THE COGNITIVE APPROACH TYPES OF PROCESSING

Adapted from http://psiexp.ss.udi.edu by E.Day

Areas of Study

 Cognition is about internal processes that are often unobservable , e.g.: Perception, Attention, Memory, Visual Imagery, Language, Concept Learning, Reasoning

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 Need converging evidence from different perspectives to really understand cognitive processes Adapted from http://psiexp.ss.udi.edu by E.Day

Information Processing

 Information processing models resemble processing in computers – made cognitive psychology popular  Information made available by the environment is processed by a series of processing systems  Processing system is a set of processes that work together to accomplish a type of task, using and producing representations as appropriate  The major goal of research is to specify these processes and representations Adapted from http://psiexp.ss.udi.edu by E.Day

Types of Processing

 Bottom-up processing. Processing directly affected by the stimulus input is usually described as stimulus-driven or bottom-up processing.  Top-down processing Processing. expectations

processing.

. Processing is influenced by past experience and

These influences constitute top-down or conceptually driven

Adapted from http://psiexp.ss.udi.edu by E.Day

Types of Processing



Serial processing

In serial processing, it is argues that each cognitive process is accessed in turn. (i.e. one process is completed before the next starts) 

Parallel processing

A very different possibility is that some or all of the processes involved in a cognitive task occur at the same time. This is known as parallel processing. 

Parallel Distributed Processing (PDP)

parallel processing is the idea that these processes operate simultaneously but One problem with distributed processing (PDP), cognitive processes operate at the same time and connections final outcome. This approach is also referred to as

Connectionism.

independently of each other. In parallel between them also influence the Adapted from http://psiexp.ss.udi.edu by E.Day

Bottom Up Processing

: An early version of the information processing approach  purely

bottom up

or stimulus driven Adapted from http://psiexp.ss.udi.edu by E.Day

A Demonstration of Top-Down Processing

Adapted from http://psiexp.ss.udi.edu by E.Day

Top-down processing: perception affected by knowledge of world Why do we seem to have a fairly robust interpretation of which shapes are concave and convex when the perceptual information is perfectly ambiguous? -> perception affected by knowledge Adapted from http://psiexp.ss.udi.edu by E.Day

(Kleffner & Ramachandran, ’92)

Sound Induced Illusory Flashes

 Example of parallel and interactive processing : visual perception affected by auditory perception  http://www.cns.atr.jp/~kmtn/soundIndu cedIllusoryFlash2/ Adapted from http://psiexp.ss.udi.edu by E.Day

Top-down processing Later stages of processing affect earlier stages  can explain effects of Knowledge, memory, expectations and context Adapted from http://psiexp.ss.udi.edu by E.Day

Serial, Parallel and PDP Processing

  To illustrate the differences between serial, parallel and parallel distributed processing, consider the Sternberg task  Goal: what steps are involved in comparing information to memory? How long do these steps take?

Task:  give subjects memory sets. E.g. 3 9 7   Probe memory with targets and foil digits: 9 = “yes”, 6=“no”. Measure reaction time. Vary the size of these memory sets Adapted from http://psiexp.ss.udi.edu by E.Day

Typical Sternberg Results

 Plot reaction time as function of memory set size and type of trial (targets/foils)  What are the implications of seeing a linear increase in reaction time as a function of memory set?

Adapted from http://psiexp.ss.udi.edu by E.Day

A serial information processing model for Sternberg task

9 Perceive Stimulus Is it a 3?

Is it a 9?

Is it a 7?

Make Decision yes This serial information processing model predicts a linear increase Adapted from http://psiexp.ss.udi.edu by E.Day

9

A parallel information processing model for Sternberg task

Is it a 3?

Perceive Stimulus Is it a 9?

Make Decision yes Is it a 7?

This parallel information processing model also predicts a linear increase Adapted from http://psiexp.ss.udi.edu by E.Day

9 A parallel distributed information processing model for Sternberg task Is it a 3?

Perceive Stimulus Is it a 9?

Make Decision yes Is it a 7?

What is the difference between this model and the Parallel model of processing?????

Adapted from http://psiexp.ss.udi.edu by E.Day