!! Affective Cognition (Emotion) !! Following Plato. !! Renaissance & Enlightenment Period. !! Descartes (Nativist); Locke, Berkeley (Empiricists)

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1 Domains of Cognitive Psychology!! Perception (vision, audition, touch)!! Attention, Awareness, Consciousness!! Working memory, Long term memory, Learning!! Higher Cognition (Categorization, Decision Making, Reasoning & Problem Solving)!! Language!! Social Cognition!! Affective Cognition!! Action/motor control!! Development of all of the above!! Neural basis of all of the above!! Genetic basis of all of the above!! Individual differences in all of the above Domains of Cognitive Psychology!! Perception (vision, audition, touch)!! Attention, Awareness, Consciousness!! Working memory, Long term memory, Learning!! Higher Cognition (Categorization, Decision Making, Reasoning & Problem Solving)!! Language!! Social Cognition!! Affective Cognition (Emotion)!! Action/motor control!! Development of all of the above!! Neural basis of all of the above!! Genetic basis of all of the above!! Individual differences in all of the above!! Ancient Questions (The Greeks) Platonic dialogue the Meno!! First extended discussion of Epistemology: o! Where does knowledge come from? o! What does it consist of? o! How is it represented in the mind?!! Extended dialogue between Socrates & a young slave!! Socrates demonstrates that the boy possesses within him (or can recollect ) all the knowledge necessary to compute various geometrical relationships!! abstract math = knowledge par excellence!! Conclusion: Understanding of all domains implanted in soul at birth and can be recollected = Nativism (Western) Philosophical Context!! Following Plato!! Aristotle introduced idea of the mind as an unscribed tablet = empiricism!! Much of intellectual life in the Middle Ages revolved around the soul rather than the mind: purview of theologians!! Renaissance & Enlightenment Period!! Descartes (Nativist); Locke, Berkeley (Empiricists)!! Discussions now began to draw on findings from the newly established empirical sciences!! 19th Century!! Proliferation of new sciences and philosophical specialties!! Several deal with nature of the human mind

2 Antecedents of Cognitive Psychology!! Structuralism!! Wilhelm Wundt ( ) & his student Edward B. Titchener ( )!! Focus: discover elemental components of mind (analogy with chemical elements); describe conscious experience in terms of mode, quality, intensity and duration!! Method: Introspection o! Report on the basic elements of consciousness o! Not Internal perception but experimental self observation o! Must be done in laboratory under controlled conditions!! Wundt established what is thought to be the first psychological laboratory in Leipzig in 1879 Wundt Tichener Antecedents of Cognitive Psychology!! Functionalism!! William James ( )!! Focus: why does the mind work as it does? What is its purpose in promoting survival and reproduction? Influenced by Darwin!! Methods: o! Introspection in natural settings!must study the whole organism in natural habitats o! Experimentation o! Comparative study of men, animals, and savages G. Stanley Hall Hermann Ebbinghaus Hall ( ) was an American psychologist and educator. He earned his PhD under Wm James at Harvard and spent time in Wundt s lab. Joined the faculty at Johns Hopkins University in 1882 and established the first psychological laboratory in the United States. He founded the American Journal of Psychology in 1887 and was elected the first president of the American Psycological Association. ( ) Ebbinghaus was a German Professor of Philosophy who studied memory in his spare time.

3 Ebbinghaus studies of memory Memory Curve!! Über das Gedächtnis (On Memory) published 1885.!! Subject memorized lists of CVC nonsense syllables (e.g., kak miv poz wib)!! Examined recall performance over time!! Many of his methods are still used today Antecedents of Cognitive Psychology!! Behaviorism!! John B. Watson ( ) & B.F. Skinner ( )!! evolved as a reaction to the lack of progress using introspection!! learning was emphasized: develop laws to predict how inputs (stimuli) give rise to outputs (responses): laws of operant conditioning (Watson s Little Albert experiment; Skinner s conditioning expts with rats)!! Viewed as unscientific any discussion of mental representations because they are not directly observable!! unfortunately threw the baby out with the bathwater!! (Watson himself was kicked off the JHU faculty in 1920 for having an affair with his graduate student, Rosalie Rayner) Psychology as the Behaviorist sees it is a purely objective, experimental branch of natural science. Its theoretical goal is the prediction and control of behavior. Introspection forms no essential part of its methods, nor is the scientific value of its data dependent upon the readiness with which they lend themselves to interpretation in terms of consciousness.... What we need to do is start work upon psychology making behavior, not consciousness, the objective point of our attack. (Watson, 1913, pp. 158, 176) Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors. I am going beyond my facts and I admit it, but so have the advocates of the contrary and they have been doing it for many thousands of years. (Waston (1930). Behaviourism, p. 82)

