Unit 1

What Is Cognitive Psychology?

Example Scenario:

You’re walking along a dark, unfamiliar city street. It’s raining and foggy, and you are cold and a bit apprehensive. As you walk past a small alley, you catch some movement out of the corner of your eye. You turn to look down the alley and start to make out a shape coming toward you. As the shape draws nearer, you are able to make out more features, and you realize that it’s...

^Cognitive psychology aims to understand this kind of complex mental processing

• the branch of psychology that is concerned with how people acquire, store, transform, use, and communicate information

• study of mental processes by which humans learn about and interact with the world

Specific Topics

• perception

• attention

• memory

• language

• problem-solving

• planning

influences on cognitive psychology:

philosophical antecedents

• philosophical influences on the study of cognition

  • empiricism vs. nativism

  • nurture vs. nature

• ENVIRONMENT/EXPERIENCES

  • Aristotle

  • Locke

    • “blank slate”

• HEREDITY & BIOLOGY

  • Descartes

  • Plato

psychological antecedents

• Wilhelm Wundt (1832-1920)

  • structuralism

  • introspection

    

• William James (1842-1910)

  • Principles of Psychology (1890)

  • functionalism

• Hermann von Ebbinghaus (1850-1909)

  • experimental observation

• Sigmund Freud (1856-1939)

  • subconscious

• Karl Popper (1902-1994)

  • philosopher of science

  • falsifiability

    • can make progress by disproving theories as well as proving theories

• Gestalt Psychology

  • the whole is greater than the sum of the parts

    

behaviorism

• Ivan Pavlov (1849-1936)

  • classical conditioning

• Thorndike (1874-1949)

  • instrumental/operant conditioning

  • reinforcement, punishment

• behaviorism takes over American psychology

  • mental processes unobservable

    • should simply describe the relationship between stimuli and responses

  • introspection rejected

  • concepts such as ID, Ego, and Superego rejected as untestable fantasies

• John Broadus Watson (1878-1958)

  • radical behaviorism

• Burhus Frederic Skinner (1904-1990)

  • continues to push for “radical behaviorism”

  • all behavior (even language) is the result of classical and instrumental/operant conditioning

  • “verbal behavior” (1957)

• the decline of behaviorism

  • other science requires unobservable theoretical entities (atoms, genes, gravity)

  • still passes Popper’s test

    • Edward C. Tolman (1886-1959)

      • internal representations

      • cognitive maps

    • Noam Chomsky (1928-)

      • refutes Skinner’s attempts to explain language in “verbal behavior”

      • critique (1959) had big impact on behaviorism

the post-war context

• developments during and after war

  • engineering

    • idea of humans as information processors

  • thinking as computation

    • development of computers made concept of thinking-as-computation more plausible

  • artificial intelligence

    • computers’ ability to do “smart” things (chess)

    • thinking-as-computation even more plausible

early cognitive psychology

• late 1950s, early 1960s

• “computer metaphor” is psychology

  • one type of information processing approach

    • consequences

      • architecture of mind

      • seperate systems

        • how large

      • sequences of steps during cognitive processing

      • format of information

      • parts of a task

        • how quickly performed

• “information processing” approach

  • subtypes

• 1967: first textbook

  • Cognitive Psychology by Ulric Neisser

cognitive science

• intersection of several disciplines including:

  • psychology

  • linguistics

  • philosophy

  • computer science

• computer simulation

neuroscience

• aim:

  • integrate cognitive science, neuroimaging, neuropsychology

• computer metaphor gradually losing favor

• “network metaphor”

cognitive psychology today

• increasing emphasis on:

  • formal models

  • neuroscience

  • fine-grained measures

  • statistical analyses

• still information processing approach

• “network” metaphor > computer metaphor

neural information processing and learning

• information transmission in the brain

• neural basis of learning

  

information transmission

1. presynaptic action potential

2. neurotransmitter release

3. neurotransmitter binding

4. ion flow

5. postsynaptic potential

6. excitatory postsynaptic potential may - action potential (spike)

