PSYCH 240 LEC 9 (VISUO-SPATIAL PROCESSING)

Imagery vs. perception

Perception: Has metric qualities that images do not

• Delivers length + distance info. at high resolution than imagery does

• Better at extracting partial info. from perception

Imagery

• Create mental perception of a stimulus

Enormous capacity of visual memory

• Toscanini was a composer remembers 250 symphonies via memory

• Shepard (1967): 612 pictures with each image having 6 sec interval

  • Retained majority of the pictures participants saw

  • Compared to words memory (that dropped off chance lvl by 50% in 3 days, picture memory was better

• Result: visual info holds a special place in memory

Exceptions to good visual memory

• Foils/Distractors are similar

• Meaningless stimuli

• Unimportant/Unattended details

Problems with richer visual code hypothesis

• Hyp: Visual code is richer (more info.) = memory is better

• Results: 3 visual images had the same result (all were better than memory for words

Dual code hypothesis

• MUST use Verbal and Visual code used to encode information to remember it MORE

  • Concrete Words

    • Can have both verbal and non-verbal code (Dual-code representation)

    • Words you can visualize

  • Abstract Words

    • Can have verbal code only

    • No benefit with dual-code

Dual code hypothesis explains poor visual memory

• unattended/unimportant details

  • doesn’t create verbals for those details

  • penny demo

• foils are simmar

  • visual code doesn’t help differentiate them

  • need verbal code

Tolman’s maze expt with rats

• Supports cognitive map idea

• Demos that they mad a spatial layout of maze, not just randomly making turns bc they also take shortcuts

Cognitive Map

• In humans, we can make accurate points to cities and keep track of items when orientation changes

• Humans are good at distance estimation with familiar places

Distance estimates

• 2 familiar landmarks (coffee shops)

  • Underestimate distance

• 2 different landmarks (coffee vs gas station)

  • Overestimate distance

Distortions of shape/position

Heuristics

• Weakness of Cognitive Map

• Help us remember things

• Also cause distortions

Right-angle bias

• Represent/Assume angles as 90 degree angles

Symmetry heuristic

• Shapes are represented as more symmetrical than they are

Rotation heuristic

• Remembers tilted figures a more vertical or horizontal than they actually are

• We rotate them

Alignment heuristic

• People mentally shift two or more separate geographic structures to line up more neatly with one another than they do in reality.

Relative-position heuristic

• People use conceptual knowledge to represent relative positions

  • i.e. Canada is above U.S.

Subjective clusters

• Conceptual knowledge affects representations of distances

  • the under/over estimate between similiar/diff. landmarks

Observer perspective

• Estimated distance from familiar to unfamiliar > unfamiliar to familiar

  • Why? We focus on details of familiar places and stretch areas relative to unfamiliar places