Cog Sci Test 1 Attention

Attention

“glue” that holds our cognitive processes together!! “Attention is the means by

which we actively process a limited amount of information from the enormous amount of

information available through our senses, our stored memories, and other cognitive”

processes.

William James defined it over 135 (1890) years ago as focusing on one thought

while excluding others. James' definition is partially correct; attention is indeed

limited and cannot encompass multiple stimuli simultaneously.

Bottleneck theories suggest that attention has limits, and not all information can

be processed simultaneously, leading to selective attention

The 'All or None' theory is challenged by findings that some information can be

processed even when not consciously attended to, indicating a more nuanced

understanding of attention.

Attenuation theory posits that unattended information is not completely blocked

but rather weakened, allowing for some processing.

Signal detection theory

is a framework used to measure the ability to

differentiate between signal (stimulus) and noise (background). It is widely used

in perceptual experiments to assess how individuals respond to stimuli under

uncertainty.

The theory provides a structured approach to understanding errors in perception,

including hits, misses, false alarms, and correct rejections.

Hits: Correctly identifying the presence of a stimulus.

Misses: Failing to identify a present stimulus.

False Alarms: Incorrectly identifying a stimulus as present when it is

absent.

Correct Rejections: Correctly identifying the absence of a stimulus.

The balance between hits and false alarms is crucial for understanding

perceptual accuracy.

Absent versus false alarm, Memory effect: as hits go up, so do false alarms

SDT Receiver operator characteristic

maps probability of hits by probability of

false alarms

ROC curves graphically represent the trade-off between sensitivity (true

positive rate) and false alarm rate.

The area under the ROC curve indicates the effectiveness of the signal

detection process.

Sensitivity (d') and bias (β) are key metrics derived from ROC analysis,

helping to quantify detection performance.

The ROC curve can be influenced by experimental conditions and

participant instructions.

Sisnol= sensitivity(ability to hear) + bias (we want to cut out bias)

Subtraction: there is always signal and noise

Vigilance

requires attending to a particular area for a prolonged period of

time/sustained attention is required to detect infrequent events over

prolonged periods/Vigilance refers to the ability to maintain attention and

alertness over prolonged periods, especially in environments where

specific stimuli must be detected. It is critical in various real-world

applications, such as monitoring security systems or air traffic control (A

scenario of walking through a cemetery at night illustrates vigilance and

the need for heightened awareness of surroundings, and air traffic control

exemplifies the complexity of attention, requiring simultaneous monitoring

of multiple aircraft and decision-making, Radiology: Radiologists analyze

medical images for abnormalities, requiring them to be vigilant to detect

subtle changes that could indicate serious health issues, Security

Screening: Airport security personnel use X-ray machines to identify

contraband, necessitating a high level of vigilance to prevent dangerous

items from boarding flights, Quality Control in Manufacturing: Workers

monitor production lines for defects, needing to quickly identify and

address any issues to maintain product quality.)

Factors influencing vigilance and study examples

Fatigue: Prolonged periods of vigilance lead to fatigue,

which significantly decreases performance and increases

the likelihood of missing critical stimuli.

Expectation Bias: Posner and Railey's 1994 study

demonstrated that expectations can influence attention,

where valid cues improve reaction times while invalid cues

slow them down.

Cognitive Load: High cognitive demands can detract from

the ability to maintain vigilance, necessitating strategies to

manage workload effectively.

High-stakes environments require individuals to be in a heightened state

of awareness, continuously scanning for specific signals or anomalies.

Studies show that vigilance can decline over time, leading to increased

errors, which is known as the vigilance decrement. Factors affecting

vigilance include task complexity, duration, and individual differences in

attention span.

Mackworth (1948): 25% of stimuli missed after 30 minutes

Involved tasks where participants monitored a clock for

irregularities, revealing significant lapses in attention over time.

Findings indicated that even after 30 minutes, participants missed

about 25% of critical stimuli, raising concerns about the

effectiveness of vigilance in prolonged tasks.

This research has implications for designing work environments,

suggesting that frequent breaks and task rotation can enhance

vigilance and performance.

Fisk & Schneider (1981): training can improve vigilance, but fatigue

decreases performance

“Spotlight” metaphor

The spotlight metaphor describes how attention can be directed

towards specific areas in the environment, akin to a spotlight

illuminating a stage.

This metaphor illustrates the trade-off between focused attention

and the risk of missing stimuli outside the spotlight's beam,

especially when expectations are incorrect.

Engaging the spotlight requires cognitive effort, and disengaging

from it to scan other areas can lead to delays in response time.

Battle is the fastest

Invalid is the slowest (expectation is elsewhere, may have

an emotional spotlight)

Search

involves actively seeking out the target. Vigilance involves passive

monitoring for stimuli, while search is an active process of locating a

specific target once it is identified. The transition from vigilance to search

is critical in situations where a stimulus is detected, such as hearing footsteps and determining their source. Effective search strategies are essential in environments where quick identification of targets is necessary, such as in emergency response scenarios.