7. inhibitory postsynaptic potential may - prevent spike

information flow

• basis of all cognitive (and non-cognitive) processing

• determined by synaptic strengths between neurons

changing information flow

• change synaptic strengths

• synaptic modification

if based on experience

• learning

the consequence

• next time- postsynaptic action potential more likely

• long-term change in response

• learning

• “long-term potentiation”

brain structures and cognitive processing

major divisions of the brain

• brainstem

  • hindbrain

    • rhombencephalon

      • medulla

      • pons

      • cerebellum

  • midbrain

    • mesencephalon

      • tectum

      • tegmentum

      • reticular formation

• forebrain

  • prosencephalon

    • basal ganglia

    • limbic system

      • thalamus

      • hypothalamus

    • cerebral cortex/neocortex

Methods for Linking Brain & Cognition

A. Brain Imaging

B. Neuropsychology

A. BRAIN IMAGING

Brain Imaging Techniques

• Electrical Activity in the Brain

• Functional Brain Imaging

ELECTRICAL ACTIVITY

Single-Unit Recording

• Focuses on action potentials from individual neurons

• Includes components:

  • Display

  • Electrode

  • Stimulus

  • Electrical Signal from Brain

Overview of Brain Imaging Methods

• Examines electrical activity in the context of single-unit recording.

From Stimulus to Response

• Process Flow: External World → Stimulus → Response

• Involves:

  • Sensory Relay Nuclei

    • Thalamus

  • Receptors

  • Primary Sensory Areas

  • Secondary Sensory Areas

  • Primary Motor Cortex

  • Association Cortex

  • Motor Neurons

Single-Unit Recording Details

• Examines particular processing within tiny brain regions,

• Contrasts with multiunit techniques that look at properties of multiple cells.

Learning Check

• Single-cell recording enables understanding the response properties of:

  • C. One or a relatively small number of neurons at a time

The Electroencephalogram (EEG)

• Utilizes scalp electrodes to record voltage fluctuations.

Characteristics of EEG

• Not specific to individual neurons;

• Records waves generated by neurons;

• Weaker signals diminish with distance;

• Multiple electrodes help triangulate locations;

• Characteristic wave patterns identified.

Learning Check

• Which statement is INCORRECT?

  • B. The invasiveness of EEG recording techniques is the same as that of single and multi-unit recording techniques.

Event-Related Potentials (ERPs)

Overview

• Patterns of EEG triggered by a stimulus

• Embedded within the overall EEG

Example of ERP

• P1, N1, P2, N2, P3

• Fluctuations illustrated in an averaged ERP waveform.

Single Unit Recording vs. ERP

• Single-Unit Recording: Insight into inner workings, individual neurons' responses.

• ERP: Aggregated data, equivalent to crowd noise within a stadium.

ERP Study

Example: Processing Emotion Words

• Kissler et al. (2007) study on emotional word responses

• High emotional words trigger greater responses 200-300 ms in left occipito-temporal areas.

FUNCTIONAL BRAIN IMAGING

Functional Brain Imaging Key Ideas - 1

• Increased brain activity correlates with:

  • Higher oxygen utilization in blood,

  • Greater changes in blood oxygen content.

Functional Brain Imaging Key Ideas - 2

• Methods:

  • fMRI: Detects magnetic properties of blood

  • fNIRS: Tracks optical properties of blood

Functional Brain Imaging Key Ideas - Summary

• Measures variations in brain activity through blood flow.

Functional Magnetic Resonance Imaging (fMRI)

Description

• Relies on the magnetic properties of oxygenated/deoxygenated hemoglobin in blood.

Functional Near-Infrared Spectroscopy (fNIRS)

• Based on optical properties of blood's hemoglobin.

Comparing ERPs with fMRI/fNIRS

• ERP: Excellent temporal resolution; poor spatial resolution.

