Sensory memory in psychology refers to the short-term retention of sensory information, like sights, sounds, and smells, immediately following stimuli input.
It’s a crucial stage in memory processing that briefly stores vast amounts of sensory data before it’s selectively filtered into conscious awareness as working memory.
Key Takeaways
- Very Brief Store: Sensory memory holds sensory information for a fraction of a second to a few seconds, depending on the modality, before it fades or is lost.
- First Store: It is the first stage of the multi-store model of memory, feeding selected information into short-term memory.
- Sensory Registers: It is divided into separate registers, including iconic, echoic, haptic, olfactory, and gustatory memory.
- Modality-Specific: Iconic memory handles vision, echoic memory handles hearing, and haptic memory handles touch.
- Sperling’s Experiments: George Sperling’s 1960 partial-report studies gave the first evidence that the visual register holds far more than we can report.
- Modern Evidence: Recent research (Pratte, 2018) shows iconic memory disappears through the sudden loss of whole items, not a gradual fade.
What is Sensory Memory?
Sensory memory is a brief storage of information in humans wherein information is momentarily registered until it is recognized and perhaps transferred to short-term memory (Tripathy & Öǧmen, 2018).
Sensory memory allows for retaining sensory impressions following the cessation of the original stimulus (Coltheart, 1980).
Throughout our lives, we absorb tremendous information via our visual, auditory, tactile, gustatory, and olfactory senses (Coltheart, 1980).
We cannot permanently register every impression these senses capture. Instead, as we focus on one detail in our environment, sensory memory registers a brief snapshot of it. This snapshot lasts only a few hundred milliseconds.
Attention is the first step in remembering something. If a person’s attention focuses on one of the sensory stores, the data transfers to short-term memory.
Types of Sensory Memory
Sensory memory can be divided into subsystems called the sensory registers: such as iconic, echoic, haptic, olfactory, and gustatory.
Iconic Memory
Iconic memory is the visual sensory memory register that stores visual images after its stimulus has ceased (Pratte, 2018). While iconic memory contains a huge capacity, it declines rapidly (Sperling, 1960).
Information stored in iconic memory generally disappears within half a second (depending on the brightness).
This fleeting storage of visual information allows the brain to process and understand visual stimuli from our environment. It’s named ‘iconic’ due to its relation to visual icons or images.
Activity
Close your eyes for one minute, and hold your hand about 25cm from your face, and then open and close your eyes. You should see an image of your hand that fades away in less than a second (Ellis, 1987).
Examples of Iconic Memory
- Seeing an ant on the wall
- Seeing an aircraft in the sky as you walk down the road
- Seeing the change in traffic lights
Averbach and Coriell (1961): Masking the Icon
Aim: Averbach and Coriell (1961) wanted to measure the visual store’s duration more precisely. They also tested how a stimulus appearing just after the display affects an item already held in it.
Method: Observers viewed 16 letters arranged in two rows of eight for 50 milliseconds. A marker then indicated which single letter to report.
In one condition, a bar appeared just above the target; in another, a circle flashed around it. The researchers also varied the delay between the letters and the marker.
Results: With the bar marker, accuracy was high right after the display and fell as the delay grew. The letters stayed available for about 250 milliseconds.
The circle marker did something different. Instead of pointing out the letter, it seemed to “erase” it, and observers often could not report it at all.
Conclusion: The visual store lasts only about a quarter of a second. A later stimulus falling on the same spot can overwrite, or mask, an item before it is read out.
A recent study examined the hypothesis that iconic memory comprises fine-grained and coarse-grained memory traces (Cappiello & Zhang, 2016). The study employed a mathematical model to quantify each trace.
A recent study examined the hypothesis that iconic memory comprises fine-grained and coarse-grained memory traces (Cappiello & Zhang, 2016). The study employed a mathematical model to quantify each trace.
The outcome suggested that the dual-trace iconic memory model might be superior to the single-trace model.
Echoic Memory
Echoic memory is a type of sensory memory that specifically pertains to auditory information (sounds). It refers to the brief retention of sounds in our memory after the original noise has ceased.
This short-term auditory trace can last several seconds. It lets the brain process sounds and spoken language even after the sound itself has stopped.
Activity
Clap your hands together once and see how the sound remains for a brief time and then fades away.
Examples of Echoic Memory
- Hearing the bark of a dog
- Hearing the whistle of a police officer
- Hearing the horn of a car
The information which we hear enters our organism as sound waves. These are sensed by the ears’ hair cells and processed afterward in the temporal lobe.
