Cognitive Psychology and Neuroscience Study Guide PDF

Cognitive Psychology and Neuroscience  1 Cognitive Psychology Overview ​ Definition: Study of the mind and mental processes, including perception, attention, memory, language, and decision-making. ​ ○​ Basic Mental Proce...

Cognitive Psychology and Neuroscience  1 Cognitive Psychology Overview ​ Definition: Study of the mind and mental processes, including perception, attention, memory, language, and decision-making. ​ ○​ Basic Mental Processes: ​ Perception (Ernst Weber) ​ Attention (Donald Broadbent) ​ Memory. (Herman Ebbinghaus) ○​ Higher Mental Processes: ​ Knowledge ​ Imagery ​ Language (Noah Chomsky) ​ Problem-solving ​ Reasoning ​ Decision-making. (Franciscus Donders)  2 Analytic Introspection (Wilhelm Wundt) Experiment/Discovery: ​ Wilhelm Wundt is often considered the father of experimental psychology. He pioneered the method of analytic introspection, which was a way to study the contents of consciousness. Key Contributions: ​ Analytic Introspection: Participants were trained to describe their conscious experiences in a highly detailed and systematic manner. Wundt believed that by analyzing these introspective reports, he could break down complex mental processes into simpler components, similar to how chemists analyze substances into their elements. ​ Structuralism: Wundt's approach was aligned with structuralism, a theory that focused on identifying the structure of the mind by breaking down consciousness into basic elements such as sensations, feelings, and images. Limitations: ​ While Wundt’s methods laid the foundation for experimental psychology, analytic introspection was criticized for being subjective and unreliable because the results depended on individuals' reports of their own experiences, which could vary widely.  3 Introspection (William James) Experiment/Discovery: ​ William James, in contrast to Wundt, took a more holistic view of introspection. He focused on stream of consciousness, which referred to the continuous flow of thoughts and mental processes. James believed that rather than isolating basic elements of consciousness, the focus should be on understanding the flow and functions of mental states. Key Contributions: ​ Stream of Consciousness: James argued that consciousness is not static or composed of distinct elements but is instead a flowing, dynamic process. He described the mind as constantly shifting and adapting, with no clear-cut boundaries between thoughts. ​ Functionalism: James is considered a leading figure in the development of functionalism, a theory that emphasized the functions of mental processes and their role in helping individuals adapt to their environment, rather than merely analyzing their structure. Limitations: ​ While James was less interested in structured, experimental introspection, his focus on subjective experiences lacked the precise, controlled methods that would later be developed in cognitive psychology.  4 Decision Making (Franciscus Donders) Experiment/Discovery: ​ Franciscus Donders was a pioneering Dutch physiologist who contributed to the study of decision making and reaction times. His most famous work involved measuring the time it takes for the brain to make decisions by using a reaction time paradigm. Key Contributions: ​ Subtractive Method: Donders is known for his development of the subtractive method, which is a technique to infer cognitive processes involved in decision making. ○​ For example, in one experiment, participants were asked to press a button as soon as they saw a light (simple reaction time) and then in another condition, they were asked to press the button only if a red light appeared (choice reaction time). The difference in reaction times between these tasks allowed Donders to infer the time it took to make a decision. Key Findings: ​ Donders demonstrated that decision-making processes involve measurable cognitive delays, and reaction time could be used as an indirect measure of mental processing. Limitations: ​ Although Donders’ work laid the foundation for measuring cognitive processes, the subtraction method has limitations in terms of isolating specific mental operations.  5 Memory (Herman Ebbinghaus) Experiment/Discovery: ​ Hermann Ebbinghaus was a German psychologist who made groundbreaking contributions to the study of memory. He was the first to conduct rigorous, controlled experiments on memory, focusing on how information is learned, retained, and forgotten. Key Contributions: ​ Ebbinghaus’ Forgetting Curve: Ebbinghaus is famous for discovering the forgetting curve, which describes how information is forgotten over time. He found that memory retention drops rapidly shortly after learning, but the rate of forgetting slows down as time passes. ​ Nonsense Syllables: Ebbinghaus used nonsense syllables (such as "DAX," "BOK," "VIF") to study memory because they were free from prior associations, ensuring that the results would reflect purely cognitive processes. ​ The Learning Curve: He also discovered the learning curve, which shows that the more times a person reviews information, the faster they will learn and recall it, with diminishing returns as the number of repetitions increases. Key Findings: ​ Ebbinghaus’s research showed that memory involves both the initial learning process and the forgetting process, providing evidence that memory retention is not a static phenomenon but is affected by time and repetition.  