PSY305 Revision Notes PDF

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CHAPTER 1: Introduction to Cognitive PsychologyCognitive psychology is the study of mental processes, which includes determining the characteristics and properties of the mind and how it operates 2 definitions of the mind:  The mind creates and controls mental functions such as perception, attentio...

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PSY305e Revision Notes: Chapter 1 CHAPTER 1: Introduction to Cognitive Psychology Cognitive psychology is the study of mental processes, which includes determining the characteristics and properties of the mind and how it operates 2 definitions of the mind:  The mind creates and controls mental functions such as perception, attention, memory, emotions, language, deciding, thinking, and reasoning – different types of cognition  The mind is a system that creates representations of the world so that we can act within it to achieve our goals – representations and functions The human brain constantly strives to achieve cognitive economy – when it comes to performing cognitive tasks, the brain tries to be more efficient with its cognitive resources by employing heuristics: shortcuts or rules of thumb that provide a best-guess solution to a problem. However, this method does not yield the correct solution all the time. Algorithms, is a method that is guaranteed to yield the correct solution every time. Person Procedure Results and Conclusions Contribution First cognitive psychology Donders (1868) Simple reaction time vs. Choice Choice reaction time takes 1/10 experiment reaction time seconds longer; therefore, it takes 1/10 second to make a decision Wundt (1879) Analytic introspection No reliable results Established the first laboratory of scientific psychology Quantitative measurement of Ebbinghaus (1885) Savings method to measure Forgetting occurs rapidly in the mental processes forgetting first 1-2 days after original learning Descriptions of a wide range of First psychology textbook; some James (1890) No experiments; reported experiences of his observations are still valid observations of his own today experience Watson (1913) Behaviourism: ‘Little Albert’ Associated with classical  Behaviour can be analyzed without any reference to the experiment conditioning – pairing one mind (irrelevance of stimulus with another (neutral physiological and mental stimulus) causes changes in the processes in the brain) responses to the neutral stimulus  Behaviour can be Skinner (1938) Operant conditioning Behavior is strengthened by the presentation of positive understood by studying stimulus-response reinforcers (e.g., food, social approval) or withdrawal of relationships negative reinforcers (e.g., shock,  Applied to classroom social rejection) teaching, treating psychological disorders, and testing the effects of drugs on animals Resurgence of the mind in Tolman (1948) Used behaviour to infer mental Rat in maze experiment psychology processes; cognitive maps developed a cognitive map – a conception within the rat’s mind of the maze’s layout Cognitive Revolution: A decline in the influence of behaviorism and a reemergence of the study of the mind Language is a product of the way Chomsky (1959) Language Acquisition Device – the mind is constructed, rather language development is than a result of reinforcement determined by an inborn biological program Cherry (1953) Attention experiment When people focused on the attended message, they could hear the sounds of the unattended message but were unaware of the contents of that message The Dartmouth and MIT McCarthy (1956) Introduced the term artificial “Making a machine behave in conferences are seen as historic intelligence ways that would be called events in the birth of a new way intelligent if a human were so of thinking about the mind; “the behaving” Able to create proofs of Logic theorist program – used Newell and Simon birthday of cognitive science” mathematical theorems that humanlike reasoning processes (1956) involve principles of logic to solve problems Miller (1956) “The Magical Number Seven There are limits to a human’s Plus or Minus Two” ability to process information –

PSY305e Revision Notes: Chapter 1

Broadbent (1958)

Flow diagram of the mind when directing attention to one stimulus in the environment

Neisser (1967)

Published the first cognitive psychology textbook

Tulving (1972)

LTM is subdivided into 3 components

Physiological Techniques

1.

that the capacity of the human mind is limited to about seven items Input  Filter  Detector  To memory

Provided a way to analyze the operation of the mind in terms of a sequence of processing stages and proposed a model that could be tested by further experiments Introduced the cognitive approach to the scientific community

