Chapter 7: Imagery

what is mental imagery?

a form of thinking that involves mental representations of stimuli that are not physically present

what is the difference between mental imagery and perception?

mental imagery uses top-down processing and is slower, perception uses bottom-up and top-down processing and is faster

is a stimulus required for perception?

yes

is a stimulus required for imagery?

no

are sensory receptors required for perception?

yes

are sensory receptors required for imagery?

no

what does perception come in the form of?

illusions

what does imagery come in the form of?

hallucinations, dreams

what are the similarities between imagery and perception?

the representation (visual, auditory, etc.) is the same, and they use the same or similar brain regions

what did Wilhelm Wundt and Francis Galton do for mental imagery?

trained subjects to report characteristics about images to access their nature and quality

what did John Watson suggest about mental imagery?

that mental images could not be connected to observable behaviour therefore not worth of investigation

Shepard and Metzler (1971) study on line drawings

presented pairs of 3D line drawings and asked students to judge them as the same or different. Second pair is rotated either in 2D or 3D

what was early research on mental imagery focused on?

whatever is imagined has to be visual (or picture like) in form

Images and rotation (reaction time) experiment

ppts. judged 1600 pairs of line drawings with rotations ranging from 20 to 180 degrees. Reaction times increased linearly as the angle of rotation increased (regardless of 2D or 3D), suggesting an analog representation of images

features of analog codes

picture-like

images are like perception and retain some of the sensory qualities of perception

relations presented implicitly

simultaneous

different representation for each sensep

features of propositional code

word-like

images are descriptions of visual scenes

relations represented explicitly

sequential

same representation for each sense