Cognitive Psychology Midterms

COGNITIVE PSYCHOLOGY is the study of how people perceive, learn, remember, and think about information

- Memory, Attention, Perception, Reasoning, Problem Solving, Decision Making, Language

- A cognitive psychologist might study how people perceive various shapes, why they remember some facts but

forget others, or how they learn language.

Dialectic is a developmental process where ideas evolve over time through a pattern of transformation. A THESIS IS PROPOSED.

•A thesis is a statement of belief. AN ANTITHESIS EMERGES.

•An antithesis is a statement that counters a previous statement of belief. A SYNTHESIS INTEGRATES THE VIEWPOINTS.

•A synthesis integrates the most credible features of each of two (or more) views.

PHILOSOPHICAL ANTECEDENTS

2 approaches to understanding the human mind

1.) Philosophy • seeks to understand the general nature of many aspects of the world, in part through introspection, the examination of inner ideas and experiences (from intro-, “inward, within,” and -spect, “look”)

2.) Physiology • seeks a scientific study of life-sustaining functions in living matter, primarily through empirical (observation-based) methods.

Rationalist - Acquire knowledge through thinking and logical analysis Empiricist - Acquire knowledge via empirical evidence

2 Greek philosophers who have profoundly affected modern thinking in psychology and many other fields.

1. Plato (a rationalist)

2. Aristotle (An Empiricist)

• Rationalist - believes that the route to knowledge is through thinking and logical analysis. Rene Descartes (1596-1650) - dualism between a material body and immaterial mind or soul

- mechanistic explanations for the body’s functions.

Pineal Gland

• Empiricist - believes that we acquire knowledge via empirical evidence (through experience and observation)

- would design experiments and conduct studies in which they could observe the behavior and processes of interest to them.

John Locke (1632–1704) - An English philosopher who theorized that the human mind was a tabula rasa at birth, and that all human knowledge comes through experience

Immanuel Kant (1724-1804)

2 domains of reality: noumenal and phenomenal

• The phenomenal world is the world we are aware of;

• The noumenal world consists of things we seem compelled to believe in, but which we can never know.

PSYCHOLOGICAL ANTECEDENTS

Psychology as science

•It can be described spatially

•It is not too transient to observe/measure •It can be manipulated experimentally

•It can be described mathematically

The 2 “fathers” of psychology Structuralism - What are the elementary contents (structures) of the human mind?

1.) Wilhelm Wundt (1832– 1920) • German Psychologist

• Introspection

Functionalism - How and why does the mind work? 2.) William James (1842– 1910)

• Principles of Psychology (1890/1970)

• Structuralism • seeks to understand the structure (configuration of elements) of the mind and its perceptions by

analyzing those perceptions into their constituent components (affection, attention, memory, sensation, etc.)

Example:

The perception of a flower

• Structuralists would analyze this perception in terms of its constituent colors, geometric forms, size relations, and so on.

In terms of the human mind

• structuralists sought to deconstruct the mind into its elementary components

they were also interested in how those elementary components work together to create the mind

➢ Functionalism - focus on the processes of thought rather than on its contents. - seeks to understand what people do and why they do it.

William James (1842–1910) - A Harvard professor who established the first psychology laboratory in America. • Philosophy of pragmatism (1890)

• Pragmatism - includes those who claim that an ideology or proposition is true if it works satisfactorily, that the meaning of a proposition is to be found in the practical consequences of accepting it, and that unpractical ideas are to be rejected.

Edward Lee Thorndike (1874–1949) - An American comparative psychologist who studied with James.

• Studies the trial-and-error learning and formulation of the law of effect, and his studies with Woodworth on the transfer of training.

Law of Effect - Thorndike’s assertion that when certain stimulus response are followed by pleasure, they are strengthened, while responses followed by annoyance or pain tend to be “stamped out.”

➢ Associationism - examines how elements of the mind, like events or ideas, can become associated with one another in the mind to result in a form of learning.

* It may result from:

* contiguity (associating things that tend to occur together at about the same time)

* similarity (associating things with similar features or properties)

* contrast (associating things that show polarities, such as hot/cold, light/dark/, day/ night)

Hermann Ebbinghaus (1850–1909) - studied how people learn and remember material through rehearsal, the conscious repetition of material to be learned.

The Ebbinghaus Forgetting Curve shows that the first few repetitions result in a steep learning curve. Later repetitions result in a slower increase of remembered words.

➢ Behaviorism - What is the relation between behavior and environment? Proponents of Behaviorism

John Watson (1878–1958) - The “father” of radical behaviorism. He believed that psychologists should concentrate only on the study of observable behavior

B. F. Skinner (1904–1990) - believed that almost all forms of human behavior, not just learning, could be explained by behavior emitted in reaction to the environment

• Operant conditioning

➢ Gestalt Psychology (The Whole Is More Than the Sum of Its Parts)

•We best understand psychological phenomena when we view them as organized, structured wholes. •We cannot fully understand behavior when we only break phenomena down into smaller parts.

Gestalt Psychology - Cognitions should play an active role in psychology (Wertheimer, Kohler)

EMERGENCE OF COGNITIVE PSYCHOLOGY

• In the early 1950s (“cognitive revolution”)

• Cognitivism is the belief that much of human behavior can be understood in terms of how people think.

