Sensory memory

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During every moment of an organism's life, sensory information is being taken in by sensory receptors and processed by the nervous system. Sensory information is stored in sensory memory just long enough to be transferred to short-term memory. [1] Humans have five traditional senses: sight, hearing, taste, smell, touch. Sensory memory (SM) allows individuals to retain impressions of sensory information after the original stimulus has ceased. [2] A common demonstration of SM is a child's ability to write letters and make circles by twirling a sparkler at night. When the sparkler is spun fast enough, it appears to leave a trail which forms a continuous image. This "light trail" is the image that is represented in the visual sensory store known as iconic memory. The other two types of SM that have been most extensively studied are echoic memory, and haptic memory; however, it is reasonable to assume that each physiological sense has a corresponding memory store. Children for example have been shown to remember specific "sweet" tastes during incidental learning trials but the nature of this gustatory store is still unclear. [3] However, sensory memories might be related to a region of the thalamus, which serves as a source of signals encoding past experiences in the neocortex. [4]

Contents

Characteristics

SM is considered to be outside of cognitive control and is instead an automatic response. The information represented in SM is the "raw data" which provides a snapshot of a person's overall sensory experience. Common features between each sensory modality have been identified. However, as experimental techniques advance, exceptions and additions to these general characteristics will surely evolve. The auditory store, echoic memory, for example, has been shown to have a temporal characteristic in which the timing and tempo of a presented stimulus affects transfer into more stable forms of memory. [5] Four common features have been identified for all forms of SM: [5]

  1. The formation of a SM trace is only weakly dependent on attention to the stimulus. [6]
  2. The information stored in SM is modality specific. This means, for example, that echoic memory is for the exclusive storage of auditory information, and haptic memory is for the exclusive storage of tactile information.
  3. Each SM store represents an immense amount of detail resulting in very high resolution of information.
  4. Each SM store is very brief and lasts a very short period of time. Once the SM trace has decayed or is replaced by a new memory, the information stored is no longer accessible and is ultimately lost. All SM stores have slightly different durations which is discussed in more detail on their respective pages.

It is widely accepted that all forms of SM are very brief in duration; however, the approximated duration of each memory store is not static. Iconic memory, for example, holds visual information for approximately 250 milliseconds. [7] The SM is made up of spatial or categorical stores of different kinds of information, each subject to different rates of information processing and decay. The visual sensory store has a relatively high capacity, with the ability to hold up to 12 items. [8] Genetics also play a role in SM capacity; mutations to the brain-derived neurotrophic factor (BDNF), a nerve growth factor, and N-methyl-D-aspartate (NMDA) receptors, responsible for synaptic plasticity, decrease iconic and echoic memory capacities respectively. [9] [10]

Types

Iconic memory

The mental representation of the visual stimuli are referred to as icons (fleeting images.) Iconic memory was the first sensory store to be investigated with experiments dating back as far as 1740. One of the earliest investigations into this phenomenon was by Ján Andrej Segner, a German physicist and mathematician. In his experiment, Segner attached a glowing coal to a cart wheel and rotated the wheel at increasing speed until an unbroken circle of light was perceived by the observer. He calculated that the glowing coal needed to make a complete circle in under 100ms to achieve this effect, which he determined was the duration of this visual memory store. In 1960, George Sperling conducted a study where participants were shown a set of letters for a brief amount of time and were asked to recall the letters they were shown afterwards. Participants were less likely to recall more letters when asked about the whole group of letters, but recalled more when asked about specific subgroups of the whole. These findings suggest that iconic memory in humans has a large capacity, but decays very rapidly. [11] Another study set out to test the idea that visual sensory memory consists of coarse-grained and fine-grained memory traces using a mathematical model to quantify each. The study suggested that the dual-trace model of visual memory out-performed single-trace models. [12]

