Chapter 5 Flashcards
3 structural features of the modal model
- sensory memory
- short-term memory
- long-term memory
modal model of memory
- describes memory as a mechanism that involves processing information through a series of stages
- proposed by atkinson and shiffrin
sensory memory
- stimuli enter sensory memory
- info is held there briefly
- limit to how much information can enter
short-term memory
- holds approximately 5-7 items for about 15-20 seconds without rehearsal/repetition
- output refers to a response or action based on the processing of information in short-term memory
long-term memory
can hold an unlimited amount of information for an unlimited duration
control processes
- in the modal model of memory, active processes that can be controlled by the person and that may differ from one task to another
- rehearsal is an example of a control process.
sperlingers study (sensory memory)
- involved the brief presentation of an array of numbers
- participants were instructed to recall as many of the letters as they could
- results showed that on average 4.5 letters could be recalled out of the 12
- some participants reported they saw all the numbers but forgot them before they could report them
partial report method
- consisted of an array of numbers would be presented briefly and then a high, medium or low pitch tone would indicate which row they need to report
- found that people could report 3.3 out of the 4 letters in that row (would have been 9.5 in the original study)
working memory (baddeley and hitch)
- stores and manipulates information for action
- learning, completion of tasks and reasoning
- similar to short-term memory
- temporary storage of information
central executive
directs attention and coordinates between the visuospatial sketchpad and the phonological loop
visuospatial sketchpad
- stores visual and spatial information
- e.g. when you form a picture in your mind or do tasks like solving a puzzle or finding your way around campus
phonological loop
- stores verbal and auditory info
- made of two components; phonological store and articulatory rehearsal process
- e.g. when you are trying to remember a telephone number or a person’s name
persistence of vision
- the continued perception of light for a fraction of a second after the original light stimulus has been extinguished
- e.g. perceiving a trail of light from a moving sparkler is caused by the persistence of vision. See also Iconic memory.
delayed partial report method
determined the speed as which the visual trace decayed
digit span
- the number of digits a person can remember
- digit span is used as a measure of the capacity of short-term memory
- the average capacity of STM is about five to nine items
chunk/chunking
- has been defined as a collection of elements that are strongly associated with one another but are weakly associated with elements in other chunks
- increases our ability to hold information in STM
cavanagh & alvarez on capacity of memory
- suggested that rather than describing memory capacity in terms of “number of items,” it should be described in terms of “amount of information.”
- performed a change detection experiment with more complex objects
- determined that participants’ ability to make the same/different judgment depended on the complexity of the stimuli
luck and vogel experiment
- measured the capacity of STM by using a procedure called change detection
- two displays flashed, in between them was a dark screen
- results from the experiment indicated that performance was almost perfect when there were one to three squares in the arrays and that performance began decreasing when there were four or more squares
2 properties of focus of short-term memory
- how long information is held in STM
- how much information can be held in STM
phonological store
holds a limited amount of verbal and auditory information for a few seconds.
articulatory rehearsal process
involved in working memory that keeps items in the phonological store from decaying
phonological similarity effect
- the confusion of letters or words that sound similar
- e.g. t, p, and b
r. conrads similarity effect experiment
- flashed a series of target letters on a screen and instructed his participants to write down the letters in the order they were presented
- found that when participants made errors, they were most likely to misidentify the target letter as another letter that sounded like the target not as likely to be confused of letters that look like the target
word length effect
occurs when memory for lists of words is better for short words than for long words
articulatory suppression
- interference with the phonological loop that occurs when a person repeats an irrelevant word such as “the” while carrying out a task that requires the phonological loop
- reduces memory because speaking interferes with rehearsal
perseveration
- difficulty in switching from one behavior to another, which can hinder a person’s ability to solve problems that require flexible thinking
- observed in cases in which the prefrontal cortex has been damaged.
chunking and working memory
the capacity of working memory can be increased by chunking
episodic buffer
- a proposed fourth component of working memory
- serves as a “backup” store that communicates with both long-term memory and the components of working memory
- it holds info longer and had greater capacity than the phonological loop or visuospatial sketch pad
effect of damage on the prefrontal cortex
- causes problems in controlling attention, which is an important function of the central executive because the PFC is important for holding information for brief periods of time
delayed-response task
- information is provided, a delay is imposed, and then memory is tested
- studied by testing monkeys’ ability to hold information about the location of a food reward during a delay
delayed-response task monkey experiment
- the monkey sees a food reward in one of two food wells. Both wells are then covered, a screen is lowered, and there is a delay before the screen is raised again
- the monkey must remember which well had the food and uncover the correct food well to obtain a reward
- if their PFC is removed, their performance drops to chance level, so they pick the correct food well only about half of the time
prefrontal neurons
- physiological mechanisms that hold information about events after they are over
prefrontal neurons (Funahashi et al. 1989)
- recorded from neurons in a monkey’s PFC while the monkey carried out a delayed-response task
- funahashi found neurons that responded only when the square was flashed in a particular location and that these neurons continued responding during the delay
neural dynamics of working memory (mark stokes 2015)
- proposed that information can be stored by short-term changes in neural networks
- Stokes model states that information is held in memory not by continuous nerve firing but by a brief change in the connectivity of neurons in a network
- discusses 3 ideas: activity state, synaptic state. and activity silent network
activity state
in which information can be remembered causes a number of neurons to briefly fire
synaptic state
the previous firing in the activity state causes the synatpic state, in which a number of connections between neurons are strengthened
activity-silent working memory
changes connectivity between activity state and synaptic state
reading span test
- a test for working memory capacity and then determining how individual differences were related to reading comprehension
- each sentence was seen briefly as it was being read, then the next sentence was presented
- participant was asked to remember the last word in each sentence in the order that they occurred
- the participant’s reading span was the number of sentences they could read, and then correctly remember all of the last words.