Types of search

Feature searches and feature singletons: distinctiveness makes the

target “pop out” A feature singleton is a distinctive attribute that pops out,

such as a red donut among a box of regular donuts.

Conjunction search: a combination of features is the target. Conjunctive

searches require identifying a target based on a combination of features,

which is more effortful and time-consuming.

Visual search: involves actively seeking a target among distractors,

similar to localizing sounds like footsteps. The process of search can be illustrated through examples like Where's Waldo? where the target (Waldo) is distinctive yet can

be hard to find in a busy display.

Searches can be categorized into easy searches, where a target

stands out (feature singleton), and more complex searches

requiring conjunctions of features. The difficulty of search tasks

can be influenced by the number of stimuli present, leading to the

display size effect, where search time increases with more items.

Display size effect: wheres waldo (T and L example in class)

Feature-Integration Theory (Treisman, 1986)

focusing on how we

detect features in our environment.

Physiological data from studies, including single-cell recordings in

cats, provided evidence for how visual stimuli activate specific

brain cells.

The theory posits that simple searches are automatic, while

conjunctive searches require more cognitive effort.

Single-cell recordings show how different cells in the visual cortex

respond to specific stimuli, illustrating the brain's programming to

detect certain features.

The Nobel Prize-winning research in 1981 highlighted the different

layers of cells in the occipital cortex that respond to various

stimuli, supporting the theory's claims.

Simple cells respond to basic features, while complex and

hyper-complex cells respond to more intricate combinations of

features.

Similarity Theory (Duncan & Humphreys, 1989)

examines the

relationship between targets and distractors, emphasizing that

similarity can hinder search efficiency.

When distractors closely resemble the target, it complicates the

search process, making it harder to identify the target.

To enhance searchability in design, increasing contrast between

the target and distractors is recommended

Movement filter theory

movement in conjunction with distinctive

features enhances search, whereas movement in conjunction with subtle

features may cause illusory conjunctions that hinder search/suggests that

movement is a significant attribute that can enhance visual search/The

presence of movement, combined with distinctive features, can facilitate

quicker identification of targets in a dynamic environment.

This theory highlights the importance of considering motion in

visual search tasks, as it can draw attention to relevant stimuli.

Movement Filter Theory suggests that movement is a significant

attribute that can enhance visual search. Movement is considered

a special attribute that enhances visual search when combined

with distinctive features. A moving object, such as a red ball, can

draw attention more effectively than static objects, especially in a

contrasting environment. However, subtle features in a complex

background can hinder search efficiency, leading to illusory

conjunctions where features are miscombined.

Movement is defined as a vector, which is a conjunction of

different features, suggesting that it should slow down processing

according to feature integration theory. Research by Livingston

and Biggs in the 1990s identified specialized movement cells in

the visual system that respond specifically to movement, indicating

that movement can act as a singleton rather than a conjunction.

This suggests that our evolutionary focus on movement is crucial

for survival, as it helps detect potential threats or changes in the

environment.

The concept of movement as a singleton challenges previous

theories that categorized all visual stimuli as conjunctions,

highlighting the need for updated models in visual attention

research.

Selective attention

cognitive process of focusing on specific stimuli while ignoring

others/focusing on specific stimuli while ignoring others, such as reading during a noisy

cafe and working on a plane while ignoring the sounds of crying babies or loud

conversations (aligns with William James's metaphor of focusing on one train of thought

among many)/ We make a choice to attend to some stimuli but ignore others. A classic

study from 1960 demonstrated that participants could follow information from one

channel while ignoring another, indicating that attention can switch based on the

relevance of the information.

Cherry’s (1953) Cocktail Party Phenomenon and “All or None Filter”

Early research in the 1950s introduced the concept of a filter that

determines which stimuli are processed and which are ignored, leading to

the cocktail party phenomenon. The cocktail party phenomenon illustrates

how individuals can focus on a specific conversation while filtering out

others, demonstrating the selective nature of attention. Individuals can focus on a single conversation in a noisy environment, yet still hear their

name mentioned elsewhere.

Shadowing, binaural, and dichotic listening experiments

Bineural: information from both A & B is going into both ears (people are

really bad at this)

Dichotic listening tasks where participants were asked to shadow one

message while ignoring another, revealing the limitations of the

all-or-none filter. Dichotic listening task: One source going into one ear

(only listen to one source and ignore the other) -> All or none filter

Results showed that while participants could focus on one message,

some information from the ignored message still penetrated awareness,

challenging the strict filter theory.

Early filter approach- no semantic information

Broadbent’s (1958) Filter Theory

Attention acts as a gatekeeper, allowing only certain information to be

processed based on its relevance.

Moray’s (1959) Selective Filter Model and the “Yes Dear” Effect

Later theories, such as those proposed by Moray, introduced the concept

of a selective filter, suggesting that some perceptual information can still

be processed even when not attended to, leading to a more nuanced

understanding of attention.