The processing of echoic memories generally takes 2 to 3 seconds (Darwin, Turvey & Crowder, 1972).
The recent use of the Mismatch Negativity (MMN) paradigm, which employs MEG and EEG recordings, has unveiled many characteristics of echoic memory (Sabri, Kareken, Dzemidzic, Lowe & Melara, 2004).
Consequently, language acquisition and change detection have been identified as some crucial functions of echoic memory.
A single presentation of a sound is enough to shape a trace in echoic memory. That trace can then be compared against a later, different sound (Inui et al., 2010).
Moreover, a study of language acquisition indicates that children who start speaking late are likely to have an abridged echoic memory (Grossheinrich, Kademann, Bruder, Bartling & Suchodoletz, 2010).
Furthermore, lesions on or damage to the parietal lobe, the hippocampus, or the frontal lobe, would likely shorten echoic memory or/and slow its reaction time (Alain, Woods & Knight, 1998).
Haptic Memory
Haptic memory stores tactile sensations picked up through the skin’s sensory receptors, including pressure, temperature, and pain (Shih, Dubrowski, & Carnahan, 2009).
These memories tend to last for about two seconds.
It enables us to combine a series of touch sensations and to play a role in identifying objects we can’t see. E.g., Playing a song on the guitar or a sharp pencil on the back of the hand.
Examples of Haptic Memory
- Feeling a raindrop on your skin
- Feeling a key while typing on the keyboard
- Feeling a string as you play the guitar
The information which enters through sensory receptors travels via the spinal cord’s afferent neurons to the parietal lobe’s postcentral gyrus through the somatosensory system (Shih, Dubrowski & Carnahan, 2009; D’Esposito, Ballard, Zarahn & Aguirre, 2000).
fMRI studies suggest that certain neurons within the prefrontal cortex engage in motor preparation and sensory memory. Motor preparation provides a significant link to haptic memory’s role in motor responses.
Olfactory Memory
Olfactory sensory memory involves the brief retention of smell stimuli. It’s a type of sensory memory that allows us to retain and process odors momentarily.
Examples of Olfactory Memory
- Smelling the scent of chlorine and instantly remembering childhood spent at a public swimming pool.
- The scent of a specific soap brand triggers memories of a hotel stay during a memorable vacation.
- The aroma of fresh-cut grass evokes memories of playing in the backyard during summer.
- The smell of books evokes memories of studying in a library or a favorite reading spot.
- The smell of rain on dry soil, known as petrichor, triggers memories of rainy days.
This form of memory is powerful due to the strong links between olfaction and emotion/memory centers in the brain.
Gustatory Memory
Gustatory sensory memory is the temporary storage and recall of taste information. It refers to our ability to hold briefly and process tastes after we’ve experienced them.
This type of sensory memory is closely linked with olfactory (smell) memory due to the interconnected nature of taste and smell, and it can powerfully evoke recollections of specific events, places, or experiences associated with certain tastes.
Examples of Gustatory Memory
- Tasting a specific brand of ice cream and being reminded of your childhood when you used to eat it.
- The taste of a particular spice or ingredient in a dish reminds you of your grandmother’s cooking.
- Tasting an exotic fruit and recalling a trip to a foreign country.
- The flavor of a certain candy triggers memories of Halloween trick-or-treating.
- Tasting a type of wine and remembering a special occasion or celebration where it was served.
Sperling’s Experiments
In 1960, cognitive psychologist George Sperling used a tachistoscope to briefly present participants with a grid of 12 letters arranged in three rows of four (Sperling, 1960).
Participants viewed the letters for about 1/20th of a second, then tried to recall as many as possible. This is known as the whole-report method.
On average, they recalled only 4 or 5 of the 12 letters (Sperling, 1960). The conventional view at the time was that this simply reflected the limits of memory.
Sperling disagreed. He believed participants had briefly registered all 12 letters, but the memory faded before they could name more than a few.
In his view, the letters were stored for a very short time and then decayed. That decay, not a lack of registration, explained why only 4 or 5 letters could be reported.
Afterward, Sperling ran a second, slightly different experiment using the partial report technique. As earlier, the participants were shown three rows of letters for 1/20th of a second (Sperling, 1960).
However, this time, as the letters disappeared, the participants heard either a low-pitched, a medium-pitched, or a high-pitched tone.
Those who heard the low-pitched tone reported the bottom row. A medium-pitched tone meant the middle row, and a high-pitched tone meant the top row.