• 1950s: Development of computers

• Turing (1950)-(“Turing test”) a computer program would be judged as successful to the extent that its output

was indistinguishable, by humans, from the output of humans.

• 1956: Artificial intelligence

Artificial intelligence (AI) is the attempt by humans to construct systems that show intelligence and, particularly,

the intelligent processing of information.

• In the early 1960s - developments in psychobiology, linguistics, anthropology, and artificial intelligence, and reactions against behaviorism by many mainstream psychologists, converged to create an atmosphere ripe for revolution.

• 1970s: Concept of modularity of Mind

• Jerry Fodor (1973) (concept of the modularity of mind)

• the mind has distinct modules, or special-purpose systems, to deal with linguistic and, possibly, other kinds of information.

• Modularity implies that the processes that are used in one domain of processing, such as the linguistic (Fodor, 1973) or the perceptual domain (Marr, 1982), operate independently of processes in other domains.

Psychobiology: Karl Spencer Lashley (1890– 1959)

• considered the brain to be an active, dynamic organizer of behavior.

• sought to understand how the macro-organization of the human brain made possible such complex, planned activities as musical performance, game playing, and using language.

• “His monograph Brain Mechanisms and Intelligence (1929) contained two significant principles:

1.) Mass action - certain types of learning are mediated by the cerebral cortex (the convoluted outer layer of the cerebrum) as a whole, contrary to the view that every psychological function is localized at a specific place on the cortex. 2.) Equipotentiality - associated chiefly with sensory systems such as vision, relates to the finding that some parts of a system take over the functions of other parts that have been damaged.

Alan Turing (1912-1954) - Founder of computer science, mathematician, philosopher

• Broke German Enigma code in WWII • Openly gay in 1950s

• Arrested and convicted

• Likely committed suicide as a result.

Ada, Countess of Lovelace (1815-1852) - Daughter of the poet, Byron

• Gifted mathematician

• wrote first computer program – calculated sequence of Bernoulli numbers

• The Lovelace Objection - Machines can only do what we know how to order them to do

Cognition and Intelligence

Intelligence - is the capacity to learn from experience, using metacognitive processes to enhance learning, and the ability

to adapt to the surrounding environment.

Intelligence involves:

• the capacity to learn from experience

• the ability to adapt to the surrounding environment.

3 COGNITIVE MODELS OF INTELLIGENCE

1.) Carroll: Three Stratum Model of Intelligence -intelligence comprises a hierarchy of cognitive abilities comprising

three strata (Carroll, 1993)

• Stratum III is just a single general intelligence (sometimes called g). • Stratum II includes various broad abilities

• Stratum I includes many narrow, specific abilities

In the middle stratum are fluid ability and crystallized ability.

1.) Fluid ability - is speed and accuracy of abstract reasoning, especially for novel problems (Cattell, 1971). 2.) Crystallized ability - is accumulated knowledge and vocabulary (Cattell, 1971).

Caroll includes several other abilities in the middle stratum:

• learning and memory processes

• visual perception

• auditory perception

• facile production of ideas (similar to verbal fluency)

• speed (which includes both sheer speed of response and speed of accurate responding).

2.) Gardner: Theory of Multiple Intelligences

•Howard Gardner - intelligence comprises multiple independent constructs, not just a single, unitary construct

Gardner’s Eight Intelligences

Type of Tasks Reflecting This Type of Intelligence Intelligence

1. Linguistic intelligence

2. Logical- mathematical intelligence

3. Spatial intelligence

4. Musical intelligence

5. Bodily- kinesthetic intelligence

6. Interpersonal intelligence

7. Intrapersonal intelligence

Used in reading a book; writing a paper, a novel, or a poem; and understanding spoken words

Used in solving math problems, in balancing a checkbook, in solving a mathematical proof, and in logical reasoning

Used in getting from one place to another, in reading a map, and in packing suitcases in the trunk of a car so that they all fit into a compact space

Used in singing a song, composing a sonata, playing a trumpet, or even appreciating the structure of a piece of music

Used in dancing, playing basketball, running a mile, or throwing a javelin

Used in relating to other people, such as when we try to understand another person’s behavior, motives, or Emotions

Used in understanding ourselves—the basis for understanding who we are, what makes us tick, and how we can change ourselves, given our existing constraints on our abilities and our interests

8. Naturalist Used in understanding patterns in nature intelligence

3.) Robert Sternberg: The Triarchic Theory of Intelligence

• Creative abilities are used to generate novel ideas.

• Analytical abilities ascertain whether your ideas (and those of others) are good ones. • Practical abilities are used to implement the ideas and persuade others of their value

RESEARCH METHODS

- Controlled Laboratory Experiments - Obtain samples of performance at a particular time and place In an Experiment...

• Manipulate the independent variable

• The “cause”

• Measure the dependent variable

• The “effect”

• Control all other variables

• Prevent confounds

➢ Independent Variable – variable that is changed.