Echoic memory

Echoic memory represents SM for the auditory sense of hearing. Auditory information travels as sound waves which are sensed by hair cells in the ears. Information is sent to and processed in the temporal lobe. The echoic sensory store holds information for 2–3 seconds to allow for proper processing. The first studies of echoic memory came shortly after Sperling investigated iconic memory using an adapted partial report paradigm. [13] Today, characteristics of echoic memory have been found mainly using a mismatch negativity (MMN) paradigm which utilizes EEG and MEG recordings. [14] MMN has been used to identify some of the key roles of echoic memory such as change detection and language acquisition. Change detection, or the ability to detect an unusual or possibly dangerous change in the environment independent of attention, is key to the survival of an organism. [14] One study focusing on echoic sensory changes suggested that when a sound is presented to a subject, it is enough to shape an echoic memory trace that can be compared to a physically different sound. Change-related cortical responses were detected in the superior temporal gyrus using EEG. [15] With regards to language, a characteristic of children who begin speaking late in development is reduced duration of echoic memory. [16] In short, "Echoic memory is a fast-decaying store of auditory information." [17] In the case of damage to or lesions developing on the frontal lobe, parietal lobe, or hippocampus, echoic memory will likely be shortened and/or have a slower reaction time. [18]

Haptic memory

Haptic memory represents SM for the tactile sense of touch. Sensory receptors all over the body detect sensations such as pressure, itching, and pain. Information from receptors travel through afferent neurons in the spinal cord to the postcentral gyrus of the parietal lobe in the brain. This pathway comprises the somatosensory system. Evidence for haptic memory has only recently been identified resulting in a small body of research regarding its role, capacity, and duration. [19] Already however, fMRI studies have revealed that specific neurons in the prefrontal cortex are involved in both SM, and motor preparation which provides a crucial link to haptic memory and its role in motor responses. [20]

Proprioceptive memory

Patients undergoing regional anesthesia can have incorrect, "phantom" perception of their limb positions during a procedure. A longstanding neurological explanation of this effect was that, without incoming signals from proprioceptive neurons, the limb perception system presented to consciousness a default, slightly flexed position, considered to be a universal, inborn "body schema". [21] However, more deliberate experimentation, varying patient limb position prior to anesthesia, has established that there is a proprioceptive memory store, which informs these perceptions. [22] [23] More task-oriented experimentation with limb position—asking subjects to return their arm to a remembered position—has revealed a rapidly decaying, high-precision memory available for two to four seconds, which is theorized to be the proprioceptive equivalent of iconic memory and echoic memory. [24]

A somewhat different theory of proprioceptive memory has been put forward as an explanation of phantom limb phenomena. [25] The hypothesis states that we remember limb positions which are used in common tasks, such driving, riding a bike, eating with a fork, etc. The formation of a "proprioceptive memory bank" over the course of our lives contributes to our proficiency with these tasks, and the ease with which they are performed. Memories of specific limb positions can also be associated with expected sensations, including pain. In the theory as described by Anderson-Barnes et al., these memories aid us to rapidly ascribe location and cause when pain does occur, especially pain caused by an overextended joint; and these memories also help us rapidly choose a motion which will relieve the pain. However, in the case of amputation, the remembered pain is being continually or intermittently ascribed to the perceived limb position, often because the most recent limb position prior to amputation was in fact painful. This pain, and the role of proprioceptive memory in perpetuating it, has been compared to tinnitus [26] and the role of echoic memory in its etiology.

Relationship with other memory systems

SM is not involved in higher cognitive functions such as consolidation of memory traces or comparison of information. [27] Likewise, the capacity and duration of SM cannot be influenced by top-down control; a person cannot consciously think or choose what information is stored in SM, or how long it will be stored for. [5] The role of SM is to provide a detailed representation of our entire sensory experience for which relevant pieces of information can be extracted by short-term memory (STM) and processed by working memory (WM). [2] STM is capable of storing information for 10–15 seconds without rehearsal while working memory actively processes, manipulates, and controls the information. Information from STM can then be consolidated into long-term memory where memories can last a lifetime. The transfer of SM to STM is the first step in the Atkinson–Shiffrin memory model which proposes a structure of memory.

See also

Related Research Articles

An illusion is a distortion of the senses, which can reveal how the mind normally organizes and interprets sensory stimulation. Although illusions distort the human perception of reality, they are generally shared by most people.