Participants could recall the cued row if the tone sounded within about a third of a second of the display (Sperling, 1960).
Beyond that delay, accuracy declined sharply. Once the delay passed one second, recall was almost impossible.
The experiment indicated that the participants could recall the information as long as they were focused on the pertinent row before the memory of the letters vanished.
Hence, they could not recall the letters if the tone was heard after the memory had faded.
Critical Evaluation
Sensory memory is one of the most secure ideas in cognitive psychology. Even so, it raises real debates about what the sensory registers actually store, and whether they count as memory at all.
Strengths of the Sensory Memory Model
Sperling’s (1960) partial-report technique remains a model of experimental ingenuity. It recovers a store’s true capacity by sampling it before the trace decays, and researchers have replicated and extended it for over sixty years.
The evidence also converges across methods. Partial report, backward masking, and the auditory suffix effect all point to the same brief, modality-specific buffer.
Brain-based measures back this up too. Mismatch negativity, an electrical brain response, confirms the echoic store exists without needing any verbal report at all.
The model also explains everyday puzzles, from perceptual continuity across eye movements to the auditory recency advantage and change blindness, all from one buffer concept.
Iconic Memory vs. Informational Persistence
Psychologist Max Coltheart (1980) raised the most influential challenge to Sperling’s account. He argued that “iconic memory” actually ran together two separate things.
Visible persistence is the felt experience that a bright stimulus lingers briefly after it disappears. Informational persistence is the continued availability of readable content that drives partial-report performance.
Coltheart showed the two behave differently. A brighter or longer stimulus produces a shorter-lasting visible afterimage, the opposite of what a simple fading-image account predicts.
Informational persistence does not show this pattern. This means partial-report superiority reflects available information, not a literal lingering picture, so many researchers now avoid the word “icon” altogether.
Is Sensory Memory Really “Memory”?
A deeper worry is whether sensory memory is a genuine memory store, or simply the tail end of perception, continued firing of the sense organs after a stimulus ends.
The trace is pre-categorical, cannot be rehearsed, and sits outside voluntary control, none of which resembles memory as usually understood. Whether it belongs to memory research or perception research remains partly a matter of definition.
Ecological Validity and Measurement
The classic paradigms use tachistoscopic arrays of unrelated letters and cued single-item recall. Both are far removed from how people actually use vision and hearing.
So it is unclear how far the neat duration estimates generalize to cluttered, everyday scenes. Measurement is also self-limiting, since reading the store out takes time and may interfere with what is being measured.
Landman, Spekreijse, and Lamme (2003) tested this using a simpler same-or-different response instead of letter naming. They found integrated visual information can remain available for up to 1,600 milliseconds, far longer than the classic quarter-second estimate.
The “Persistence of Vision” Myth
A popular claim holds that films look continuous because images “persist” on the retina. This is at best a half-truth.
Visible persistence and flicker fusion do help blend successive frames into a flicker-free image. Modern vision science, however, attributes the actual perception of motion mainly to specialised motion detectors, not to a lingering icon.
Contemporary Research
Recent work no longer asks whether a brief sensory register exists; Sperling’s result is among the most secure in the field. Instead, researchers ask how, exactly, information is lost from the register as it decays.
Aim: Pratte (2018) tested whether iconic memory is lost through a gradual decline in the precision of stored items, or through a sudden, all-or-none loss of whole items.
Method: Using a continuous-report partial-report paradigm, observers viewed arrays of simple oriented stimuli and, after variable delays, reported a probed item’s feature on a continuous scale. Mixture modelling then separated the probability an item was retained at all from the precision of the items that survived.
Results: As the delay lengthened, iconic memory suffered a complete loss of whole items, while the precision of surviving items was only marginally affected by time. Items did not blur gradually; they dropped out abruptly.
Conclusion: Iconic decay is better described as the discrete loss of individual items, not the graceful fading of a continuous trace. This supports a discrete-capacity view of how iconic memory hands off to working memory.
FAQs
Which process transfers information from sensory memory to short-term memory?
The process that transfers information from sensory memory to short-term memory is known as attention.
When we pay attention to a particular sensory stimulus, that information is transferred from the sensory memory (iconic, echoic, haptic, olfactory, or gustatory) to the short-term memory, also known as working memory, where it becomes part of our conscious awareness and can be further processed and encoded for longer-term storage.
How long does information last in sensory memory?
The duration of information in sensory memory varies based on the type of sensory input.