Focused on vision and hearing, and little focus on higher mental processes; complete absence of physiological mechanisms in understanding how the mind operates Modern cognitive psychology involves more-sophisticated flow diagrams of the mind, a consideration of higher mental processes, and also a large amount of physiological research Atkinson and Model of memory Shiffrin (1968)

Neuropsychology: The study of the behavior of people with brain damage, had been providing insights into the functioning of different parts of the brain since the 1800s 2. Electrophysiology: Measuring electrical responses of the nervous system, made it possible to listen to the activity of single neurons (mostly done on animals) Brain Imaging 1. Positron Emission Tomography (PET): Introduced in 1976, PET made it possible to see which Techniques areas of the human brain are activated during cognitive activity (disadvantage – expensive and involved injecting radioactive tracers into a person’s bloodstream) 2. Functional Magnetic Resonance Imaging (fMRI): Introduced in 1990 and replaced PET; didn’t involve radioactive tracers and was capable of higher resolution Studying Cognition The behavioural approach studies cognition by measuring the The physiological approach studies cognition by measuring relationship between stimuli and behaviour the relationship between physiology (i.e., brain activity) and behaviour. The goals of psychological research are to observe, explain, Cognitive neuropsychology is the study of the structure and predict, and, where applicable, control behaviour/environment function of the brain and how they relate to specific psychological processes. E.g., Case studies such as that of Phineas Gage reveal how damage to certain parts of the brain can result in behavioural change.

PSY305e Revision Notes: Chapter 3 CHAPTER 3: Perception

Gestalt ofHelmholtz’s

Purpose

sCharacteristic

Perception: Experiences resulting from stimulation of the senses Can involve a process Can be based on a Can involve Occurs in conjunction similar to reasoning or perceptual rule, which complex/invisible with action – we problem solving processes (e.g., organize the actions may be based on the reasoning) – not that occur as we person’s past interact with the experiences automatic although it Perception is the outcome of an interaction To create our awareness of what is Enable us to interact with the between bottom-up information, which flows happening in the environment, as environment, which is essential for from receptors to brain, and top-down when we see objects in scenes, or accomplishing what we want to accomplish, and for our survival information, which usually involves knowledge when we perceive words in a about the environment or expectations related to conversation Bottom-up Processing: Sequence of events from eye to brain Top-down Processing: Originates in the brain, at the “top” of the perceptual system Perception also involves factors such as a person’s knowledge Perception is built on a foundation of information from the of the environment, and the expectations people bring to the environment. Looking at something creates an image on the perceptual situation. This knowledge we have of the retina. This image generates electrical signals that are transmitted through the retina, and then to the visual receiving environment is the basis of top-down processing. area of the brain. E.g., “the multiple personalities of a blob,” identical blobs are perceived as different objects depending on their orientation E.g., people identify a rapidly flashed object in a kitchen scene and the context within which they are seen more accurately when that object fits the scene Humans vs. Machines Objects Can Be Hidden or Blurred: The Stimulus on the Receptors Is Ambiguous:  This problem of hidden objects occurs anytime one object  Inverse projection problem: The task of determining the obscures part of another object. People can easily object responsible for a particular image on the retina; it understand that the part of an object that is covered involves starting with the retinal image and extending rays continues to exist, and are able to use their knowledge of out from the eye the environment to determine what is likely to be present  When we consider that a particular image on the retina can be created by many different objects in the environment, it  Despite the degraded nature of these images, people can often identify most of them, whereas computers perform is easy to see why we say that the image on the retina is poorly on this task (Sinha, 2002). ambiguous  Humans typically solve the inverse projection problem easily, even though it still poses serious challenges to computer-vision systems Scenes Contain High-Level Information: Objects Look Different from Different Viewpoints:  Moving from objects to scenes adds another level of  Objects are often viewed from different angles, so their complexity images are continually changing  People’s ability to recognize an object even when it is seen  Two types of information used by the human perceptual system: (1) environmental energy stimulating the receptors from different viewpoints is called viewpoint invariance and (2) knowledge and expectations that the observer brings to the situation o Cues like this, although obvious to a person, would need to be programmed into a computer Object Perception  Based on his realization that the image on the retina is ambiguous  Likelihood principle: We perceive the object that is most likely to have caused the pattern of stimuli we have received  Unconscious inference: Our perceptions are the result of unconscious assumptions, or inferences, that we make about the environment (due to experiences we have had with similar situations in the past)  Gestalt psychologists rejected the idea that perceptions were formed by “adding up” sensations  Although a person’s experience can influence perception, the role of experience is minor compared to the perceptual principles  The whole is different than the sum of its parts Can change based on added information