Treisman’s Attenuation Model (Late filtering model)

Early filter theories posited that irrelevant

information is completely blocked from processing, but this was

challenged by findings that some information can still be processed at a

lower level. Treisman's attenuation model suggests that instead of

blocking non-target stimuli, the brain weakens their processing, allowing

for some level of awareness even if not fully attended to. This model

indicates that attention is not a binary process but rather a gradient,

where some stimuli are processed more deeply than others based on

their relevance or meaning. The attenuation model aligns with the idea

that attention can be distributed across multiple channels, allowing for a

more nuanced understanding of cognitive processing.

The concept of bottlenecks in information processing highlights the

limitations of our cognitive capacity, which can lead to errors in attention

and memory.

(3 stages): we attend to several channels; non-target stimuli are

weakened, not filtered/blocked

Analysis of physical characteristics

Pattern analysis

Assigning semantic meaning

Capacity Model= task difficulty

William James (jammies in bed example after work)

Automated vs. Controlled Processing

Controlled processing: requires conscious effort (more attentional

resource), performed step-by-step, longer to execute, used with novel

tasks typically used for novel or complex tasks, such as learning to drive a

manual transmission vehicle.

Automated processing: occurs with familiar tasks that have been

practiced extensively, allowing them to be performed with little conscious

thought, such as driving an automatic car/require less conscious effort

(less attentional resource), performed in parallel with other tasks,

relatively fast execution, used with familiar tasks

The transition from controlled to automated processing illustrates the

practice effect, where repeated exposure to a task leads to increased

efficiency and reduced cognitive load.

An example of this transition is learning to play a musical instrument,

where initial practice is slow and deliberate, but over time becomes fluid

and automatic.

The negative acceleration curve describes how performance improves

rapidly at first with practice but levels off as one becomes more skilled,

indicating diminishing returns on further practice.

This curve is significant in understanding how expertise develops and why

even experts can make errors when performing automated tasks due to

over-familiarity.

Through PRACTICE, controlled tasks become automatized

Automized Stroop test example

It consists of three parts: reading color words, naming the color of

the words, and naming the color of the ink used to print the words,

with increasing difficulty in each part.

The test illustrates how automatic reading can interfere with the

task of naming colors, highlighting the challenges of controlling

automatic processes. Participants typically perform best in the first

part (reading words) and worst in the third part (naming ink

colors), demonstrating the impact of automaticity on performance.

The decline in performance from part one to part three indicates

the cognitive load required to suppress automatic responses.

When Automatic Processes go bad (Human error)

Errors in automated tasks can occur when attention is divided or when

individuals become complacent due to familiarity with the task.

An example of an error in an automated task is forgetting to lock a door

after repeated actions, highlighting how routine tasks can lead to lapses in

attention.

Strategies for reducing errors in automated tasks include increasing

awareness of potential lapses and implementing checks to ensure tasks

are completed correctly.

òTraining and practice can help individuals maintain a level of conscious

attention even in familiar tasks, reducing the likelihood of errors.

James Reason's taxonomy of

error categorizes mistakes into different types

Mistakes: errors in controlled processing/Mistakes are errors in

judgment or decision-making, often due to a lack of knowledge or

incorrect assumptions, such as deciding to skip studying for a test.

Slips: errors in automatic processing (pressing the wrong button) Likely to occur when 1) we deviate from routine or

2) when the routine is interrupted/when an automatic process is

interrupted, leading to unintended outcomes, such as mixing up

tasks (e.g., feeding a cat while making tea)

Captured errors happen when individuals fail to deviate

from a routine, leading to unintended actions, as illustrated

by William James's anecdote about coming home and

going to bed instead of preparing for dinner.

Lapses: A failure of memory or omission, forgetting a step

Stroop Effect (1935)

Inability to control the automatic process of reading.

Divided attention

used when attention must be allocated to perform multiple tasks at the

same time/refers to the ability to multitask(which can affect performance on individual

tasks), though there is debate on whether it is true multitasking or task switching/Divided

attention refers to the ability to process multiple sources of information simultaneously,

which can lead to performance decrement

Divided attention is often tested in studies measuring performance on dual-task

scenarios, revealing limitations in cognitive resources.

Dual task paradigm (1976)

is a method used to study divided

attention by requiring participants to perform two tasks at once,

revealing how attention is allocated/dual task paradigm allows

researchers to measure the effects of multitasking on

performance, revealing that simultaneous tasks can lead to

decreased accuracy and speed.The dual task paradigm involves

three conditions: performing Task A alone, Task B alone, and both

tasks together. The performance metrics help to quantify the

cognitive load and efficiency of multitasking.

Continuous practice of tasks can lead to automation,

improving performance over time, but initial attempts often

result in errors.

Change blindness

is the phenomenon where individuals fail to notice significant

changes in their visual environment.

Coined by researchers Rensink, O'Regan, and Clark, this concept emerged from

studies involving rapid image changes.

Example: In a study, participants failed to notice a plane disappearing from an

image, demonstrating the limits of visual attention.

