Iconic Memory And How It Works
Iconic memory is just one component of your overall memory function, but it plays an important role in your ability to interpret the world around you. Typically lasting only milliseconds, iconic memory helps you process what you see and use that information to form new memories. Below, we’re discussing iconic memory, its functions, and how it works.
What is iconic memory?
Sensory memory is ultra-short-term memory that lasts only milliseconds for most people. Because snap impressions of scenes are used to round out perceptions and reach conclusions regarding visual cues, iconic memory can be vital to our ability to interpret our surroundings and determine when things are askew.
Some people confuse iconic memory with photographic memory. While there is little evidence that photographic memory is a real phenomenon, iconic memory is a proven component of memory function, with a wide body of research confirming its existence. Photographic memory is the ability to see something and remember it from a brief image alone. Iconic memory is simply your brain's way of processing visual information via the initial display of any given visual stimuli.
You can experience iconic memory through a simple exercise. Close your eyes for a few seconds, then open them for one or two seconds (just long enough to focus on an object), and then close them again. For a very brief time, you should continue to see the image in your mind's eye. That is iconic memory at work, keeping the image intact for a brief time after the stimulus is no longer present.
Persistence and iconic memory
Persistence refers to the continuation of a visual impression even after the stimuli have passed. It is thought to be the main mechanism underlying the function of iconic memory. Three types of persistence have been implicated in visual stimuli and iconic memory tasks: neural persistence, visible persistence, and informational persistence.
Neural persistence occurs when your neural activity continues after the stimuli are gone. Visible persistence is when you continue to see the image after it is gone, such as with a bright flash of light. Informational persistence is when information about the visual stimuli is still available to you for some time after the stimuli are gone.
Informational persistence is a primary aspect of iconic memory. Informational persistence has distinct properties from visible or neural persistence, as both visible and neural persistence rely heavily upon the visual cortex. Informational persistence does not rely as heavily on the visual cortex, as it converts the visual display to abstract ideas and information instead of a simple image.
Researchers once believed that these three forms of visual persistence rely upon one another and are the source of visual information relayed after stimuli are no longer available. However, new research has found that this is not the case. According to recent studies, two phenomena consistently occur with visual stimuli: the inverse duration effect, in which the longer a stimulus lasts, the briefer its persistence after stimulus offset; and the inverse intensity effect, which describes the duration of persistence based on the strength of the stimulus.
Temporal characteristics of iconic memory
Iconic memory decays rapidly after the visual stimulus is no longer present. Iconic memory is regarded by most to allow for the perceptual integration of two or more images, even if separated by a brief period. Many studies have been conducted to determine the duration of iconic memory, usually after the stimulus has been removed (called stimulus offset).
One study hypothesized that iconic memory has a set temporal property starting from the onset of the visual stimulus, regardless of how long the stimulus is displayed. This would account for the inverse action of the iconic memory lasting for a briefer period with a longer duration. The previous studies measured the duration of iconic memory from stimulus offset, but this measures it from stimulus onset.
The new study's results seem conclusive, showing that regardless of how long visual stimulus is displayed, iconic memory has a fairly set duration. Most often, the duration of iconic memory is less than one second. Only when iconic memory is put into context in the brain and relegated to short-term memory does the information persist beyond the single second associated with visual short-term memory.
Iconic memory’s journey through the brain
The primary part of the brain that is involved in iconic memory is the occipital lobe, which is home to the primary visual cortex. The occipital lobe and its primary visual cortex are responsible for processing and controlling visual information. The visual stimulus travels from the visual system of the eyes to the occipital lobe, where it is stored for mere milliseconds, before being discarded or transferred to the temporal lobe. The hippocampus within the temporal lobe is primarily responsible for converting that memory from short-term to long-term memory.
The path of visual memory is one that is traveled extremely quickly. Iconic memory, visual working memory, and short-term memory have limited capacities and brief temporal characteristics, some of them housed within the primary visual cortex. Only by moving information all the way through the process to long-term memory can visual stimuli be remembered for more than a few minutes; iconic memory requires attention and focus to transfer information to longer-term memory banks.
The first thing that must happen, of course, is for visual stimuli to be presented. The visual system and the occipital lobe process visual stimulus. Automatic recognition occurs, and it is then placed into iconic memory. This happens very quickly—said to occur in as little as one second in iconic memory and less than one minute in visual working memory.
