Cognitive Psychology Notes

Study of Cognition

The study of cognition aims to understand the workings of the human mind. This is often achieved by:

  • Studying human behavior using experimental methods.
  • Computational modeling.
  • Neuroscience.
  • Neuropsychological/patient data.

Cognitive psychology relies on:

  • Observable human data.
  • Making inferences about what’s not observable about the human mind.
  • Using logic to support arguments.

The goal is to understand major theories of cognitive processes. Cognitive psychology operates on theories supported or refuted by data, rather than axioms.

Cognitive Processes Diagram

The diagram illustrates the flow of information and cognitive processes:

  • Sensory System: Receives input from the environment.
  • Pattern Recognition: Identifies patterns in sensory input.
  • Attention: Selects and focuses on relevant information.
  • Working Memory: Holds and manipulates information temporarily.
  • Permanent Memory: Stores long-term knowledge.
    • Declarative Memory:
      • Semantic Knowledge: General world knowledge.
      • Episodic Knowledge: Personal experiences.
    • Procedural Memory: Skills and habits.
  • Linguistic Knowledge: Language abilities.
  • Central Processor: Higher-level cognitive functions.
    • Reasoning and Problem Solving: Cognitive processes for decision-making.
    • Immediate Goals: Current objectives.
  • Responses: Mental, vocal, or physical actions.

Focused Auditory Attention

Attention is limited. Therefore, the brain selects certain aspects of the environment to focus on.

Focused Auditory Attention:

  • Studies of auditory selective attention:
    • Dichotic listening task.
    • Findings by Cherry, Moray (“Cocktail party effect”).
  • Bottleneck models:
    • Broadbent’s filter model.
    • Treisman’s attenuation model.
    • Deutsch & Deutsch’s late selection model.
  • Early vs. late selection:
    • Findings by Treisman & Riley.
    • Flexible bottleneck.
      • Findings by Johnston & Wilson.

Dichotic Listening Task

  • Focus on only one stimulus.
  • Cherry’s experiment:
    • The person ignores the messages in the background (dichotic messages).
    • The participant is asked to repeat the relevant message (shadowing).
  • Participants were able to report physical characteristics (if it was male/female, soft/loud, high/low voice) and also their names (identification paradox, cocktail party problem).
  • Participants were not able to report the meaning.
    • Did not notice when it changed to foreign speech or when it was reversed.

Bottleneck Models

Due to the limited capacity of Short Term Memory, there is a bottleneck created from a lot of sensory input.

  • Different models explain where and how the bottleneck occurs.
  • The flow of information is unidirectional.
  • Broadbent’s model can’t explain the cocktail party effect, while Treisman’s and Deutsch’s can.
  • Physical characteristics demand less attentional capacity.
  • Meaning (semantic) demands more attentional capacity.
  • Selection occurs as early in processing stages as possible to minimize attentional demands.

Broadbent's Filter Theory

  • The selective filter protects Short-Term Memory from being overloaded.
  • The sensory register has a large capacity.
  • Semantic processing occurs when the input remains in Short-Term Memory.
  • Only physical characteristics will remain in short-term memory (high/low pitch, male or female voice, loud or soft, etc.).

Treisman's Attenuation Theory

  • Attenuator: Processing is turned down, not turned off.
  • Depending on the context (top-down processing) you select the information you’ll be aware of.
  • Your name has a low threshold of attention.
  • Words related to food have a low threshold of attention in the context of a picnic, even if it’s on the unattended ear.

Deutsch and Deutsch's Theory

  • The bottleneck occurs later.
  • The attenuator or filter is redundant.
  • Physical and semantic information is analyzed even if it’s unattended.

