Chapter 11: Attention and Consciousness
- Two basic features of attention:
1. Selection of sensory information form several simultaneously available inputs
Selective attention – process that allows the selection of inputs, thoughts, or actions
while other ones are ignored.
Inputs can be sensory; attention can be directed to internal mental processes
2. Selection of mental state, allowing either an internal or external flow of information
Voluntary attention – intentionally shifts attention from one input to another OR
Reflexive attention – shifts occurs in response to some external event
-Even without eye movements, and without changes of accommodation, one can concentrate
attention on the sensation from a particular part of our peripheral nervous system and at the
same time exclude attention from all other parts.
-Cocktail party effect – ability to focus one’s listening attention on a single speaker among a
cacophony of conversations and background noises.
EARLY VS. LATE SELECTION
-Early selection – attention to an input and the decision to further encode and analyze it (e.g.
categorizing and naming) occurs very early in the perceptual process.
Stimulus does not need to be completely encoded or perceived prior to selection or
rejection from further processing.
One possible mechanism: the accommodation or adjustment of sensory organs
E.g. some animals clearly orient their sensory organs when they shift attention, e.g.
shifting position/orientation of ears. However, covert changes that are relatively “low” or
“early” in our sensory systems.
Inner ear function is vulnerable to higher perceptual and attentional processes.
-Late selection – attention operates after the sensory information has been perceived,
identified, and/or categorized.
Stroop effect, where people are presented colour word with different colour inks
slower to name the colour of the print
This effect can happen only if the word is recognized at a semantic level, despite the fact
that the individuals were told not to read the word.
HOW DOES ATTENTION SHIFT?: VOLUNTARY VS. REFLEXIVE ORIENTING
-Attention can be overt (e.g. moving eyes when shifting visual attention), or covert (e.g. in
Helmholtz’s experiment, visual attention didn’t correspond to the location of visual fixation)
Voluntary Shifts in Attention
-Changes that you intentionally initiate, changing the focus of your attention from one thing to
-Attention experiment – people learn to use cue to help anticipate the location of target
reduction in their average reaction time (benefit in this paradigm); invalid cues increase
average reaction time (cost)