Example: Amount of Water

•Characteristics of the situation

• Presence vs. absence of a stimulus

•Characteristics of the task

Typical Independent Variables

• Reading vs. listening to words for comprehension

•Characteristics of participants

• Age differences

➢ Dependent Variable – variable affected by the change Example: Size of Plant, Number of Leaves, Living or Dead

•Percent correct/error rate

• Accuracy of mental processing

•Reaction time (milliseconds)

• Speed of mental processing

• Correlational Studies

• Cannot infer causation • Nature of relationship

• Positive correlation • Negative correlation

Typical Dependent Variables

• Strength of relationship - Determined by size of “ r ”

Example: Correlational Study - An examination of the relationship between confidence and accuracy of eyewitnesses • What do you think the relationship is? Positive? Negative? Strong? Weak?

It is not a strong positive correlation!

(Many studies indicate that high confidence does not mean high accuracy)

• Psychobiological Research - investigators study the relationship between cognitive performance and cerebral events and

structures.

• Study animal brains and human brains, using postmortem studies and various psychobiological measures or imaging techniques

These techniques generally fall into 3 categories:

• Self-Reports (Verbal Protocols, Self-Rating, Diaries)

•Obtain participants’ reports of own cognition in progress or as recollected • An individual’ s own account of cognitive processes

• Verbal protocol, diary study

• Case Studies • Engage in intensive study of single individuals, drawing general conclusions about behavior

In-depth studies of individuals

• Genie, Phineas Gage, H.M.

• Naturalistic observation - Observe real-life situations, as in classrooms, work settings, or homes

COMPUTER SIMULATIONS AND ARTIFICIAL INTELLIGENCE Simulations - Attempt to make computers simulate human cognitive performance on various tasks

- researchers program computers to imitate a given human function or process.

AI - Attempt to make computers demonstrate intelligent cognitive performance, regardless of whether the process resembles human cognitive processing

BASIC IDEAS IN COGNITIVE PSYCHOLOGY

1. Empirical data and theories are both important—data in cognitive psychology can be fully understood only in the

context of an explanatory theory, and theories are empty without empirical data. 2. Cognition is generally adaptive, but not in all specific instances.

3. Cognitive processes interact with each other and with noncognitive processes.

4. Cognition needs to be studied through a variety of scientific methods.

5. All basic research in cognitive psychology may lead to applications, and all applied research may lead to basic understandings.

KEY THEMES IN COGNITIVE PSYCHOLOGY

NATURE VS. NURTURE Thesis/Antithesis: Which is more influential in human cognition— nature or nurture?

Synthesis: We can explore how covariations and interactions in the environment (e.g., an impoverished environment) adversely affect someone whose genes otherwise might have led to success in a variety of tasks.

RATIONALISM VERSUS EMPIRICISM

Thesis/Antithesis: How should we discover the truth about ourselves and about the world around us?

Synthesis: We can combine theory with empirical methods to learn the most we can about cognitive phenomena.

STRUCTURES VERSUS PROCESSES

Thesis/Antithesis: Should we study the structures (contents, attributes, and products) of the human mind?

•Or should we focus on the processes of human thinking?

Synthesis: We can explore how mental processes operate on mental structures.

DOMAIN GENERALITY VERSUS DOMAIN SPECIFICITY

Thesis/Antithesis: Are the processes we observe limited to single domains, or are they general across a variety of domains?

• Do observations in one domain apply also to all domains, or do they apply only to the specific domains observed?

Synthesis: We can explore which processes might be domain-general and which might be domain specific. VALIDITY OF CAUSAL INFERENCES VERSUS ECOLOGICAL VALIDITY

Thesis/Antithesis: Should we study cognition by using highly controlled experiments that increase the probability of valid inferences regarding causality?

• Or should we use more naturalistic techniques, which increase the likelihood of obtaining ecologically valid findings but possibly at the expense of experimental control?

Synthesis: • We can combine a variety of methods, including laboratory methods and more naturalistic ones, so as to converge on findings that hold up, regardless of the method of study.

APPLIED VERSUS BASIC RESEARCH Thesis/Antithesis: Should we conduct research into fundamental cognitive processes?

• Or should we study ways in which to help people use cognition effectively in practical situations? Synthesis: • We can combine the two kinds of research dialectically so that basic research leads to applied research, which leads to further basic research, and so on.

BIOLOGICAL VERSUS BEHAVIORAL METHODS

Thesis/Antithesis: Should we study the brain and it’s functioning directly, perhaps even scanning the brain while

people are performing cognitive tasks?

• Or should we study people’s behavior in cognitive tasks, looking at measures such as percent correct and reaction time?

Synthesis: • We can try to synthesize biological and behavioral methods so that we understand cognitive phenomena at multiple levels of analysis.

UNIT 2. COGNITIVE NEUROSCIENCE

The field of study linking the brain and other aspects of the nervous system to cognitive processing and, ultimately, to behavior.

Brain and Nervous System

Brain - the organ in our bodies that most directly controls our thoughts, emotions, and motivations. Nervous System – the basis of our ability to perceive, adapt to, and interact with the world around us.

- Through this system we receive, process, and respond to information from the environment.

Gross Anatomy of the Brain

The forebrain, the midbrain, and the hindbrain contain structures that perform essential functions for survival and for high-level thinking and feeling.

Forebrain - High-level thinking and emotions. Midbrain - Eye movement and coordination. Hindbrain - Basic survival functions.

A. Forebrain Structures

The region of the brain located toward the top and front of the brain.

