• Global communications improved
• improvement on measurement

**extremely influential in psych in terms of how we measure data in scientific settings**

Bessel--Dutch Astronomer

Personal Equation

-The fraction of a second btwn two astronomers' measurements remains constant

-He finds that measurements are different btwn astronomers as well as at different times

F.C. Donders

(Physiologist)

1. Chronogram

2. Simple Response Task

3. Choice Response Task

1. Very effective time-keeper 

-introduces the idea that humans keeping time is not as accurate as a regulated machine

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**Significance: lays foundation for Mental Chonometry

Helmholtz

1. Theory of Unconscious Inference

1. We interpret the world in predictable and stereotypical ways by way of an unconscious process

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(i.e. we know that the image is a car behind a tree and not 2 pieces of a car)

Note: Difference btwn how the world is and how it is experiences would explain this unconscious inference.

Helmholtz and Donders 

Significance

-They shed light to new approaches to measure behavior with regard to lower-level processes

1. Time course of cognition

2. Content of cognition

1. Lower-Level Processes

vs.

2. Higher-Level Processes

(Does not imply rank, but the order in which they develop)

1. Perception, Attention

2. -Memory

-Learning

-Problem solving

-Language

Ebbinghaus

(Philosopher)

-Focused on consciousness

Savings Method (experiment)

1. Non-Words

1. group of letters that make non-sensible words (QEH, LIM, KEP)

-Non-words: are learned by repitition 

-Time interval: over time, participants re-learn with fewer repitions

2. Savings= (initial # of reps.) - (# of reps for relarning)

_________________________________                           (X100 for %)

(initial # of reps.)

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** Memory loss is not a steady decline therefore our intuitions are wrong!**

Wundt

-First to call himself an "Experimental Psychologist"/Set up a formal laboratory(official institute)

-Contributions:

1. Structuralism

2. Analytic Introspection

1. Our experience is a collection of many low-level sensory experiences

-Contributes to the association of ideas or sensations

-Cognition is vital to understand any human experiences (emotional/conceptual/sensory)

2. Too subjective/personal to be "observable cognition"

-This would provide too many differences in results

-He pushes this approach as the only way to assess the inner-workings of the mind (VERY DETRIMENTAL)

Jerry Fodor (1983)

"Modularity of Mind"

1. Domain Specificity

2.  Information Encapsulation

1. Each processor must be domain specific which means that each processor can only handle 1 specific input

2. Each processor is aware of their own domain, but they have no idea of the responsibilities of other processors.

**Note: these two theories allow NO room for flexibility

**Significance: Raises question: What kind of behaviors should be viewed with this type of lens? ==>Attention

Attention:

1. Passive Senses:

2. Visual Perception:

1. -Senses that are being used constantly w/o effort (i.e. Vision, audition, smell, temperature

2. Can be distinguished into: 

-Social info, informative info, survival info, colorful, out of ordinary, high contrast, movement

Parkhurst (Experiment)

1. Eye-Tracker: 

2. Salience Map:

1. uses camera to measure pupil movement/dialation and corneal reflections

-Fixations: when pupil stops moving for longer than 250ms.

-Saccades: ballistic (little control over path from pt.A to pt. B) eye movement. 

2. Parkhurst wanted to determine what someone else is focusing on in a still picture

-uses eye-trackers while showing static pictures of the world while focusing on 3 observational criteria: color, intensity, and orientation

3. Salience Map: -people look at salient (obvious) bits of info but cannot control what is salient to them==> the conclusion that there is an initial processor which organizes all data as well as determining what is salient.

- Parkhurst finds that salience affects attention early on, but after some time, fixations on Meaningful parts of the scene based on their own knowledge/experience (human faces, informative objects in a scene

**Significance: gives rise to==> Scene Schema  as well as evidence of Bottom-up Processing

Scene Schema

(Parkhurst)

-Has to do with out memories of how a scene should look 

(i.e. street scene should have cars, traffic lights, parking meters, ppl, etc.)

Land & Hayhoe

(attention experiment)

-participants make a PB&J

-in this scene, salience has nothing to do with the process

-instead, the participants eye-mvmt (attention) depends on the way they do the process normally

**Significance: evidence of Top-Down Processing: when higher mental processes (language/memory) draw our attention to a specific stimulus

Balasubramanian

(attention experiment)

-has participants move a ball to top shelf

-he found that participants will focus on the object itself, as well as the objective/goal(moving it to top shelf)

Bottom-up Processing

vs.

