Cognition Lecture 2 Modern Cognitive Psychology and techniques

+ Cognition: Lecture 2 Modern Cognitive Psychology and techniques (Ch 1) Perceptual Processes I (Ch 2)

+ Plan for today’s class n Registering your iclicker n Finish Ch 1 n n n Rise of and current status of cognitive psychology Cognitive Neuroscience n Techniques Related disciples: Artificial intelligence n Start Section I: Perceptual Processes

+ Registering Your Clicker n n To register i>clicker: n Log in to My. Concordia Portal at http: //www. myconcordia. ca n In the left-side menu, select Student Services. n Select i>clicker registration. n Enter their i>clicker remote ID and click Enter You only have to register your i>clicker once unless they have changed your remote.

+ Summary/Review of Last class n n Course syllabus and contact information n Does everyone have the textbook? n Does everyone have the i. Clicker and/or REEF? Origins of cognitive psychology n Philosophy, Early psychologist and cognitive psychologists n Early memory researchers n Behaviorism and Gestalt Approach n Ready for review questions?

+ Chapter 1 cont. An Introduction to Cognitive Psychology

+ Rise of Cognitive Psychology n The cognitive psychology revolution began in 1956 n Factors driving revolution: n Disappointment in behaviorism n Difficulty explaining complex human behavior n I. e. , Advancements in linguists (Reinforcement ≠ Language complexity and ease) n Human behavior can’t be entirely explained by learning principles from lab animals

+ Rise of Cognitive Psychology n Factors driving revolution (cont. ): n Research in human memory began to blossom n Awareness of memory altered by previous knowledge n ‘Discovery’ of Frederic Bartlett’s work n Developmental psychology research n Jean Piaget n Children actively explore their world in order to understand important concepts n Cognitive strategies change throughout development n Enthusiasm surrounding Information-Processing Approach

+ Rise of Cognitive Psychology n n Information processing approach n Theoretical approach to human memory originating in the 1960’s n Asserts that: n Mental processes are similar to the operations of a computer n Information is processed in a series of stages Example: The Atkinson-Shiffrin model (1968) n Memory involves a a sequence of separate steps n Information is transferred from one storage ‘area’ to another at each step

+ Rise of Cognitive Psychology

+ Current Status of Cognitive Psychology n Widespread influence of cognitive psychology Pure behaviorism is extremely rare n Importance of mental representations n n Concern and focus on designing studies with ecological validity n the extent to which the findings of a research study are able to be generalized to real-life settings

+ Cognitive Neuroscience n Cognitive Neuroscience combines research from cognitive psychology with neuroscience theory and techniques for assessing brain structure and function n Related social cognitive neuroscience uses neuroscience to explore cognitive processes involved in social interactions n Cognitive neuroscience pop psychology findings must be treated with caution n Extremely complex system; multiple processes and active regions

+ Cognitive Neuroscience: Techniques n Study of brain lesions n Destruction of a region of the brain often due to stroke or accident n Assumption: Relationship between damaged region and cognitive deficit n Example n Aphasia: Loss of ability to understand or produce speech following brain damage

+ Cognitive Neuroscience: Lesions n Broca’s aphasia n Expressive aphasia n Sentence formation n Wernicke’s aphasia n Receptive n Comprehension

+ Cognitive Neuroscience: TMS n Transcranial Magnetic Stimulation (TMS) n technique for temporary disrupting the function of specific cortical regions n non-invasive and no residual effects

+ Cognitive Neuroscience: Techniques n Imagery Techniques: n Positron emission tomography (PET) v. Functional magnetic resonance Imaging (f. MRI) n Both measure brain activity indirectly n n Increased blood flow in active brain regions PET measures blood flow using radioactively labeled compounds named radiotracers n Benefit use of different chemicals ie. , glucose, raclopride etc

+ Cognitive Neuroscience: Techniques n Imagery Techniques: n f. MRI measures relies on paramagnetic properties of oxygenated and deoxygenated hemoglobin n Blood-oxygen-level dependent contrast (BOLD signal) events)

+ Cognitive Neuroscience: Techniques n Event-related potential technique (ERP) n Able to assess timing of neural events through electrodes places on scalp n Each electrode records from a group of neurons located directly under skull n n Cannot penetrate the cortex Stereotypic electrophysiological response to stimulus n Raw electroencephalogram (EEG) recordings averaged to eliminate random brain activity

+ Artificial Intelligence n n n A branch of computer science concerned with making computers behave like humans Theory and development of computers able to complete complex human tasks n Ie. , visual perception, speech recognition and decisionmaking Pure AI v Computer Simulation n n Pure AI n Computer programs designed to as efficiently as possible Computer simulation (or computer modeling) n Program computer to preform task in the same way as a human n Produces human errors

+ Artificial Intelligence n Connectionist Approach: n Emerged due to advances in neuroscience and AI n n Cognitive processes can be understood in terms of networks (network approach) n n Mc. Clelland et al. , 1986 Simultaneous (parallel distributed processing) operations rather than serial processing (information-processing approach) Like the brain model focuses on ‘neuron-like’ units with numerous interconnections and distributed neural activity

+ Textbook Themes n Recurring themes throughout the text n Review these and note when you see these themes reemerging n Theme 1: Cognitive processes are active rather than passive n Examples?