Iconic (visual) memory lasts about 100-200 milliseconds, echoic (auditory) memory can last up to 3-4 seconds, while haptic (touch), olfactory (smell), and gustatory (taste) memories have less defined durations but are generally considered brief.
If attention is not focused on these sensory impressions, they disappear quickly and are replaced by new sensory input.
What is the difference between iconic memory and echoic memory?
Iconic and echoic memory are types of sensory memory, but they differ in the sensory modality they process. Iconic memory refers to briefly retaining visual information, lasting about 100-200 milliseconds.
On the other hand, echoic memory relates to auditory information, maintaining sounds for a slightly longer duration, approximately 3-4 seconds. Their difference lies in the type of sensory input they handle – visual versus auditory.
In which memory store does information first have meaning?
Information first attains meaning in short-term memory, also known as working memory.
This is where the conscious processing of information occurs. Unlike sensory memory, which merely stores raw sensory input, short-term memory interprets and assigns meaning to these stimuli, allowing us to understand and respond to our environment.
Encoding in working memory can also facilitate the transfer of information to long-term memory for more permanent storage.
References
Alain, C., Woods, D. L., & Knight, R. T. (1998). A distributed cortical network for auditory sensory memory in humans. Brain Research, 812(1-2), 23-37.
Averbach, E., & Coriell, A. S. (1961). Short-term memory in vision. Bell System Technical Journal, 40(1), 309-328. https://doi.org/10.1002/j.1538-7305.1961.tb03987.x
Cappiello, M., & Zhang, W. (2016). A dual-trace model for visual sensory memory. Journal of Experimental Psychology: Human Perception and Performance, 42(11), 1903-1922. https://doi.org/10.1037/xhp0000274
Coltheart, M. (1980). Iconic memory and visible persistence. Perception & Psychophysics, 27(3), 183-228. https://doi.org/10.3758/BF03204258
Darwin, C. J., Turvey, M. T., & Crowder, R. G. (1972). An auditory analogue of the Sperling partial report procedure: Evidence for brief auditory storage. Cognitive Psychology, 3(2), 255-267. https://doi.org/10.1016/0010-0285(72)90007-2
D’Esposito, M., Ballard, D., Zarahn, E., & Aguirre, G. K. (2000). The role of prefrontal cortex in sensory memory and motor preparation: an event-related fMRI study. Neuroimage, 11(5), 400-408.
Grossheinrich, N., Kademann, S., Bruder, J., Bartling, J., & Von Suchodoletz, W. (2010). Auditory sensory memory and language abilities in former late talkers: a mismatch negativity study. Psychophysiology, 47(5), 822-830.
Inui, K., Urakawa, T., Yamashiro, K., Otsuru, N., Takeshima, Y., Nishihara, M., … & Kakigi, R. (2010). Echoic memory of a single pure tone indexed by change-related brain activity. BMC Neuroscience, 11(1), 1-10.
Landman, R., Spekreijse, H., & Lamme, V. A. F. (2003). Large capacity storage of integrated objects before change blindness. Vision Research, 43(2), 149-164. https://doi.org/10.1016/S0042-6989(02)00402-9
Pratte, M. S. (2018). Iconic memories die a sudden death. Psychological Science, 29(6), 877-887. https://doi.org/10.1177/0956797617747118
Sabri, M., Kareken, D. A., Dzemidzic, M., Lowe, M. J., & Melara, R. D. (2004). Neural correlates of auditory sensory memory and automatic change detection. Neuroimage, 21(1), 69-74.
Shih, R., Dubrowski, A., & Carnahan, H. (2009). Evidence for haptic memory. In World Haptics 2009-Third Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (pp. 145-149). IEEE. https://doi.org/10.1109/WHC.2009.4810867
Sperling, G. (1960). The information available in brief visual presentations. Psychological Monographs: General and Applied, 74(11), 1-29. https://doi.org/10.1037/h0093759
Tripathy, S. P., & Öǧmen, H. (2018). Sensory memory is allocated exclusively to the current event-segment. Frontiers in Psychology, 9, 1435. https://doi.org/10.3389/fpsyg.2018.01435
Further Information
- Sperling, G. (1960). The information available in brief visual presentations. Psychological monographs: General and applied, 74(11), 1.
- Öğmen, H., & Herzog, M. H. (2016). A new conceptualization of human visual sensory-memory. Frontiers in Psychology, 7, 830.
- Sligte, I. G., Vandenbroucke, A. R., Scholte, H. S., & Lamme, V. (2010). Detailed sensory memory, sloppy working memory. Frontiers in Psychology, 1, 175.
