PSYCH 240 Lecture Notes - Lecture 6: Adaptive Behavior, Smoking And Pregnancy, Frontal Lobe
Lecture 6 Reading Notes
Chapter 4
The Nature of Attention and Consciousness:
Attention: the means by which we actively select and process a limited amount of information
from all the information captured by our senses, our stored memories, and our other cognitive
processes; includes conscious and unconscious processes
Attention allows us to use our limited mental resources judiciously
We focus more on the stimuli that interest us by focusing less on outside stimuli
(sensations) and inner stimuli (thoughts and memories) that are not of interest to us
Heightened attention also paves the way for memory processes
We attend to and process some sensory info and memories without our conscious
awareness
Consciousness: includes both the feeling of awareness and the content of awareness some of
which may be under the focus of attention
Consciousness and attention form two partially overlapping sets
Conscious attention plays a causal role in cognition and serves 3 purposes: helps monitor
our interactions with the environment, assists us in linking our past memories to our present
sensations to give us a sense of continuity of experience, and helps us control and plan for
our future actions based on the information from monitoring and from the links between
past memories and present sensations
Four Main Functions of Attention: signal detection and vigilance, search, selective attention, and
divided attention
Signal Detection: Finding Important Stimuli in a Crowd:
Signal Detection Theory is a framework to explain how people pick out the important
stimuli embedded in a wealth of irrelevant, distracting stimuli
It is often used to measure sensitivity to a target’s presence
When we try to detect a target stimulus (signal), there are 4 outcomes: first it hits (true
positives), false alarms (false positives), misses (false negatives), and correct rejections
(true negatives)
The presence of a target is difficult to detect; thus, we make detection judgments based on
inconclusive info with some criteria for target decisions
SDT can be discussed in the context of attention, perception, or memory
Attention: paying enough attention to objects that are there
Perception: perceiving faint signals that may or may not be beyond your perceptual range;
memory: indicating whether you have or haven’t been exposed to a stimulus before
Vigilance: Waiting to Detect a Signal
Vigilance: refers to a person’s ability to attend to a field of stimulation over a prolonged period,
during which the person seeks to detect the appearance of a particular target stimulus of interest
Expectations regarding stimulus location strongly affect response efficiency but signals
appearing outside the concentrated range of attention may not be detected as quickly; the
abrupt onset of stimuli captures our attention
The cost of failure of vigilance can be great loss of life and property and more
Both the amygdala and thalamus are involved in vigilance
Amgydala plays a pivotal with recognition of emotional stimuli
find more resources at oneclass.com
find more resources at oneclass.com
An EEG will show less low-frequency activity and bigger event-related potentials the more
vigilant a person is
Search: Actively Looking:
Search: refers to a scan of the environment for particular features
When we are searching, we may respond with false alarms
Search is made more difficult by distracters, nontarget stimuli that divert our attention
away from the target stimulus
Two different kinds of searches: feature and conjunction searches
Feature Search: we look for just one feature that makes our search object different
Conjunction Search: we have to combine 2 or more features to find the stimulus we’re looking
for; these searches are more difficult than feature searches
The number of targets and distracters affects the difficulty of conjunction searches
The dorsolateral prefrontal cortex and both frontal eye lids and the posterior parietal cortex
play a role in conjunctive searches (not in feature)
Feature Integration Theory: explains why it is relatively easy to conduct feature searches and
relatively difficult to conduct conjunction searches
Anne Treisman developed a model of how our minds conduct visual searches and
suggested there are 2 stages involved when we perceive objects: The first stage, we
perceive features of objects: it is automatic and doesn’t need our conscious attention; The
first stage occurs in feature searches
The second stage of object perception involves our connecting two or more features with
some sort of mental glue- which requires conscious attention
This model has some neuropsychological support
David Hubel and Torsten Weisel identified specific neural feature detectors: cortical
neurons that respond differently to visual stimuli of particular orientations, corresponding
to features we may use during feature searches
More resent research suggests that the brain doesn’t necessarily increase the activity of
neurons that respond to target stimuli, instead, a better strategy is to activate neurons that