Change blindness illustrates how our attentional capacity can create a false

sense of continuity in our perception of reality.

The phenomenon is often showcased in media, such as the book 'The Invisible

Gorilla, which discusses the illusion of memory.

Practical implications: Change blindness can affect everyday situations, such as

failing to notice changes in a familiar environment.

The Doors Study

Conducted by Simons and Chabris in 1998, the Doors Study exemplifies change

blindness in social interactions.

Participants engaged in a conversation about directions were unaware when the

person they were speaking to was replaced by another individual.

This study highlights how focused attention on a task can lead to missing

significant changes in the environment. The results suggest that our expectations influence our perception; we do not anticipate changes during social interactions.

Change blindness can have real-world implications, such as in eyewitness

testimony, where individuals may overlook critical details.

The study emphasizes the importance of understanding cognitive limitations in

social cognition.

Understanding attention and change blindness can improve educational

strategies by minimizing distractions.

In workplace settings, awareness of multitasking costs can lead to better task

management and productivity.

Training programs can be developed to enhance attentional control and reduce

the impact of change blindness.

A classic example is the use of video clips where elements are altered, and

viewers do not notice these changes, illustrating the concept effectively

Inattention blindness

distractions in the environment lead to missed information that is

right in front of us.

Inattention blindness occurs when our focus is directed elsewhere, causing us to

overlook obvious stimuli, such as a gorilla in a basketball game video.

The term 'inattention blindness' was coined by Mack and Rock in 1998,

emphasizing the role of attention in perception.

The famous awareness test involving counting basketball passes demonstrates

change blindness; viewers often miss the moonwalking bear due to their focus on

the task.

Simons and Chabris conducted a study in 1999 that showcased how 60% of

participants failed to notice a gorilla while counting passes, highlighting the

impact of focused attention on perception. Title was gorrilas in our midst

Perception

the set of processes that we use “to recognize, organize, and make

sense of the sensations (raw data recieved from stimuli) we receive from

environmental stimuli.

” (ex: temperature->58 degrees when you are from the

north or the south)

Vision is the most dominant sense

Perception is influenced by the relative distance of objects, leading to size

distortion; objects further away appear smaller, while closer objects seem larger.

Early perceptual experiments often involved conflicting cues to determine which

perception dominated, revealing insights into human cognition.

Expectations in perception: mistaking a dark shape for a dog in a dimly lit room

Bottom Up

(Data-driven) approach

Perception starts with sensory input-> processed to form a higher

understanding

Gibsons Theory of Direct Perception

posits that all

necessary information for perception is derived from

sensory data, minimizing the role of higher-order cognition.

This theory has significant implications in fields like

environmental psychology and design, emphasizing how

physical environments shape human interaction.

An example of this is the design of door handles, where

their shape inherently suggests how they should be used,

demonstrating the concept of affordances.

The idea of affordances indicates that the characteristics of

an object guide our interactions with it, reducing the need

for cognitive processing.

Environmental affordance

what’s in the

environment directs how you interact with

something

Gibson's theory challenges traditional cognitive

approaches by suggesting that perception can occur

without extensive mental processing.

Template theory

Only an exact match will do (work for

computers not humans)

Template theory suggests that recognition occurs by

matching sensory input to stored templates in memory,

requiring an exact match for identification.

This theory is effective for machines, such as barcode

scanners, which rely on precise matches to function

correctly.

An example of template theory in action is the scanning of

UPC codes at a grocery store, where any deviation from

the expected code results in an error.

The limitations of template theory in humans arise from the

vast number of potential templates needed for recognition,

leading to inefficiencies in memory retrieval.

The complexity of human writing recognition illustrates the

inadequacy of template theory, as it would require an

impractical number of templates for different fonts and

styles.

Feature Theories

posits that recognition is based on

identifying specific features or attributes of an object rather

than matching it to a template or prototype/Feature

theories propose that we recognize objects by analyzing

their individual features rather than relying on holistic

templates or prototypes.

This approach allows for greater flexibility and efficiency in

recognition, as it focuses on key characteristics that define

an object.

An example of feature theory in practice is recognizing

letters based on their distinct features, such as lines and

curves, rather than requiring a complete template for each

letter.

Feature theory can explain how we can recognize

variations of objects, such as different fonts or handwriting

styles, by focusing on their essential features.

This theory is particularly relevant in cognitive psychology,

as it aligns with how humans process visual information.

The term 'feature' was popularized by Gordon Bower's

research at Stanford, emphasizing the importance of

features in memory storage and recognition.

Selfridges Pandemonium

Features are the building blocks of recognition, allowing us

to identify and categorize objects in our environment.

The Selfridge Model of Feature Identification

The Selfridge model, also known as the pandemonium

model, illustrates the process of feature identification in a

structured manner.

It involves taking a high-fidelity snapshot of an object,

creating an internal representation for further analysis.

