

Anterograde amnesia is the inability to form new memories. This is the kind of amnesia that H.M. from the beginning of the lecture had.  

Lecture: Thinking and Intelligence

This lecture can be reviewed additionally to chapter 8

When we think, what we are really doing is manipulating the knowledge that we have. In order to understand how thinking works, we first have to look at how our knowledge is organised. We organise our knowledge using representations of the information we receive; for example, a map is a representation of the streets we have to navigate. There are two types of representations:

Analogical representations include physical characteristics of an object, while symbolic representations are more abstract and do not correspond to an object's physical attributes.

Schemas and Stereotypes

We use concepts and schemas for a wide range of things, including the perception of other people. We use these categories in order to organise our thoughts and keep our perception of the world comprehensible. One example of the use of stereotypes in society is in advertising. Often times, toys for girls are advertised on pink paper and include toys like dolls and household 'toys,' while toys for boys are often advertised on blue paper and include things like science sets and action figures. A stereotype is a widely held but fixed and oversimplified image or idea of a particular type of person or thing.

Decision Making and Problem Solving

An important part of problem solving is reasoning, or using your observations of the world to draw conclusions. There are two types of reasoning:

• Inductive reasoning is using a specific instance and generalising it to a principle. For example, if you bump into a friend at a coffee shop, you can conclude that he or she enjoys coffee.

• Deductive reasoning is the opposite of that, where you take a general principle and make a specific decision based on that, for example, you know that your friend likes coffee, so as a birthday present, you buy him or her a gift card for a coffee shop.

In decision-making, one thing to keep in mind is that most people are open to ideas they already agree with. Often times, it is difficult to take in the information pertaining to a new idea, much less make a decision about one.

Heuristics

Heuristics are shortcuts that we use in decision-making. The following are some common ones that often get in the way of rationality:

Availability: we go for the most readily available answer and are strongly influenced by the information available to us. For example, one might conclude that smoking is not harmful because you had a grandfather who smoked throughout his life and lived until 92 years of age.

Base-rate neglect: we often neglect the actual likelihood of a particular event taking place. We sometimes forget how rare a situation actually is, for example, by reading a list of symptoms on WebMD, we may conclude that we have many symptoms attributed to rare form of cancer, forgetting to take into account that the actual likelihood of having that cancer is very low.

The context of a particular decision, or the framing, is very important. For example, the perceived loss of losing €1000 is much stronger than the perceived gain of winning €1000. We assign more value to things that we already have than things that we have yet to gain. This leads to irrational behaviour and irrational decision-making.

Affective forecasting is when we take into account what might happen as a result of a particular decision.

Intelligence

Intelligences is someone's ability to use knowledge to reason, solve problems, and make inferences about the world. One of the biggest questions in psychology and society is about intelligence, namely, is it important, and how can it be measured?

Whether or not intelligence is as important as some make it out to be is still a matter of debate. Intelligence is often measured using standardised tests. Alfred Binet, French psychologist first launched the psychometric approach to testing intelligence with the intention of identifying children who needed extra help in school. It appeared to Binet that some children behaved like children older or younger than their peers, which led him to introduce the term mental age. The mental age is simply a child's intellectual standing compared to that of children of the child's age. Later, psychologist Wilhelm Stern developed the intelligence quotient (IQ) using this mental age.

• IQ = (mental age / biological age) x 100

It is important to note that this measure of IQ only applies to children. In adults, IQ scores are measured against scores of other adults, regardless of age. IQ is normally distributed with a mean of 100 and a standard deviation of 15.

General Intelligence

General intelligence is a term used to describe the idea that one factor underlies intelligence. This factor, g, is said to contribute to a person's performance on any task involving intellect. This generalised intelligence consists of two sub-types of intelligence: fluid and crystalised.

• Fluid intelligence is being able to think abstractly and logically without the need of prior knowledge. This kind of intelligence involves information processing and thinking quickly and flexibly.

• Crystalised intelligence, on the other hand, is intelligence that is acquired through experience, such as cultural information.