1. Cognitive psych 1

Cognitive Psychology Overview

Definition and Scope

Cognitive psychology is a branch of psychology focused on understanding human cognition. This includes observing how people engage in cognitive tasks and the underlying processes of the mind. Cognitive psychology intersects with cognitive neuroscience, which aims to comprehend human cognition by combining behavioral observations with brain activity insights.

Key Concepts

1. Cognitive Neuroscience: Combines behavioral data and brain imaging to understand cognition.

2. Cognitive Psychology: Primarily concentrates on observing behavior during cognitive tasks. This includes an understanding of the brain's structure and function.

Historical Context

Behavioral Paradigm

• Behaviorism: Emphasized observable behaviors and dismissed internal mental states, pioneered by Watson in 1913.

• Cognitive Revolution: Emerged in the mid-20th century, marked by a shift toward understanding mental processes. Key contributors included:

  • Tolman (1948): Proposed "cognitive maps".

  • Chomsky (1956): Introduced the concept of universal grammar in language.

  • Miller: Suggested the "magic number 7" for short-term memory capacity.

  • Alan Newell & Herbert Simon: Developed the theory of human problem-solving.

  • Bruner et al.: Focused on human concept formation.

Information Processing Model

Insights into Processing

• The information processing model likens the mind to a computer, indicating key distinctions between cognitive processes:

  • Bottom-Up Processing: Begins with sensory input leading to perception.

  • Top-Down Processing: Involves perceptual organization influenced by prior knowledge.

  • Parallel Processing: Multiple cognitive processes occur simultaneously.

  • Cascade Processing: Information flows in multiple stages, influencing one another.

Cognitive Tasks and Challenges

Task Impurity Problem

• This concept pertains to the methodological challenges in cognitive psychology:

  • Using various tasks like Stop-signal task and Stroop task to measure cognitive processes can lead to ambiguous results regarding what precisely is being assessed.

Limitations and Validity

1. Ecological Validity: Concerns over how well findings from lab experiments translate into real-world settings.

2. Experimenter Bias: Issues surrounding manipulation and control in experimental conditions can compromise results.

3. Paradigm Specificity and Replication Crisis: Calls for replicability in psychological studies have raised awareness of the need for standardized methodologies.

Key Themes in Perception

Understanding Perception

Perception refers to the process by which sensory stimuli are integrated and interpreted, resulting in conscious experience. The importance of perception lies not only in practical applications, such as aiding in medical fields or enhancing technology designed for the disabled, but also in our curiosity about how we interpret the world around us.

Sensory Processes

• Sensation: The initial stage where sensory organs detect raw stimuli.

• Perception: The interpretation of these raw experiences into meaningful understandings, involving active organization and categorization of sensory data.

Neural Mechanisms of Perception

• The journey begins with sensory receptors absorbing energy from environmental stimuli (e.g., light and sound) and converting it into neural impulses for processing by the brain. This neural processing is critical for forming cohesive perceptual experiences.

• The stimulation travels through visual pathways, where neural signals relay to relevant areas of the brain, such as the occipital lobes, responsible for visual processing.

Advanced Perceptual Processes

Steps in Perception

1. Stimulus: External stimuli that prompt sensory reception.

2. Receptor Processes: Sensory transduction wherein stimuli are converted to electrical signals.

3. Neural Processing: The transformation of these signals as they propagate through neural circuits, enabling interpretation.

4. Action: Behavioral responses based on recognition and interpretation of stimuli.

Dynamic Interaction

• The processing of perception involves continual interaction with existing knowledge, expectations, and memory, indicating that perception is not purely reflexive but also shaped by cognitive frameworks.

Measuring Perception

Absolute Thresholds and Just Noticeable Differences

• Absolute Threshold: The minimum intensity at which a stimulus can be detected.

• Difference Threshold (DL): The minimum detectable difference between two stimuli, adhering to Weber's law, which posits this difference is a constant proportion of the original stimulus intensity.

Psychophysical Methods

• Method of Limits: Stimuli presented in ascending/descending intensity until detection threshold reaches crossover point.

• Method of Adjustments: The intensity is continuously adjusted by the observer until detection occurs.

• Method of Constant Stimuli: A range of stimuli intensities presented randomly, averaging detection threshold across multiple trials.

Signal Detection Theory

• This theory assesses perceptual sensitivity and response bias by examining the observer's detections (hits vs. false alarms) across different stimulus conditions, providing insight into cognitive processing under uncertainty.