paCorenceBayesianalEnvironment Principles of Perceptual Organization

PSY305e Revision Notes: Chapter 3 The principle of good continuation states the following:  Points that, when connected, result in straight or smoothly curving lines are seen as belonging together, and the lines tend to be seen in such a way as to follow the smoothest path  Objects that are overlapped by other objects are perceived as continuing behind the overlapping object

The law of pragnanz, also called the principle of good figure or the principle of simplicity, states: Every stimulus pattern is seen in such a way that the resulting structure is as simple as possible.  E.g., the Olympic symbol is perceived as five circles

The principle of similarity: Similar things appear to be grouped together.  Grouping can occur because of similarity of e.g., colour, size, shape, orientation

Physical Regularities: Regularly occurring physical Semantic Regularities: The characteristics associated with properties of the environment the functions carried out in different types of scenes  There are more vertical and horizontal orientations in  Our visualizations contain information based on our knowledge of different kinds of scenes, which is called the environment than oblique (angled) orientations a scene schema, and the expectations created by scene which causes the oblique effect: People can perceive Bayesian inference was named after Thomas Bayes (1701–1761), who proposed that our estimate of the probability of an outcome is determined by two factors: 1. The prior probability, or simply the prior, which is our initial belief about the probability of an outcome 2. The likelihood of the outcome, which is the extent to which the available evidence is consistent with the outcome

Helmholtz, Regularities, and Bayes Gestalt Top down processing We use data about the  Bottom up processing Perception is affected by Neurons and Knowledge About the Environment Natural Selection: Characteristics that Experience-Dependent Plasticity: Movement Facilitates Perception enhance an animal’s ability to survive, Shaping of neural responding by  Helps us perceive objects in the and therefore reproduce, will be passed experience environment more accurately by on to future generations revealing aspects of objects that are  Provides evidence that experience can shape the nervous system not apparent from a single viewpoint  There are more neurons in the animal and human visual cortex that  E.g., Blakemore and Cooper’s  Seeing an object from different respond to horizontal and vertical (1970) experiment showed that viewpoints provides added orientations than to oblique (slanted) rearing cats in horizontal or vertical information that results in more orientations environments can cause neurons in accurate perception the cat’s cortex to fire preferentially  Movement is important because of  Through this evolutionary process, the visual system may have been the coordination that is continually to horizontal or vertical stimuli shaped to contain neurons that  Continued exposure to things that occurring between perceiving stimuli respond to things that are found occur regularly in the environment and taking action toward these frequently in the environment can cause neurons to become stimuli adapted to respond best to these regularities Mirror Neuron System: Neurons ‘Where’ Pathway: The pathway that ‘What’ Pathway: The pathway that distributed throughout the brain in a leads to the parietal lobe is responsible leads to the temporal lobe is responsible network for determining an object’s location for determining an object’s identity  Involved in determining the goal or  Also known as the ventral pathway  Also known as the dorsal pathway intention behind an action because the upper part of the brain, because the lower part of the brain, where the parietal lobe is located, is where the temporal lobe is located,  A number of different intentions can be associated with perception of the the dorsal part of the brain is the ventral part of the brain same action  Perception pathway corresponds to  Action pathway (or how pathway) corresponds to the where pathway, the what pathway, which is the  Codes the “why” of actions and respond differently to different which is the pathway from the visual pathway from the visual cortex to intentions, which is determined by cortex to the parietal love, and is the temporal lobe the sequence of actions that are most associated with how the person takes likely to occur in a particular context action  E.g., The intention films caused greater activity than the nonintention film in areas of the brain known to have mirror neuron properties 