1. Cerebral Cortex - the outer layer of the cerebral hemispheres.

- involved in receiving and processing sensory information, thinking, other cognitive processing, and planning and sending motor information

2. Basal Ganglia - collections of nuclei and neural fibers

- crucial to the function of the motor system dysfunction of the basal ganglia can result in motor deficits including:

● tremors

● involuntary movements

● changes in posture and muscle tone ● slowness of movement.

- deficits can be found in Parkinson’s disease and Huntington’s disease 3. Limbic System - important to emotion, motivation, memory, and learning.

- suppress instinctive responses

- help us to adapt our behaviors flexibly in response to our changing environment.

The limbic system comprises three central interconnected cerebral structures:

1. Septum - influences anger and aggression

1. Amygdala - influences anger and fear

1. Amygdala - influences anger and fear

Do you know that ??

★ Damage to (lesions in) or removal of the amygdala can result in maladaptive lack of fear.

★ In humans, lesions to the amygdala prevent the enhancing e"ect for the perception of emotional stimuli Persons with autism display limited activation in the amygdala.

★ Lesions to the amygdala can lead to visual agnosia (inability to recognize objects) and hyper sexuality.

4. Hippocampus - influences learning and memory - from a Greek word meaning “seahorse”

- is essential for flexible learning and for seeing the relations among items learned as well as for spatial memory

Do you know that ??

Korsako"’s Syndrome - a disease that produces loss of memory function.

★ Symptoms include: apathy, paralysis of muscles controlling the eye, and tremor

★ associated with deterioration of the hippocampus and is caused by a lack of thiamine (Vitamin B-1) in the brain

★ can result from excessive alcohol use, dietary deficiencies, or eating disorders

5. Thalamus - primary relay station for sensory information coming into the brain - helps in the control of sleep and waking.

Comprises several nuclei that receive specific kinds of sensory information and project that information to specific regions of the cerebral cortex, including four key nuclei for sensory information:

1. from the visual receptors, via optic nerves, to the visual cortex, permitting us to see

2. from the auditory receptors, via auditory nerves, to the auditory cortex, permitting us to hear

3. from sensory receptors in the somatic nervous system, to the primary somatosensory cortex, permitting us to sense pressure and pain

4. from the cerebellum (in the hindbrain) to the primary motor cortex, permitting us to sense physical balance and equilibrium

Do you know that ??

★ When the thalamus malfunctions, the result can be pain, tremor, amnesia, impairment of language, and disruptions in waking and sleeping.

★ In cases of schizophrenia, imaging and in vivo studies reveal abnormal changes in the thalamus.

★ These abnormalities result in di#culties in filtering stimuli and focusing attention, which in turn can explain why people su"ering from schizophrenia experience symptoms such as hallucinations and delusions.

6. Hypothalamus - controls the autonomic nervous system

- involved in regulation of behavior related to species survival - plays a role in controlling consciousness

- involved in emotions, pleasure, pain, and stress reactions

Plays a role in sleep

● dysfunction and neural loss within the hypothalamus are noted in cases of narcolepsy (a person falls asleep often and at unpredictable times)

Important for the functioning of the endocrine system. ● involved in the stimulation of the pituitary

B. Midbrain Structures

It helps to control eye movement and coordination

● Superior Colliculi - processes vision. ● Inferior Colliculi - processes hearing

● Reticular Activating System - important in controlling consciousness (sleep arousal), attention, cardiorespiratory function, and movement.

● Gray matter, red nucleus, substantia nigra, ventral region - important in controlling movement.

C. Hindbrain Structures

It comprises the medulla oblongata, the pons, and the cerebellum

Medulla Oblongata

- controls heart activity and largely controls breathing, swallowing, and digestion.

- serves as juncture at which nerves cross from one side of the body to opposite side of the brain

Pons

Cerebellum

- from Latin, “little brain”

- controls bodily coordination, balance, and muscle tone, as well as some aspects of memory involving

procedure-related movements

PRENATAL DEVELOPMENT OF THE HUMAN BRAIN

1. The hindbrain is evolutionarily the oldest and most primitive part of the brain. It also is the first part of the brain to develop prenatally.

2. The midbrain is a relatively newer addition to the brain in evolutionary terms. It is the next part of the brain to develop prenatally.

- Involved in consciousness (sleep and arousal)

- bridges neural transmissions from one part of the brain to another •its name derives from the Latin

for “bridge

3. Finally, the forebrain is the most recent evolutionary addition to the brain. It is the last of the three portions of the brain to develop prenatally.

FETAL BRAIN DEVELOPMENT

Over the course of embryonic and fetal development, the brain becomes more highly specialized and the locations and relative positions of the hindbrain, the midbrain, and the forebrain change from conception to term.

Cerebral Cortex

● enables us to think (we can plan, coordinate thoughts and actions, perceive visual and sound patterns, and use language)

● comprises 80% of the human brain Three elements:

1. Sulci/Sulcus (small grooves)

2. Fissures (large grooves)

3. Gyri/Gyrus (bulges between adjacent sulci or fissures)

The surface of the cerebral cortex is grayish. It is sometimes referred to as gray matter. This is because it primarily comprises the grayish neural cell bodies that process the information that the brain receives and sends.

CEREBRAL CORTEX PRINCIPLES 1. Contralateral

● Right side of brain controls left side of body

● Left side of brain controls right side of body

2. Ipsilateral transmission - on the same side

The hemispheres also communicate directly with one another.