<span class="mw-page-title-main">Phantom limb</span> Sensation that an amputated or missing limb is attached

A phantom limb is the sensation that an amputated or missing limb is still attached. Approximately 80–100% of individuals with an amputation experience sensations in their amputated limb. However, only a small percentage will experience painful phantom limb sensation. These sensations are relatively common in amputees and usually resolve within two to three years without treatment. Research continues to explore the underlying mechanisms of phantom limb pain (PLP) and effective treatment options.

The Atkinson–Shiffrin model is a model of memory proposed in 1968 by Richard Atkinson and Richard Shiffrin. The model asserts that human memory has three separate components:

  1. a sensory register, where sensory information enters memory,
  2. a short-term store, also called working memory or short-term memory, which receives and holds input from both the sensory register and the long-term store, and
  3. a long-term store, where information which has been rehearsed in the short-term store is held indefinitely.

Iconic memory is the visual sensory memory register pertaining to the visual domain and a fast-decaying store of visual information. It is a component of the visual memory system which also includes visual short-term memory (VSTM) and long-term memory (LTM). Iconic memory is described as a very brief, pre-categorical, high capacity memory store. It contributes to VSTM by providing a coherent representation of our entire visual perception for a very brief period of time. Iconic memory assists in accounting for phenomena such as change blindness and continuity of experience during saccades. Iconic memory is no longer thought of as a single entity but instead, is composed of at least two distinctive components. Classic experiments including Sperling's partial report paradigm as well as modern techniques continue to provide insight into the nature of this SM store.

<span class="mw-page-title-main">Sensory neuron</span> Nerve cell that converts environmental stimuli into corresponding internal stimuli

Sensory neurons, also known as afferent neurons, are neurons in the nervous system, that convert a specific type of stimulus, via their receptors, into action potentials or graded receptor potentials. This process is called sensory transduction. The cell bodies of the sensory neurons are located in the dorsal ganglia of the spinal cord.

Baddeley's model of working memory is a model of human memory proposed by Alan Baddeley and Graham Hitch in 1974, in an attempt to present a more accurate model of primary memory. Working memory splits primary memory into multiple components, rather than considering it to be a single, unified construct.

Multisensory integration, also known as multimodal integration, is the study of how information from the different sensory modalities may be integrated by the nervous system. A coherent representation of objects combining modalities enables animals to have meaningful perceptual experiences. Indeed, multisensory integration is central to adaptive behavior because it allows animals to perceive a world of coherent perceptual entities. Multisensory integration also deals with how different sensory modalities interact with one another and alter each other's processing.

George Sperling is an American cognitive psychologist, researcher, and educator. Sperling documented the existence of iconic memory. Through several experiments, he showed support for his hypothesis that human beings store a perfect image of the visual world for a brief moment, before it is discarded from memory. He was in the forefront in wanting to help the deaf population in terms of speech recognition. He argued that the telephone was created originally for the hearing impaired but it became popularized by the hearing community. He suggested with a sevenfold reduction in the bandwidth for video transmission, it can be useful for the improvement in American Sign Language communication. Sperling used a method of partial report to measure the time course of visual persistence.

Sensory substitution is a change of the characteristics of one sensory modality into stimuli of another sensory modality.

<span class="mw-page-title-main">Associative visual agnosia</span> Medical condition

Associative visual agnosia is a form of visual agnosia. It is an impairment in recognition or assigning meaning to a stimulus that is accurately perceived and not associated with a generalized deficit in intelligence, memory, language or attention. The disorder appears to be very uncommon in a "pure" or uncomplicated form and is usually accompanied by other complex neuropsychological problems due to the nature of the etiology. Affected individuals can accurately distinguish the object, as demonstrated by the ability to draw a picture of it or categorize accurately, yet they are unable to identify the object, its features or its functions.

A sensory cue is a statistic or signal that can be extracted from the sensory input by a perceiver, that indicates the state of some property of the world that the perceiver is interested in perceiving.

