Feb 1 Visual Imagery

• Mental Imagery is our ability to mentally recreate perceptual experience in the absence of a sensory stimulus.
• Perception, without sensation, is a concept in Mental Imagery.
• Dual-Coding Theory (Paivio, 1971) suggests that human knowledge is represented in two separate systems:

  1. Non-Verbal (Modality-specific system based on sensory-motor information; Image system)
  2. Verbal (symbolic system, abstract; Language system).
• Images in the Non-Verbal system resemble what they stand for and maintain perceptual features of the stimulus they represent.
• Information in the Verbal system does not resemble what it stands for.
• The Imagery Debate states that people experience mental images and that imagery influences cognition.
• Shepard and Metzler’s (1971) investigated the time it took for individuals to rotate mental images of abstract figures.
• Researchers have conducted experiments to resolve the imagery debate, including Kosslyn (1978) who found that mental images maintain the spatial characteristics of physical stimuli.
• Mental Scanning (Kosslyn, 1973) found that if visual images are analog/depictive codes of physical stimuli, it should take more time to travel longer physical distances than shorter ones.
• Pylyshyn (1973) argues that images are descriptive representations, symbolic codes that convey abstract conceptual information and do not resemble the real world.
• Mental Scaling (Kosslyn, 1975, 1978) states that when things get closer to you, they appear physically bigger until they fill your entire visual field.
• Mental Rotation (Shepard and Metzler, 1971) investigated the time it took for individuals to rotate mental images of abstract figures.
• Abstract-Code Terms include

  • Verbal Representation
  • Propositional Representation
  • Descriptive
  • Amodal Representations
  • which have no direct connection to the features of a stimulus such as computer code.
• Depictive Representation Terms include

  • Non-Verbal Representation
  • Analog Representation
  • Depictive & Modal Representations
  • which maintain perceptual features of a stimulus such as a photograph.
• Descriptive Processing (Pylyshyn, 1973) argues that knowledge is represented propositionally, via the manipulating of cognitive symbols and propositional codes are the only requirement for thought.
• Epiphenomenon: a mere by-product of a process that has no effect on the process itself (APA dictionary).
• Kosslyn (1994) and Pylyshyn (1973) argue that images are depictive representations, analog codes that maintain perceptual and spatial characteristics of objects.
• Neuropsychological study of patients with brain lesions can provide insights into the relationship between perception and imagery.
• If imagery is perception without sensation, then it follows that imagery and perception should use similar cognitive mechanisms.
• The Concreteness Effect: concrete words are more easily remembered than abstract words.
• Winawer et al., (2010) demonstrated that mental imagery can create similar perceptual illusions.
• Imagery impacts cognitive functioning and behavioral manifestation, regardless of its nature.
• The Picture Superiority Effect suggests that image-based memory uses two codes (images and labels) instead of one (just labels).
• Motion aftereffects result when sensory stimulation leads to perceptual overcompensation leading to the illusion of motion in the opposite direction.
• Neuroimaging results tend to support shared mechanisms between perception and imagery, although they are not exactly the same.
• Damage to a specific area can lead to deficits in one or more cognitive processes.
• Kosslyn (1999) found that brain areas involved in planning, cognitive control, attention, and memory showed the most similarity in visual perception and imagery tasks.
• Imagery is beneficial to memory, as memory is better when items are stored as pictures compared to words.
• There is a lot of evidence suggesting that there is depictive representation of knowledge.
• Depression is characterized by persistent feelings of sadness, frequently accompanied by a loss of interest

  • Is associated with an increase of negative imagery
  • Specifically suicidal ideation, and a decrease in positive imagery
• Easier to imagine, more likely to spontaneously create visual images are remembered better than abstract words, which are harder to visualize and rely only on one verbal code (labels).
• Individuals vary greatly in their ability to create mental images, as evidenced by Galton (1880), who asked a group of scientists to describe their breakfast and found some gave vivid descriptions while others reported no mental imagery at all.
• Those with hyperphantasia are more likely to occupy a creative profession.
• Hyperphantasia is the condition of experiencing extremely vivid visual imagery, although little is known about this population, and it is likely much rarer.
• Objective Performance Tasks are another method of measuring mental imagery

  • Ex. Paper Folding Test (Ekstrom et al., 1976)
  • Where participants view diagrams of paper being folded and must 'mentally unfold' the paper and identify the placement of the holes
• Anxiety Disorders are characterized by intense, persistent, and excessive worrying that interferes with daily life

  • Are associated with an increase of negative imagery of future events, which can exacerbate anxiety
• Negative intrusive imagery is a characteristic trait of individuals with PTSD, involving re-experiencing traumatic events through involuntary and unwanted memories.
• Self-Report is a method of measuring mental imagery by asking people to write or explain their imagery experiences, such as the Visual Imagery Questionnaire (Marks, 1973), which assesses vividness of imagery on a 1-5 Likert Scale.
• Aphantasia is the inability to form mental images at all

  • Ex. MX who claimed to have lost all ability to form mental images following heart surgery
  • Scored as low as possible on the Vividness of Visual Imagery Questionnaire
  • Had his visual cortex and fusiform gyrus inhibited in fMRI
• Imagery Rescripting is a technique used to treat mental disorders linked to abnormal mental imagery

  • Patients are guided through memories of past negative events
  • Instructed to imagine themselves acting the way they wish they could have during the event