THE HEMISPHERES

Left Hemisphere - examines past experiences to find patterns.

Apraxia

★ disorders of skilled movements

★ damage to the left hemisphere.

★ damage to the left hemisphere.

★ lost the ability to carry out familiar purposeful movements like forming letters when writing by hand

Right Hemisphere - good semantic knowledge ★ practical language use

★ People with right-hemisphere damage tend to have deficits in following conversations or stories. They also have di#culties in making inferences from context and in understanding metaphorical or humorous speech

★ plays a primary role in self recognition

★ responsible for the identification of one’s own face CORPUS CALLOSUM

● allows transmission of information back and forth.

● if the corpus callosum is cut, the two cerebral hemispheres—the two halves of the brain—cannot

communicate with each other

CEREBRAL CORTEX PRINCIPLES

Localization of function

● Specific areas of the brain that control specific skills or behaviors.

Hemispheric Specialization

● Each lobe of the brain has specialized function

EVIDENCE FOR SPECIALIZATION OF LEFT LOBE

● Wernicke’s area - contributes to language comprehension

● Broca’s area - critical in speech

Split-brain patients - people who have undergone operations severing the corpus callosum

LOBES OF THE CEREBRAL HEMISPHERES

Temporal lobe

● directly under your temples

● associated with auditory processing and comprehending language

● retention of visual memories

● also matches new things you see to what you have retained in visual memory.

Occipital lobe

● Visual processing

● contains numerous visual areas, each specialized to analyze specific aspects of a scene, including

color, motion, location, and form

Frontal lobe

● located toward the front of the head (the face)

● plays a role in reasoning, judgment, problem solving, personality, and intentional movement

● contains the primary motor cortex, which specializes in the planning, control, and execution of movement, particularly of movement involving any kind of delayed response.

Parietal lobe

● at the upper back portion of the brain

● associated with somatosensory processing (Touch, Temperature, Pain, & Pressure) ● involved in consciousness and paying attention

NEURONAL STRUCTURE AND FUNCTION

Neurons – basic unit of the brain.

Neuronal Structure and Function (Four Basic Parts)

1. Soma

● contains the nucleus of the cell (the center portion that performs metabolic and reproductive functions for the cell)

● responsible for the life of the neuron and connects the dendrites to the axon.

2. Dendrites

● are branchlike structures that receive information from other neurons, and the soma integrates the

information

3. Axon

● a long, thin tube that extends (and sometimes splits) from the soma and responds to the information by transmitting an electrochemical signal, which travels to the terminus (end), where the signal can be transmitted to other neurons

● are of two basic, roughly equally occurring kinds, distinguished by the presence or absence of myelin

4. Terminal button

● small knobs found at the ends of the branches of an axon that do not directly touch the dendrites of

the next neuron.

5. Myelin sheath

● a white, fatty substance that surrounds some of the axons of the nervous system, which accounts for some of the whiteness of the white matter of the brain

● which insulates and protects longer axons from electrical interference by other neurons in the area, also speeds up the conduction of information.

6. Nodes of Ranvier

● are small gaps in the myelin coating along the axon, which serve to increase conduction speed even more by helping to create electrical signals, also called action potentials, which are then conducted down the axon.

7. Synapse

● a very small gap

● serves as a juncture between the terminal buttons of one or more neurons and the dendrites (or sometimes the soma) of one or more other neurons

● are important in cognition

Neurotransmitters

Neurotransmitters

● are chemical messengers for transmission of information across the synaptic gap to the receiving dendrites of the next neuron.

Types of chemical substances are involved in neurotransmission:

monoamine neurotransmitters - are synthesized by the nervous system through enzymatic actions on one of the amino acids (constituents of proteins, such as choline, tyrosine, and tryptophan) in our diet (e.g., acetylcholine, dopamine, and serotonin)

amino acid neurotransmitters - are obtained directly from the amino acids in our diet without further synthesis (e.g., gamma-aminobutyric acid, or GABA)

neuropeptides - are peptide chains (molecules made from the parts of two or more amino acids)

IMPORTANT NEUROTRANSMITTERS

Acetylcholine

● associated with memory functions, and the loss of acetylcholine through Alzheimer’s disease ● has been linked to impaired memory functioning in Alzheimer’s patients

● plays an important role in sleep and arousal

Dopamine

● is associated with attention, learning, and movement coordination

● is associated with attention, learning, and movement coordination

● involved in motivational processes, such as reward and reinforcement

● Schizophrenics (high levels of dopamine)

● Parkinson’s disease (very low dopamine levels)

● Gambling is a compulsive disorder that results from impaired impulse control. When dopamine treatment is suspended, these patients no longer exhibit this behavior.

Serotonin

● plays an important role in eating behavior and body weight regulation •High serotonin levels (anorexia)

● involved in aggression and regulation of impulsivity

METHODS TO STUDY THE BRAIN

Postmortem Studies - identify disorder and then examine after death

STUDYING LIVE NON-HUMAN ANIMALS

1. In vivo techniques - monitor activity of a single neuron.

2. Single cell recordings - researchers insert a very thin electrode next to a single neuron in the brain of an animal (usually a monkey or a cat). They then record the changes in electrical activity that occur in the cell when the animal is exposed to a stimulus.

