Visual Knowledge Flashcards
What is the concern about “self-report” data, and Galton’s data in particular?
Francis Galton conducted the first systematic research on the “minds eye” using self report (introspection). Some reported images rich in detail, whilst others claimed to be seeing no “picture” at all. With this type of data, there is a “translation gap” - there’s no guarantee people translate their mental pictures the same way. Instead Galtons research may have revealed more about how people talk about imagery, rather than the imagery itself.
What is a chronometric study?
Imagery researches are careful about the problems with introspection I’m reporting mental pictures, so they rarely ask people to describe their pictures, instead the ask perhaps to make a judgment on it. The time is measured on how quickly they make their judgements about their mental picture - this is called a chronometric study (time measuring). An experiment was done where participants were asked to picture a cat, and then another group to think about cats. The first group responded quicker to if he cat had a head over if it had claws, and vice versa for the second group. This suggests that people have the option of thinking about cats via imagery and also the option to think without imagery. With the memorisation of a map and landmark, participants had to press a button once they’d reached certain landmarks. Similar results occurred when participants were asked to zoom in and out of a picture (if the mouse was standing next to the elephant it took longer than if next to a paper clip). The data from this image scanning procedure revealed that response one is directly proportional to the amount of zoom required,
Why do image-scanning studies indicate that images depict a scene rather than describing the scene?
The chronometric study preserves the spatial relationships within that scene, therefore rather directly represents the geometry of the scene. In this way, images depict the scene rather than describing it. Thus they are much more similar to pictures of maps then they are to descriptions. With the mental rotation tasks using blocks, the larger the rotation that participants had to visualise matched with their response time. In cases where they had no choice but to picture the images rotating on the vertical axis (so it was a 3D depth rotation), participants showed 95% accuracy. Therefore we can imagine mental sculptures rather than just mental pictures in our heads.
What does it mean to say that a chronometric experiments results might be influenced by demand character?
A possibility that distance/rotation time matched that of results is perhaps because participants wanted to give “good data”, and therefore subconsciously responded to how they thought they were “supposed to” in the experiment. To tackle this, experimenters may ask participants to make judgements about spatial layout but have taken care not to mention that imagery might be relevant to a task.
What’s the evidence that visual imagery relies on some of the same mental processes as actual vision?
In a study by Segal and Fusella, participants were asked to detect very faint signals, whether visual or auditory. Participants did this by either forming a visual image in their “minds eye” or forming the auditory image before their “minds ear”. Experimenters showed that doing both of these at once showed interferences rates with imaging and perceiving (ie. forming a visual image interferes with seeing and forming an auditory image interfere with hearing). Although effects were relatively low. Shows that mental images are not mere hallucinations. If stimuli is similar to what participants have to perceive, however, it primes them to it. Binocular rivalry occurs when different stimuli presented in a different eye. Unable to combine inputs, your mental picture switched between the stimuli. The parts of the brain that are activated during imagery has also been shows using fMRI scans to match that same area when its perceived (visual for visual, auditory for auditory etc). By observing this, it has allowed researches to correctly guess what the participant is thinking at that time.
What do we learn from the fact that some forms of brain damage have SIMILAR effects on a persons ability to see and the persons ability to perform many imagery tasks?
Participants with brain damage who fail to see colour also fail to visualise it, and similarly with seeing fine detail. We see this using transcranial magnetic stimulation. Brain damage also causes parallels in how people pay attention to visual inputs and to visual images. A patient who suffered neglect syndrome (could only observe the right hand side of pictures) was asked to visualise he was standing in a city - depending on where he was standing he only reported seeing building on the right hand side of where he was standing. In the case of spatial reporting, blind people displayed similar results to those who were sighted (though they had to feel a sculptor to determine distance). Same with rotation tasks.
What do we learn from the fact that some forms of brain damage have different effects on a persons ability to see and the persons ability to perform many imagery tasks?
Some exceptions to people with brain damage include cases where brain damage causes problems in imagery but not perception and vice versa. This is because unlike visual imagery, the brain relies on different areas for spatial imagery. Therefore damages to visual imagery won’t intefer with this form of imagery, and brain site needed for this imagery will not affect vision. In patient LH who suffered a severe automobile accident and struggled with judgements about visual appearances (eg colour) but performed well on image scanning and mental rotation.
What evidence confirms that people do actually differ in the vividness of their visual images?
With Galtons data,people with vivid memory reported that their images are extremely picture like. People without vivid imagery do not say these things at all. Roughly 10% of the population will, in this way, declare themselves entirely deficient in the power of seeing mental pictures - this is called aphantasia. In an fMRI scan where people were asked to report how well their vivid imager was, the results indicate a clear relationship between self- reported vividness and degree of activation in the brains visual cortex. Visual imagers were more likely to succeed in the arts, while people with spatial memory were more likely careered in science or engineering. Also affects autobiographical memory, with non-imagers less likely to feel as if they can “relive” their memories. May be a link between visual imagery and mental illness.
What is eidetic imagery?
Eidetic memory is when people seem to have memory that is in fact photographic, rather than just a really good memory.
Images are certainly picture- like, but what evidence points to a distinction between mental images and actual out in the world picture?
The necker cube is ambiguous, and requires a configuration in depth to perceive it. The duck/rabbit is also ambiguous and can be viewed in a couple of different ways. Percepts, therefore, are not responding just to the stimuli, they’re organised depictions of a stimulus.
The duck/rabbit interpretation experiment showed that we have 100% chance failure rate in reinterpreting these forms (picture) with images, but 100% chance of doing so a moment later with drawings. Therefore, what participants see in their image isn’t a “picture” - neutral with regard to interpretation and open to new interpretations. Instead, images are inherently organised, just as percepts are.
What evidence suggests that visual information is often stored in long term memory via a representation that’s not really visual?
We’ve suggest that certain things like “animals” represent a number of nodes in long term memory. One possibility is that nodes in long term memory represent entire, relatively complete pictures. However, evidence suggests that images seem to be stored in a piece by piece way. In support of this claim, more detailed images and images with more parts take longer to create. How to construct an image can be drawn from our image files in long term memory and tells us how to create an image, like a recipe. Experiments show that those with large colour vocabularies have better colour memories, probably because they’re remembering the verbal label for each colour rather than the colour itself.
What’s the evidence that imagery can help you to memorise?
Materials that evoke imagery are easier to remember then those that don’t. An example is where participants rated words to his image evoking they were. Sure enough, the new participants memorised the words rated higher, better. Imagery mnemonics provided the highest recall, but only if the list of objects were remembered as interacting in some way. Patients with left spatial neglect have a harder time remembering past facts about Marta.
What is dual coding first proposed by Pavio?
There is no question that imagery mnemonics helps recall, and one reason for this but be dual coding. For high imagery words, they are double represented in memory. The word itself, and the corresponding picture. This may suggest that we have multiple types of inform in long term storage- eg verbal and imagery.