PSY305e Revision Notes: Chapter 4 CHAPTER 4: Attention

Broadbent’s Filter Model of Attention (Early Selection Model)

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    Treisman’s Attenuation Model of Attention

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

Attention as Information Processing Designed to explain the results of Cherry’s experiment, which used a technique called dichotic listening (dichotic: presenting different stimuli to the left and right ears) o People are not aware of most of the information being presented to the unattended ear o Cocktail party effect: The ability to focus on one stimulus while filtering out other stimuli

Sensory memory holds all of the incoming information for a fraction of a second and then transfers all of it to the filter The filter identifies the message that is being attended to based on its physical characteristics (e.g., speaker’s tone of voice, pitch, speed of talking, and accent) and lets only this attended message pass through to the detector in the next stage The detector processes all the information from the attended message to determine higher-level characteristics of the message (e.g., meaning) The output of the detector is sent to short-term memory, which holds information for 10–15 seconds and also transfers information into long-term memory, which can hold information indefinitely The attenuator analyzes the incoming message in terms of (1) its physical characteristics—whether it is highpitched or low-pitched, fast or slow; (2) its language—how the message groups into syllables or words; and (3) its meaning—how sequences of words create meaningful phrases o Represents a process and is not identified with a specific brain structure o Language and meaning can be used to separate the messages o The analysis of the message proceeds only as far as is necessary to identify the attended message

Once the attended and unattended messages have been identified, both messages pass through the attenuator, but the attended message emerges at full strength and the unattended messages are attenuated—they are still present but are weaker than the attended message  The dictionary unit contains words, stored in memory, each of which has a threshold (refers to the smallest signal strength that can be barely detected) for being activated o Words that are common or especially important (e.g., listener’s name) have low thresholds, so even a weak signal in the unattended channel can activate that word o Uncommon words or words that are unimportant to the listener have higher thresholds, so it takes the strong signal of the attended message to activate these words Processing Capacity: The amount of information people can Load Theory of Attention  The ability to ignore task-irrelevant stimuli is a function handle and sets a limit on their ability to process incoming not only of the load of the task you are trying to do but also information of how powerful the task-irrelevant stimulus is Perceptual Load: Related to the difficulty of a task  E.g., The Stroop Effect is an example of a situation in which task-irrelevant stimuli are difficult to ignore  Easy, well-practiced ones, have low perceptual loads and o Reading words is highly practiced and has become use up only a small amount of the person’s processing capacity (more likely to be distracted) so automatic that it is difficult not to read them  Tasks that are difficult and perhaps not as well practiced are high-load tasks and use more of a person’s processing capacity (less likely to be distracted)

PSY305e Revision Notes: Chapter 4 Attention as Selection Scanning a Scene with Eye Movements Scanning a Scene based on Stimulus Salience  Central and Peripheral vision  Bottom-up process because it depends solely on the physical characteristics (e.g., pattern of light  Saccadic eye movement: A rapid, jerky movement from on fixation to the next and dark, color and contrast) in a stimulus, without considering its meaning  Attentional capture – involuntary shift of attention  Saliency map – a combination of values after analyzing characteristics (e.g., color, orientation, and intensity) at each location in the scene o E.g., an object is highly salient if it contrasts with the scene Scanning a Scene based on Cognitive Factors Scanning a Scene based on Task Demands  After the first few fixations, scanning begins to be  The timing of when people look at specific places influenced by top-down, or cognitive, processes is determined by the sequence of actions involved that depend on things such as the observers’ goals in the task and expectations determined by their past  The person fixated on few objects or areas that were irrelevant to the task, and eye movements experiences in observing the environment and fixations were closely linked to the action the  Top-down processing is also associated with scene schemas (an observ...