The model consists of a hierarchy of 'demons' that process

visual information, starting from image capture to feature

analysis.Describes a model of perception where different

'demons' (feature detectors) respond to various aspects of

stimuli, working together to recognize patterns

Recognition involves several stages: capturing an image,

analyzing features, and reconstructing the object from its

components.

The initial stage captures a snapshot, followed by breaking

down the image into features such as lines and angles.

Cognitive units interpret these features to hypothesize

what the object could be, leading to a final recognition

decision.

Feature theories are applicable in various cognitive tasks,

including memory research, where binding features

together is crucial for memory formation.

Researchers like Marsha Johnson have explored how

feature finding contributes to effective memory recall.

The theories highlight the cognitive processes involved in

recognizing both visual stimuli and written words.

Structural Description Theory

expands on feature theories

by addressing more complex objects beyond simple

letters.

Irving Biederman proposed a three-stage recognition

process for complex objects, emphasizing the breakdown

of objects into simpler components.

The theory suggests that humans are pre-programmed

with a set of geometric icons that aid in object recognition.

Stages of Recognition

The first stage involves taking a snapshot of the object and

identifying its basic contours and features.

The second stage classifies these features into geometric

icons, which are innate shapes that help in recognizing

patterns.

The final stage reconstructs the object from its classified

components, allowing for pattern recognition.

Biederman identified 36 geometric icons (Biederman’s

“Geons”) that serve as the foundation for recognizing

complex objects.

These icons include basic shapes like cones and cylinders,

which combine to form more intricate structures.

The process of recognizing an object involves identifying

these icons and understanding their arrangement to form a

coherent image.

Marr (1982): Computational model of perception

computational model of perception utilizes binary data to

analyze visual information.

The model operates on the principle of 'on' and 'off' states,

similar to binary coding in computer systems.

It effectively breaks down objects into their component

features but struggles with the reconstruction phase of

recognition. While the computational model excels at

analyzing data, it faces difficulties in synthesizing

information back into recognizable patterns. The challenge

lies in the vast number of potential combinations that could

arise from the analyzed features, complicating the

recognition process.

Top Down

(Conceptually-driven) approach

Previous expectations and experiences shape how we interpret

sensory data (ex: focus affects perception). Involves higher-order

cognitive processes that influence perception. It suggests that our

expectations and prior knowledge shape how we interpret sensory

information.

Examples: When reading a sentence, we often fill in missing

letters based on context. Top-down processing involves using prior

knowledge and experiences to interpret sensory information. This

allows us to make sense of incomplete or ambiguous stimuli/Case

Study: Research on visual perception has shown that individuals

can recognize objects faster when they are familiar, illustrating the

efficiency of top-down processing.

A classic example is recognizing a stop sign partially obscured by

foliage. Despite not seeing the entire sign, previous knowledge allows us to infer its meaning based on context and partial visual

cues.

Perceptual Sets

habitual way of perceiving based on

expectations/ Perceptual sets are mental frameworks that

influence how we perceive the world. They are shaped by

our experiences and expectations, guiding our

interpretations of sensory data/The concept of 'perceptual

sets' refers to the mental predispositions that shape how

we perceive stimuli based on past experiences.

Social perceptual sets can also influence our

interactions. For instance, if we expect a friendly

greeting, we may overlook unusual responses, as

demonstrated in a study where a professor

received different reactions based on context.

Context effects: influence of surrounding

environment on perception

Contextual cues can significantly affect

recognition speed and accuracy, as

demonstrated in studies with household

items in different settings.

For example, Palmer (1975) objects like

toilets are quickly recognized in a bathroom

context but delayed in a kitchen context,

highlighting the role of context in perception.

This phenomenon illustrates how

mismatched contexts can lead to slower

reaction times and errors in identification.

Balancing Top-Down and Bottom-Up Processing

Both processes

work together in perception. For instance, when we see a familiar face,

top-down processing helps us recognize it quickly, while bottom-up

processing allows us to analyze the facial features.

Top-down processing involves using existing knowledge and

expectations to interpret sensory information, while bottom-up

processing starts with the sensory input itself.

Both processing types are essential for understanding perception,

as they work together to help us navigate our environment

effectively.

Evidence from various studies supports the idea that both

processes are utilized in different contexts and situations.

Depth Cues

features of the stimuli that indicate how far an object is from the

observer, or from other objects in the world.

Two Types

Bi and monocular

Binoculor

requires both eyes to see the cue; used for viewing objects

that are close

Require both eyes to perceive depth. They include binocular

disparity, where each eye sees a slightly different image, helping to gauge

distance. For example, when you cover one eye and switch, objects appear to

jump, illustrating depth perception.

Monoculor

only requires one eye; used for objects farther away

Can be perceived with one eye and include various pictorial

cues. They help us understand depth in two-dimensional images, such as

paintings.

Interposition/Occlusion

One object partially covers another because

it’s closer to you.When one object overlaps another, we perceive the

overlapping object as closer. This cue is commonly used in art to create

depth. Example: In an image with lily pads and flowers, the flowers

appear closer because they occlude the lily pads.

