Attention theories

SENSES > STS > SELECTIVE FILTER > LIMITED CAPACITY CHANNEL ((P system) loops back to STS) > SYSTEM FOR VARYING OUTPUT UNTIL SOME INPUT IS SECURED
or     > STORE OF CONFITIONAL PROBABILITIES OF PAST EVENTS (back to selective filter)

Choose which info is passed through limited capacity channel early on in selective filter 
STM- sensory register/buffer, immediate/iconic/echoic memory 
Filter- selects info for processing, selected by physical stim properties of STM
PARALLEL PROCESSING of location/pitch/intensity (simple physical stim properties) through STM into selective filter 
Channel has a LIMITED CAPACITY (serial processor) e.g. word meaning
For processing stim are identifiedd, recognised, fully analysed, meaning analysed

Unselected info does not pass through 

x no meaning analysis of irrelevant or unselected information

x Moray (1959) Wood and Cowan (1995) shadowing- 1/3 pp notice own name in irrel channel= proof on analysis. OWN NAME EFFECT. Requires processing beyond physical 

x Moray (1969) the S system (STM and SM) comprises parallel inputs because they map to the other senses as well as seeing (hearing, touch)

x Treisman (1960) might switch listening ears (upper-case shadowied) 3pp never switched, 15 did for 1/2 words- irrelevant info analysis- CHANNEL SWITCHING- breakthrough in 6% of trails

x Corteen and Wood (1972) p1 words paired with shocks, p2 words presented on irrel channel R: words affect skin conductance responses 

x strictural constraint of bottleneck in limited capacity channel 

ATTENUATION THEORY (Tresiman, 1960, 1964)

Filter is PARTIALLY SELECTIVE
Some concepts are more readily available to us e.g. own names
Weak signals are sufficient to activate these concepts (some irrelevant info will pass through the filter)
input > sensory register > attenuator > limited capacity channel > STM

LATE SELECTION THEORY (Deutsch and Deutsch, 1963)

Meaning is analysed before the filter
Assumptions:
- automatic/involuntary
- unlimited capacity (all analysed) 
Processing of perceptual input BUT maybe not both properties together 
Input > sensory register > STM

Tresiman (1960, 1964)

Filter does not fully block but ATTENUATES info from irrelevant channel.
Can leak through the filter if sufficiently strong 
This activates concepts in LTM e.g. identifying stimuli like our names 

Lachter et al., (2004) ID without attention is not true 
Concluding Broadbent was correct. 
Meaning only analysed with attention. If stimuli in irrel channel identified it must have been attended to 

Evidence against= 1. OWN NAME EFFECT
2. Words from wrong ear reported when semantically coherent switched between ears
3. Words assoc with elec shocks presented in unatteneded channel > skin conductance changes 

Lachter et al. no control for slippage in these experiments (dedication of attentional resources to irrelevant channel) 

SLIPPAGE- cannot attenuate precisely enough so give some of attentional resources to irrelevant channel as a result 

Dawson and Schell (1982) attempted replication
Skin conductance changes in subjects who sometiems attended to irrelevant channel (shadow failure, recall material from irrel channel)= SLIPPAGE

Lachter et al.
Hyp- "If we can exclude slippage, no identification without attention"
Exclude slippage by ensuring enough time to shift attention to irrel channel so visual stim presented ofr 55ms

Different locations for relevant and irrelevant channel 
Repetition priming- briefly presented, IRRELEVANT stimuli speed up responses to subsequently presented word or psuedoword e.g. bluck 
Faster RT when prime and target the same.
55ms for prime (presented above where target will appear) 500ms for target (middle of screen) Control condition- classical repetition priming effect (same words in same location)

R: signif effect but not enough bc maybe pp distracted when cue in dif location so slower RT
Therefore need to show NO PRIMING EFFECT FOR DIFFERENT- LOCATION VERSION

2 additional control conditions, 2x2 design. 

If meaning analysis only happens with attention, when fastest RT?
1. Prime identical to target, irrel of location
2. Prime different to target, same location 
3. Prime identical to target, same location
4. Prime identical to target, different location 

R: When prime and target not identical (2) no longer effect of location/doesnt matter where stim are presented in this case. INTERACTION EFFECT- meaning of prime wasn't processed as didn't have enough to time shfit attention to irrel location 
RT not faster in condition where prime and target are not identical 

C: no identification without attention when you control for slippage in the visual domain 

Trained pp with auditory stimuli, if here animal name LHresp, man-made object RHresp

During sleep presented untrained words they hadn't heard before 

R: pp prepared response in sleep shown via EEG

Could see them preparing a motor response SO pp must have understood the meaning of words or wouldn't have been able to generate a response to the word 

C: auditory domain could have identification with attenion, assuming we don't pay attention while we sleep

Compared to visual domain where no identification without attention 

If have left over attentional resources from relevant channel they spillover into the irrelevant channel. Limited perceptual capacity. Have to use up all of attentional resources/cannot stop deploying them

Lavie (1995) 2 main assumptions LOAD THEORY
1. Perceptual capacity is limited- typical assumption from early selection theory 
2. Perceptual processing is automatic- typucal assumption from late selection theory 

HYBRID THEORY- assumptions from both but mainly EARLY SELECTION THEORY b/c "no ID wihtout attention" (Benoni and Tsal, 2013)

ID of irrel stim only if processing of rel stim doesn't use up all of attentional resources. Cannot stop giving resources ot irrel channel if we have some left. BUT if processing of relevant stim consumes all resources, no ID of irrel stimuli at all 

Lavie (2000) perpceutal load can influence what is processed- ignore irrel info abilities enhanced if p.load increased. Use both early and late sleection theories. Amount of attention allocated to the main task depends on p.olad. Ealry perception with p.load is high, late perceptuion when p.load is low 

How to test LOAD THEORY of attention 

P: detect target letter in circle (X/N) press left ofr N right for X. Flanking distracotr letter or side that was irrelevant.
COMPATIBLE TRIALS- target and flanker identical
INCOMPATIBLE TRIALS- target and flanker different e.g. X target and flanker was N

Low p.load= target immediately visible, no search required. Attentional resources SPILLOVER to flanking letter (irrel channel due to location) 

High p.load= have to search for target among neutral disractors that don't require a response. Central circle (relevant channel) consumes all attentional resources, so no spillover to irrel, so don't attend to flanker later 

Hyp: COMPATIBILITY EFFECT- difference in RTs between compatible (target X flanker X) and incompatible trials (target X flanker N) for low p.load but not high 
Low p load 40ms slwoer when t and f different, high load- 4ms 

C: perceptual load of rrle channel influences extent info in irrel channel is processed. High p.load: info in irrel channel not ID'd where it is in low p.load