3. Selective lesioning - surgically removing or damaging part of the brain—to observe resulting functional deficits

4. Genetic knockout Procedures/genetic manipulations - animals can be created that lack certain kinds of cells or receptors in the brain.

STUDYING LIVE HUMANS

Static Imaging Techniques

Electrical Recordings - The transmission of signals in the brain occurs through electrical potentials. When recorded, this activity appears as waves of various widths (frequencies) and heights (intensities).

Electroencephalograms (EEGs)

● are recordings of the electrical frequencies and intensities of the living brain, typically recorded over relatively long periods

● used as a tool in the diagnosis of epilepsy Event related potential (ERP)

● the record of a small change in the brain’s electrical activity in response to a stimulating event ● used to examine language processing

● used to examine developmental changes in cognitive abilities.

- Psychologists use still images to reveal the structures of the brain. Angiography - examine the blood flow

Metabolic Imaging

BRAIN DISORDERS

I. Stroke - occurs when the flow of blood to the brain undergoes a sudden disruption.

- marked loss of cognitive functioning

- the nature of the loss depends on the area of the brain that is a"ected by the stroke.

Two kinds of stroke: ● Ischemic Stroke

○ occurs when a buildup of fatty Hemorrhagic stroke tissue occurs in blood vessels over a period of years, and a piece of this tissue breaks o" and gets lodged in arteries of the brain

○ can be treated by clot-busting drugs

● Hemorrhagic Stroke

○ occurs when a blood vessel in the brain suddenly breaks. Blood then spills into surrounding tissue

○ As the blood spills over, brain cells in the a"ected areas begin to die. This death is either from the lack of oxygen and nutrients or from the rupture of the vessel and the sudden spilling of blood.

II. Brain Tumors - also called neoplasms, can a"ect cognitive functioning in very serious ways. - Primary brain tumors start in the brain. Most childhood brain tumors are of this type.

- Secondary brain tumors start as tumors somewhere else in the body, such as in the lungs. - Diagnosis: neurological examination, CT scan, and/or MRI.

- The most common form of treatment is a combination of surgery, radiation, and chemotherapy.

Computed tomography (CT or CAT) - consists of several X-ray images of the brain taken from di"erent vantage points that, when combined, result in a three dimensional image.

Magnetic Resonance Imaging (MRI) scan - reveals high-resolution images of the structure of the living brain by computing and analyzing magnetic changes in the energy of the orbits of nuclear particles in the molecules of the body.

● Structural MRIs provide images of the brain’s size and shape

● Functional MRIs visualize the parts of the brain that are activated when a person is engaged in a

particular task.

- rely on changes that take place within the brain as a result of increased consumption of glucose and oxygen in active areas of the brain. The basic idea is that active areas in the brain consume more glucose and oxygen than do inactive areas during some tasks.

Transcranial magnetic stimulation (TMS)

● temporarily disrupts the normal activity of the brain in a limited area. ● It can imitate lesions in the brain or stimulate brain regions.

● requires placing a coil on a person’s head and then allowing an electrical current to pass through it. The current generates a magnetic field.

Magnetoencephalography (MEG)

● measures activity of the brain from outside the head (similar to EEG) by picking up magnetic fields emitted by changes in brain activity.

● This technique allows localization of brain signals so that it is possible to know what di"erent parts of the brain are doing at di"erent times.

Two general types of tumors: 1. Benign brain tumors

● do not contain cancer cells.

● typically can be removed and will not grow back

● Cells from benign tumors do not invade surrounding cells or spread to other parts of the body.

● If they press against sensitive areas of the brain, they can result in serious cognitive impairments.

2. Malignant brain tumors

● contain cancer cells

● They are more serious and usually threaten the victim’s life.

● they often grow quickly

● they also tend to invade surrounding healthy brain tissue

● in rare instances, malignant cells may break away and cause cancer in other parts of the body.

III. Head Injuries - result from many causes, such as a car accident, contact with a hard object, or a bullet wound

- Loss of consciousness (sign of damage to the brain as a result of the injury)

- Damage resulting from head injury can include spastic movements, di#culty in swallowing, and

slurring of speech, among many other cognitive problems.

Two types of Head injuries:

● Closed head injuries

○ The skull remains intact but there is damage to the brain, typically from the mechanical force of a blow to the head.

○ Example: Slamming one’s head against a windshield in a car accident

● Open head injuries - the skull does not remain intact but rather is penetrated, for example, by a bullet.

INTELLIGENCE AND NEUROSCIENCE

★ The amount of gray matter in the brain is strongly correlated with IQ in many areas of the frontal and temporal lobes

★ Frontal areas are of relatively more importance in women, whereas posterior areas are of relatively more importance in men, even if both genders are matched for intelligence

★ The relationship between brain size and intelligence does not hold across species (Jerison, 2000). Rather, what holds seems to be a relationship between intelligence and brain size, relative to the rough general size of the organism.

Intelligence and Neurons - Complex patterns of electrical activity in the brain, which are prompted by specific stimuli, appear to correlate with scores on IQ tests.

Intelligence and Brain Metabolism - Higher intelligence correlates with reduced levels of glucose metabolism during problem-solving tasks. That is, smarter brains consume less sugar and therefore expend less e"ort than less smart brains doing the same task.

The P FIT Theory of Intelligence

● called the parietal-frontal integration theory (P-FIT), stresses the importance of interconnected brain regions in determining di"erences in intelligence.