Linear Perspective

When two lines (which we know are parallel) seem

to be converging/Parallel lines appear to converge in the distance, giving

a sense of depth. This is often used in landscape paintings. Can create

Pozzo illusion.

Texture gradient

At greater distances, the texture (or details) of the

scene are packed together, telling us that objects in the distance are

farther away. Objects that are closer appear more detailed, while those further away appear smoother and less detailed.

Relative Size

When looking at two objects, the larger object will appear

to be closer/If two objects are known to be of similar size, the one that

appears smaller is perceived as being further away.

Aerial Perspective

Distant objects appear hazier and bluer due to

atmospheric effects, providing depth cues.

Artists like M.C. Escher exploit linear perspective to create impossible

figures that challenge perception

Q conflict occurs when different depth cues provide conflicting

information, leading to misinterpretation of spatial relationships.

Example: The waterfall in Escher's work appears to flow upward,

defying gravity and creating confusion about spatial orientation.

Binocular Diaparity

the eyes are 2.5 inches apart, so each eye sees a slightly

different view of the same object

Helps determine how far away the object is from you.

Convergence

As you focus on an object coming towards you, your eyes will

turn inward slightly

Helps determine how close an object is, compared to other objects in the

visual field.

Refers to the inward or outward movement of the eyes to focus on objects

at different distances. This muscle movement provides important depth

information.

Collimated Light: When objects are far away, light rays become parallel,

leading to similar images in both eyes, which affects depth perception.

Case Study: The 'visual cliff' experiment demonstrated that depth

perception is crucial for infants, indicating a combination of innate and

learned aspects.

Figure and Ground in Perception in Object Identification

The distinction between figure and ground is crucial in understanding how we

perceive objects in relation to their backgrounds.

Attention can shift dynamically, altering what is perceived as figure or ground

based on focus; for example, a lamppost can be seen as either the figure or the

background depending on attention.

Reversible Figures and Dynamic Perception

objects that can be perceived in more than one

way/Reversible figures, such as the Necker cube and the old woman/young

woman illustration, demonstrate how perception can switch based on attention

and interpretation.

These figures exemplify the dynamic nature of attention, where the viewer can

alternate between different interpretations of the same visual stimulus.

The phenomenon of reversible figures illustrates the brain's ability to process

multiple interpretations, showcasing the complexity of visual perception.

Auditory perception also involves figure-ground distinctions; background noises

can become the focus when they become relevant, such as sniffling during a test.

The example of a backup alarm transitioning from background noise to a figure

illustrates how context can shift auditory perception. This highlights the

importance of attention in auditory processing, similar to visual perception.

Form Perception

we perceive objects as the individual parts, plus the

relationship between the parts.

Gestalt Principles of Perceptual Organization

“The whole is perceived as being greater than the sum of its parts.”

Law of Pragnanz

Every stimulus pattern is seen in such a way that the

resulting structure is as simple as possible.

Gestalt laws of grouping

The laws of grouping, such as proximity, similarity, and closure, help us organize

sensory information and make sense of complex stimuli. These laws guide our

understanding of distance and relationships between objects, influencing how we

perceive our environment. Understanding these laws is essential for grasping

how we interpret visual and auditory information in everyday life.

Proximity

objects close together are perceived to be in the same group. For

example, in a visual display of shapes, closely positioned red squares and

triangles are grouped together, leading to a consensus of two groups rather than

eight individual shapes

Similarity

objects that look similar (shape, color, size, etc.) are grouped

together. For instance, in a football game, players wearing the same color

uniforms are perceived as a team, facilitating quick recognition of their

movements

Continuation

We tend to fill in the gaps when lines or shapes are interrupted.

For example, if a line is obscured, we still perceive it as a continuous line based

on our previous experiences

Closure

When a familiar object is interrupted, we imagine the rest of the figure.

For instance, if part of an object is hidden, we still recognize it based on our

familiarity with the object.

Four perceptual constancies

shape

size

location

color

Shape constancy

we perceive things to have a constant shape even though

we look at it from different angles. For example, a door appears rectangular

regardless of whether it is open or closed

Size comstancy

we perceive an object to still be the same size, even though

it’s coming closer to you and projecting a larger retinal image. For instance, a

person walking away appears smaller, but we know they are not shrinking

Location constancy

we perceive things as staying in the same place, even as

we move around relative to the object

Color constancy

we see an object as the same color even when the actual

wavelengths hitting our retina change. Our perception of an object's color

remains consistent under varying lighting conditions. For instance, a cherry red

car may appear darker in low light, but we still recognize it as the same color.

Unconscious perception

Blindsight phenomenon (agnosia)

Agnosia: condition characterized by the inability to process visual

information can result from occipital cortex damage

Weiskrantz (1986): Demonstrated that patients with cortical blindness

could still detect and localize stimuli unconsciously, suggesting that visual

processing can occur without awareness. Challenges the assumption that

perception and consciousness are inseparable; supports dual-route

models of visual processing.

