bottom up attention
(passive modes of attention, exogenous attention)
• Alertness or arousal
• Reflexive attention (e.g. towards a bolt of lightning)
top down attention
(active modes of attention, endogenous attention)
• Selective attention (e.g. you choose whether to listen or look at me or not)
the eye as a camera
The film (the retina), in the case of the human eye is made up of photoreceptor cell and can be broken down into 2 main areas:
Fovea (more cells with most of them are cones)
Parafovea (less cells and most are rods)
our eyes don’t see like we think they do
saccadic suppression
overt attention
Hemholtz on covert attention (1867)
Helmhotlz observed that we can enhance perception if we focus our attention on a location in the visual field
But this comes at the expense of other areas of the visual field
capacity limitation
• Our limited ability to carry out various mental operations at the same time needs a way to prioritise information
perceptual gating (selection)
• Conscious perception is always selective, but selection is not always conscious
selective/ focussed attention
divided attention
aka multitasking
attentional modalities - vision
Limit on how much we can take in, because things in environment placed in different spatial location
attentional modalities - auditory
Streams of sound from different locations
welford 1952
cherrys cocktail party effect (1953)
shadowing task
Dichotic listening procedure - Shadow means to repeat aloud the message told to attend to. Cherry found:
in the shadowing task, ppts were able to
in shadowing task, ppts werent able to
broadbent (1958)
Dichotic listening procedure, 3 digits presented to one ear at same time as another 3 digits presented to the other ear:
• Participants would recall numbers ear by ear better than in pairs
• Suggested that the stimuli are accessed in parallel by a sensory buffer
• Buffer filters stimuli on the basis of the physical characteristics.
• The other input remains in the buffer.
attention as an early selection process
What does attention do?
• It allows us to selectively process information
• To filter out irrelevant information
• Argues that we cannot identify or process something without attention
evaluating broadbent
Filter theory is based on physical properties and therefore rather inflexible…
attentuation
late selection
all messages get through, but only one response can be made (Deutsch & Deutsch, 1963)
inattentional blindness
What we don’t attend to, we are not aware of (Mack & Rock, 1992, Simons & Chabris, 1999)
• typically things such as transients can capture visual attention – but if those resources are fully in use and there are other transients, things may be missed!
• Inattentional blindness is a great demonstration that attention is required for identification