+ Section I: Perceptual Processes and Mental Imagery

+ Section I: Perceptual Processes & Mental Imagery n Section I: Perceptual Processes n n n Chapter 2: Perceptual Processes I: Visual and Auditory Recognition Chapter 7: Mental Imagery and Cognitive Maps Chapter 3: Perceptual Processes II: Attention and Consciousness

+ Perception v Sensation n Perception and sensation are related but not the same n Sensation: the process allowing our brains to take in information via our senses, which can then be experienced and interpreted by the brain n Perception: Uses previous knowledge to gather and interpret stimuli registered from the senses. n Perception = experience and interpretation by the brain n Combines external world (stimuli) and internal world (previous knowledge)

+ Perception is Complex n Perception is complex n Object are recognized even with less than perfect visible information n n Ie. , Missing components (Gestalt), 2 -D representation, Inverted image, changing visual scene, short presentation Shape constancy: Refers to the ability to perceive objects as having a constant shape despite receiving different sensory images

+ Perception: Iconic Memory n n Visual sensory memory (iconic memory) n Large capacity storage system that records information for each of the senses with reasonable accuracy n Preserves an image of a visual stimulus for a brief period after the stimulus has disappeared Can identify visual stimuli presented for less than a 1/10 s

+ Gestalt and Visual Perception n Visual system is designed to impose organization on a richly complicated visual world n n Gestalt Psychology principle: Humans have basic tendencies to organize what they see; without any effort we patterns rather than random unrelated arrangements Gestalt Principles of Perception n Figure-Ground n Element are perceived as either figures (distinct elements of focus) or ground (the background or landscape the figure(s) rest on) n Figures seem closer and more dominant

+ Gestalt and Visual Perception n Gestalt Principles of Perception: Figure-ground relationships n n n Stable: Figure and ground are clear and distinct Ambiguous-figure ground relationship: The figure and ground can reverse n In ambiguous situations our perceptual system imposes organization Accustomed to the certainty of figure ground relationships; it is surprising when figure and ground reverse n n Adaptation of neurons in visual cortex Reversal related to solving visual paradox

+ Gestalt and Visual Perception n Why to these images have the quality of Gestalt? n Prägnanz Principle/Law n German word loosely translated into of good figure n Most general Gestalt principle states that the simplest organization, requiring the least cognitive effort, will emerge as the figure

+ Gestalt and Visual Perception n Why to these images have the quality of Gestalt? n Proximity Principle: Elements tend to be perceived as aggregated if they are near each other n Common Fate or Continuity Principle Continuity: Elements tend to be perceived as aggregated if they move together n https: //www. youtube. com/watch? v=nu. H 6 d. Icgao. U

+ Gestalt and Visual Perception n Why to these images have the quality of Gestalt? n Similarity Principle: Elements tend to be perceived as aggregated if they are similar to each other n Closure Principle: Objects grouped together are seen as a whole n We ignore groups and create contour lines n Illusory contours (Subjective Contours) n Rational perceptual error (fill-in the blanks)

+ Visual System

+ The Visual System: Stimuli n Perceptual Stimuli n Distal Stimuli n n n The actual object that is “out there” in the environment Proximal Stimuli n The information registered on your sensory receptors n Image created on retina Retina convers images to electrical signals sent via the optic nerve to the primary visual cortex

+ The Visual System n Primary visual cortex n Located in the occipital lobe n Basic processing of visual stimuli n n n First place visual information from both eyes is combined First stop in cortex before further processing At least 30 additional areas of the cortex have been shown to be involved in visual perception n Ie. , Parietal lobe: involved in recognition of tools

+ Visual Object Recognition

+ Visual Object Recognition: Introduction n Object Recognition (Pattern Recognition) n Involves identifying a complex arrangement of sensory stimuli into distinct objects or patterns separate from the background and separate from each other n Transformation of raw sensory information into perceptual units based on information in memory

+ Theories of Visual Object Recognition n Three theories of visual object recognition n Matching to Templates n Feature-Analysis Approach (F-A) n Recognition-by-components (RC)

