Week 12 (Attention) Flashcards
Definition of attention?
A state in which cognitive resources are focused on certain aspects of the environment rather than on others and the central nervous system is in a state of readiness to respond to stimuli.
Four key functions of attention.
- Signal detection and vigilance= detecting the appearance of a stimulus
- Visual search = actively searching for a stimulus
- Selective attention = Consciously attending to something over others
- Divided attention = deliberately attending to more than one task
What do we use visual search for (real-life) example
-Searching through books in a library for the one we want
-Look for a friend in a crowded room
-Scan the fridge in a bar for a drink we like.
Feature integration theory (Treisman & Gelade, 1980)
-Targets that differ on one dimension = number of distractors makes no difference to search time.
-Targets that differ on two or more = number of distractors does make a difference to the search time.
What are the findings of feature searches
-Searching for something based on a single feature only
-The thing you are looking for “pops out”, reaction time is independent of set size.
What are findings of conjunction searches
-Searching for a target based on a combination of two or more features
-Reaction time in conjunction searches is dependent upon set size.
Who challenged the the feature integration theory and what did they conclude?
Duncan and Humphreys (1989)
-Used T’s and L’s, when the orientations of T’s was mixed, participants took longer to find the ‘L’
-Suggests that we may automatically allocate some attention to the distractors even in feature searches.
What is selective attention?
-Consciously attending to something over and above other information
Results of the dichotic listening task
-Introduced by Broadbent (1952)
-Involves wearing headphones and listening to two messages.
-Easy to attend to one sound, however, couldn’t recall any words presented in the non attended ear, even when the same words repeated.
-Didn’t notice when the language switched to German.
-But would notice basic physical characteristics like gender, and if a tone was inserted instead of a word.
-If not attended to, sounds are heard not understood, not processed at a semantic level.
Filter theory (Broadbent, 1958)
Basic principles are
- We filter out information on the basis of physical characteristics
- Filtering occurs very early, right after stimuli had been registered by our senses, and before any higher level perceptual processing has taken place.
E.g., 2 simultaneous stimuli both gain access in parallel to a sensory register, one of these inputs is allowed through a filter on the basis of physical characteristics. The other remains in the sensory register for latter processing but fades fast.
Attenuation model (Treisman, 1964)
-Designed to account for attentional breakthroughs (from un-shadowed ear)
-Attenuation refers to info not being filtered out completely, but few cognitive resources being allocated to it.
-Info being focused on gets priority, But some stimulus can break into consciousness even if partialy processed.
-Info that is meaningful may have a low threshold, meaning that it only needs a small number of cognitive resources to come into consciousness.
Late selection model for attenuation (Deutsch & Deutsch, 1963)
-The bottleneck/ filter is t the point when people respond
Inattentional deafness
-Experiment combined visual and auditory stimuli
-When visual load was high, the tones were less likely to be detected
-This occurred at a cortical level (responses in associated brain areas)
-As well as at a behavioural level (participant responses to detecting a signal)
