PSYC_224_Fall_2024.pdf

History

• End of 19th century: the field of psychology became interested in normal processes, not just breakdown of normal processes
• William James
  • Pragmatism
  • Functionalism
  • Opposed introspection & structuralism
  • An associationist memory model.
• Connectionism.
  • McClelland & Rumelhart. Parallel Distributed Processing. (1986).

Cognitive Psych

• Sternberg study → A serial information-processing model
• Classic Methods
  • Reaction time.
  • Rate of errors.
  • EEG. Non-invasive. Event-related potentials (ERPs). Good temporal resolution but bad spatial resolution.
  • fMRI (Functional Magnetic Resonance Imaging). Compared with MRI, it is dynamic. Yet, it takes 4-6s to reflect the activity.
  • Positron Emission Tomography (PET).
  • Transcranial Magnetic Stimulation (TMS). Apply strong magnetic pulses over the skull to change activities in the cerebral cortex.

Sensation and Perception

• Theories of pattern recognition, motivated by character recognition
  • Bottom-up processing

    • Template matching thesis

      • [Extension] Mental transformation like rotation.

    • Feature analysis thesis

      • Experiment by Gibson (1969): comparing P and R takes longer than comparing G and N.
      • Have problem with dealing with relationships between features

    • Recognition by components theory (RBC) of object

      • Idea: exploit non-accidental properties of 2D image edges
        • They are useful not for recognizing the whole object but for parts.
        • Parts first, configuration (object model) later.
      • 24 Geons: classes of Generalizaed cylinders: a shape moving along a 3D curve. Shape varying in the movement process.
        • Parallel edges → parallel sides
        • Curve intersection different from striaght intersection
        • Relying on categorical differences rather than finer details. Robust to variation of viewpoint and noise.
      • Imagine matching by propositions rather than matching by images. (Too vague to be a 3D model)
      • Experiment support: junctions of geons are critical for objects recognition
      • Challenge: structural info is not enough. How could we tell apart similar objects? Also, how experience and context come into play in perception?
      • Biederman argued that face recognition is separate and distinct from the recognition of objects.
  • Word superiority effect: word is such a powerful contextual info for letter recognition that a word can be recognized faster than even a single letter.
  • Top-down (contexual) processing
    • Information from the general context is used to help with local recognition
• Face recognition
  • Fusiform gyrus: a region of temporal lobe that responds to faces are present → damage → prosopagnosia

Attention

• Two types

  • goal directed attention
  • Stimulus attention

• search

  • Disjunctive feature search

  • Conjunctive feature search: search for a combination of features

  • Treisman & Gelade (1980): feature integration theory

    • color and feature map
    • Stage 1: distributed attention for disjunctive search. Parallel processing
    • Stage 2: Focused attention (attributed to Parietal lobes). Serial search.
    • Per Treisman and Gelade (1980), a conjunction target’s features are represented by independent feature maps. By directing focused attention onto a master location map, you can conjoin features at corresponding locations on the feature maps to perceive a unified object. However, this means you can only search a subsection of each image at a time, or you might incorrectly bind features into objects. So, search is serial because you can only search a subsection of an image at a time to perceive objects, and it is self-terminating because focused attention is no longer directed towards objects once the target is found. (Sylvia)

    

    1. linear → serial proecs. 2. usually slope doubles → self-terminating search in this experiment, therefore on average only half is processed

• Two types of process

  • Selective attention
    • Perceptual selection [posterior attention network]
      • Spotlight theory: eyes only decide the spotlight. Attention can be paid to different locations in the spotlight.
      • Object-based theory: (almost settled here)
    • Inhibitory selection [anterior attention network]: stop from performing an automatic action
      • The (John) Stroop effect
        • word naming is more automatic than color naming
      • Frontal lobes
  • Divided attention / multi-tasking
    • Attentional cost theory: how much does x slows down doing y (without compromising quality). Have an amount of total resources as an upper bound
    • Multiplication and addition at the same time

• Eye-tracking

  • Fixation takes 200-300ms

• Simons & Chabris (1999)

  • Change blindness: in the absense of motion cues, brain makes assumption that things do not change unexpectedly, especially in unattended parts
  • Inattention blindness

Memory

• Atkinson & Shiffrin (1968) information-processing model of memory
  • Sensory memory. Unattended information is lost after 250ms.
  • Short-term memory. Unrehearsed information is lost after 20s.
  • Long-term memory.

Sensory memory