Experiments to Determine the Correct Model

Early vs. Late Selection (Treisman & Riley’s experiment)
  • Subjects were presented with two messages to two ears.
  • Shadowed one message.
  • At the same time, made a tapping response to a target word in either message (e.g., LIFE).
  • Results:
    • Attenuation model works.
    • Target detection was worse in the nonshadowed message.
    • Target detection 87%87\% in shadowed message; 8%8\% in non-shadowed message.
  • Deutsch & Deutsch countered that the shadowed message was more important because it required two responses (shadowing + tapping) --> It is late selection model.
Johnston & Heinz (1978)
  • Proposed that the location of bottleneck is flexible (it may be early or late).
  • Unattended message is not always processed fully to the level of meaning.
Johnston & Wilson’s (1980) experiment
  • Subjects were presented with a list of words dichotically.
  • Instructed to detect a target = member of a semantic category (e.g., musical instrument) in either ear: e.g., PIANO, GUITAR, TRUMPET, etc.
  • “Non-target” = Word presented coincidentally with target e.g., button – PIANO.
  • The target is defined only in terms of the broad semantic category that it belongs to.
  • Critical targets = Words with ambiguous meaning:
    • Example: “Organ” can be an instrument and also not.
      • Appropriate: church-ORGAN (musical instrument).
      • Neutral: paper-ORGAN.
      • Inappropriate: kidney-ORGAN.
  • 2 conditions for the experiment:
    • Focused attention condition: Subjects told which ear targets would arrive.
    • Divided attention condition: Subjects did not know which ear targets would arrive.
  • Results:
    • For focused attention condition there was no meaning processing from the ear ignored.
    • In the Focused attention: No effect of type of non-target on target detection --> non-targets were NOT processed to the level of meaning.
    • In the Divided attention: target detection: Appropriate > Neutral > Inappropriate --> non-targets were processed to the level of meaning.
    • Meaning (of non-target) was processed (late selection) when attention was divided over two ears but not when attention was focused on the other ear (early gating).

Divided Attention

Dual Task Performance and Automaticity

Dual task performance:

  • Similarity of modality affects whether you can do two things well together.
    • Driving & listening to music - compatible.
    • Driving & writing a text message - incompatible.
  • The more different the tasks, the easier to do both.

Automaticity

Automaticity – Well-practiced.

  • With practice the task becomes automatic.
  • Inflexible.
  • Unavoidable (occur without intention).
  • Unavailable (unconscious events can drive an automatic process).
  • Automatic processes are fast.
    • They require one-step retrieval of solutions from memory.
    • They require little attentional capacity because retrieval of over-learned information is effortless.

Shiffrin & Schneider’s Memory Search Experiment

  • Subjects memorize 1, 2, 3 or 4 targets on the memory set.
  • Subjects are shown a display containing 1, 2, 3 or 4 items on the display set.
  • Respond as quickly as possible whether the display contained a target from the memory set.
Conditions:
  1. Consistent mapping (CM) condition:
    • Target set and distractor set do not overlap from trial to trial e.g.
      • Memory set: (always) numbers.
      • Distractors: (always) consonant letters.
  2. Varied mapping (VM) condition:
    • Target on one trial may be a distractor in the next trial (and vice versa), e.g.
      • Memory set: numbers.
      • Distractors: consonant letters and numbers.
Results:
  • Following extensive training with Consistent mapping (CM):
    • RT does not increase with set size = parallel search --> Does not consume attentional capacity.
  • Varied mapping (VM):
    • RT increases with set size = serial search.
    • CM training led to automatic processes (Does not require attentional capacity).

Inflexible Automatic Responses: The Stroop Effect

  • Demonstrates the failure of selective attention (we can’t selectively attend to the color and ignore the word).
  • Word reading interferes with colour naming.
  • Demonstrates the automaticity of word reading: Unavoidable/obligatory. You have years of experience reading English words.

How does automaticity develop with practice?

  • Automaticity is associated with gradual reduction in the use of attentional resources.
    • Shiffrin & Schneider: Extended practice with consistent mapping resulted in parallel search pattern (absence of set size effect).
    • But Shiffrin & Schneider’s experiment doesn’t tell us how automaticity develops.

Logan’s Instance Theory

  • “Automaticity is memory retrieval”.
  • Instance representation: Each encounter with a stimulus is encoded, stored and retrieved separately as a memory episode.
  • With practice, performance becomes automatic when it is based on a single-step direct-access retrieval of solution from a memory episode, rather than application of rules or algorithm which is time- consuming.
  • Similar to learning the multiplication table:
    • Initially, an algorithm is applied e.g., 3∗4=3+3+3+33*4=3+3+3+3.
    • With the learning of the multiplication table, the solution is retrieved directly from memory e.g., “3 * 4 = 12”.