Once the stimulus has initially been presented, iconic memory begins. The automatic recognition of the visual stimulus display is processed by the occipital lobe and transferred to iconic memory, where it remains for only milliseconds before being transferred to visual working memory or being discarded.
From iconic memory, the information moves to visual working memory. This is like an extremely short-term memory in vision and visual stimuli. Visual working memory can last for several seconds. For information to move to visual working memory, the subject must have focused attention on the visual display or set of information.
The short-term memory lasts only a few minutes and has limited capacity. With focused attention and interrelated memories and thought, visual working memory can be transferred to short-term memory. There, the information remains for several minutes before being discarded or being shuffled along to long-term memory. If information from iconic memory is to last beyond a few minutes, it needs to be stored in long-term memory.
Storage of iconic memory
Many studies have been done to determine the rate of transfer of information from iconic memory to long-term memory. Most studies have found that it takes significant attention for our brains to store iconic memory. Without focused attention, the iconic memory fades rapidly and is not put into a context that commits it to more long-term memory.
The amount of information that can be moved from iconic memory to long-term storage is limited by the capacity of the short-term memory and the availability of iconic memory. One study showed that iconic memory, with attention, could be transferred to visual working memory, which lasts several seconds. This memory in turn only lasts seconds, less than a full minute, without being transferred again to long-term memory.
Online therapy for memory-related emotional challenges
If you struggle to remember things you have seen, you might be experiencing early memory loss in visual areas. Memory impairment has been connected to mental health conditions such as depression, anxiety, and bipolar disorder. So, managing the emotional effects of memory loss can be important.
Studies show that online therapy can help individuals reduce the negative emotional and cognitive effects of memory impairment. In one study, participants displayed improvements in memory and mood following an online therapy program. These results can be added to those of an increasingly large number of studies that point to the efficacy of online therapy for a range of mental health and cognitive challenges.
If you’re struggling to process emotions related to memory loss or similar challenges, online therapy can help. For those experiencing memory loss, it may be difficult to keep track of appointments. With online therapy through BetterHelp, you can be frequently reminded of upcoming sessions and schedule appointments at times that are most compatible with your cognitive function. Your therapist can also connect you with useful resources, such as articles about memory or at-home memory-enhancing exercises.
Takeaway
What is iconic memory with an example?
Iconic memory is part of the visual memory processing system. Visual memory allows the brain to perceive, process, understand, and remember visual information received from the eyes. Iconic memory is the first stage of visual memory, contributing to the next step, visual short-term memory.
Iconic memory begins as soon as the retinal cells in the eyes are stimulated by light particles. It is often referred to as a sensory register. The term “register” is borrowed from computer science. In a computer, a register is a section of memory designed to hold information for a short time before it is saved or processed. Iconic memory works similarly in the brain. It holds visual data briefly, providing an information stream to the primary visual cortex.
Iconic memory has two main components: visual and informational persistence. Visual persistence refers to the illusion that occurs when visual cues update more quickly than the brain can process the information. The part of iconic memory responsible for persistence of vision stores information for 150 - 300 milliseconds, limiting the number of “snapshots” the brain can process in a limited space of time. When information is presented rapidly, the brain may not see changes between snapshots.
Informational persistence is not as well understood. It likely lasts much longer than visible persistence, on the order of several hundred milliseconds. There is also evidence that suggests informational persistence may involve higher-order memory functions, creating controversy regarding its role in iconic memory.
Iconic memory has been presented as a theory which explains the apparent motion of television and film. In a traditional film-based projector, still images move rapidly past a bright light source, which shines a light through them and onto a screen. Although the film is made up of a series of still images, the projected images appear to blend seamlessly to produce motion.
What are iconic and echoic memories?
Iconic and echoic memory are both short-lived memory registers that allow sensory data to be stored and processed by the brain. Iconic memory tasks are quickly discarded from the visual system. It holds data for a very short period of time, usually around 150 - 300 milliseconds. Echoic memory is part of the auditory memory system, and while it serves a similar function to iconic memory, it holds auditory information much longer.
Echoic memory can hold auditory information for two to four seconds, significantly longer than iconic memory. Researchers theorize that this is due to the transient nature of sounds, while visual stimuli are often persistent. In other words, visual data can often be accessed in the environment for a longer time than auditory information.
