PSYCH UNIT 3/4 MEGASET

Central nervous system

Comprises the brain and its extension, the spinal cord. 

Role of the CNS

Receive and process information from the body’s internal and external environments and to activate appropriate responses and transmit these messages in order to control human functioning.

The spinal cord

The long, thin bundle of nerve fibres that extends from the base of the brain to the lower back.

Spinal cord functions

Receive sensory information from the PNS and send these messages to the brain for processing and receive motor information from the brain and send it to the PNS.

Peripheral nervous system

The entire network of nerves located outside the CNS. 

Role of the PNS

• carries information to the CNS from the body’s muscles, organs and glands (about the internal environment) and from the sensory organs (about the external environment)

• carries information from the CNS to the body’s muscles, organs and glands

Somatic nervous system (SNS)

Network of nerves that carries sensory information from sensory receptors in the body to the CNS and motor information from the CNS to the skeletal muscles.

Autonomic nervous system (ANS)

Subdivision of the PNS that connects the CNS to the body’s visceral organs (eg: heart, stomach and liver) and glands (eg: sweat, salivary and adrenal), to regulate their function.

Sympathetic nervous system

Prepares the body for action by increasing the activity of most visceral muscles, organs and glands in times of vigorous activity, stress or threat. 

Parasympathetic nervous system

 Responsible for decreasing the activity of most visceral muscles, organs and glands, and restoring body functioning to its normal state (homeostasis).

Enteric nervous system

Embedded within the walls of the gastrointestinal tract and is dedicated to regulating its functioning. 

Conscious response

Response to a sensory stimulus is a reaction that involves awareness. You will have paid attention to the stimulus and therefore know about it. 

Unconscious response

Response to a sensory stimulus is a reaction that does not involve awareness. It is involuntary, unintentional, automatic and we cannot ordinarily control its occurrence. Bodily responses regulated by the ANS occur automatically without conscious effort.

Spinal reflex

An unconscious, involuntary and automatically occurring response to certain stimuli without any involvement of the brain.

Sprouting

Creation of new extensions on a neuron to allow it to make new connections with other neurons. This occurs through the growth of nerve endings (‘sprouts’) on axons or dendrites, thereby enabling new links to be made, including rerouting of existing connections.

Rerouting

When new connections are made between neurons to create alternate neural pathways. The rerouting may involve the existing synaptic connections and/or new connections from the sprouts.

Pruning

The elimination of weak, ineffective or unused synapses (and therefore connections to other neurons). 

Long-term potentiation (LTP)

Refers to the long-lasting strengthening of synaptic connections, resulting in enhanced or more effective synaptic transmission.

Long-term depression (LTD)

The long-lasting decrease in the strength of synaptic transmission and neuronal response

Neurotransmitter

Chemical substance produced by a neuron that carries a message to other neurons or cells in muscles, organs or other tissues. 

Glutamate

Main excitatory neurotransmitter in the CNS, enhances information transmission by making postsynaptic neurons more likely to fire. Second most common neurotransmitter.

GABA

Primary inhibitory neurotransmitter in the CNS. It works throughout the brain to make postsynaptic (‘receiving’) neurons less likely to fire (so it ‘inhibits’ firing). 

Neurdomodulators

‘modulate’, or influence, the effects of other neurotransmitters and are therefore called modulatory neurotransmitters

Dopamine

Neuromodulator that primarily enhances feelings of motivation enhancing the excitatory effects of neurotransmitters involved in learning and memory through reward based learning

Serotonin

Neuromodulator that primarily stabilises mood to state of wellbeing by enhancing inhibitory effects of neurotransmitters destimulating brain activity and counterbalancing effects of dopamine

Stressor

Stimuli that cause or produce stress and challenge our ability to cope.

Stress

A state of physiological and psychological arousal (tension) produced by internal or external stressors that challenge an individual’s ability or resources to cope.

Acute stress

Is brief and specific to the demands of a particular situation, it produces a very high level of arousal for a relatively short time.

Chronic stress

Involves ongoing demands, pressures and worries that are long-lasting and produce an increased arousal level that persists over a relatively long time, negatively effecting health (physical) and wellbeing (psychology.)