● The regions this theory focuses on are the prefrontal cortex, the inferior and superior parietal lobe, the anterior cingulated cortex, and portions of the temporal and occipital lobes.

● describes patterns of brain activity in people with di"erent levels of intelligence; it cannot, however, explain what makes a person intelligent or what intelligence is.

UNIT 3. VISUAL PERCEPTION

Perception - The process of recognizing, organizing, and interpreting depth). Sensory adaptation

● Occurs when sensory receptors change their sensitivity to the stimulus ● Constant stimulation leads to lower sensitivity

The Ganzfeld E"ect - “Ganzfeld” is German and means “complete field.” - It refers to an unstructured visual

- When your eyes are exposed to a uniform field of stimulation , you will stop perceiving that stimulus after a few minutes and see just a gray field instead. This is because your eyes have adapted to the stimulus.

Perceptual Illusions

● Sometimes we cannot perceive what does exist ● Sometimes we perceive things that do not exist ● Sometimes we perceive what cannot be there

● example, by a bullet.

How Does Our Visual System Work?

➔ light passes

➔ Cornea (continue to pass)

➔ Pupil (continue to pass)

➔ Iris (continue to pass)

➔ crystalline lens and the vitreous humor (continue to pass) ➔ Retina (light focuses and converted)

➔ fovea

● Cornea, is a clear dome that protects the eye.

● Pupil, the opening in the center of the iris. •Iris, the colored part of the eye.

● Vitreous Humor is a gel-like substance that comprises the majority of the eye.

● Retina where electromagnetic light energy is transduced—that is, converted—into neural electrochemical impulses.

● Fovea, a small, thin region of the retina, the size of the head of a pin. When you look straight at an

● Fovea, a small, thin region of the retina, the size of the head of a pin. When you look straight at an object, your eyes rotate so that the image falls directly onto the fovea.

The Retina

● The first layer of neuronal tissue—closest to the front, outward-facing surface of the eye—is the layer of ganglion cells, whose axons constitute the optic nerve.

● The second layer consists of three kinds of interneuron cells:

★ Amacrine cells and horizontal cells make single lateral (i.e., horizontal) connections among adjacent areas of the retina in the middle layer of cells.

★ Bipolar cells make dual connections forward and outward to the ganglion cells, as well as backward and inward to the third layer of retinal cells.

● The third layer of the retina contains the photoreceptors, which convert light energy into electrochemical energy that is transmitted by neurons to the brain.

● There are two kinds of photoreceptors (rods and cones)

● Each eye contains roughly 120 million rods and 8 million cones.

● Within the rods and cones are photopigments, chemical substances that react to light and transform physical electromagnetic energy into an electrochemical neural impulse that can be understood by the brain.

RODS

CONES

Pathways to Perceive the What and the Where:

- a pathway is the path the visual information takes from entering the human perceptual system through the eyes to its being completely processed.

Why are there two pathways? It is because the information from the primary visual cortex in the occipital lobe is forwarded through two fasciculi (fiber bundles):

WHERE PATHWAY - ascends toward the parietal lobe (along the dorsal pathway) - responsible for processing location and motion information

● Are long and thin photoreceptors.

● Are more highly concentrated in the periphery of the retina than in the foveal region. ● Are responsible for night vision and are sensitive to light and dark stimuli.

● Are short and thick photoreceptors and allow for the perception of color.

● Are more highly concentrated in the foveal region than in the periphery of the retina.

WHAT PATHWAY - descends to the temporal lobe (along the ventral pathway)

- responsible for processing the color, shape, and identity of visual stimuli

APPROACHES TO PERCEPTION: MAKING SENSE OF WHAT WE SEE

THEORIES OF PERCEPTION

● BOTTOM UP THEORIES - parts are identified, put together, and then recognition occurs

● TOP DOWN THEORIES - people actively construct perceptions using information based on expectations

Gibson’s Theory of Direct Perception/ ecological perception

● The information in our sensory receptors is all we need to perceive anything •Do not need the aid of complex thought processes to explain perception

● Use texture gradients as cues for depth and distance

● Allows us to perceive directly the relative proximity or distance of objects Cues Used in Depth Perception

- The farther away an object is, the fewer details you can see. You can see small holes and the rough texture of the rock in the foreground whereas the rocks in the background look much smoother. The rock that is partly obscured is located behind the rock that obscures it. We use these cues to aid us in depth perception.

Template Theories

● We have stored in our minds myriad sets of templates.

● compare to templates in memory until a match is found

● multiple templates are held in memory

● to recognize the incoming stimuli, you compare to templates in memory until a match is found.

Weakness of theory

● Problem of imperfect matches

● Cannot account for the flexibility of pattern recognition system

Feature Matching Theories

● Recognize objects on the basis of a small number of characteristics (features) ● Detect specific elements and assemble them into more complex forms

● Brain cells that respond to specific features such as lines and angles are referred to as “feature detectors”

Oliver Selfridge’s Pandemonium Model

★ “pandemonium” refers to a very noisy, chaotic place and hell

★ “demons” with specific duties receive and analyze the features of a stimulus

★ there are four kinds of demons: image demons, feature demons, cognitive demons, and decision demons.

