PSYB57H3 Chapter Notes - Chapter 1-6: Pineal Gland, Visual Cortex, Diffusion Mri
The new oxford American dictionary defines cognition as “the mental action or process of acquiring
knowledge and understanding through thought, experience and the senses.”
● This definition underscores a key point: that cognition is the mental action of knowing
There are 3 stages to human cognition
● First stage: from the late 1950s to the early 1960s, was one of rapid progression propelled by the
methods of traditional psychophysics (the scientific relationship between sensation and stimulus)
and experimental psychology
● Second stage: underway by the mid-1970s, fuelled by computational analysis and marked the
arrival of cognitive science
● Third phase: began in the mid-1980s, has incorporated evidence from neuropsychology and
animal neuropsychology, and most recently an ever increasing array of imaging techniques that
allow us to observe the brain in action
● The fundamental idea is that the world contains information that’s available for humans to
process
● Cognitive psych sees humans as active information selectors
○ Only some of the information is selected for processing as our nervous systems are only
able to handle so much
○ The amount of information provided by a given event can be quantified in terms of bits
(short for “binary digits”)
Information theory: Posits that the information provided by a particular message is inversely related to the
probability of its occurrence: the less likely it is, the more information it conveys
Limitations on information processing
● Experiment by Hick (1952) and Hyman (1953)
○ Demonstrates that it takes time to translate a visual signal to either a key-press or visual
response
○ The more information a visual signal conveys, the longer it takes for the viewer to make
an appropriate response
○ The nervous system has a capacity limitation for the amount of information that it can
handle within a fixed period of time
○ Simultaneous auditory messages suggest a similar conclusion
● Webster and Thompson (1953)
○ Had airport control-tower operators listen to recorded voice transmissions stimulating
messages from pilots
○ It consists of the aircraft’s call signal and three unrelated words
○ The call signals (have 10 possibilities) was easily identified compared to the 3 unrelated
words (full of possibilities)
● Findings suggest that there are limits to the nervous system’s capacity for information processing
● The limit is one of information rather than stimulation
● Hyman showed that people respond faster to an expected stimulus than to one that’s unexpected
Models of information processing
Broadbent’s filter model
● First complete theory of attention
● information processing is restricted by channel capacity
● Argues that the whole nervous system can be regarded as a single channel with limits to the rate
at which it can transmit stimulus information
● Overloading of this limited capacity channel is prevented by a selective divide or filter, which
allows only some of the available incoming information to enter the system
● Preceding the filter is a capacity-free sensory buffer or temporary store
● When 2 or more signals/messages occur at one time, they enter the sensory buffer together
● The buffer extracts simple stimulus characteristics as color (vision), voice (hearing), or spacial
location
● The filter selects messages that share some basic physical characteristic and passing them along
to the limited capacity system that is responsible for the analysis of “higher-order” stimulus
attributes, such as form and meaning
● Any messages that were not selected are held, in parallel in the sensory buffer, where they’re
subject to decay with the passage of time.
● Example: having participants listen to 3 pairs of digits; one member of each pair arrived at one
ear at the same time that the other member of the pair arrived at the other ear
○ E.g. “73-42-15,” the participant would hear “7,4,1” in the left ear and “3-2-5” in the other
ear
○ Participants would recall all the digits presented to one ear, followed by all the digits
presented to the other ear (e.g. “741--325” or the other way around)
○ The ears function as separate channels for information input
○ The different physical locations for the two messages initially entered and preserved in
the short term sensory buffer’
○ Selective attention operates to determine which channel is recalled first
○ As attention is switching between locations, the info in the sensory buffer continues to
decay, and thus becomes less and less available with the passage of time
Distracted driving
● Any distraction can compromise your ability to use the information that your eyes take in: you
might look but fail to see
● Example
○ Driving simulator and asked them to complete a driving course
○ Conversing a phone led to significantly poorer driving performance
○ It made no difference if the phone was hands-free
○ Eye tracker results
■ Driving w phone was roughly half as likely as the phone-less control group to
remember details from the course
■ Even if their eyes had rested on those details for the same length of time
Waugh and Norman’s Model of Information Processing
● The flow of information is indicated by the arrows
● Upon being stimulated, we may have an experience called primary memory, a concept derived
from William James (who used introspection as an approach)
● Primary memory consist of the “immediately present moment” so is also known as “immediate
memory”
● “Rehearsal” - refers to the fact that primary memories tend to be quickly forgotten unless they are
repeated
● Secondary memory - belongs to the past
● Waugh and Norman (1965) noted that James's distinction was based on introspective evidence,
which is self treated as definitive in cognitive psychology, but can be paired & proven with
evidence
● The evidence - Brown-Peterson task
○ One of the most widely used experimental tasks in memory research
○ Participants are given a set of items to remember, then a number from which they
immediately begin counting backward by threes
○ The interval is filled with the counting exercise, the participant is presumably prevented
from rehearsing the letters and therefore unable to retain them in his/her primary memory
○ Unfolded interval: would allow the participants to rehearse the items and keep them in
primary memory
○ Showed that participants’ ability to recall letters declined as the number of interfering
items increased
● Waugh and Norman pointed out that primary memory makes it possible for us to immediately
and accurately recall our most recent experiences
Ecological Validity
● J.J. Gibson
○ took more interest in the richness of the information provided by the environment in
which people find themselves
○ He argued for the development of an ecological approach to perception that would
describe environmental stimulation at the appropriate level
○ Argued that the meaning of objects and events can be perceived through ‘affordances,’
which he defined as “simply what things furnish, for good or ill”
Document Summary
The new oxford american dictionary defines cognition as the mental action or process of acquiring knowledge and understanding through thought, experience and the senses. This definition underscores a key point: that cognition is the mental action of knowing. First stage: from the late 1950s to the early 1960s, was one of rapid progression propelled by the methods of traditional psychophysics (the scientific relationship between sensation and stimulus) and experimental psychology. Second stage: underway by the mid-1970s, fuelled by computational analysis and marked the arrival of cognitive science. Third phase: began in the mid-1980s, has incorporated evidence from neuropsychology and animal neuropsychology, and most recently an ever increasing array of imaging techniques that allow us to observe the brain in action. The fundamental idea is that the world contains information that"s available for humans to process. Cognitive psych sees humans as active information selectors.