+ Theories of Visual Object Recognition n Matching to Templates n Earliest of theories n Stimuli compared with a set of stored templates n Similar to the idea of prototypes n Problems with more complex stimuli and deviations from template

+ Theories of Visual Object Recognition n Feature-Analysis Theory n Visual stimuli composed of a small number of distinct characteristics or components called distinct features n Features are extracted and compared to memory n Ie. , For letters we store a set of distinct features: n For R we have n 1 straight component n 1 curved component n 1 diagonal component

+ Theories of Visual Object Recognition n Feature-Analysis Theory: Eleanor Gibson (1969) n More time needed to distinguish between letters with more similar features

+ Theories of Visual Object Recognition n Lets have a look at the Feature Analysis Theory n i. Clicker n Press 1 if the letters are the same n Press 2 if the letters are different n E and F n I and Z n G and C

+ Theories of Visual Object Recognition n Support for Feature-Analysis Theory n Longer time to recognize differences b/t letters sharing features (Reaction Time Studies) n Using F-A structure AI models can recognize 95% of envelope addresses n Hubel & Wiesel (1960’s-1980’s): Neurobiological evidence of feature detector neurons in the primary visual cortex

+ Theories of Visual Object Recognition n Hubel & Wiesel (1960’s-1980’s) n Additional Info n https: //www. youtube. com/watch? v=y_l 4 k. Q 5 wjiw

+ Theories of Visual Object Recognition n Problems with Feature-Analysis Theory n Theory constructed to explain relatively recognition of letters n Does not address complex shapes n Ie. , what are the features of a dog n Distortion of features with movement (moving dog) n Relationship between features can be different

+ Theories of Visual Object Recognition n Recognition-by-components (RC) theory: Irving Biederman (1987) n Deal with recognition of complex shapes n Objects are represented as an arrangement of geometric icons called Geons n n Geons are like 3 D features Biederman listed 36 geons that can be used to form 3 D objects Recognition-by-components theory is essentially a 3 -D Feature-Analysis Theory

+ Theories of Visual Object Recognition n What are Geons?

+ Theories of Visual Object Recognition n n Support of Recognition-by-components theory n f. MRI and neuronal responses to Geons n Young children may perceive undifferentiated object but older children represent objects as geons Modification to Recognition-by-components theory n Viewer-centered approach: Proposes we store a small number of views of 3 -D objects n Storage or ‘regular’ viewing angles n Quicker recognition at standard viewing angles n Viewing from unusual angle requires mental (slower reaction times)

+ Visual Object Recognition: Bottom-Up and Top-Down Processing

+ Bottom-Up and Top-Down Processing n Thus far we have focused on the nature of visual stimuli n n Bottom-Up Processing n n Data driven (sensory input) Observable patterns inform higher order cognitive processes Stimulus characteristics influences cognition (behavior) Top-Down Processing n n Ie. , features, geons Behavior is influenced by conceptual data Higher order conceptual processes construct our experiences and expectations Perception and behavior directed by expectations Syn: Conceptually driven perception or construct perception https: //www. youtube. com/watch? v=TLHlf. PTRek. A

+ Bottom-Up and Top-Down Processing Object recognition requires both bottom-up and top-down processing.

+ Top-Down Processing: Context n What is this object(s)? n Based on what we have learn how might our brain this out? n n Feature Analysis n 1 straight line component n 2 connected curved components Gestalt perspective? (Top down- Imposed organization) n Is this two objects or one

+ Top-Down Processing: Context n Let’s put this in context n What about now?

+ Top-Down Processing: Context n A new context n What about now?

+ Top-Down Processing & Reading n Read this aloud (Rayner et al. , 2006) n “Aoccdring to a rscheeaech at Cmabrigde Uinervtisy, it deosn’t mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and the lsat ltteer be at the rghit pclae. The rset can be a tatol mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. ”

+ Top-Down Processing & Reading n Word Superiority Effect: Letter more rapidly and more accurately identified when appearing in a meaningful word then when alone or in non-sense word n Richer, 1969 n Brief presentations of four letter words, same letter non-words and single letters n WORD n OWRD n Each followed by masking n Forced letter choice

+ Top-Down Processing & Reading n Word Superiority Effect

+ Top-Down Processing & Reading n Word-in-a-sentence effect (Ruecki & Oden, 1986) n Bottom-up processing: Varied the shape (features) of a stimulus n Top-down processing: Varied the context of the sentence n Example: “The ____ raised to supplement his income” lion tamer zookeeper botanist dairy farmer

+ Top-Down Processing & Reading