Imagine standing in the woods. If you are trying to remember the features of a specific tree, you can likely look at the tree as long as you like until the information is retained; the visual cue persists. On the other hand, if you are trying to identify a bird species by its call alone, you need to wait for the bird to produce sound before you can identify it. Because the bird’s auditory information is intermittent, it is likely helpful for the brain to access that information for a longer period.
How long does the iconic memory last?
There are two parts of iconic memory: visual and information persistence. The first component is extremely short-lived, lasting only 150 to 300 milliseconds. It refers to a sensory “snapshot” of visual data the brain can access, store, and process. The duration of iconic memory regarding information is less well-defined.
There is evidence to suggest that the second component of iconic memory can last for hundreds of milliseconds. Information persistence may also include higher-order categorization and processing, while the first component contains only a snapshot of the visual environment.
What is true about iconic memory?
Iconic memory, along with the entire visual memory processing system, has been studied extensively. However, researchers are still debating several explanations for all types of memory. Visual memory, auditory memory, and other types are relatively poorly understood. New technology has spurred research forward, and scientists are continuing to make new discoveries regarding what is true about iconic memory.
For example, researchers recently presented evidence contradicting a previously accepted assertion about iconic memory. In its traditional conceptualization, iconic memory was seen as a pre-attention store of information, meaning it did not require focus and attention to function. New research found that the opposite is likely true; evidence strongly suggests that attention is required for iconic memory to function properly.
What is an example of an echoic memory?
Echoic memory is a short-term memory register that holds auditory information for the brain to store and process. It typically holds information for two to four seconds, and it is involved anytime a person hears a sound. Echoic memory is the first stage in the auditory processing and auditory memory systems.
An example can be found in spoken conversation. When a person is listening to someone talk, echoic memory stores each syllable of the words they are saying. It acts as a buffer for the auditory processing center of the brain. The brain pulls information out of echoic memory, processes it, and the information is deleted from echoic memory as it is discarded or moved further along in the memory process.
What is an example of an implicit memory?
Implicit memory is one of two forms of long-term memory, the other being explicit memory. Explicit and implicit memory are also referred to as declarative and nondeclarative memory, respectively. Implicit memory refers to memory that is acquired and accessed unconsciously. A person does not need to actively memorize implicit memories; they are learned through experience and need little conscious exertion to recall.
Procedural memory is an excellent example of implicit memory. Procedural memories are skills that, while they took effort to learn, were not learned consciously and require little conscious thought to access. Riding a bike is a common example. If a person memorized a list of the steps required to ride a bicycle (putting the knowledge into explicit memory), they would likely struggle to apply their consciously-learned knowledge when sitting atop a bicycle seat. Learning to ride a bike requires practicing the skill to place it into implicit memory. Once the skill is mastered, it requires very little thought to execute repeatedly.
What is the difference between sensory memory and iconic memory?
Sensory memory refers to brief memory stores that hold data from human senses. It holds the information for a very short period of time, acting as a buffer that transfers information into short-term memory before being processed and placed into long-term memory. Commonly studied versions of sensory memory include echoic memory, which stores information related to sound, haptic memory, which stores information related to touch, and iconic memory, which stores information about a visual scene.
Iconic memory stores a visual image received from the eyes for about 150 to 300 milliseconds. In many cases, a person can continually view visual cues they are trying to process, allowing the ionic memory buffer to be consistently refreshed, which may explain why iconic memory lasts for a shorter amount of time than other forms of sensory memory. After entering iconic memory, visual data moves into visual short-term memory, where it is processed and either discarded or placed into long-term memory.
What's another word for iconic memory?
Iconic memory is a form of sensory memory, sometimes called visual sensory memory. It is a short-term buffer that briefly stores a visual display before it is moved into short-term memory. It is sometimes referred to as a visual sensory register because it is designed to hold mostly unprocessed information that higher brain functions can quickly access.
Iconic memory is sometimes incorrectly referred to as visual working memory. Working memory provides partially processed and encoded information to higher-order cognitive systems and comes after iconic memory in the memory-creation process. Iconic memory stores information for a very short period of time, about 150 - 300 milliseconds, before information is passed along to working memory.
- Previous Article
- Next Article