Introduction - summary of chapter 1 of Cognitive Psychology by Gilhooly, K & Lyddy, F, M

Cognitive Psychology
Chapter 1
Introduction

Introduction

Cognitive psychology is concerned with how the mind represents and uses information about the outside world.
The study how humans (and other animals)

• Acquire information
• Store information in memory
• Retrieve information
• Work with information to reach goals

In all these cases we are dealing with mental representations.

Information is taken in through perceiving what is attended to, and is stored initially in short-term or working memory.
Then selected items are retained in long-term memory through learning processes and form knowledge that can be represented in a variety of ways.
Later, stored information may be retrieved if it has been retained, or it may turn out to be forgotten.
Perceived and recalled information shapes skilled actions on the environment and enters into problems solving, reasoning and decision processes.
Information can be shared with others via language and frequently involves an emotional aspect.

History and approaches

Mnemonics: a learning device used to aid memory.

• The method of loci. → Relies on associating a visual image with the object to be remembered, and placing these images in a familiar location or along a familiar route.
• The keyword method → used when learning a foreign language vocabulary. The learner makes an association between the unfamiliar word and a familiar word in the native language that sound like the unfamiliar word. The use of an interactive visual image underlies the mnemonic effect. Imagery can be a useful mnemonic device.
• The phonetic number system (or major system) → commonly used by memory experts, increases memory capacity of numbers. This system converts numbers into constant sounds, which can then be made into words, and potentially viewed as mental images.

Spatial learning are of particular importance for such techniques.
Mnemonic techniques allow us to create associations between unrelated pieces of information. But they are less likely to help us complete meaningful task specific memory tasks.

Associationism

Empiricist held that all knowledge came from experience and that ideas and memories were linked by associations. Closeness in space as well as in time fosters associations also.

Introspectionism

Wundt tried to analyze normal perceptions into simpler sensations which combined to give the perception.

Behaviourism

This approach abandoned the attempt to look inside the mind and took only observable behavior and stimuli as its data. This approach essentially aimed to be a psychology without reference to internal cognitive processes. The focus was on learning and particularly about how behavioral responses could be predicted form knowing the history of rewards and punishments following behavior in response to particular stimuli.

Mental maps: mental representations of a spatial layout.

Information processing: the cognitive revolution

The information processing approach
Inspired by the first computers. A metaphor for understanding mental activity, based on computing.
Strategies; systematic ways to carry out a cognitive task such as solving a problems.
In humans and computer programs, there are defined steps to be carried out, decisions to be made, storage of new information and retrieval of old information from memory.

Simulation: involves programming computers to solve problems in a similar way to humans.
Artificial intelligence: the attempt to program computers to carry out complex tasks such as medical diagnosis, planning and using natural language.

Cognitive psychology theorists attempt to explain performance in cognitive tasks by using concepts of:

• Internal representations; mental representations of external objects and events
  These are transformed by mental operations (inner actions manipulating mental representations) using both long-term and short-term memories.

Connectionism

An approach to cognition in terms of networks of simple neuron-like units that pass activation and inhibition through receptor, hidden an output units.
The units are connected by excitatory or inhibitory links of varying strengths through which activation flows.
Link strengths are modified through learning rules such as backwards propagation (a way of modifying weights on the links between units in a connectionist network, in response to errors, to obtain the desired output.
These models are more brain like. But, the units in such models are much simpler in their properties and functioning than the real neural units that constitute the brain and so the similarity of a connectionist network to real neural networks is limited.
The basic components are:

• A set of processing units
• Weighted connections between units
• A learning strategy

The processing units can be input, output of hidden units.
The network’s architecture is determined by the way in which the units are connected.

• Feedforward network; input units are connected to output units such that information flows in one direction from input to hidden to output layers.
• An recurrent network; some of the connections feed back to earlier layers.

All units have some level of activity, denoted by their activation value. This determines how much activation or output a unit passes onto connected units.

The functional level of analysis

Overall, the information processing approach can be said to focus on our ‘mental software’.
It asks: What strategies are followed in processing information?
These questions are about functions and functional properties and can be answered without referring to any underlying hardware.

Cognitive neuroscience

Brain basics

• Two hemispheres, connected by the corpus callosum.
• Four main lobes are apparent in the outer layer (the cerebral cortex). The frontal lobes, the parietal lobes, the occipital lobes and the temporal lobes.
• At the base of the brain is the cerebellum (that is important for movement control)

Deeper inside the brain

• Thalamus
• Hippocampus
• Amygdala

Terms used to indicate locations in the brain:

• Dorsal → the top
• Ventral → towards the bottom
• Anterior → towards the front
• Posterior → towards the back
• Lateral → at the side
• Medial → in the middle

All structures in the brain are composed of neurons.

Cognitive neuropsychology

Examines the effect of brain damage on behavior, with a view to identifying how psychological functions are organized.

The basic idea: most, not all functions, are linked closely to the healthy working of specific brain areas and that impairments following localized damage can indicate which areas are important for which functions and be informative about how broad functions are organized into narrower functions.

Phrenology: an early form of localization that attempted unsuccessfully to link psychological functions to bumps in the skull taken to reflect growth of brain in specific areas.

Double dissociation of functions arises when, following brain injury, some people do well on one Task A and poorly on a second task B while others with different brain injuries show the opposite pattern. Then the two tasks are said to be doubly dissociated.

Recently neuropsychology had benefited form the development of imaging or scanning techniques which enable researchers to see and accurately measure the location and extent of dame in living patients.

Brain imaging

Two main categories:

• Structural imaging: shows the static anatomy of the brain
  The dominant method is Magnetic resonance imaging (MRI)
  Functional imaging: represents brain activity over time
• Electroencephalography (EEG)
  Event-related potentials (ERPs). Recording electrical activity during repeated stimulus presentations.

Positron emission tomography (PET): a functional imaging method which uses positron emissions form radioactive glucose to indicate areas of increased blood flow in the brain.

Functional magnetic resonance imaging (fMRI): a method of imaging brain activity that uses oxygenation levels of blood flow and has good temporal and spatial resolution.