Four kinds of demons:

1. “image demons” receive a retinal image and pass it on to “feature demons.”

1. “image demons” receive a retinal image and pass it on to “feature demons.”

2. “feature demon” calls out when there are matches between the stimulus and the given feature.

3. “cognitive (thinking) demons” in turn shout out possible patterns stored in memory that conform to

one or more of the features noticed by the feature demons.

4. “decision demon” decides on what has been seen, based on which cognitive demon is shouting the most frequently

Navon (1977)

● Participants asked what they saw on the ◦Global level ◦Local level Results depended on whether letters are more widely spaced ◦Participants were faster at identifying local features of the letters

Recognition (RBC) by Components Theory

● Biederman (1987)

● Describes how 3D images are identified

● Breaks objects down into geons (the simple 2D or 3D forms) ● Objects are identified by geons, relationship between them.

Top Down (Constructive Processing Approach)

● Perception is not automatic from raw stimuli

● Processing is needed to build perception

● Top-down processing occurs quickly and involves making inferences, guessing from experience, and basing one perception on another.

Configural Superiority E"ect

● Objects presented in context are easier to recognize than objects presented alone

● Subjects more readily perceive di"erences among integrated configurations comprising multiple lines (c) than they do solitary lines (a). In this figure, the lines in panel (b) are added to the lines in panel (a) to form shapes in panel (c), thereby making panel (c) more complex than panel (a)

PERCEPTION OF OBJECTS AND FORMS

OBJECT CENTERED REPRESENTATION - stored in a way that best represents the object and viewpoint invariant process

VIEWER CENTERED REPRESENTATION - Object is stored in the perspective seen. Store multiple views of objects as seen under various conditions. Viewpoint dependent process

LANDMARK CENTERED ORIENTATION

● Information is coded by its relation to a well-known or prominent item ● Consider your college campus

● What is a prominent item you use to orient yourself on campus?

GESTALT VIEW OF PERCEPTION

● “The whole is more than a sum of its parts”

LAW OF PRÄGNANZ - Individuals organize their experience in as simple, concise, symmetrical, and complete manner as possible

FIGURE-GROUND - When perceiving a visual field, some objects (figures) seem prominent, and other aspects of the field recede into the background (ground).

PROXIMITY - When we perceive an assortment of objects, we tend to see objects that are close to each other as forming a group.

- In Figure (a), we tend to see the middle four circles as two pairs of circles. SIMILARITY - We tend to group objects on the basis of their similarity.

- In Figure (b), we tend to see four columns of xs and os, not four rows

CONTINUITY - We tend to perceive smoothly flowing or continuous forms rather than disrupted or discontinuous ones.

- Figure (c) shows two fragmented curves bisecting, which we perceive as two smooth curves, rather than as disjointed curves.

CLOSURE - We tend to perceptually close up, or complete, objects that are not, in fact, complete.

- Figure (d) shows only disjointed, jumbled line segments, which you close up to see a triangle and a circle

SYMMETRY - We tend to perceive objects as forming mirror images about their center.

- Figure (e), a configuration of assorted brackets, we see the assortment as forming four sets of brackets, rather than eight individual items, because we integrate the symmetrical elements into coherent objects

Fusiform Gyrus in Temporal Lobe

● Studies illustrate it is Temporal Lobe it is Temporal Lobe active in facial recognition ● However, also active if high expertise in any item (birds, cars) recognition

● expert individuation hypothesis

EVIDENCE FOR SEPARATE SYSTEMS PROSOPAGNOSIA

● Inability to recognize faces after brain damage ● Ability to recognize objects is intact

ASSOCIATIVE AGNOSIA

● Di#culty with recognizing objects ● Can recognize faces

THE ENVIRONMENT HELPS YOU SEE

Depth Perception - The ability to see the world in three dimensions and detect distance . Monocular and Binocular Cues for Depth Perception

● various perceptual cues aid in our perception of the 3 world. some of these cues can be observed by one eye alone; other cues require the use of both eyes.

Monocular Depth Cues

● Texture gradients - Grain of item ● Relative size - Bigger is closer

● Interposition - Closer are in front of other objects

● Linear perspective - Parallel lines converge in distance

● Aerial perspective - Images seem blurry farther away

● Motion parallax -Objects get smaller at decreasing speed in distance

Binocular Depth Cues

BINOCULAR CONVERGENCE - The closer the object you are trying to see, the more your eyes must turn

inward.

BINOCULAR DISPARITY - The closer an object is to you, the greater the disparity between the views of it as sensed in each of your eyes.

DEFICITS IN PERCEPTION

Disruption of the “what” pathway:

AGNOSIA - Inability to recognize and identify objects or people, despite having knowledge of the

characteristics of the objects or people SIMULTAGNOSIC - Normal visual fields, yet act blind

- Perceives only one stimulus at a time—single word or object

PROSOPAGNOSIA

● Inability to recognize faces, including one's own ● Cannot recognize person from face

● Knows a face is a face

● Can recognize individuals from voice

● Can recognize individuals from voice

● Can recognize objects

● Can discriminate whether two faces are same or di"erent

OPTIC of ATAXIA the “how”

● Cannot use vision to guide movement

● Unable to reach for items

ANOMALIES IN COLOR PERCEPTION

- There are several kinds of color deficiency, which are sometimes referred to as kinds of “color blindness.