Lecture 3: Perception & Attention

A set of vocabulary flashcards derived from the lecture on perception and attention in cognitive psychology.

Psychophysics

The study of the relationship between physical stimuli and perceptual experience.

Physical vs Perceived Magnitude

Relationship between objective stimulus intensity (e.g., lumens) and subjective experience (e.g., brightness).

Weber’s Law

The smallest detectable change in a stimulus is proportional to the original stimulus intensity.

Just Noticeable Difference (JND)

The minimum difference between two stimuli that can be detected.

Fechner’s Law

Perceived intensity increases logarithmically with actual stimulus intensity.

Weber-Fechner Law

Combines Weber’s and Fechner’s laws to describe perception as a logarithmic function of stimulus intensity.

Stevens’ Power Law

Perceived intensity is a power function of stimulus intensity, varying across sensory modalities.

Sensation

The encoding of physical stimulus properties by the nervous system.

Perception

The interpretation and processing of sensory input into meaningful information.

Direct Perception

The idea that perception comes directly from sensory input without need for interpretation.

Constructive Perception

The idea that perception involves mental interpretation and inference.

Affordances

Features of objects that suggest how they can be used (e.g., a handle invites pulling).

Stimulus Ambiguity

The idea that sensory input is often unclear and requires interpretation.

Unconscious Inference

The brain’s automatic interpretation of ambiguous stimuli.

Perceptual Illusions

Cases where perception differs from physical reality, showing interpretation processes.

Bistable Stimuli

Stimuli that can be perceived in two different ways (e.g., Necker cube).

Bottom-up Processing

Perception driven by sensory input.

Top-down Processing

Perception influenced by knowledge, expectations, and context.

Depth Perception

The ability to perceive distance and three-dimensional structure.

Occlusion

A depth cue where closer objects block farther ones.

Linear Perspective

Parallel lines appear to converge in the distance.

Motion Parallax

Closer objects move faster across visual field than distant ones.

Binocular Disparity

Depth cue based on differences between images from each eye.

Object Identification

The process of recognizing objects.

Classification

The process of grouping objects into categories.

Context Effects

Recognition is influenced by surrounding context.

Perceptual Representation

Internal representation of objects that allows recognition across variations.

Invariant Features

Features that remain constant across different views of an object.

Attention

The process of focusing cognitive resources on specific stimuli or tasks.

Overt Attention

Directing sensory organs toward a stimulus (e.g., eye movements).

Covert Attention

Attending to something without moving sensory organs.

Endogenous Attention

Voluntary, goal-directed attention (top-down).

Exogenous Attention

Involuntary attention driven by external stimuli (bottom-up).

Cocktail Party Effect

The ability to focus on one conversation while filtering out others.

Selective Attention

The ability to focus on some stimuli while ignoring others.

Cognitive Limitations

The brain cannot process all incoming information simultaneously.

Dichotic Listening Task

A task where different messages are presented to each ear.

Shadowing

Repeating one message while ignoring another.

Dichotic Listening Result

Little information from unattended ear is retained (except basic features like voice).

Broadbent’s Filter Model

Early selection model where unattended information is filtered out before semantic processing.

Early Selection

Filtering occurs before meaning is processed.

Breakthrough Stimuli

Important stimuli (e.g., your name) can bypass attentional filters.

Late Selection Model

All stimuli are processed for meaning before selection occurs.

Attenuator Model (Treisman)

Unattended information is weakened (not blocked) and may still be processed.

Dictionary Unit

A component that processes word meanings with varying thresholds.

McKay (1973) Study

Context from unattended ear influences interpretation, supporting attenuation.

Attention as a Resource

Attention is limited and must be distributed across tasks.

Attentional Load

The amount of cognitive resources required for a task.

Attentional Load Theory

High-load tasks reduce processing of irrelevant stimuli; low-load tasks allow distraction.

Flanker Task

A task where target stimuli are surrounded by distracting stimuli.

Congruent Trials

Flankers match the target response.

Incongruent Trials

Flankers conflict with the target response.

Flanker Effect

Slower responses when flankers are incompatible with the target.

Lavie (1995) Finding

Distraction occurs mainly under low attentional load.

Automatic Processing

Processes that occur without conscious effort or attention (e.g., reading).

Divided Attention

Trying to focus on multiple tasks simultaneously.

Divided Attention Effect

Performance typically decreases when attention is split.

Posner Cueing Task

A task measuring how attention shifts to spatial locations.

Valid Cue

A cue correctly indicates target location.

Invalid Cue

A cue incorrectly indicates target location.

Posner Finding

Responses are faster for valid cues, supporting attention as a 'spotlight.'

Spotlight Model of Attention

Attention enhances processing at a specific location.

Visual Search

The process of finding a target among distractors.

Feature Search

Target differs by one feature; fast and automatic.

Conjunction Search

Target defined by multiple features; slower and attention-demanding.

Interparietal Sulcus

Brain region involved in controlling attention.

MT (Middle Temporal Area)

Brain region involved in motion processing.

Balint’s Syndrome

A disorder impairing ability to perceive multiple objects simultaneously.

Simultanagnosia

Inability to perceive entire scenes, only individual elements.

Hemispheric Neglect

A disorder where patients ignore one side of space.

Right Parietal Damage

Causes neglect of the left visual field.

Asymmetry of Neglect

Left parietal damage typically does not cause right neglect.

ADHD

A neurodevelopmental disorder involving inattention, hyperactivity, and impulsivity.

ADHD Brain Activity

Increased frontal/parietal activity may compensate for reduced basal ganglia activity.

Autism Spectrum Disorder (ASD)

A condition involving differences in attention and perception.

ASD Attention Pattern

Individuals may focus on different features (e.g., faces) compared to controls.