6 Perception (Ernst Weber) Experiment/Discovery: ​ Ernst Weber was a German physician and experimental psychologist who studied sensory perception, particularly how we perceive physical stimuli. He is best known for discovering Weber’s Law, which quantifies the relationship between the magnitude of a stimulus and the just noticeable difference (JND). Key Contributions: ​ Weber’s Law: Weber’s Law states that the smallest detectable difference in a stimulus (the just noticeable difference, or JND) is proportional to the original intensity of the stimulus. For example, the ability to detect a difference in weight is more easily noticeable when comparing lighter weights than heavier ones. This law was a significant step in understanding the relationship between physical stimuli and perception. ○​ Mathematically, Weber’s Law is expressed as:​ ΔII=kIΔI​=k where ΔIΔI is the difference threshold (the JND), II is the initial stimulus intensity, and kk is a constant specific to the type of stimulus. Key Findings: ​ Weber’s work demonstrated that perception is not just a direct reflection of the physical world but is influenced by the context in which stimuli are presented, showing the subjective nature of perception. ​  7 ​ ○​ ​ Focus of cognitive psychology ○​ Behavior (expression of the mind) ○​ Brain (physical basis of the mind). ○​ ​ Historical Development: ○​ 1600s: Beginnings of modern physics ○​ 1700s: Beginnings of modern chemistry ○​ 1800s: Beginnings of modern cognitive psychology. ○​ ​ Delayed Study of the Mind ​ Difficulty in empirically measuring mental processes (e.g., introspection had limitations) ​  8 Behaviorism (Early 1900s) ​ Core Idea: Focus on observable behavior, not the unobservable mind. ​ ​ Key Figures: ○​ Ivan Pavlov: Classical conditioning (e.g., dogs salivating to a metronome). ○​ John Watson: Little Albert experiment (learned fear through conditioning). ○​ B.F. Skinner: Operant conditioning (reinforcement and punishment shaping behavior). ○​ ​ Tools: Skinner box for controlled experiments. ​ ​ Decline of Behaviorism: ○​ Limitations: Couldn’t explain complex behaviors (e.g., mental maps in rats). ○​ Linguistics: Noam Chomsky argued language learning is partly innate (poverty of stimulus argument). ○​ Computers: Inspired the mind-as-information-processor model.  9 Cognitive Psychology Emergence (1950s-1960s) ​ Key Developments: ​ ○​ Information Processing Model: Mind as a system transforming sensory input into behavior. ○​ ​ Examples: ​ Donald Broadbent: Attention as a filter. ​ ​ Saul Sternberg: Memory retrieval and reaction time studies. ​ ​ First Textbook: Published in 1967.  10 Cognitive Neuroscience Basics ​ Neurons: Basic units of brain function. ​ ○​ Structure: Dendrites (input), axon (output), synapse (communication gap). ○​ ○​ Signal Transmission: Electrical (action potentials) and chemical (neurotransmitters). ○​ ​ Neural Representation: ​ ○​ Retinal Cells: Represent light intensity. ○​ Retinal Ganglion Cells: Represent light differences (center-surround organization). ○​ Simple Cells in Visual Cortex: Represent edge orientation.  11 Key Concepts in Neural Representation ​ Receptive Field: The sensory area a neuron responds to (e.g., retinal location for ganglion cells). ​ Tuning Curve: Describes how a neuron’s response varies with stimulus properties (e.g., orientation for simple cells). Summary ​ Cognitive psychology evolved from early introspection and behaviorism to a focus on mental processes and neural mechanisms. ​ ​ Behaviorism emphasized observable behavior but was limited in explaining complex cognition. ​ ​ The rise of cognitive psychology was fueled by advances in linguistics, computer science, and neuroscience. ​ ​ Cognitive neuroscience explores how neural activity underlies mental processes, using tools like receptive fields and tuning curves to understand neural representation.  12 Behaviorism  13 Core Principles of Behaviorism: 1.​Focus on Observable Behavior: ○​ Behaviorism emphasizes studying observable actions and responses rather than internal mental states (e.g., thoughts, emotions, or consciousness). ○​ The mind is considered a "black box" that cannot be directly studied; only inputs (stimuli) and outputs (responses) are measurable. ○​ 2.​Environment Shapes Behavior: ○​ Behaviorists believe that behavior is learned through interactions with the environment. ○​ Individuals are born as "blank slates" (tabula rasa), and all behavior is acquired through conditioning. ○​ 3.