Cognitive Psychology PSYC2360 Agenda adds, drops and who is in and who is not Course Outline Brief Review of Brain Structures course supports Memory span demonstration Assignment for next week’s class Assignments Prior to class Readings Discussion Forum: introduce yourself by posting to the online discussion question In class at 19:00 – quiz on Today a practice quiz with answer sheets Cognitive Psychology Cognitive Psychology deals with how people perceive, learn, remember, and think about information In many ways Cognitive Psychology is the ground on which other areas of psychology are built in the same way that physics is the ground on which many of the physical sciences are built Recurrent Issues in Cognitive Psychology Nature versus Nurture (evolution video clip) Rationalism versus Empiricism Structures versus Processes Domain generality versus Domain specificity Validity of inferences versus ecological validity Applied versus basic research Biological versus Behavioural Key Themes Data versus Theory Adaptiveness of cognition Interaction of cognitive processes and non-cognitive processes Interrelation of basic and applied research Concept Map Purple lines for influence Red lines for rejection Cognitive Psychology is the product of many influences What does it mean to be a human? Historic Views The Rational Animal The singular self The soul embodied The product of a long successful evolution Video clip Emerging Views A community of about 500 cooperating organisms Multiple parts loosely coupled operating in parallel Neurons - odd shaped building blocks Basic model and Varieties Neurotransmitters Myelin and nodes of Ranvier Neural Transmission up to 224 miles per hour (1/3 the speed of sound) Support Structures - glial cells transport between the capillary and the neuron cell body (glucose viewed with PET and fMRI scans) Structure Structure Central Nervous System Brainstem & RAS Cerebellum Hemispheres brain Temporal Lobe gyrus Cortex size Cortex Layers Excitatory layers Inhibitory Layers Column structures 1 to 3 millimeters thick outer layer that is spread out would be about 2 square feet of surface or 2 12”x12” pages of paper) Cortex Layers Excitatory layers Inhibitory Layers Column structures Input/output Afferent axon Efferent axon location specific processing provides an EEG localization Core Organization Brainstem Thalamus Limbic System Neuroscience Methods postmortem studies ..\360s2005\c01-firstclass\female_files\headF90-1-600.mov ..\360s2005\c01-firstclass\male_files\headM90-1-200.mov animal studies electrical recording MRI PET fMRI Plasticity hydrocephalus (video) Split Brain (video) Corpus Callosum (under plastic) Language Localization (video) Broca's Area Wernicke's Area Primary Auditory area Motor area Neurons Density highest in neocortex Synapse Action potential threshold Brain Stimulation (video clip) optional ACT-R article on sleep deprivation http://act-r.psy.cmu.edu/papers/596/gunzelmann_gluck_etal-2005.pdf Adaptive Control of Thought ACT-R ACT-R Model Brain Images on the Web Save bookmarks if you like Harvard Medical School [http://www.med.harvard.edu/AANLIB/home.html] From Visible Human Project [http://rad.usuhs.mil/rad/vhproject/vhcoronal.html] Google search on brain_images http://directory.google.com/Top/Science/Biology/Neurobiology/Brain_Images/ Brain dissection http://www.vh.org/adult/provider/anatomy/BrainAnatomy/BrainAnatomy.html Psychology and Neuroscience : Making Peace By Miller and Keller (Readings p 155) A failure of Reductionism aka psychology in not reducible to biology “Brain tissue as implementing psychological functions” – the functions are not the same as the living tissue as in the case of fear This is not a settled issue as are many other issues that you will encounter in this course. Automatic Brains – Interpretive Minds by Roser and Gazzaniga Readings p. 162 “The cortex is not a homogeneous, general-purpose computing device, but rather is a complex of circumscribed, modular processes occupying distinct locations” Consciousness seems unitary (as does the personal narrative that is constructed) The future theory will need to integrate the separate and circumscribed mental processes Why is cognition so limited by “memory span” – a plausible ACT- style account By Bruce Landon with help from the students in cognitive psychology winter 05 Digit Span Lets try remembering a few digits How did you do what you did? Write down you answer as it will become the basis for your first electronic discussion assignment (due by next class) The magic number 7 George Miller (now working on WordNet) Examples in the common share experiences Telephone number error patterns Serial Position Effect Juggling The invention of chunks and chunking Chunks are bigger organized collections that seem to operate as “single units” Starts out small and grows but only to 7+2 Consider learning a new list How does is work? Now we will do a little demonstration in class I will slowly flash three groups of three numbers on the screen one at a time. At the