Top-down processing

1. Processing of info from the low-levels(attention) to the higher level processors(perception)

-Going from input to perception in an orderly manner 

(i.e. salience)

2. When higher mental processes (language/memory) draw our attention to a specific stimulus (i.e. PB&J)

Spivey & Geng (2001)

(top-down info only study)

1. Hypothesis: eye movement is apparent even when thinking

-participants stare at white screen while hearing stories about a 40 story building

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Fixation = Attention

(assumption throughout attention studies)

Does fixation always = attention? 

1. Fixation w/o Attn.

2. Attn. w/o Fixation

a.k.a. Inattentional Blindness

Mack & Rock (1998) -attempt to induce attention

-place foreign object in fixation point (mask)

-Present a mask after & participants are asked if anything else appeared

-Answer: NO

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2. Posner: introduces Pre-cueing Stage: during which a light is presented for 200ms while participants are fixating on object

-Finds that Reaction time was faster in condition 2 when the object is presented where the light was during the pre-cueing stage.

**Significance: finds that Attn. is like a spotlight ==> gives benefit in processing, but this does not mean that UNATTENDED stimuli is not processed.

1. Object-Based Visual Attention

2. Duncan (1984)

3. Egley

1. (i.e. Being able to remain attentive to objects even if they move)

2. Shows participants pictures--16 different combos of boxes and lines

-Condition 1: participants are asked to describe:

1 characteristic of box

1 characteristic of line

-Condition 2: participants are asked to describe:

-2 characteristics of same object

Conclusion:participants do better when focused on 1 object rather than 2

3. Disentangles object-based/location-based attention

-Phenomenon developed during Moray/Cherry&Broadbent

-People have incredible ability to divide and control attention

**Significance: leads to Selective Attention research studies

1. Colin Cherry (1953-during computational revolution)

2. Filter Model of Attention(early selection model)

Donald Broadbent

1. -has participants listen to 2 different stories, 1 in each ear

-controls where attn. goes by having them shaddow a specific ear

-Finds: when shaddowing, the other ear is not perceived (with exception of gender of speaker)

2. input==> sensory memory==> filter==>detector==>Memory

-Filter: tunes out any excess sensory input that is not being attended to (operates in terms of acoustic/visial features)

-Detector: responsible for conscious awareness

3. Proposes Filter Model of Attention to explain dichotic listening theory

-Split message in half; playing story word by word in alternating ears

-when asked what was heard in unattended ear, participants still heard the full story even though they were not trying to attend there (dear aunt jane example)

**Significance: proposes the idea that the filter does not tune out all unattended info ==>implies that the filter is not as strict as broadbent thought

Moray (1959)

-Proves Cherry/broadbent's model to be too strict

-In Dichotic channel, if attn. is focused on right channel & participant's name is said in unattended channel, people will switch their attn.

**Significance: proves cherry/broadbent's model to be too strict

==> Anne Treisman's research

Anne Treisman

(1960--Attenuator model--refined version of Broadbent's)

1. Attenuator Model

2. Thresholds

3. High-frequency words

1. Attenuator Model: 

INPUT=> Sensory memory=>Attenuator(Dictionary Unit)=>Processed to memory

- The Attenuator  filters through input stimuli based on linguistic properties of an individual's Dictionary Unit: words in an individual's vocabulary

2. The amount of energy(stimuli) necessary for perception (each word has a different threshold)

3. Words that occur often in an individual's every-day life (High Freq. words have Low threshold

**Significance: This insinuates that threshold and frequency are inversely related

- opens a new door by discussing thresholds as a way of simplifying things

MacKay (1973) 

1. Lexically ambiguous words

2. Late-selection Model

 Primes attention with the use of Lexically Ambiguous Words: words that can take on different meanings depending on the context (i.e. BANK)

- Attended ch= "we threw rocks at the bank yesterday"

-Unattended ch= Plays words to sway the interpretation of ambiguous word (i.e. money or river) 

-Finds: stimulus in unattended channel strongly pushes the interpretation of the attended channel

-When asked about unattended channel, participants cannot recall, but were still strongly influenced by the unattended channel

** This disproves the idea that unattended info is not processed so he argues for a Late-Selection Model: suggests that we process attended and unattended info (@lower freq.) and then dump what we don't need for proper understanding

**Significance- This realization leads to the question: Is selective attention possible if we process unattended info? 

Green & Bevelier (2003) 

Flanker Compatibility Task

(selective attention experiment)

Part 1 = Low level cognitive task

Part 2 = More difficult cognitive task

Part 1: Found that the more difficult the task, the stronger the filter because attention is amplified therefore unattended stimuli is less likely to interfere