​Rejection of Introspection: ○​ Behaviorism rejects subjective methods like introspection (e.g., Wundt’s analytic introspection) because they lack reproducibility. ○​ 4.​Objective Measurement: ○​ Behaviorists aim to measure behavior quantitatively and scientifically, using controlled experiments.  14 Key Figures and Experiments 1. Ivan Pavlov (1849–1936) ​ Classical Conditioning: ○​ Pavlov discovered that a neutral stimulus (e.g., a metronome) could elicit a reflexive response (e.g., salivation) if paired with an unconditioned stimulus (e.g., food). ○​ ○​ Experiment: ​ Dogs naturally salivate when presented with food (unconditioned response). ​ Pavlov paired the sound of a metronome (neutral stimulus) with food. ​ Over time, the dogs salivated at the sound of the metronome alone (conditioned response). ​ ○​ Key Concept: Learning occurs through association between stimuli.  15 2. John B. Watson (1878–1958) ​ Founder of Behaviorism: ○​ Watson argued that psychology should focus solely on observable behavior, rejecting the study of the mind. ○​ ○​ Little Albert Experiment: ​ Watson conditioned a baby (Albert) to fear a white rat by pairing the rat with a loud, frightening noise. ​ Over time, Albert generalized his fear to other white, furry objects (e.g., a rabbit, a fur coat). ​ ○​ Key Concept: Emotions and behaviors are learned through conditioning. ○​ ​  16 3. B.F. Skinner (1904–1990) ​ Operant Conditioning: ○​ Skinner focused on how behavior is shaped by consequences (reinforcement or punishment). ○​ ○​ Key Concepts: ​ Reinforcement: Increases the likelihood of a behavior (e.g., giving food for pressing a lever). ​ Punishment: Decreases the likelihood of a behavior (e.g., delivering an electric shock for pressing a lever). ​ ○​ Skinner Box: ​ A controlled environment where animals (e.g., rats or pigeons) learn to perform behaviors (e.g., pressing a lever) to receive rewards or avoid punishments. ​ Demonstrated how complex behaviors could be shaped through gradual reinforcement. ​  17 Types of Learning in Behaviorism 1. Classical Conditioning (Pavlovian Conditioning) ​ Definition: Learning through association between two stimuli. ​ ​ Components: ○​ Unconditioned Stimulus (US): Naturally triggers a response (e.g., food). ○​ Unconditioned Response (UR): Natural response to the US (e.g., salivation). ○​ Conditioned Stimulus (CS): Initially neutral stimulus that becomes associated with the US (e.g., metronome). ○​ Conditioned Response (CR): Learned response to the CS (e.g., salivation to the metronome). ○​ ​ Example: Fear of dogs after being bitten (dog = CS, bite = US, fear = CR).  18 2. Operant Conditioning (Instrumental Conditioning) ​ Definition: Learning through consequences of behavior. ​ ​ Components: ○​ Reinforcement: Increases behavior. ​ Positive Reinforcement: Adding a pleasant stimulus (e.g., giving a treat for good behavior). ​ Negative Reinforcement: Removing an unpleasant stimulus (e.g., stopping an alarm by waking up). ○​ Punishment: Decreases behavior. ​ Positive Punishment: Adding an unpleasant stimulus (e.g., scolding for misbehavior). ​ Negative Punishment: Removing a pleasant stimulus (e.g., taking away a toy for misbehavior). ​ ​ Example: A child cleans their room to receive praise (positive reinforcement). ​  19 Strengths of Behaviorism 1.​Scientific Rigor: ○​ Behaviorism introduced objective, measurable methods to psychology, moving away from subjective introspection. ○​ 2.​Practical Applications: ○​ Behaviorist principles are widely used in: ​ Education: Reinforcement systems (e.g., gold stars for good work). ​ Therapy: Behavior modification techniques (e.g., treating phobias through systematic desensitization). ​ Animal Training: Shaping behaviors through reinforcement. ​ 3.​Focus on Observable Behavior: ○​ Provided a clear framework for studying and modifying behavior.  20 Limitations of Behaviorism 1.​Neglect of Mental Processes: ○​ Behaviorism ignores internal states like thoughts, emotions, and motivations, which are central to understanding human behavior. ○​ 2.​Overemphasis on Environment: ○​ Behaviorism underestimates the role of biology, genetics, and innate factors in shaping behavior. ○​ 3.​Inability to Explain Complex Behaviors: ○​ Behaviorism struggles to account for: ​ Language Acquisition: Noam Chomsky argued that language learning cannot be fully explained by conditioning (poverty of stimulus argument). ​ Cognitive Maps: Edward Tolman showed that rats form mental maps of mazes, suggesting internal representations. ​ 4.​Ethical Concerns: ○​ Experiments like Little Albert raised ethical questions about manipulating human behavior.  21 Decline of Behaviorism ​ Cognitive Revolution (1950s–1960s): ○​ Behaviorism declined as psychologists began to focus on mental processes and information processing. ○​ Key factors: ​ Linguistics: Chomsky’s critique of Skinner’s verbal behavior theory. ​ Computers: Inspired the mind-as-information-processor model. ​ Neuroscience: Advances in understanding brain function. ​ ​ Integration with Cognitive Psychology: ○​ Modern psychology combines behaviorist principles (e.g., conditioning) with cognitive approaches to provide a more comprehensive understanding of behavior.  