can distinguish between the target and distracters while ignoring those neurons that
respond best only to target directly
Similarity Theory: the more similar target and distracters there are, the more difficult it is to find
the target; furthermore, the difficulty of search tasks depends on how different distracters are
from each other; doesn’t depend on number of features to be integrated
Neuroscience: Aging and Visual Search:
Younger adults were more accurate and faster than the searches of older adults
Also, participants were slower when doing guided searches as compared with feature
searches; older adults had lower cortical volume, which is consisten with an approximate
2% decline in volume of 2% per decade
The most difficult search (conjunction) search led to activation in the dorsal and ventral
visual pathways as well as the prefrontal cortex in both young/old adults
There was lower activation in the right occipital cortex in older adults but the activation
was about the same in the prefrontal/superior parietal regions
The more difficult a search task was, the more the occipitotemporal cortex was activated
in younger adults
Older adults seem to have that brain region activated during easier search tasks
find more resources at oneclass.com
find more resources at oneclass.com
Selective Attention:
Cocktail party problem: the process of tracking one conversation while distracted by other
conversations
Dichotic presentation: presenting a separate message to each ear
You shift your attention to the one in which their name is said
Distinctive sensory characteristics of the target’s speech, sound intensity, and location of
the sound source help us to attend only to the message of the target speaker
Factors that show how harmonious and rhythmic the target sounds may be even more
important than other cues
Theories of Selective Attention:
These theories belong to the group of filter and bottleneck theories
A filter blocks some of the info going through and selects only a part of the total of
information to pass through to the next stage while a bottleneck slows down info passing
through
Models differ in whether or not they have a distinct filter for incoming info and if the filter
occurs early or late in the processing of information
Early Filter Model: we filter info right after we notice it at the sensory level
All the incoming information is being perceived and stored in sensory memory
Sensory memory only stores the information for a split second and then forwards it to a
filter that allows only one message to move forward to be processed in detail
That message is distinguished by characteristics like loudness, pitch, or accent
Stimuli that are filtered out at the sensory level may never reach perception
Short term memory then enables us to respond to the message ands tore necessary info for
future use in long term memory
Sensory info sometimes may be noticed by an unattended ear if it doesn’t have to be
processed elaborately but info involving higher perceptual processes isn’t noticed if not
attended to; (Donald Broadbent)
Selective Filter Model:
Moray found that even when participants ignore most other high-level aspects of an
unattended message, they frequently still recognize their name in an unattended ear; the
reason is that messages that are of high importance to a person may break through the
filter of selective attention
The filter blocks out most info at sensory levels but some personally important messages
are so powerful that they burst through the filtering mechanism
Attenuation Model:
To explore why some unattended messages pass through, Anne Treisman conducted
some experiments
If the unattended message was identical to the attended one, all participants noticed it and
even if one of the messages was slightly out of temporal sync
Treisman noticed that some fluently bilingual participants noticed the identity of
messages if the unattended message was a translated version of the attended one
Moray’s modification of Broadbent’s filtering mechanism was clearly not sufficient to
explain Treisman’s modification
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Attention: the means by which we actively select and process a limited amount of information from all the information captured by our senses, our stored memories, and our other cognitive processes; includes conscious and unconscious processes. Attention allows us to use our limited mental resources judiciously. We focus more on the stimuli that interest us by focusing less on outside stimuli (sensations) and inner stimuli (thoughts and memories) that are not of interest to us. Heightened attention also paves the way for memory processes. We attend to and process some sensory info and memories without our conscious awareness. Consciousness: includes both the feeling of awareness and the content of awareness some of which may be under the focus of attention. Consciousness and attention form two partially overlapping sets. Four main functions of attention: signal detection and vigilance, search, selective attention, and divided attention. Signal detection: finding important stimuli in a crowd:
