CH. 10 CP

Visual Imagery

• Definition: Visual imagery occurs when a person sees something in their mind that isn't physically present.

• Properties: Visual imagery shares many properties with visual perception, but is often less detailed and more fragile.

Imagery in the History of Psychology

• Key Topics:

  • Early ideas about imagery

  • Imagery and the cognitive revolution

  • The relationship between imagery and perception

  • Specific methods: Paired-Associate Learning, Mental Scanning

  • Imagery and the brain

  • Techniques to use imagery for memory improvement

  • Individual differences in visual imagery

Early Ideas About Imagery

• Wilhelm Wundt: Proposed images as a basic element of consciousness, linking them to thought.

• Imageless Thought Debate: Conflicts over whether thoughts require images; some believed in

  • Francis Galton's Observation (1883): Noted periodic difficulties in forming visual imagery did not hinder an individual's ability to think.

Cognitive Revolution and Imagery

• 1960s Shift: A revival of interest in cognitive processes led to renewed study in imagery.

• Alan Paivio (1963): Developed paired-associate learning technique, showing recall of concrete nouns is often easier than abstract nouns, supporting the conceptual peg hypothesis.

Method: Paired-Associate Learning

• Procedure: Participants learn pairs of words such as boat-hat. During recall, the first word is presented, and participants must recall the second.

• Hypothesis: Concrete nouns create image associations for memory retrieval.

Imagery and Perception

• Mechanisms:

• Mental and perceptual images show spatial representation; longer decision times correlate with larger angle differences in mental rotation tasks.

• Shepard and Metzler (1971): Demonstrated mental rotation experiments indicating perception-imagery links.

Kosslyn's Mental Scanning Experiments

• Hypothesis: Imagery is spatial, requiring longer search times when parts of an object are physically farther apart in mind.

• Example Experiments: Scanning images of objects and maps; findings supported the spatial nature of imagery.

The Imagery Debate: Spatial vs. Propositional

• Kosslyn's view: Imagery involves spatial representations; parts of an image correspond to real-world locations.

• Pylyshyn's Counter: Argues imagery is propositional, represented by abstract symbols instead of spatial layouts.

Comparing Imagery and Perception

• Size in the Visual Field: Kosslyn investigated how mental image size affects perception.

• Findings: Larger imaginary objects fill the visual field more completely, requiring closer proximity for "overflow".

Interactions Between Imagery and Perception

• Cheves Perky (1910): Experiment demonstrated that actual visual stimuli affected participants' descriptions of mental images.

• Martha Farah (1985): Imagining letters influenced participants' success in detecting target letters flashed on-screen.

Imagery and the Brain

• Imagery Neurons: Brain cells responding similarly to perceiving and imagining objects (Kreiman et al., 2000).

• Brain Imaging Studies: Showed overlapping activation in the visual cortex for perception and imagery (Le Bihan et al., 1993).

• Physiological Methods: Includes TMS, MVPA, and neuropsychological case studies showing functional overlaps and differences.

Neuropsychological Insights

• Case Study: M.G.S. showed visual field reduction affected her imaginary distance judgments, supporting the role of the visual cortex in imagery.

• Dissociations: Cases where impairment in imagery does not affect perception or vice versa suggest unique cognitive mechanisms involved.

Using Imagery to Improve Memory

• Method of Loci: A technique that involves placing mental images at specific locations to enhance recall.

• Pegword Technique: Involves associating items to be remembered with mnemonic images based on rhyme and visualization.

Individual Differences in Visual Imagery

• Variations in Imagery: People experience imagery differently, influencing memory, problem-solving, and perceptions.

• Kozhevnikov's Studies (2005): Distinction between visualizers (good object imagery) and verbalizers (poor object imagery), supported by performance on various tasks.