Subliminal perception

Subliminal perception: occurs when stimuli are presented below the

threshold of conscious awareness but still influence thoughts, feelings, or

behavior.

Marcel (1983) studies with priming: Used masked priming—presenting

a word briefly and then masking it—to show that unconscious stimuli can

facilitate semantic processing.

Findings: Participants responded faster to target words when

preceded by related subliminal primes, even though they were

unaware of the prime.

Implication: Suggests that semantic activation can occur without

conscious awareness, supporting models of unconscious

cognition and challenging strict thresholds for perception

Memory definition

is “the means by which we retain and draw on our past experiences to use this

information in the present.”

The cognitive economy concept suggests that memory allows us to efficiently

process information without needing to relearn everything constantly.

Memory is not just a passive storage system; it actively shapes our perceptions

and interactions with the world.

Three operations of memory

encoding

storage

retrieval

Encoding

The process of transforming sensory input into a format that

can be stored in memory. This can involve visual, auditory, or semantic

encoding.

Encoding Errors: Occur when information is not accurately

transformed into a memory trace, leading to incorrect or

incomplete storage.

Example: If a bank teller miscounts money during a transaction,

this represents an encoding error, as the information was not

accurately recorded.

Storage

The retention of encoded information over time, which can vary

in duration and capacity depending on the type of memory (e.g.,

short-term vs. long-term).

Storage Errors: Happen when stored information is lost or

corrupted, such as through decay or interference from other

memories.

Retrieval

The process of accessing and bringing stored information into

consciousness when needed. This can be influenced by various factors,

including cues and context.

Retrieval Errors: Arise when the information is stored but cannot

be accessed, often due to lack of appropriate cues or contexts

The bank metaphor illustrates how memory processes work: depositing

money (encoding), storing it in an account (storage), and withdrawing it

(retrieval).

Real-life implications of memory errors can be seen in eyewitness

testimonies, where encoding and retrieval errors can lead to false

memories.

Studies on memory recall tasks show that the effort required varies

significantly between recognition and recall tasks, impacting performance.

Recall

Requires generating information from memory without cues, which

can be more challenging and effortful.

Different types of recall tasks include free recall (no cues) and

cued recall (with prompts), each varying in difficulty and cognitive

load.

Retrieving information without cues, which can be tested through

short answer or essay questions.

Recognition

Involves identifying previously encountered information from a set

of options, making it generally easier than recall tasks.

Identifying previously learned information from a set of options,

often used in multiple-choice tests.

Implicit

Refers to unconscious retention of information, often

demonstrated through priming effects, where prior exposure

influences later retrieval without conscious awareness.

Example: A person may recall lyrics to a song after hearing it

repeatedly, even if they were not actively trying to memorize it,

riding a bike, playing an instrument, classical conditioning

Includes skills and conditioned responses

Explicit

Involves conscious recollection of information, such as recalling

facts or events that one has studied.

Examples: recalling historical dates and facts from a textbook

Priming

Setting a participant up for specific outcome by giving them stimuli that would prep them for that outcome, for example asking for them to talk about birds as a B word, but before giving them that task showing them a picture of a crow.

Sensory Memory

Brief storage of high-fidelity information from the

environment, lasting only a few seconds.

Information in sensory memory is fleeting; if not attended to, it

quickly fades away, illustrating the transient nature of sensory

input.

Sensory Memory

The concept of auditory replay is likened to old technology, where

functions like rewind allow for brief access to information before it

disappears.

Sensory memory serves as the first stage in the memory process,

filtering what information is deemed important enough to transfer

to short-term memory.

Sperling's experiments demonstrated the limitations of sensory

memory, showing that individuals can recall only a small portion of

information presented briefly.

Whole report technique

In the whole report technique, participants are

shown a visual stimulus for a brief period (e.g., 50

milliseconds) and asked to recall as much

information as possible.

This method often leads to frustration, as

participants struggle to retrieve all the information

they perceived, highlighting the limitations of STM.

The results indicated that individuals could only

recall a limited number of items, demonstrating the

rapid decay of sensory memory.

The technique emphasizes the importance of

attention and focus in memory retrieval, as

distractions can lead to incomplete recall.

Sperling's findings laid the groundwork for

understanding the fleeting nature of sensory

memory and its transition to STM.

Partial report technique

The partial report technique improved upon the

whole report method by directing participants to

focus on a specific row of information after a brief

presentation.

This approach allowed participants to recall a

higher number of items (9-12) from the designated

row, illustrating the capacity of sensory memory

when attention is directed appropriately.

The technique revealed that even though sensory

memory holds a wealth of information, retrieval is

contingent on focused attention and the specific

cues provided.

Delaying retrieval by even one second significantly

reduced recall ability, emphasizing the rapid decay

of sensory information.

Sperling's partial report technique is a pivotal

example of how methodological innovations can

enhance our understanding of cognitive processes.

