COGNITIVE PSYCH EXAM 2

Sensation

The process of detecting physical energy from the environment through sensory receptors and sending information to the nervous system.

Perception

The process of organizing and interpreting sensory information so it becomes meaningful.

Sensory adaptation

A decrease in sensitivity to a constant, unchanging stimulus over time; for example, noticing a perfume less after being in the room for several minutes.

Absolute threshold

The minimum intensity of a stimulus that a person can detect 50% of the time under specified conditions.

Differential threshold (just noticeable difference/JND)

The smallest difference between two stimuli that a person can detect 50% of the time.

Characteristics of the differential threshold

The JND depends on the original intensity of the stimulus; a larger starting stimulus usually requires a larger change to notice a difference.

Subliminal message

A stimulus presented below the level of conscious awareness; whether it meaningfully changes behavior depends on the circumstances and evidence.

Types of subliminal messages

Common examples discussed in psychology include subliminal visual messages (brief images or words) and subliminal auditory messages (sounds or words masked by other sounds).

Psychophysics

The study of the relationship between physical properties of stimuli and the sensations or perceptions they produce.

Weber's law

The just noticeable difference is a constant proportion of the original stimulus intensity, rather than a fixed amount. The proportion is called the Weber fraction.

Weber-Fechner law

A proposed relationship in which perceived intensity increases roughly logarithmically as physical stimulus intensity increases.

Signal detection theory

A theory explaining how people decide whether a faint or uncertain signal is present, taking into account both sensory evidence and decision criteria.

Hit

A signal is present and the person correctly reports detecting it.

Miss

A signal is present but the person reports that it is absent.

False alarm

No signal is present, but the person reports detecting one.

Correct rejection

No signal is present and the person correctly reports that it is absent.

Distal stimulus

The actual object or event in the environment, such as a real tree across the street.

Proximal stimulus

The pattern of energy that reaches a sensory receptor, such as the image of the tree projected onto the retina.

Bottom-up processing

Perception driven mainly by incoming sensory information, beginning with basic features and building toward recognition.

Top-down processing

Perception influenced by prior knowledge, expectations, context, and experience.

Visual object-recognition pathways

The ventral 'what' pathway supports identifying objects; the dorsal 'where/how' pathway supports spatial processing and guiding actions toward objects.

Ambiguous figures

Images that can be perceived in more than one way, such as the duck-rabbit; they show how perception can change despite the same visual input and are often used to illustrate constructive/top-down influences on perception.

Agnosia

A difficulty recognizing objects, people, sounds, or other stimuli despite adequate basic sensation; it is usually associated with brain damage.

Apperceptive agnosia

A recognition disorder in which a person has difficulty forming a coherent percept or matching basic visual features into a whole; often associated with damage to visual-processing regions, especially occipital areas.

Associative agnosia

A recognition disorder in which a person can perceive or copy an object but cannot connect the percept to its meaning or identity; often associated with damage to visual-association pathways, including occipito-temporal regions.

Other subtypes of agnosia

Examples include prosopagnosia (difficulty recognizing faces), achromatopsia or color agnosia (difficulty perceiving/recognizing color, depending on the condition), and auditory agnosia (difficulty recognizing sounds).

Change blindness

Failure to notice a change in a visual scene, especially when the change occurs during a brief interruption or visual disruption.

Inattentional blindness (attention blindness)

Failure to notice a visible but unexpected object or event because attention is focused elsewhere.

Perceptual reversibility

When perception switches back and forth between two interpretations of the same ambiguous stimulus.

Template-matching theory

Pattern recognition occurs by comparing a stimulus with a stored, exact template; it is simple but has difficulty explaining recognition across different sizes, angles, fonts, or variations.

Feature-analysis theory

Pattern recognition occurs by detecting basic features, such as lines, edges, angles, or curves, and combining them to identify an object or pattern.

Recognition-by-components theory

Objects are recognized by their basic three-dimensional components, called geons, and the relationships among those components.

Geons

Basic three-dimensional geometric components, such as cylinders, blocks, and cones, proposed as building blocks for recognizing many objects.

Word superiority effect

A letter is identified more accurately or quickly when it appears in a meaningful word than when it appears alone or in a meaningless string.

Perceptual confusion effect

Similar-looking letters or patterns are more likely to be confused with one another; this is commonly used to discuss the role of visual features in pattern recognition.

Attention

The process of selectively allocating limited mental resources to information or tasks.

Selective attention

Focusing on one source of information while filtering out competing information.

Divided attention

Attempting to attend to and perform more than one task at the same time.

