CH5 Flashcards
Inhibition
is whenever decreases in some activity are seen as a result of manipulating some
aspect of the task environment.
decreases in some activity as result of manipulating some aspect of task environment
Neurological inhibition
at a neurological level, inhibition works by lowering the
activation level of neurons. Does not require conscious effort.
(both neurological and reactive inhibition depend to some extent on excitatory
processes)
Reactive inhibition
inhibition that arises as a result of performing some process. It
is like a side effect of executing a process that must subsequently be overcome.
- (both neurological and reactive inhibition depend to some extent on excitatory
processes)
Behavioural inhibition:
increases in reaction time or decreases in performance may
be referred to as inhibition without specifying how that inhibition occurs.
Paradigms that explore the ability to inhibit the processing of irrelevant information:
Stroop effect
Simon effect
Flanker-compatibility effect
Stroop effect
filter out irrelevant information. Difference in response time and accuracy. Incongruent
phenomenon (one-way effect). When irrelevant stimulus dimension is processed within same system
as responses or similar manner of coding, interference.
an important property is that it is asymmetric, meaning that incongruent
colour words slow colour naming, but incongruent ink colours do not slow colour-
word reading. Some scientists argue that the stroop effect does not imply a pure form
of automatic processing in which words can never be ignored. For example, if only
one letter of a word is coloured, colour-naming responses are less influenced by the
presence of incongruent colour words. This shows that the requirement to focus
attention on just one letter of a word stops the automatic reading of the entire word.
Stroop effects can also be affected by changing the proportion of congruent and
incongruent stimuli.
Simon effect
the finding that responses are faster when the stimulus appears on the
same side as the assigned response than when it does not. It shows that it is not
necessary that the relevant and irrelevant dimensions of the stimuli be related (like
colours and their names) in order for interference effects to occur. The Simon effect is
the result of conflicting spatial codes. Hommel: the spatial code associated with
stimulus position forms rapidly when the stimulus is presented and then decays
automatically, without the application of voluntary inhibitory strategies.
Stroop and Simon effects have been attributed to
the stage of processing called
response selection. Both the relevant and irrelevant stimulus dimensions are
assumed to be processed in parallel, and both result in the activation of a response
code. When the response code for the irrelevant dimension is different than that for
the relevant dimension, the irrelevant response code must be suppressed before the
correct response can be selected.
Race models assume that
the relevant and
irrelevant stimulus dimensions are processed in parallel and then queue up for entry
into a single-channel central processor. Whichever stimulus is finished processing
first gains entry into the channel. These models are wrong though: the effects of
irrelevant information depend on the relation between the stimulus dimensions and the type of response. Also: pre-exposure often reduces Stroop effects.
Ideomotor
compatibility:
when the stimuli closely resembles the assigned responses.
Ideomotor
compatibility theory:
response selection occurs directly when ideomotor compatibility
is high, bypassing the usual bottlenecks.
Flanker-compatibility effect:
responses are relatively slow and inaccurate when the target is flanked by incongruent letters, intermediate when the flankers are neutral letters, and faster when the flanker letters require the same response as the target. The flanker letters are perceptually processed even though instructions are to focus on only the central letter, but also information is often processed to the point of producing a lateralized readiness potential, which is indicative of motor preparation. Flankers assigned to an incompatible response produce more interference than flankers not assigned to any response, which suggests that the interference arises because of conflicting response information.This is an example of the failure of early selection in that people are not able to filter out flanker information.
Flanker letters are
letters that are assigned to different responses, e.g. S might
require that a letter be moved to the left.
The flanker-validity effect is
that people can learn a probabilistic relation between the target and the flanker, even
when instructed to ignore the flankers.
Reducing the flanker effect can
only be done with spatial separation.
Research has suggested that making the task easier actually makes selection
more difficult, because there is spare capacity
flanker effects reflect
difficulty in suppressing irrelevant
information.
Endogenous (observer-based) and exogenous cues are
both effective in directing attention,
but exogenous cues often have a larger and faster acting effect on performance. Also, the
facilitation produced by an exogenous cue can turn to inhibition. Observers are slower to
detect a target at an exogenously cued location when 300 or more milliseconds elapsed
between the cue and target. It seems that exogenous attention has a short lifetime and is
biased not to return to a location where it has recently been. This is called inhibition of
return.
Inhibition of return and visual search:
the function of inhibition of return may be to
ensure efficient search of complex environments by creating a bias against returning
to locations that have already been investigated. The inhibition of return effect is
largest at the most recently searched location and declines in a linear fashion.
inhibitory tagging
Inhibition of return to locations in a search display, and it seems to be bound to an object rather than a location. In general, object-based
inhibition of return is less pronounced than location-based inhibition of return.
Attentional and motor effects in inhibition of return:
inhibition can be associated with
many locations at the same time, which shows that a purely oculomotor account
(saccades by the eyes) of inhibition of return is oversimplified. There is also a motor
component that contributes to inhibition of return. So, it seems to consist of both an
oculomotor and an attentional component
Top-down performance can
also influence search performance.
Visual marking
when there
is an effect of pre-exposure of distractors to a mechanism. This results in the active inhibition
of the distractor locations. The marking of static items can be location-based, whereas the
marking of moving items depends on a feature map.
perceptual load hypothesis
Increasing attentional demands can reduce interference from irrelevant distractor
Negative
priming occurs when
responses to a target are slower when the target was present as a
distractor on the previous trial than if the target was unrelated to the previous trial. It is
action-centered: when actions are directed at objects in the environment, attention is
directed to action-centered representations in which the relationship between the target and
the effector takes center stage.