end I will ask you to write them down in order. This is like a visual version of the Digit Span task from the WAIS without the shorter strings of digits first. Get ready and have you pen or pencil ready for when we get to the end. Start How did you do what you did? That is the question that the ACT-R theory is trying to answer by precisely describing the mental steps and the timing of mental operations to arrive at the performance ACT-R as a theoretical model Model has the mind/brain divided into functional parts that can interconnect The functional parts work in parallel but interconnect through a single processor The processor is a serial processor with a cycle time of 50 ms The process works on chunks that can be matched to a buffer and send a chunk to a buffer The processor can detect a match between a buffer and the chunk in the processor and respond with a production (if chunk then do) There are several identified buffers that connect special module neural networks to the processor: Goal Buffer (keeping track of place in the path to goal) Imaginal Buffer (internal representation without external support) Retrieval Buffer (declarative memory module) Visual Buffer (two parts: where part and what part) Manual Buffer (does actions like pressing keys) Speech Buffer (new in /PM makes words – rehearsal ) Hearing Buffer (new in /PM listens to words for processing) Errors can arise from several places due to “noise” – random fluctuations of a living organism in the neural interconnections Memory module retrieval – flow from chunk cue to chunk response in buffer When a memory “node” is activated by the chunk cue then the activation lingers on When one memory “node” is activated then the “nodes” connected to it will also be activated (Fan Effect) in a “semantic network” of nodes The “node” with the highest activation above “threshold” is the chunk pattern that ends up in the response buffer The spreading of activation process is inherently “noisy” and sometimes the noise added to the activation from a connected node will cause an “error chunk” to end up in the buffer Learning a short list – one item External Visual stimulus of first element Visual module responds Where is the element -> code-x to buffer What is the element object -> code-y to buffer (description adapted from Altman (2000)) Processor sends the code-x to retrieval buffer Processor sends the code-y to retrieval buffer Hearing buffer – “start” cue to repeat Processor moves start to retrieval buffer Processor checks retrieval buffer and gets code for first location Processor moves first location code-x to retrieval buffer Processor checks retrieval buffer and gets code-y Processor moves code-y to the speech buffer Speech buffer triggers speech module to say it Learning a longer list - 9 Anderson and Matessa (1997) Production Rules for serial memory Get-Next If the goal is to retrieve an element at position p in group g and x is the element at p in group g. Then set a subgoal to generate x and change the goal to retrieve the element in the next position. Production Rule – Generate-Item Generate-Item If the goal is to generate an item and the item is associated with a motor program Then execute the motor program and the goal is satisfied. Production Rule – Next-Group Next-Group If the goal is to retrieve an element at position p in group g and g* is the next group Then change the goal to retrieve the first element of g* Done If the goal is to retrieve an element at position p in group g and there is no element at position p in group g and there is no next group. Then the goal is satisfied and stop recalling. See Table 1 (handout) on page 74 of Anderson and Matessa (1997) – they did the demo on individual terminals and had the participants type their answer Table 1 Anderson and Matessa Digit span for 5 7 9 Why is memory span so small? The longer the list the greater the likelihood of errors so that by 9 items the chance of an error is over 40% There is interference from items next to each other (serial position effect) and this increases with each additional item. Grouping (chunking) can help but the fundamental problem of limited capacity remains as a basic cognitive limitation. Errors in ACT-R serial memory Declarative Memory activation includes an random error component that can make an “error” easier to retrieve than the correct one Decay of the memory strength also produces low activation levels and this can also lead to error (lack of practice style) Partially matching errors of commission are the cause of intrusions and transpositions Retrieval failure is the cause of recall blanks (nothing above retrieval activation threshold) For Next week Make your personal study plan Review the material from tonight Chapter 1 plus 2 short readings Post your discussion message Read messages of others in the class Comment and clarify as appropriate Prepare for in-class quiz on Chapter assigned readings and slides from tonight Begin thinking about what would make a good Term Project topic – within the scope