Cognitive Revision

Cognitive Revision

1. History

   • Herman Ebbinghaus
     • Memory processes can be measured
     • Pure memory, nonsense CVC syllables and forgetting curve, tested 20 mins or 31 days later
   • Wundt
     • STRUCTURALISM
       • Described mental functions in terms of underlying elements
       • Developed experimental methods and main focus was on use of introspection
   • Watson, Hull & Skinner
     • BEHAVIOURISM
       • Rejected concept of mind as unscientific, instead viewed brain as blank slate
   • Tolman
     • COGNITIVE MAP
       • Rat wouldn't always behave as expected (S-R), stead had a CM
   • BF Skinner (1959)
     • Explanation of language development
       • Could be due to S-R reinforcement, speech develops due to environmental reinforcement
         • Chomsky
           • Critique of Skinner
             • Couldn't account for all language development as language involves sentences we haven't heard before therefore not reinforced

2. Allied disciplines of Cognitive Psychology

   • Cognitive Neuro-psychology
     • Study of brain injury to inform about cognitive systems
     • Associations
       • 2 effects found together, H/E poor basis for understanding mental operations as tasks may be equally difficult
     • Dissociations
       • Lesions affect behaviour in one task but not other, can infer tasks involve difference processes H/E one task could just require fewer resources
     • Double Dissociations
       • Comparisons of 2 pts, one impaired on task A but good at task B, and other pt vice versa
     • Issues
       • Individual differences
   • Cognitive Neuroscience
     • 1980
     • Aim = to understand how normal cognitive processes map onto brain function
     • Pulvermuller 2005
       • Showed action words are associated with arm action

3. Cognitive Models

   • Symbolic Model
     • Cognition involves rule based storage and manipulation of symbolic info
       • Info processing occurs on meaningful units of info and is a serial process
     • Anderson 1973
       • Cognitive architecture states a fixed set of processes are argued to explain a wider range of cognitive tasks
   • Connectionist Model
     • Cognition at sub symbolic level
       • Info flow is a network of neuro activation and representation of info is distributed across a network
         • A fully distributed model represents connection weights in the system - the process is parrallel
     • Rumelhart
       • Connectionist model of semantic activation

4. Cognitive Psychology Methods

   • Response Selection
     • Person in challenging task involving 2 alternative force choice responses eg YES/NO
   • Produced Response Method
     • Pts can give free report eg story
       • Produces much richer data
   • Response Latency
     • How long it takes for response to be elicited
   • Cognitive Subtraction Method
     • Donders 1969
       • Tasks broken down into sub component possesses
         • Compare reaction time to noticing stimuli with that required to identify it before responding
           • H/E based on pure assumption
   • Additive Factors Method
     • Sternberg 1961
       • Avoids pure insertion problem as task requires utilisation of all hypothesised stages
         • If two manipulations affect two independent stages, then their effects on overall reaction times with be additive
           • Strict Serial Stage
             • Each stage completed before next stage begins
           • Cascade Process Model
             • Processing of next stage begins before previous stage complete

5. Functional Neuroimaging Methods

   • PET
     • Measures emission of positron from brain areas after injecting glucose into artery
       • Good spatial resolution but no temporal resolution
   • Functional Magnetic Resonance Imaging
     • Uses pulses generated in strong magnetic fields to measure density of hydrogen atoms
       • Can measure blood oxygenation (BOLD)
   • Event Related Potential
     • High temporal accuracy but poor spatial precision
     • P300 Wave
       • Analysis of time course of process without requirement of behaviour response
         • Elicited using oddball paradigm where low probability target items are mixed with high probability non target
     • N400 Wave
       • Occurs after semantically incorrect sentence is completed
     • Error Related Negativity Response
       • Response found immediately after person makes incorrect response
   • Trans-Cranial Magnetic Stimulation
     • Coil used to induce brief pulses
       • Magnetic field disrupts firing of neurons to immediate region below skull
         • Creates virtual lesion