Mental imagery: representation of nonpresent
object or event that is subjectively experienced as
the object or event itself. Note: visual imagery is just
one form of mental imagery
1.Dual code: (Allan Paivio) – info can be encoded into
two possible system: verbal system or imagery
system. Recall is best if represented in both rather
than single system.
Words high in imagery value (tornado) better
recalled than words low in imagery value (reciprocal)
Brooks study – selective interference – verbal task
not affected if paired with spatial response; affected
in paired with verbal response.
*Important point – image systems seen as
independent form of representation; but is this so?
• Hypo 2: Conceptual/propositional hypo: all info is stored as
conceptual/propositional information. When propositional info is
especially elaborate it may be experienced as ‘image’ but this is
illusion, does not reflect true nature of representation.
• Pylyshyn’s arguments against imagery:
• Pictures in head
• Mind’s eye
• Tacit knowledge
• Epiphenomenalism: Images as ‘dependent’ on more basic form of
• Empirical evidence
• Mental rotation studies – shoes rotated more slowly than feathers?
• Ambiguous figures: reversal as stimulus not as image
Image switching: perception vs. imagery
• Subjects report image
switching in perception,
• Hypo 3: Functional equivalency – images
formed in STM based on more basic
(propositional) LTM representation, but
posses independent features.
• Kosslyn – mental scanning, mental image size
studies; Shepard – mental rotation
• Kosslyn – fMRI studies showing visual
system/imagery system equivalency
• Mental rotation and mental scanning studies
Neuroscience of Imagery
1. Same areas of brain important for imagery and visual perception:
Occipital/temporal visual pathway
2. Damage to occip/temp visual pathway leads to visual not spatial deficits
(case of LH)
3. Occipital parietal pathway important for spatial tasks – see below.
• Cognitive mapping: mental representation of
spatial layout of navigatable space.
• Combination of conceptual and imagery
• Route vs. Survey knowledge
• Conceptual distortions of spatial
representations (ex: which is farther west San
Diego, CA or Reno, NV?)
Conceptual distortions of survey knowledge