Visual memory
Visual memory describes the relationship between perceptual processing and the encoding, storage and retrieval of the resulting neural representations.
A majority of experiments highlights a role of human posterior parietal cortex in visual working memory and attention.
We therefore have to establish a clear separation of visual memory and attention from processes related to the planning of goal-directed motor behaviors.
[4] Activity in the posterior parietal cortex is tightly correlated with the limited amount of scene information that can be stored in visual short-term memory.
[4] These results suggest that the posterior parietal cortex is a key neural locus of our impoverished mental representation of the visual world.
The visual cortex also receives information from subcortical regions, such as the lateral geniculate body, located in the thalamus.
However, ample evidence indicates that object identity and location are preferentially processed in ventral (occipito-temporal) and dorsal (occipito-parietal) cortical visual streams, respectively.
Although visual short term memory is essential for the execution of a wide array of perceptual and cognitive functions, and is supported by an extensive network of brain regions, its storage capacity is severely limited.
[4] The retrieval of long term visual memories is associated with activation of both anterior and posterior temporal cortices.
[9] After the time has passed participants are asked to immediately reproduce the designs from each card using their visual memory.
[9] The participants results from each task are then assessed and placed into six categories; omissions, distortions, preservations, rotations, misplacements, and sizing errors.
With the use of brain imaging devices researchers able to further investigate memory performance above and beyond standard tests based on exact response times, and activation.
[10] Subjects are blindfolded and instructed to lay motionless while simultaneously eliminating any visual imagery present in their mind's eye.
[10] After the scan is complete a control has been formed which can be compared with activated regions of the brain while performing visual memory tasks.
[10] During encoding, participants are typically exposed to 1–10 visual patterns while connected to a brain imaging device.
It is thought of as a three-dimensional cognitive map, which contains spatial features about where the person is and visual images of the area, or an object being concentrated on.
A classic test of spatial memory is the Corsi block-tapping task, where an instructor taps a series of blocks in a random order and the participant attempts to imitate them.
Visual memory, in an academic environment, entails work with pictures, symbols, numbers, letters, and especially words.
When teachers introduce a new vocabulary word, generally they write it on the chalkboard, have the children spell it, read it and then use it in a sentence.
In a recent study where a visual search task was administered quiet rest or sleep is found to be necessary for increasing the amount of associations between configurations and target locations that can be learned within a day.
[22] Studies have shown that with aging, in terms of short-term visual memory, viewing time and task complexity affect performance.
In a task to store and combine two different spatial configurations to form a novel one young people out-performed the elderly.
In a recent study visual working memory and its neutral correlates was assessed in university students who partake in binge drinking, the intermittent consumption of large amounts of alcohol.
This study looked at the neural correlated of the low level of response to alcohol using functional magnetic resonance imaging during a challenging visual memory task.
The results were that young people who report having needed more alcohol to feel the effects showed higher levels of brain response during visual working memory, this suggests that the individual's capacity to adjust to cognitive processing decreases, they are less able to adjust cognitive processing to contextual demands.
"All of the hallucinatory palinopsia symptoms occur concomitantly in a patient with one lesion, which supports current evidence that objects, features, and scenes are all units of visual memory, perhaps at different levels of processing.
"[3] Studying the excitability alterations associated with palinopsia in migraineurs could provide insight on mechanisms of encoding visual memory.
It has also been found in postmortem examinations of the brains of people with reading disabilities that they have fewer neurons and connections in the areas representing the transient visual systems.
[29] However, there is debate over whether this is the only reason for reading disabilities, scotopic sensitivity syndrome, deficits in verbal memory and orthographic knowledge are other proposed factors.
[30] These case studies show that these two types of visual memory are located in different parts of the brain and are somewhat unrelated in terms of functioning in daily life.