4 The Death of Radical Behaviorism!! Skinner s (1957) Verbal Behavior: claimed that children learn language by imitation and reinforcement!! Chomsky s (1959) devastating critique!! Children produce sentences they never heard ( I hate you mommy )!! They use incorrect grammar ( the boy hitted the ball ) even though it is not reinforced, suggesting they are applying abstract rules of grammar!! Language is generative The Cognitive Revolution!! Human factors engineering tackled new practical problems in the 40s and 50s!! WWII: equipment design required knowledge of human cognition!! Focus was on optimal design for devices to be used by human operators, e.g. o! pilots flying aircraft o! vigilance while monitoring a radar screen o! Radio operators decoding a signal in noise The Cognitive Revolution!! Communications engineering provided new concepts!! Shannon and Information Theory!! Exchange of information through channels (phone lines, radio signals)!! People viewed as limited capacity processors of information The Cognitive Revolution!! Development of computers and artificial intelligence offered a new metaphor for the mind!! The comparison of people s cognitive activities to an operating computer!! Distinction between a mental representation and a mental process that operates on or transforms that information in some way!! People seen as composed of input, processing, storage, and output devices.

5 The Cognitive Revolution Methods in Cognitive Psychology Marked by two influential books:!! Broadbent s Perception and Communication (1958)!! Neisser s Cognitive Psychology (1967)!! Researchers started to see that they were asking common questions: how is information acquired, processed, stored, and transmitted?!! Psychophysics/accuracy!! measure perceptual detection or discrimination accuracy at threshold, or recall or recognition accuracy in memory tasks!! Response Time!! when accuracy is high, measure time to respond in order to estimate the duration of mental processes, which in turn can provide constraints on which processes are operating and how they are arranged Logic of Cognitive Subtraction: F. C. Donders (1867)!! A random series of high and low tones is presented. The subject must: (a) respond to any event! RT 1 =RT detect + RT respond (b) respond to high and not to low tones! RT 2 =RT detect + RT discriminate +RT respond (c) press right for high tones and left for low tones! RT 3 =RT detect +RT discriminate +RT decide +RT respond!! Duration of mental operations can be estimated as follows: Key Assumptions of Donders method!! We know what the underlying mental operations are!! We know that each operation is discrete and that their durations add!! We know that adding an additional mental operation does not affect the other mental operations (which ones are involved or their durations)!! All of these assumptions can be questioned!! RT discriminate = RT 2 - RT 1!! RT decide = RT 3 - RT 2

6 Information Processing! Decomposition of mental processes!multi-component memory system! Assumptions! Functionally decomposable mental processes exist!people are active information processors! Mental processes and structures can be revealed by response time and accuracy measures A Generic Information Processing model Environmental Stimuli The Mind Attention Sensory Memory Short-term / Working Memory Long-term Memory & Knowledge Overt Response S. Sternberg Memory-Scaning Paradigm (1966) Results of Sternberg (1966)! On each trial, subjects memorize a short list of digits (e.g., {4, 6, 5, 9, 3, 2})! A memor probe then appears and subject reports whether it s on the list! Measure both accuracy and response time as a function of the memory set size