Sustained attention

Maintaining focus on a task or stimulus over an extended period.

Focused attention

Concentrating on one particular stimulus or task at a given moment.

Distributed attention

Allocating attention across multiple sources, locations, or aspects of a task; terminology may vary by course.

Allport's modular resource theory

A view that attention is not necessarily one single, fixed pool of resources; different tasks may use different processing systems, so interference depends on the overlap in resources they require.

Dichotic listening

A procedure in which different auditory messages are presented to the two ears, often to study selective attention.

Shadowing

Repeating aloud a message heard in one ear while ignoring a different message in the other ear.

Cocktail party effect

The ability to focus on one conversation in a noisy setting while sometimes noticing personally important information, such as one's name, from another conversation.

Stroop task

A task in which a person names the ink color of a word; responses are slower when the word meaning conflicts with the ink color, such as the word BLUE printed in red ink.

Emotional Stroop task

A variation of the Stroop task that measures whether emotionally significant words interfere with naming ink colors more than neutral words do.

Visual search

Searching a visual display for a target among distractors.

Feature-present/feature-absent effect

In visual search, finding a target defined by a distinctive feature may be faster when the target is present; when it is absent, the search may require checking more items. Exact effects depend on the display and task.

Isolated-feature vs. combined-feature search

A target defined by one distinctive feature (such as a red item among green items) is often found quickly and in parallel; a target defined by a combination of features may require slower, more focused attention.

Saccadic eye movement

A rapid jump of the eyes from one fixation point to another.

Fixation

A brief period when the eyes remain relatively still so visual information can be taken in.

Functions of attention

Attention helps select relevant information, prioritize processing, maintain goals, coordinate actions, and reduce interference from distractions.

Neurological correlates of attention

Attention depends on interacting brain networks, including frontal and parietal regions and systems that regulate alertness and orienting; specific tasks involve different networks.

Unilateral spatial neglect / hemineglect

A disorder, often after right-hemisphere damage, in which a person fails to attend to the side of space opposite the lesion, commonly the left side; the sensory systems may still function.

ADHD

Attention-deficit/hyperactivity disorder, a neurodevelopmental condition involving persistent patterns of inattention and/or hyperactivity-impulsivity that interfere with functioning.

Blindsight

The ability to respond to visual information without conscious visual awareness, often following damage to primary visual cortex.

Broadbent's early filter model

A theory proposing that attention selects information early based on physical characteristics, such as which ear a sound enters, before unattended information is fully processed for meaning.

Attenuation theory

Treisman's theory that unattended information is weakened rather than completely blocked, allowing important or highly activated information to reach awareness.

Late-selection theory

A theory proposing that much or all incoming information is processed for meaning before attention selects which information reaches awareness or controls a response.

Capacity/resource theory of attention

A view that people have limited mental resources, and performance suffers when tasks demand more resources than are available.

Problems with Broadbent's filter model

It cannot easily explain why some unattended information—such as a person's name—can still be noticed, suggesting unattended messages are not always completely blocked.

Illusory conjunction

An incorrect combination of features from different objects, such as reporting a red X when a red item and an X were shown separately; it can occur when attention is limited.

Binding problem

The question of how the brain combines separately processed features—such as color, shape, and location—into the experience of one unified object.

mindfullness

acting automatically or with little attention to the present situation, often relying on habirs or familar routines

What are the 3 theories of pattern recognition? Which theory has limitations?

Template matching: We recognize objects by comparing them to stored patterns in our memory.

Feature analysis: We recognize objects by identifying basic features, such as lines, edges, and curves.

Recognition by components: We recognize objects by identifying basic 3D shapes called geons and how they fit together.

Template matching has limitations because objects can look different depending on their size, angle, or appearance, making it difficult to match them to one exact template.

2. What are the perceptual confusion effect and word superiority effect? Which theory do they support?

The perceptual confusion effect occurs when people confuse similar-looking letters or patterns because they share visual features.

The word superiority effect occurs when people recognize a letter more accurately when it appears in a meaningful word than when it appears alone.

The perceptual confusion effect supports the importance of visual features in recognition, while the word superiority effect shows that context can help us recognize letters. Together, they demonstrate that both visual features and context influence pattern recognition.

3. Describe signal detection theory and give an example.

Signal detection theory explains how people decide whether a signal is present when sensory information is uncertain. Decisions depend on the available evidence and a person's expectations or decision criteria.

For example, a doctor screening for a disease must decide whether a test indicates that a patient has the disease.

There are four possible outcomes:

Hit: Correctly detects a signal that is present.