• fMRI: Good spatial resolution; poor temporal resolution.

• fNIRS: Similar to ERP in pros and cons.

Learning Check

• fMRI and fNIRS enable imaging of:

  • B. Blood oxygen changes in the brain.

Learning Check

• Which statement is CORRECT?

  • E. fMRI and fNIRS both utilize differences in the properties of oxygenated vs deoxygenated blood flow.

B. NEUROPSYCHOLOGY

Neuropsychology Overview

• Study of cognitive processing in patients with brain injuries or deteriorations.

Causes of Brain Injury/Deterioration

• Conditions Leading to Brain Damage:

  • Blood flow reduction

  • Cerebrovascular disorders/strokes

  • Head injuries

  • Tumors

  • Infections

  • Degenerative disorders

First Neuropsychological Finding

• 1861 Discovery by Paul Broca:

  • Left frontal damage linked to speech impairment: Broca’s aphasia (expressive aphasia), characterized by halting and effortful speech.

Broca's Area

• Identified location linked to speech production responsibilities.

Wernicke’s Aphasia

• 1874 Discovery by Carl Wernicke:

  • Damage in the temporal lobe affecting comprehension, resulting in fluent yet nonsensical speech (receptive aphasia).

Importance of Broca and Wernicke

• Pioneered studies on language-brain-behavior relations and revealed cognitive consequences of brain lesions.

Other Neuropsychological Examples

• Spatial Cognition: Right parietal lobe injury disrupts visual-spatial tasks.

• Memory: Hippocampal injury alters specific memory types.

Methods for Linking Brain & Cognition

• A. Brain Imaging

• B. Neuropsychology

Sensation vs. Perception

• Sensation: The process of receiving external stimuli through sensory receptors.

• Perception: The cognitive process of interpreting what is sensed, allowing us to understand our environment. This process builds upon the sensory input and elaborates it into a comprehensive interpretation.

Constructivist vs. Ecological Views

• Constructivist View: Proposes that perception is constructed through cognitive processes, emphasizing the role of mental interpretation and context.

• Ecological View: Suggests that perception is inherently linked to a rich environmental structure that can be processed directly, with both traditional (direct perception with no mental processing) and modern (involving cognitive complexity) perspectives.

Neural Bases of Visual Perception

Structure of the Eye

• Light enters through the cornea, passes through the pupil (controlled by the iris), and is focused by the lens onto the retina.

• The retina contains photoreceptors that convert light into neural signals: cones (for color and detail, primarily located in the fovea) and rods (sensitive to light and motion but color-blind, located in the periphery)

Visual Pathway from Retina to Cortex

1. Optic Nerve: Transmits visual information from the retina.

2. Thalamus: Acts as a relay station for sensory information before reaching the cortex.

3. Primary Visual Cortex (V1): Located in the occipital lobe, responsible for initial visual processing.

4. Secondary Cortical Areas: Further processing occurs in areas associated with visual perception, with parallel processing pathways identified as the:

   • Occipital-Parietal Pathway (where): Involved in spatial processing.

   • Occipital-Temporal Pathway (what): Involved in object recognition.

Organizing the Visual Scene into Objects

1. Perceptual Grouping

• The challenge of organizing visual stimuli into distinct objects involves understanding which elements group together and which do not.

• Gestalt Principles: Provide rules on how objects are perceived together, emphasizing higher-level organizational principles:

  • Pragnanz (Simplicity): Visual inputs are interpreted in the simplest way.

  • Similarity: Objects that are similar tend to be grouped together.

  • Parallelism & Symmetry: Shapes that are parallel or symmetrical are likely seen as part of the same object.

  • Proximity: Closer objects are seen as forming a group.

  • Common Fate: Objects moving in the same direction are grouped.

2. Figure-Ground Organization

• This involves segregating a visual scene into a foreground (figure) and background (ground).

• Factors that influence figure-ground assignment include geometric cues such as size, symmetry, and familiarity.