22 Legacy of Behaviorism ​ Influence on Psychology: ○​ Behaviorism laid the foundation for experimental psychology and applied behavior analysis (ABA). ​ Applications: ○​ Used in education, therapy, animal training, and organizational behavior management. ​ Enduring Concepts: ○​ Conditioning (classical and operant) remains a cornerstone of learning theory. Behaviorism revolutionized psychology by emphasizing objectivity and measurable behavior, but its limitations led to the rise of cognitive psychology, which integrates internal mental processes with observable behavior.  23 Cognitive Neuroscience  24 Neurons and Neural Representation Cognitive neuroscience investigates the mind by examining both behavior and brain activity. While behavior reveals the output of cognitive processes, studying the brain reveals the physical mechanisms underlying these processes. Basic Neuroscience Concepts ​ Neurons: The fundamental units of brain function. The brain contains over 100 billion neurons, and all cognitive functions arise from neural activity. ○​ Dendrites: Receive signals from other neurons. ○​ Axon: Sends signals to other neurons. ○​ Synapse: The small gap between neurons where signals are transmitted.  25 Neural Communication Neurons transmit information via electrical signals: ​ Resting Potential: When at rest, a neuron has a negative charge inside relative to the outside, caused by ions (mainly sodium and potassium) that cannot pass through the membrane. This electrical charge difference is called the "resting potential."’ ​ Action Potential: When a neuron is activated, ion channels open, allowing ions to flow in and out, reversing the membrane potential (becoming positive for a brief moment). This change in potential propagates along the axon, sending a signal down the neuron. Neurotransmission ​ Synaptic Transmission: When an action potential reaches the axon terminal, neurotransmitters are released into the synaptic gap and bind to receptors on the next neuron. This can either increase (excitatory neurotransmitters) or decrease (inhibitory neurotransmitters) the likelihood of an action potential in the next neuron.  26 How neurotransmitters work in the communication process between neurons: Step 1: Action Potential Initiation ​ Neurons are electrically charged cells. An electrical signal called an action potential is initiated when a neuron receives a stimulus (such as from another neuron) ​ This electrical signal travels down the axon toward the axon terminal (the end of the neuron). Step 2: Signal Reaches Axon Terminal ​ The action potential arrives at the axon terminal (the end of the neuron). ​ Here, voltage-gated calcium (Ca²⁺) channels open, allowing calcium ions to flow into the neuron. ​ The influx of calcium ions triggers the release of neurotransmitters. Step 3: Neurotransmitter Release ​ The neurotransmitters (chemical messengers) are stored in synaptic vesicles within the axon terminal. ​ The synaptic vesicles move toward the synaptic cleft (the small gap between neurons). ​ The vesicles fuse with the cell membrane at the presynaptic membrane, releasing the neurotransmitters into the synaptic cleft by a process called exocytosis.  27 Step 4: Neurotransmitter Binding ​ The neurotransmitters travel across the synaptic cleft and bind to receptors on the postsynaptic membrane (the receiving neuron or target cell). ​ These receptors are located on the dendrites of the next neuron. ​ The binding of neurotransmitters to their respective receptors causes ion channels to open or close, influencing the electrical state of the postsynaptic neuron. Step 5: Postsynaptic Potential ​ The opening of ion channels leads to either a depolarization (excitatory postsynaptic potential or EPSP) or hyperpolarization (inhibitory postsynaptic potential or IPSP) in the postsynaptic neuron. ​ If the postsynaptic neuron reaches a certain threshold, it will generate its own action potential, continuing the signal transmission. ​ If not, the signal stops. Step 6: Neurotransmitter Removal ​ After neurotransmitters have bound to receptors, they must be cleared from the synaptic cleft to stop the signal transmission and reset the system. ​ This can be achieved in three ways: 1.​ Reuptake: The neurotransmitters are taken back into the presynaptic neuron through transporter proteins.  28 2.​ Enzymatic degradation: Enzymes break down the neurotransmitters (for example, acetylcholine is broken down by acetylcholinesterase). 3.​ Diffusion: Some neurotransmitters diffuse away from the synaptic cleft. Step 7: Recycling and Reuse ​ Neurotransmitters that are taken back into the presynaptic neuron are recycled and repackaged into new synaptic vesicles, ready to be used again. ​ This cycle can repeat as neurons continuously send and receive signals. Summary of Key Steps: 1.​ Action potential triggers neurotransmitter release. 