The mismatch negativity (MMN) or mismatch field (MMF) is a component of the event-related potential (ERP) to an odd stimulus in a sequence of stimuli. It arises from electrical activity in the brain and is studied within the field of cognitive neuroscience and psychology. It can occur in any sensory system, but has most frequently been studied for hearing and for vision, in which case it is abbreviated to vMMN. The (v)MMN occurs after an infrequent change in a repetitive sequence of stimuli For example, a rare deviant (d) stimulus can be interspersed among a series of frequent standard (s) stimuli. In hearing, a deviant sound can differ from the standards in one or more perceptual features such as pitch, duration, loudness, or location. The MMN can be elicited regardless of whether someone is paying attention to the sequence. During auditory sequences, a person can be reading or watching a silent subtitled movie, yet still show a clear MMN. In the case of visual stimuli, the MMN occurs after an infrequent change in a repetitive sequence of images.

Extended physiological proprioception (EPP) is a concept pioneered by D.C. Simpson (1972) to describe the ability to perceive at the tip of a tool. Proprioception is the concept is that proprioceptors in the muscles and joints, couple with cutaneous receptors to identify and manage contacts between the body and the world. Extended physiological proprioception allows for this same process to apply to contacts between a tool that is being held and the world. The work was based on prostheses developed at the time in response to disabilities incurred by infants as the result of use of the drug thalidomide by mothers from 1957 to 1962, with the tool in this case simply being the prosthesis itself. How a person identifies with themself changes after a lower limb amputation affects body image, functioning, awareness, and future projections.

Echoic memory is the sensory memory that registers specific to auditory information (sounds). Once an auditory stimulus is heard, it is stored in memory so that it can be processed and understood. Unlike most visual memory, where a person can choose how long to view the stimulus and can reassess it repeatedly, auditory stimuli are usually transient and cannot be reassessed. Since echoic memories are heard once, they are stored for slightly longer periods of time than iconic memories. Auditory stimuli are received by the ear one at a time before they can be processed and understood.

Body schema is a concept used in several disciplines, including psychology, neuroscience, philosophy, sports medicine, and robotics. The neurologist Sir Henry Head originally defined it as a postural model of the body that actively organizes and modifies 'the impressions produced by incoming sensory impulses in such a way that the final sensation of body position, or of locality, rises into consciousness charged with a relation to something that has happened before'. As a postural model that keeps track of limb position, it plays an important role in control of action. It involves aspects of both central and peripheral systems. Thus, a body schema can be considered the collection of processes that registers the posture of one's body parts in space. The schema is updated during body movement. This is typically a non-conscious process, and is used primarily for spatial organization of action. It is therefore a pragmatic representation of the body’s spatial properties, which includes the length of limbs and limb segments, their arrangement, the configuration of the segments in space, and the shape of the body surface. Body schema also plays an important role in the integration and use of tools by humans.

<span class="mw-page-title-main">Somatosensory system</span> Nerve system for sensing touch, temperature, body position, and pain

In physiology, the somatosensory system is the network of neural structures in the brain and body that produce the perception of touch, as well as temperature (thermoception), body position (proprioception), and pain. It is a subset of the sensory nervous system, which also represents visual, auditory, olfactory, and gustatory stimuli.

<span class="mw-page-title-main">Proprioception</span> Sense of self-movement, force, and body position

Proprioception, also called kinaesthesia, is the sense of self-movement, force, and body position.

<span class="mw-page-title-main">Visual capture</span>

In psychology, visual capture is the dominance of vision over other sense modalities in creating a percept. In this process, the visual senses influence the other parts of the somatosensory system, to result in a perceived environment that is not congruent with the actual stimuli. Through this phenomenon, the visual system is able to disregard what other information a different sensory system is conveying, and provide a logical explanation for whatever output the environment provides. Visual capture allows one to interpret the location of sound as well as the sensation of touch without actually relying on those stimuli but rather creating an output that allows the individual to perceive a coherent environment.