Miss: Fails to detect a signal that is present.

False alarm: Reports a signal that is not present.

Correct rejection: Correctly identifies that a signal is absent.

4. What is the difference between absolute and differential threshold? Give examples and name one type of subliminal message.

The absolute threshold is the minimum intensity at which a stimulus can be detected 50% of the time. For example, it could be the quietest sound I can hear in a silent room about half the time.

The differential threshold, also called the just noticeable difference, is the smallest difference between two stimuli that can be detected 50% of the time. For example, it could be the smallest amount of water I need to add to a bottle before I notice that it has become heavier.

A subliminal message is information presented below conscious awareness. One example is a visual message displayed so briefly that a person does not consciously notice it.

5. Explain the differences between the following.

A. Nonambiguous and perceptually ambiguous figures

A nonambiguous figure has one clear interpretation. A perceptually ambiguous figure can be interpreted in two or more ways.

For example, a drawing of a chair is usually nonambiguous, while the duck-rabbit image can be seen as either a duck or a rabbit.

B. Top-down and bottom-up processing

Top-down processing uses prior knowledge, expectations, and experiences to interpret information. For example, I can understand a sentence with a missing letter because I know the context.

Bottom-up processing starts with sensory information and builds toward recognition. For example, I identify an unfamiliar object by examining its shape, color, and edges.

C. Proximal and distal stimuli

A distal stimulus is the actual object in the environment. A proximal stimulus is the pattern of energy that reaches our sensory receptors.

For example, a dog across the room is the distal stimulus, while the image of the dog projected onto my retina is the proximal stimulus.

6. What is sustained attention? Describe it and give three examples of tasks that require it.

Example answer:

Sustained attention is the ability to maintain focus on a task or stimulus over an extended period.

Three examples are:

Driving: A driver must continuously monitor the road for hazards.

Taking an exam: A student must remain focused throughout the test.

Monitoring a security camera: A security worker must stay alert to notice important events.

These tasks require a person to maintain attention over time, even when tired or distracted.

7. What are the four theories of attention? Describe Broadbent's filter model, its characteristics, and its problems.

Four commonly discussed approaches to attention are Broadbent's early filter model, Treisman's attenuation theory, late-selection theory, and capacity/resource theories.

Broadbent's filter model proposes that attention selects information early in processing based on physical characteristics, such as which ear receives a message. Unattended information is filtered out before it is fully processed for meaning.

The model suggests that attention has a limited capacity.

One problem is that people sometimes notice meaningful information from unattended messages. For example, someone listening to one conversation may notice their name being mentioned in another conversation. This suggests that unattended information is not always completely blocked.

8. Which attention theory best explains attention? What are the disadvantages of late-selection theory?

No single theory explains every aspect of attention perfectly. Treisman's attenuation theory is useful because it explains how people can focus on one message while still noticing important information from another.

Late-selection theory proposes that information may be processed for meaning before attention determines which information reaches awareness or guides a response.

One disadvantage is that processing all incoming information for meaning could require too many mental resources. It also does not fully explain why unattended information is often poorly remembered.

9. Explain the differences between the following.

A. Sustained and divided attention

Sustained attention means maintaining focus on a task over time, such as monitoring a security camera.

Divided attention means trying to pay attention to multiple tasks at once, such as listening to a lecture while texting.

The main difference is that sustained attention involves maintaining focus over time, while divided attention involves sharing attention across tasks.

B. Focused and distributed attention

Focused attention involves concentrating on one particular stimulus or task. For example, reading a textbook carefully requires focused attention.

Distributed attention involves spreading attention across multiple stimuli, locations, or aspects of a task. For example, scanning a room to locate several people requires attention to multiple locations.

Question 9 continued

C. Unilateral spatial neglect and blindsight

Unilateral spatial neglect, or hemineglect, occurs when a person fails to attend to one side of space, often after damage to the right hemisphere of the brain. For example, a person might eat food only from the right side of a plate.

Blindsight occurs when a person can respond to visual information without consciously seeing it, often following damage to the primary visual cortex.

The main difference is that neglect involves difficulty attending to one side of space, while blindsight involves responding to visual information without conscious visual awareness.

D. Stroop task and emotional Stroop task

The Stroop task measures interference between word meaning and ink color. For example, the word BLUE printed in red ink can make it harder to name the ink color.

The emotional Stroop task examines whether emotionally meaningful words interfere with naming ink colors. For example, an anxiety-related word may slow a person's response compared with a neutral word.

The standard Stroop task examines interference from word meaning, while the emotional Stroop task examines interference from emotional content.