Part 2: Tells us that our attentional resources are limited 

**Significance: leads to the question of whether or not it is possible to do two tasks at the same time == Divided Attention

Divided Attention (lower level complexity tasks -- Automatic tasks)

1. Dual-Task Paradigm

2.  Optimum-Maximum Method

1. -test on task 1

-test on task 2

-test tasks together

* Equal attn to 1 & 2 results in both tasks suffering

2. Giving most attn. to 1 task & whatever is left to the other (Optimum task does not suffer at all, but maximum task does

Spelke

(divided attention experiment)

-Suggests that people must be pushed to their limits (task difficulty)

- has participants do 2 relatively difficult tasks (take dictation/read short story) & they cannot do it at first

-after 85 hours of practice (different stories/dictations) participants have nearly perfect performance 

- over time, the dictation becomes an automatic process: happens without intention/uses few cognitive resources

**Significance: Suggests that over time, certain tasks can become automatic so that they require little attention. Therefore, attn can be focused elsewhere 

Shiffrin & Schneider

1. Controlled Processing

2. Consistent Mapping Condition

3. Consistent Mapping Condition

(experiment)

1. Requires intention/many cognitive resources

2. When a process becomes automatic after a certain amount of trials

3. -Plays participants 20 cards in quick succession

-Participants are to look for the same target (numbers) each trial

-Distractor on cards are always letters or dot patterns 

-1st trial= 55% accuracy

-900th trial=90% accuracy

** after about 600 trials, the targets no longer needed to be repeated therefore allowing participants to reach 100% accuracy (deeming the task as automatic)

Shiffrin & Schneider (cont'd)

Inconsistent Mapping Condition

- Targets are letters and are changed every trial

-Distractors can be letters, numbers, or random dot patterns

-They find that participants never become automatic with this because the task is too difficult when the target is changed after each trial

**Significance: Raises question==why do 2 automatic processes, when put together, still suffer? Because we are much better at doing automatic tasks seperately

Jerry Pellechia (2005) 

Automatic vs. Controlled processes

(experiment)

-measures participants Postural Sway (DV) which varies with whatever task is given

Condition 1: standing on foam & doing cognitive tasks of varying difficulty(sway increases)

Condition 2: seperates tasks in hopes to automate one

Finds: Practicing the dual-task increases performance together, but practicing the two tasks seperately does not improve performance of tasks together.

**This creates a problem for automatic vs. controlled processes

Allport, Antonis, & Reynolds (1972)

(divided attention experiment)

-Participants are asked to shaddow a word list under 3 different dualistic conditions:

1. Shaddow word list & memorize a different word list in opposite channel (auditory-linguistic: worst performance)

2. shaddow word list & memorize visually presented word list (visual-linguistic: better performance)

3. Shaddow word list & memorize a list of pictures (visual-spacial: best performance)

Brooks (1968)

-interested in whether or not it can be called a single task if both perception AND reaction are expected. Does reaction count as a task in itself?

- Has participants do two tasks: one spacial and one verbal

Task 1(spacial): participants start @ star (target)

-target is moved clock-wise and participants are asked whether or not the star is at an extreme top or bottom of the letter

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*Verbal response is better than the Spacial response*

Task 2(Verbal):  takes a sentence like "The cat ate a mouse next to the library" and asks participants whether or not a word is a noun

*Spacial response is better than Verbal response*

*Conclusions: if tasks are too similar, they will be more difficult to perform together

**Significance: this leads to the idea of task-specific resources/general purpose resources

1. Task-Specific Resources

2. General-Purpose Resources

1. Verbal, spacial, motor resources cannot be shared.

-there are different resources for different types of tasks

2. Disimilarity does not rule-out interference

*Significance: this leads to the question: How do our resources budget themselves? ====> Central Executive

Central Executive

Hypotheses:

1. CE allocates limited resources to the separate processors

2. CE acts as a Response Selector: 

- Unitary Resources

2. The CE is in control of resources that cannot be divided (unitary resources) 

==> This suggests that we can only do one thing at a time so how are dual-tasks possible? 

==>(think back to computational metaphor): computers are unable to do parallel tasks- many programs can run at once, but they do not process information at the same exact moment. Processing goes back and forth btwn tasks

Pashler 

(evidence for Central Executive --Response selector hypothesis)

- uses a simple stimulus-response task 

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Conclusion: There is a psychological refractory period (PRP) which does not allow stimulus 2 to be processed until the response to stimulus 1 is finished===> This suggests that it is impossible for two tasks to be performed at the same exact time.