Haptic memory is the form of sensory memory specific to touch stimuli. Haptic memory is used regularly when assessing the necessary forces for gripping and interacting with familiar objects. It may also influence one's interactions with novel objects of an apparently similar size and density. Similar to visual iconic memory, traces of haptically acquired information are short lived and prone to decay after approximately two seconds. Haptic memory is best for stimuli applied to areas of the skin that are more sensitive to touch. Haptics involves at least two subsystems; cutaneous, or everything skin related, and kinesthetic, or joint angle and the relative location of body. Haptics generally involves active, manual examination and is quite capable of processing physical traits of objects and surfaces.

<span class="mw-page-title-main">Limb telescoping</span>

Limb telescoping is the progressive shortening of a phantom limb as the cortical regions are reorganized following an amputation. During this reorganization, proximal portions of the residual limb are perceived as more distal parts of the phantom limb. Such effect is responsible for increased phantom pain due to the discrepancy between the patient’s body perception and their actual body. This effect may last from weeks up to years after post-amputation.

References

  1. ↑ Carlson, Neil R. (2010). Psychology the science of behavior. Pearson Canada Inc. pp.  232. ISBN   9780205645244.
  2. 1 2 Coltheart, Max (1980). "Iconic memory and visible persistence". Perception & Psychophysics. 27 (3): 183–228. doi: 10.3758/BF03204258 . PMID   6992093.
  3. ↑ Laureati, M.; E. Pagliarini; J. Mojet; E. Köster (April 2011). "Incidental learning and memory for food varied in sweet taste in children". Food Quality and Preference. 22 (3): 264–270. doi:10.1016/j.foodqual.2010.11.002.
  4. ↑ M. Belén Pardi; et al. (2020). "A thalamocortical top-down circuit for associative memory". Vol. 370, no. 6518. Science. pp. 844–848. doi:10.1126/science.abc2399.
  5. 1 2 3 Winkler, Istvan; Nelson Cowan (2005). "From Sensory to Long-Term Memory Evidence from Auditory Memory Reactivation Studies". Experimental Psychology. 52 (1): 3–20. doi:10.1027/1618-3169.52.1.3. PMID   15779526.
  6. ↑ Persuh, Marjan; Genzer, Boris; Melara, Robert D. (2012-05-07). "Iconic memory requires attention". Frontiers in Human Neuroscience. 6: 126. doi: 10.3389/fnhum.2012.00126 . ISSN   1662-5161. PMC   3345872 . PMID   22586389.
  7. ↑ Walsh, David; Larry Thompson (1978). "Age Differences in Visual Sensory Memory". Journal of Gerontology. 33 (3): 383–387. doi:10.1093/geronj/33.3.383. PMID   748430.
  8. ↑ Irvine, Elizabeth (2011). "Rich Experience and Sensory Memory". Philosophical Psychology. 24 (2): 159–176. doi:10.1080/09515089.2010.543415. S2CID   144366993.
  9. ↑ Javitt, Daniel; Mitchell Steinscheider; Charles Schroeder; Joseph Arezzo (October 1996). "Role of cortical N-methyl-D-aspartate receptors in auditory sensory memory and mismatch negativity generation: implications for schizophrenia". Proceedings of the National Academy of Sciences USA. 93 (21): 11962–11967. Bibcode:1996PNAS...9311962J. doi: 10.1073/pnas.93.21.11962 . PMC   38166 . PMID   8876245.
  10. ↑ Beste, Christian; Daniel Schneider; Jörg Epplen; Larissa Arning (February–March 2011). "The functional BDNF Val66Met polymorphism affects functions of pre-attentive visual sensory memory processes". Neuropharmacology. 60 (2–3): 467–471. doi:10.1016/j.neuropharm.2010.10.028. PMID   21056046. S2CID   14522722.
  11. ↑ Sperling, G. (1960). The information available in brief visual presentations. Psychological Monographs: General and Applied, 74(11), 1-29. doi : 10.1037/h0093759