Conclusion

Understanding perception involves unpacking both the physiological foundations and the cognitive processes that allow us to make sense of sensory information. The interplay between sensation and perception, combined with our environment's richness, creates our perception of the world around us.

MODULE 3: PERCEPTION

PART 2

D. VISUAL OBJECT RECOGNITION

Visual object recognition is a fundamental process whereby sensory input is linked to representations stored in memory. The recognition process is complex and there isn’t a definitive single theory that accounts for how we recognize objects; instead, several theories have been proposed to explain this phenomenon.

Theories of Visual Object Recognition

1. Template Matching

   • Proposes that the brain compares incoming sensory information to templates stored in memory, looking for a precise match.

2. Structural-Description Theories

   • Objects are represented abstractly in terms of their parts and the spatial relations among those parts. Recognition involves creating a structural description of the input and comparing it with existing memory representations.

3. Feature Analysis/Detection Theories

   • Focus on the identification of distinct features within a visual input and the comparison of these features with stored descriptions in memory.

4. Recognition-by-Components

   • Developed by Irving Biederman, this theory suggests that objects are recognized by the geons (geometric icons) that make them up.

5. View-Based Theories

   • These theories assert that object recognition is dependent on specific views or perspectives of an object, with multiple angles stored in memory for comparison.

Template Example in Object Recognition

Examples illustrate how different templates may correlate with various objects. For instance:

• A strong correlation (100%) means an exact match with stored templates, while a weak correlation (30%) indicates a lesser similarity.

Structural-Description Theories in Detail

• Recognition involves forming a structural description and comparing it with memory to identify the possible parts of the object and how they can be recognized.

• Different theories propose different sets of parts that can complicate recognition.

Featural Analysis in Object Recognition

• This approach analyzes incoming visual images by breaking them down into features, which are then compared with stored descriptions. For example, components like vertical and horizontal lines can help define objects.

Recognition-By-Components Theory

• This is a renowned structural description theory that suggests we identify objects based on their components known as geons. Geons are simple geometric shapes that serve as the building blocks of objects.

Types of Geons

Some commonly identified geons include:

• Wedges

• Bricks

• Cubes

• Cylinders

• ConesThese shapes possess significant properties that aid in object recognition.

Properties of Geons

1. Viewpoint Invariance

   • Geons remain recognizable from various angles and are sturdy against visual noise.

2. Robustness to Occlusion

   • Geons can still be recognized even when partially obscured. For instance, concave regions are critical cues for identifying an object.

3. Discriminability

   • This is associated with nonaccidental properties that remain consistent despite changes in the viewpoint. Examples include specific edges, vertices, and parallel lines that help in object identification.

Human and Animal Recognition Studies

Research comparing nonaccidental properties in humans and pigeons reveals that structural cueing plays a critical role across different species, showing the biological basis of visual recognition capabilities.

Stages in Recognition-by-Components Theory

• Detection of Nonaccidental Properties

• Edge Extraction

• Determination of Components

• Parsing at Regions of Concavity

• Matching of Components to Object Representations

• Object IdentificationThese stages highlight the cognitive processes involved in perceiving and identifying objects.

Challenges of Structural Description Accounts

Structural description theories may face challenges, such as instances where the same object's representation differs dramatically depending on the viewpoint (e.g., a book vs. a cigar box).

View-Based Theories

• While geons are significant, recognition can also be highly viewpoint-dependent. It’s suggested that the brain may store only a few specific views of an object and utilizes mental rotation to comprehend them from different angles.

Example of View-Based Theories

The example provided by Yanagi illustrates performance in categorizing objects based on specific views and size comparisons.

Summary

Visual recognition is enshrined in the debate between structural-description theories, like recognition-by-components, and view-based theories. Each approach sheds light on different aspects of perception, and ongoing discourse continues to explore newer models that integrate ecological and constructivist perspectives. This discourse emphasizes the rich details within stimuli and the capacity for learning from diverse exposures, aided by complex neural network models.