Sensory Memory

sensory memory contains

• Haptic-touch/pressure

• Iconic-vision

• Echoic-sounds

• Olfactory-smells

• Gustatory-taste

Iconic Memory

• Defined as a sensory register for visual input

• Mental representation termed an icon

• Iconic memory allows visual memory to outlast initial sensory perception

Span of Apprehension

Measurement designed to see how many memories we could grab onto

Jevons (1871)

• Toss beans into air, open eyes and see how many landed on the plate-immediate retention of visual input measure

• Span of apprehension-9 items

Averbach (1963)

• Tetistiscope, numbers of dots, varied number and duration

• Number of dots that were correctly reported 50% of the time

• 40ms horrible retention, 150 ms dramatically better but minimal improvement from such to 600ms

• Span of apprehension about 8-10 items

Partial Report, Sperling (1960)

• Vary array of letters or digits up to 12 items, very brief presentation (50ms)

• Enormous amount of information stored

• Held in visual code

• Held only for a very short period of time, decay occurs within a single second

• Sensory buffer does not simply sit between environment and sensory memory in modal model, instead makes contact with stored representations from long term study

Turvey (1973)

• Masking Paradigm

• brightness versus pattern mask

• a pattern mask interferes with information persistence-interference is in the brain

Single Cell Recording-Keysers et al., 2005

Anterior superior temporal sulcus

• some cells respond to particular stimulus and continue responding after disappearance of stimulus

• Initial increase in neural firing, no immediate decline rather gradual continuing for a measurable amount of time

• Suggests persistence of visual icon-central persistance

• Measures the equivalent of a brief sensory buffer that allows the neuro-representation to out last the duration of the object in the real world

Arthroscopic perception

• Board with a slit cut out of it, image passed across the slit, the perception the participant has is of the whole object instead of line segments

• Iconic memory is integrating information over time

  • The perception produced in arthroscopic perception varies in accordance with the speed in which the object passes the slit

Trans-Saccadic Memory

• Memory that occurs across eye movements

• Saccade-periods of time when our eyes move and become stuck for about 30 ms each

• Only extract information from world during fixations (stagnation), integration hence must occur over subsequent eye movements

• information Integrated based on object representation rather than based off of location (retinal or spatial)

Echoic memory

• Sensory registration of auditory information

• Critical for speech 

• Called an echo

Partial Report Procedure-Darwin, Turvey and Crowder, 1972

Partial report advantage if visual cue was presented within seconds of the digits

• Mirror results from iconic memory

  • While information remains, significant advantage to partial

  • Lasts over several seconds, better than iconic

• Conclusion

  • Large amount of info held, using an auditory code

  • Held longer about 5 seconds (iconic likely about 500 ms)

Oddball Paradigm

• Task and background stimulus, if brain reacts to odd tone, brain is maintaining a sensory record of stimulus events

• Mismatched negativity, measured using response reactivity

  • Standard and deviant sound

  • Differences in neural response

    • Only way to react differently (automatic) is if past record is being kept

  • Activates bilateral superior temporal gyrus and left insula

  • These represent correlates of echoic memory as the brain is sensitive to changes