STM

Holds a limited amount of information (about 7

items) for approximately 30 seconds without rehearsal (millers law 7

+-2items)

Information can be maintained in STM through rehearsal, which

can be either rote (maintenance) or elaborative, depending on the

depth of processing.

Rote rehearsal involves repeating information to keep it active,

while elaborative rehearsal connects new information to existing

knowledge, facilitating transfer to long-term memory.

The 'whole report' and 'partial report' techniques highlight the

challenges of retrieving information from STM, with retrieval

efficiency decreasing significantly with delays.

Short-term memory is likened to a computer's desktop, where

currently active information is readily accessible.

LTM

Theoretically unlimited storage for information

retained over extended periods, potentially a lifetime and can be

categorized to make retrieval more efficient

Long-term memory (LTM) is characterized by its potentially

unlimited capacity and duration, storing information for extended

periods, possibly a lifetime.

Unlike STM, LTM requires retrieval processes to access stored

information, which can be slow and dependent on the organization

of the information.

The use of elaborative rehearsal is crucial for transferring

information from STM to LTM, as it involves deeper processing

and connections to prior knowledge.

LTM can be conceptualized as a vast database, where information

is stored in an inactive state until actively searched for and

retrieved.

The organization of information in LTM can be influenced by

thematic connections, similar to how books are categorized on

library shelves.

Multi Store Approach

Atkinson & Shiffrin (1968, 1971)

A foundational model describing memory as a series of stages:

sensory memory, short-term memory, and long-term memory.

Sensory Register/Memory: very brief storage (milliseconds to

seconds)

STM: Limited capacity for storage, control processes located here

(15-30 seconds without rehearsal)

LTM: Unlimited, permanent storage (potentially lifelong)

Control processes of multi store approach

Mechanisms like rehearsal that help maintain information in

short-term memory.

Rehearsal: process of actively maintaining information in

short-term memory to facilitate transfer to long-term memory

Encoding Strategies: Techniques such as chunking and

mnemonic devices that enhance memory retention

Iconic Memory

A type of sensory memory that retains visual information for a very short

duration (milliseconds).

Example: Writing a name in the air with a sparkler, where the visual trace

remains for a brief moment after the sparkler is moved.

Echoic Memory

Definition: A type of sensory memory that retains auditory information for

a short period (up to a few seconds).

Example: The phenomenon where a person may not immediately

respond to a question because the auditory information has not been fully

processed.

Rote rehearsal

involves the simple repetition of information to keep it

active in short-term memory, often used for memorizing lists or phone

numbers.

This technique is effective for short-term retention but does not facilitate

deeper understanding or long-term retention of information.

An example of rote rehearsal is memorizing a phone number by repeating

it multiple times until it can be dialed, illustrating its practical application.

Rote memorization is often criticized for its lack of engagement with the

material, leading to superficial learning.

While useful for immediate recall, rote rehearsal is limited in its

effectiveness for complex or abstract concepts

Elaborative rehearsal

involves connecting new information to existing

knowledge, enhancing understanding and retention in long-term memory.

This technique encourages deeper processing, making it more likely that

information will be stored and retrievable later.

An example of elaborative rehearsal is relating a new concept in a

textbook to prior knowledge or personal experiences, which aids in

encoding.

The effectiveness of elaborative rehearsal is supported by research

indicating that meaningful connections improve memory retention.

This method is essential for academic success, as it promotes a deeper

engagement with the material being studied.

What are the three differences between LTM and STM

access

activity

captivity

Forgetting

Decay Theory: natural decay of memory trace/memories fade over time

if not actively maintained or retrieved.

Interference Theory: one memory trace disrupts another/new

information can disrupt the retrieval of previously stored memories

Serial position effects

The serial position effect refers to the phenomenon where items at the

beginning (primacy effect) and end (recency effect) of a list are

remembered better than those in the middle.

In experiments, participants typically recall the first few and last few items

from a list of words more effectively than those in the middle,

demonstrating the importance of rehearsal and short-term memory.

The primacy effect is attributed to the rehearsal of early items, while the

recency effect is due to the last items still being active in short-term

memory.

Coding

Memory is often formed through integrated episodes rather than isolated

snapshots, which allows for a more meaningful recall of events.

Integrated episodes combine sensory information (visual and auditory)

into coherent memories, enhancing long-term retention.

The concept of the episodic buffer plays a crucial role in integrating

sensory inputs into meaningful episodes for storage in long-term memory.

Example: Recalling a birthday party involves not just visual images but

also auditory memories, such as voices and sounds, creating a rich

memory.

This integration process is essential for effective memory retrieval, as it

allows for contextual cues to aid recall.

Attention acts as a control mechanism that directs sensory information to

the episodic buffer for integration.

The process of breaking down sensory information into components

(spatial and phonological) is crucial for memory formation.

Attention can be influenced by external distractions, which may interfere

with the encoding of memories.

Case Study: The impact of background noise on memory retention

illustrates how attention can be diverted, affecting recall.