Iconic memory: concept, time of action, functions performed and Sperling's experiment

2024 Author: Miguel Ramacey | [email protected]. Last modified: 2023-12-17 06:11

Iconic memory contributes to memory itself by providing a coherent representation of our entire visual experience over a very short period of time. This kind of memory helps to take into account such phenomena as the change in the clarity of vision and the continuity of experience. Iconic memory is no longer seen as a single entity. Nowadays it is already known that it consists of at least two distinctive components. Classical experiments, including experiments to test the Spurling partial report paradigm, as well as modern methods, confirm the previous conclusion. The development of iconic memory begins in early childhood. It gets worse with age. Just like any other type of memory.

Iconic memory theory

The emergence of a stable physical image of an object after it has been removed from view has been observed by many people throughout history. One of the earliest documented accounts of this phenomenon was Aristotle, who suggested that thesemental phenomena are related to the phenomenon of dreams.

Everyday observation of a light trail created by glowing coal at the end of a fast-moving stick aroused the interest of researchers in the 1700s and 1800s. The then European researchers were the first to begin empirical research on this phenomenon, which later became known as apparent persistence. The study of visible resilience will ultimately lead to the discovery of iconic memory.

In the 1900s, the role of storing such images in memory attracted considerable attention due to the hypothetical connection of this phenomenon with visual short-term memory (VSTM).

Modern Era

In 1960, George Spurling began his classic experiments to confirm the existence of visual sensory memory and some of its characteristics, including power and duration. In 1967, W. Neisser called iconic memory the property of the brain to memorize for a very short time a "cast" of an image that had just flashed before the eyes. About 20 years after Sperling's original experiments, separate components of visual sensory memory began to emerge. That is visual and information stability. Sperling's experiments mainly tested information related to the stimulus of this type of memory, while other researchers conducted tests for visual persistence. Iconic memory in psychology is, first of all, the ability to remember fleeting images imprinted in the mind for a short time.

Sound Link

In 1978Di Lollo proposed a model of visual sensory memory with two different states. Although this phenomenon has been known throughout history, the current understanding of iconic memory makes a clear distinction between visual and informational persistence, which are tested differently and have fundamentally different properties. It is assumed that information persistence is a key factor in visual short-term memory as a pre-categorical sensory "repository of information". First of all, for sounds. The retention time of the iconic memory may vary depending on the material.

Structure

The two main components of sign memory (another name for the phenomenon under discussion) are visible and informational durability. The first characteristic implies a relatively short (150 ms) pre-categorical visual representation of the physical image created by the sensory system of our brain. It will be a "snapshot" of what the person was looking at a split second before. The second component is a longer lasting memory that represents an encoded version of the visual image turned into post-categorical information. This will be the "raw data" that is received and processed by the brain. A third component can also be considered, which is called neural persistence and represents the physical activity and recordings of the visual system. Neuronal persistence is usually measured usingneurophysiological methods.

Duration

Various methods have been used to determine the duration of visible (visual) durability. The difference in the duration of visible endurance in humans lies in the different duration of the work of the "store" of visual memory. Phenomenal continuity and the moving slit method allowed us to determine an average (normal for a human) apparent tool life of 300 ms.

Neurophysiological aspect

The main apparent persistence is the neural persistence of the visual sensory channel. Long-term visual presentation begins with the activation of photoreceptors in the retina. It was found that activation in the receptors persists even after the physical displacement of the stimulus, and rod-shaped objects are stored in memory longer than, for example, cones. Cells involved in stable visual imaging include M and P cells found in the retina. M-cells (transitional) are active only during the onset of the stimulus and its displacement. P-cells (resistant) show continuous activity during stimulus onset, duration, and displacement. Cortical visual image persistence has been found in the primary visual cortex (V1) in the occipital lobe of the brain, which is responsible for processing visual information.

Other characteristics of information durability

Information persistence is information about a stimulus that persists after its physical displacement. ExperimentsSperling were a test of information fortitude. The duration of the stimulus is a key factor influencing the duration of informational persistence. As the duration of the stimulus increases, the duration of the visual signal to the brain also increases. The non-visual components represented by information persistence include the abstract characteristics of the image as well as its spatial arrangement. Due to the nature of information durability, unlike visible durability, it is immune to object cloaking effects. The characteristics of this sign memory component suggest that it plays a key role in representing a post-categorical memory store that the brain can access to analyze information.

Experiments

Although there is not much research on the neural representation of information hardness compared, new electrophysiological methods have begun to reveal regions of the cerebral cortex involved in the formation of iconic memory that no one has paid attention to before. In contrast to apparent persistence, informational persistence relies on higher-level visual areas outside the visual cortex. The anterior upper brain region has been found to be associated with object recognition and identification of their identity. The role of iconic memory in change detection is associated with activation of the middle occipital gyrus.

It was found that the activation of this gyrus persists for approximately 2000 ms, whichindicates the possibility that sign memory has a longer duration than previously thought. Iconic memory is also affected by genetics and proteins produced in the brain. Neurotrophin produced by the brain causes the growth of neurons. And it helps to improve all types of memory. Individuals with mutations in brain regions that produce neurotrophin have been shown to have much lower and less stable information hardness.

Meaning of iconic memory

This memory provides a smooth and gradual flow of visual information to the brain that can be extracted over a long period of time to be consolidated into more stable forms. One of the key roles of symbolic memory has to do with detecting changes in our visual environment, which aids in the perception of movement.

Iconic memory allows the integration of visual information during a continuous stream of images, such as when watching a movie. In the primary visual cortex, new stimuli do not erase information about previous stimuli. Instead, the responses to the most recent one contain roughly equal amounts of information about this and the previous stimulus. This one-sided memory can be the main substrate for both the integration of sign memory and the recognition of masking effects. The specific result depends on whether the two subsequent component images (i.e. "icons", "icons") are only meaningful when isolated (masked), or only when overlaid.(integration).