Defining cognitive psychology

Cognitive psychology is a branch of psychology that focuses on mental processes such as thinking, perception, attention, and memory. Cognitive psychologists view the human mind as an information processor, similar to a computer, where behaviour and emotions are influenced by how information is received, processed, and used.

This approach contrasts with other theories, such as learning theories that treat the mind like a 'black box' with little emphasis on internal processes. Instead, cognitive psychology emphasises the flow of information through the brain and central nervous system.

Key comparisons to computer processing

• Input - Information enters through the senses, much like data input via a keyboard or software in a computer.
• Processing - The brain handles this information using programs or mental operations, similar to a computer's software.
• Output - This results in behaviours, decisions, or actions, comparable to a computer's printout or display.

By studying these processes, cognitive psychologists aim to understand how people encode, store, and retrieve information to form memories, solve problems, and make decisions.

Basic processes of memory

Memory refers to the ability to take in, store, and recall information over time. It is not a single function but involves several interconnected abilities, such as remembering recent events or holding details briefly for immediate use.

Memory relies on three core processes that work together to handle information effectively:

• Encoding - The initial process of converting sensory input into a form that can be stored, such as turning sounds into meaningful words.
• Storage - Holding the encoded information over time in different memory systems, which can range from seconds to a lifetime.
• Retrieval - Accessing and bringing stored information back into conscious awareness when needed, like recalling a fact during a conversation.

The multi-store model of memory

The multi-store model (MSM), proposed by Atkinson and Shiffrin (1968), describes memory as a series of distinct stores through which information flows. It is sometimes called the two-process model because it focuses on short-term memory (STM) and long-term memory (LTM), but it also includes a sensory register, making it a multi-store system.

This model views memory as an information-processing system with input from the environment, processing through various stores, and output as behaviour. Key control processes, such as attention (focusing on relevant information) and rehearsal (repeating information to maintain it), determine how information moves between stores.

Components of the multi-store model

• Sensory register - The initial store where information from the five senses is briefly held. It has a large capacity to handle various sensory inputs but a very short duration of up to two seconds. Unattended information is quickly lost.
• Short-term memory (STM) - Information transfers here if it receives attention. STM has a limited capacity of about 7 ± 2 items (as suggested by Miller), such as digits or words, and a short duration of 15 to 30 seconds unless rehearsed. It primarily uses acoustic encoding (sound-based). Techniques like chunking (grouping items, e.g., hyphenating a phone number) can increase capacity. Unrehearsed information decays rapidly.
• Long-term memory (LTM) - Information moves here through sufficient rehearsal from STM. LTM has unlimited capacity and can store information indefinitely, though some may be lost over time. It uses various encoding types but favours semantic encoding (meaning-based).

How information flows in the multi-store model

1. Incoming sensory information enters the sensory register.
2. If attended to, it moves to STM; otherwise, it is lost.
3. In STM, rehearsal keeps information active and can transfer it to LTM via encoding.
4. Information in LTM can be retrieved back to STM when needed for use.

This linear flow highlights the role of active processes in preventing information loss and building lasting memories.

The working memory model

The working memory model (WMM), developed by Baddeley and Hitch (1974), expands on the idea of short-term memory by describing it as an active system for temporarily holding and manipulating information during tasks like problem-solving or conversation. Unlike the multi-store model's single STM, the WMM proposes multiple components that work together.

Working memory is limited in capacity and focuses on current mental activities. It was later updated by Baddeley (2000) to include an additional component.

Central executive

The central executive acts as the control centre of working memory, directing attention and coordinating the other components. It has a limited capacity for storing information briefly and is modality-free, meaning it can handle data from any sensory form (e.g., visual or auditory).

This component monitors incoming information, allocates tasks to the 'slave' systems, and integrates details from long-term memory when needed.

Phonological loop

The phonological loop handles speech-based and auditory information, allowing verbal rehearsal and storage. It consists of two subsystems and has a time-based limit of about two seconds without rehearsal.

Components of the phonological loop:

• Articulatory control system (inner voice) - Rehearses information verbally by repeating it mentally, like silently looping a phone number to remember it.
• Phonological store (inner ear) - Holds sound-based information temporarily, which decays after about two seconds unless refreshed by the articulatory system. It receives input from hearing or long-term memory, such as imagining a familiar song.

Visuospatial sketchpad

The visuospatial sketchpad manages visual and spatial information, enabling mental imagery and manipulation. It receives input from the eyes or long-term memory.

For example, if you visualise an object rotating or navigate a mental map, this component is at work. It helps with tasks requiring visual planning, like arranging furniture in a room.

Episodic buffer

The episodic buffer, added by Baddeley (2000), integrates information from the other working memory components, along with details about time and sequence. It acts as a temporary storage space that binds data together before transferring it to episodic long-term memory (memories of personal events).

This component ensures that fragmented information from visual, verbal, and long-term sources forms coherent episodes ready for longer-term storage.