  12. ↑ 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. doi : 10.1037/xhp0000274
  13. ↑ Darwin; Turvey, Crowder (1972). "An auditory analogue of the sperling partial report procedure: Evidence for brief auditory storage" (PDF). Cognitive Psychology. 3 (2): 255–267. doi:10.1016/0010-0285(72)90007-2 . Retrieved 2011-03-09.
  14. 1 2 Sabri; Kareken, Dzemidzic; Lowe, Melara (2003). "Neural correlates of auditory sensory memory and automatic change detection". NeuroImage. 21 (1): 69–74. doi:10.1016/j.neuroimage.2003.08.033. PMID   14741643. S2CID   1253981.
  15. ↑ 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, 11135-144. doi : 10.1186/1471-2202-11-135
  16. ↑ Grossheinrich, Nicola; Stefanie Kademann; Jennifer Bruder; Juergen Bartling; Waldemar Von Suchodoletz (January 2010). "Auditory sensory memory and language abilities in former late talkers: A mismatch negativity study". Psychophysiology. 47 (5): 822–830. CiteSeerX   10.1.1.654.1095 . doi:10.1111/j.1469-8986.2010.00996.x. PMID   20409011.
  17. ↑ Schacter, Daniel L (2009–2011). Psychology. Catherine Woods. pp.  226. ISBN   978-1-4-292-3719-2.
  18. ↑ Claude, Alain; David L. Woods; Robert T. Knight (23 November 1998). "A distributed cortical network for auditory sensory memory in humans". Brain Research. 812 (1–2): 23–37. doi:10.1016/S0006-8993(98)00851-8. PMID   9813226. S2CID   32493019.
  19. ↑ Dubrowski, Carnahan, Shih (2009), "Evidence for Haptic Memory", Third Joint EuroHaptics conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, pp. 145–149, doi:10.1109/WHC.2009.4810867, ISBN   978-1-4244-3858-7, S2CID   206866791
  20. ↑ D'Esposito, M.; D. Ballard; E. Zarahn; G. K. Aguirre (2002-03-15). "The Role of Prefrontal Cortex in Sensory Memory and Motor Preparation: An Event-Related fMRI Study". NeuroImage. 11 (5): 400–408. doi:10.1006/nimg.2000.0571. PMID   10806027. S2CID   6504525.
  21. ↑ Bromage PR, Melzack R (1974), "Phantom limbs and the body schema", Canadian Anaesthetists' Society Journal, 21 (3): 267–274, doi: 10.1007/BF03005731 , PMID   4838325
  22. ↑ Sheldon A. Isaacson, Matthew Funderburk, Jay Yang (July 2000), "Regulation of Proprioceptive Memory by Subarachnoid Regional Anesthesia", Anesthesiology, 93 (1): 55–61, doi: 10.1097/00000542-200007000-00013 , PMID   10861146, S2CID   11710482 {{citation}}: CS1 maint: multiple names: authors list (link)
  23. ↑ Gentili ME, Verton C, Kinirons B, Bonnet F (2002), "Clinical perception of phantom limb sensation in patients with brachial plexus block", European Journal of Anaesthesiology, 19 (2): 105–108, doi: 10.1097/00003643-200202000-00005 , PMID   11999591 {{citation}}: CS1 maint: multiple names: authors list (link)
  24. ↑ Andrew E. Brennan, Howard G. Wu, and Maurice A. Smith, The Identification of a radpidly-decaying, high-precision proprioceptive sensory memory & its effects on motor adaptation (PDF){{citation}}: CS1 maint: multiple names: authors list (link)
  25. ↑ Victoria C. Anderson-Barnes, Caitlin McAuliffe, Kelley M. Swanberg, Jack W. Tsao (2009-05-12), "Phantom limb pain - A phenomenon of proprioceptive memory?", Medical Hypotheses, 73 (4): 555–558, doi:10.1016/j.mehy.2009.05.038, PMID   19556069, S2CID   23068581 {{citation}}: CS1 maint: multiple names: authors list (link)
  26. ↑ Selcuk Peker, Alperen Sirin (June 2016), "Parallels between phantom pain and tinnitus", Medical Hypotheses, 91: 95–97, doi:10.1016/j.mehy.2016.04.023, PMID   27142154 {{citation}}: CS1 maint: date and year (link)
  27. ↑ Dick, A. O. (1974). "Iconic memory and its relation to perceptual processing and other memory mechanisms". Perception & Psychophysics. 16 (3): 575–596. doi: 10.3758/BF03198590 .
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