Mental Representation & Visual Processing
Cognition (does not necessarily happen in the given order):
1. Acquire knowledge through sensory systems
2. Organize & store info
3. Use that info the guide decisions, problem solving, and behaviour
* What we subjectively experience is directly related to electrical activity in our brain.
• In our brains, we represent information about ourselves and the environment.
• We CAN study “mental” processes, opposite to the view of original behaviourists,
who studies behaviour without taking mental processes into account
• We “see” our own representations of the world: our eyes are not cameras and we do
not directly see what’s out there in the world, thus explaining why we are often fooled
by visual illusions.
• Our mental experience appears to be unitary, but the brain actually has different parts
that represent different types of information
• Corpus callosotomy severs the corpus callosum, which connects the left and right
hemispheres of the brain
• The brain’s two hemispheres represent different kinds of information
• Left hemisphere represents information in the right visual field, controls right hand,
and controls speech
• Right hemisphere represents information in the left visual field, controls left hand,
and does not control speech
• According to previous research, the ability to recognize faces is specialized by the
right hemisphere. If a split-brain patient looks at a painting that uses fruits to
construct a human face, when the image is exposed to the right hemisphere, he
recognizes “face,” whereas wen the image is exposed to the left hemisphere, he
• Frontal lobe
• Parietal lobe
• Occipital lobe: responsible for visual processing!!
• Temporal lobe
• Eyes --> Thalamus (specifically the lateral geniculate nucleus), which is a central hub
where information is sent to and gets sent out --> Visual cortex (V1 --> V2 --> other visual areas and non-visual areas)
• Area V1: Most information from the thalamus goes to the primary visual cortex in the
occipital lobe, also known as area V1 or the striate cortex. If you close your eyes and
imagine seeing something, activity increases in area V1 in a pattern similar to what
happens when you actually see that object. Researchers found that a cortical cell that
responds well to a single bar or line responds even more strongly to a sine wave
grating of bars or lines. As such, most visual researchers now believe that neurons in
area V1 detect spatial frequencies rather than bars or edges.
Neurons respond to a single bar and line
Neurons respond best to particular spatial frequency (e.g. the number of lines
represent within a given space)
Some cells respond specifically to horizontal lines and some cells respond
specifically to vertical lines.
Different neurons detect different orientations of lines/bars
Involved in the formation of mental images
- Imagined objects activate regions within V1
- When transcranial magnetic stimulation (TMS) is directed at V1,
formation of images was significantly impaired
- Imagining and perceiving an object both ac