7 S. Sternberg Memory-Scaning Paradigm (1966)!! Time to respond was linear function of size of search string: each additional element added 38 msec to search time!! Serial position did not matter, and the slope was the same for probe present and absent trials!! Conclusion: Subjects engage in an exhaustive serial memory search!! The larger impact was the introduction of a response time method that profoundly influenced the field (still today) Cognitive Neuroscience!! Phrenology: Gall (~ )!! Localization of function: Phineas Gage; Broca (1861); Wernicke (1874)!! Neural impulse: Helmholtz!! Complexity of the human cortex: Lashley, Penfield!! Systems neuroscience: Hubel & Wiesel!! Cognitive Neuropsychology (popularized by Oliver Sacks The Man who Mistook his Wife for a Hat-a case of prosopagnosia)!! Neural Network Modeling in 1950s: Pitts and McCulloch, Hebb, Rosenblatt!! Functional neuroimaging Cognitive Neuroscience: Driven by Methods!! Single cell recording in cats, monkeys in the 50s and 60s (Hubel & Weisel)!! Measuring brain activity in humans!! Electroencephalography (EEG): 1920s-30s!! Positron Emission Tomography (PET): early 70s!! Functional Magnetic Resonance Imaging (fmri): early 90s!! Magnetoencephalography (MEG): 1990s!! Temporary (experimental) disruption of neural activity:!! Transcranial Magnetic Stimulation (TMS): late 90s Evidence for localized function in the human brain!! Phrenology (~ )!!Franz Joseph Gall ( )

8 Phineas Gage!! Railroad construction crew foreman in Vermont!! Tamping iron injury on September 13, 1848 (about 160 years ago)!! 1-1/4 inch iron rod shot through his face and skull and landed 25 yards behind him.!! Amazingly, he survived Modern reconstruction: Before and After the Accident!! BEFORE: Before the accident he had been their most capable and efficient foreman, one with a well-balanced mind, and who was looked on as a shrewd smart business man.!! AFTER: He was now fitful, irreverent, and grossly profane, showing little deference for his fellows. He was also impatient and obstinate, yet capricious and vacillating, unable to settle on any of the plans he devised for future action. His friends said he was No longer Gage. Evidence for localized function in the human brain!! Phrenology (~ )!! Franz Joseph Gall ( )!! Now discredited!! Neuropsychology!! Pierre Paul Broca (1861) [left frontal; speech production]!! Carl Wernicke (1876) [left temporal; speech recognition]!! Primate neurophysiology (1950spresent)!! Hubel & Wiesel (1960s; Nobel Prize in 1979) Bloodflow-Based Neuroimaging!! Local change in neural activity causes local change in metabolism and blood flow (Roy & Sherrington, 1890)!! Noninvasive measurements of regional cerebral blood flow using PET or fmri can reveal changes in neural activity in the brain

9 Basic Principle of Functional Neuroimaging!! Local change in neural activity causes local change in metabolism and blood flow (Roy & Sherrington, J. Physiol., 1890)!! Subjects carry out two tasks that differ in the inclusion/ exclusion of a single mental process!! Changes in the distribution of blood flow during the two tasks tasks permits one to measure the neural activity associated with the mental operation that differs between the two tasks!! Two ways to control the mental operations that subjects must carry out:!! Change the stimulus but use the same task PET activation via image subtraction: Stimulus Manipulation Basic Principle of Functional Neuroimaging!! Local change in neural activity causes local change in metabolism and blood flow (Roy & Sherrington, J. Physiol., 1890)!! Subjects carry out two tasks that differ in the inclusion/ exclusion of a single mental process!! Changes in the distribution of blood flow during the two tasks tasks permits one to measure the neural activity associated with the mental operation that differs between the two tasks!! Two ways to control the mental operations that subjects must carry out:!! Change the stimulus but use the same task!! Change the task but use identical sensory stimuli Stimulation: flickering checkerboard Control: blank screen

10 fmri activation via image subtraction: Task Manipulation Kinds of questions in functional neuroimaging!! Which brain areas are active during a mental operation?!! How active is a brain area during one mental operation vs. another?!! What is the timecourse of activation in a task?!! Is mental process X required to carry out Task Y (assumes you know what pattern of brain acivity is necessary and sufficient for X)?!! What is the functional architecture of mental process X?!! What is the pattern of connectivity between areas, and what does that reveal about cognitve function?!! What is the pattern of activity across voxels within an area, and can this be used to decode a mental state? O Craven et al. (1997). Neuron, 18,