2.​ Neurotransmitters cross the synaptic cleft and bind to postsynaptic receptors. 3.​ Ion channels in the postsynaptic neuron are opened or closed, leading to changes in the membrane potential. 4.​Neurotransmitters are cleared from the synapse through reuptake, enzymatic breakdown, or diffusion. 5.​ Neurotransmitters are recycled for future use.  29 Neural Representation and the Visual System Neural representation refers to what signals transmitted by neurons represent. Using the visual system as an example, this section discusses how different cells in the retina and brain represent visual information: Stage 1: Retinal Cells ​ Light-sensitive retinal cells detect light, and their activity encodes information about the amount of light falling on a specific location in the retina. Stage 2: Retinal Ganglion Cells ​ These cells receive input from multiple retinal cells and represent the difference in light levels between regions in the retina. ​ They have a center-surround organization, meaning the center of their receptive field responds differently to light than the surrounding area (either excitatory or inhibitory). Stage 3: Simple Cells in the Visual Cortex ​ Simple cells in the primary visual cortex respond to more complex visual stimuli like edges and contours. They represent specific orientations of light patterns (edges) rather than just light intensity or differences in light.  30 Key Concepts in Neural Representation Cognitive neuroscientists use several tools to describe how neurons represent sensory information: ​ Receptive Field: The region of sensory space (e.g., retina) that a neuron responds to. For instance, a retinal ganglion cell's receptive field is the specific part of the retina it monitors for light. ​ Tuning Curve: This is a graphical representation showing how the activity of a neuron changes with different stimuli. For example, simple cells in the visual cortex have a tuning curve for the orientation of edges—showing how the cell’s response changes depending on the angle of a line projected onto the retina..  31 Localization of Brain Functions Different cognitive functions are associated with distinct regions of the brain. This spatial arrangement is called localization of function: ​ Visual information is processed in the visual cortex (located at the back of the brain). ​ Auditory cortex handles sound, the olfactory cortex processes smell, and the gustatory cortex handles taste. ​ The somatosensory cortex represents touch sensations, and the motor cortex controls body movement. The organization of these sensory areas follows a principle called topographic organization, meaning that neurons representing nearby sensory regions are physically located near each other in the brain.  32 Methods in Cognitive Neuroscience Cognitive psychologists use various methods to study brain function, which can be broadly categorized into behavior-centered and brain-centered methods: Brain-Centered Methods These methods focus on understanding the brain itself, often providing data on where and how neural activity occurs: 1.​ fMRI (Functional Magnetic Resonance Imaging): Measures changes in blood flow, an indirect indicator of neural activity. More oxygen-rich blood flows to active brain regions, so fMRI detects these changes. ○​ Pro: High spatial resolution, allowing precise identification of brain areas involved in specific tasks. ○​ Con: Poor temporal resolution, meaning the data reflects brain activity from a few seconds ago, not in real-time.  33 2.​ EEG (Electroencephalography): Measures the electrical signals produced by large groups of neurons. It is a non-invasive method often used to study cognitive processes like attention or memory. ○​ Pro: High temporal resolution, providing millisecond-level data on brain events. ○​ Con: Poor spatial resolution, making it hard to pinpoint the exact location of the signal in the brain. 3.​ Neuron Recordings: Directly measure neural activity by inserting electrodes into the brain to record action potentials. ○​ Pro: Can provide highly detailed data from specific neurons. ○​ Con: Invasive, requiring surgery, and typically limited to animal studies.  34 Interference Methods 1.​ Lesions: Studying individuals or animals with brain lesions to observe cognitive deficits. By understanding which functions are lost, researchers can infer the roles of specific brain regions. ○​ Example: Henry Molaison (HM), who underwent brain surgery to treat epilepsy, lost his ability to form new memories due to damage to his medial temporal lobe.  35 2.​ TMS (Transcranial Magnetic Stimulation): A non-invasive technique that temporarily disrupts brain activity in specific regions by applying magnetic pulses. It allows researchers to study the causal role of different brain areas in cognitive processes. ○​ Pro: High temporal resolution, offering precise control over when and where brain activity is disrupted. ○​ Con: Spatial resolution is moderate, and the effects are temporary.