Fight, flight, freeze response

An involuntary response to a sudden and immediate threat (or stressor) in readiness to:

Fight – confront and battle the threat

Flight – escape and run away to safety

Freeze – keep absolutely still and silent to avoid detection

General adaptation syndrome (GAS)

Proposes a three stage explanation of the physiological stress response that occurs regardless of the stressor that is encountered. This model includes an explanation of the short (acute) and long term (chronic) consequences for stress exposure

Stage 1 of GAS model

Alarm Reaction Stage (with Shock and Counter Shock sub-stages) - occurs when the organism first becomes aware of the stressor

Stage 2 GAS model

Resistance – the body’s resistance to the particular stressor rises above normal for a prolonged period, maximising resources to cope and adapt.

Stage 3 of GAS model

Exhaustion – The level of resistance to the stressor falls below normal due to depleted resources and prolonged activation of the physiological stress response system which has caused wear and tear (harm) to physical and mental health.

Gut-brain axis

a paradigm that explains the two-way directional relationship between the brain and the gastrointestinal system (which is controlled by the enteric nervous system) and how they influence each other via the vagus nerve.

Transactional model of stress and coping

proposes that stress is the outcome of a transaction between the individual and their external environment.

Primary Appraisal

an individual’s assessment of the situation

Secondary Appraisal

An individual's assessment of the coping resources available to deal with demands

Context specific effectiveness

When there is a match or good fit between the coping strategy that is used and the stressful situation

Coping flexability

The ability to effectively modify or adjust one’s coping strategies according to the demands of different stressful situations.

Approach coping strategies

Efforts to confront a stressor and deal directly with it and its effects. Activity is focused towards the stressor, its causes and a solution that will address the underlying problem, and minimise or eliminate its impact.

Avoidance coping strategies

Involve efforts that evade a stressor and deal indirectly with it and its effects. Activity is focused away from the stressor and there is no attempt to actively confront the stressor and its causes.

Learning

A relatively permanent change in behaviour that occurs as a result of experience.

Conditioning

The process of learning through making associations between stimuli in the environment and a behavioural response.

Unconditioned Stimulus (UCS)

Any object or event that consistently elicits a particular involuntary response from an organism.

Unconditioned Response (UCR)

The involuntary response (reflex) elicited by an unconditioned stimulus.

Neutral Stimulus (NS)

The stimulus that does not naturally elicit the unconditioned response.

Conditioned Stimulus (CS)

The stimulus that does not naturally elicit the UCR but becomes a CS through repeated associations with the UCS.

Conditioned Response (CR)

The learned response produced consistently upon presentation of the conditioned stimulus.

Acquisition

The overall process where the organism learns to associate the UCS with the NS, transforming the NS into a CS that elicits a CR.

Operant Conditioning

A type of learning whereby the consequences of a voluntary action determine the likelihood that it will be performed again in the future.

Antecedent

The environmental stimulus that occurs before a behavior, indicating the response likely to be reinforced (e.g. petrol gauge indicating low fuel).

Behavior

The voluntary response that has an effect on the environment (e.g. pulling into a petrol station).

Consequence

The environmental event that follows the behavior, affecting its future occurrence (e.g. avoiding running out of petrol).

Operant

Any response that acts on the environment to produce some kind of consequence.

Thorndike’s Law of Effect

Behaviors followed by pleasant consequences are likely to be strengthened and repeated, while those followed by unpleasant consequences are likely to be weakened.

Reinforcement

When a pleasant stimulus is given, or an unpleasant is taken away, to strengthen or increase the frequency of a response.

Reinforcer

Any stimulus that strengthens or increases the preceding behavior.

Positive Reinforcement

The addition of a pleasant stimulus that strengthens or increases the frequency of the preceding response.

Negative Reinforcement

The removal of an unpleasant stimulus that strengthens or increases the frequency of the preceding response.

Punishment

An unpleasant consequence given, or a pleasant consequence removed, in order to weaken or reduce the frequency of a response.

Positive Punishment

The addition of an unpleasant stimulus that decreases the frequency or weakens the preceding response.

Negative Punishment

The removal of a pleasant stimulus that decreases the frequency or weakens the preceding response.

Social Cognitive Theory

Proposes that learning, thinking, feeling, and acting are influenced by both environmental factors and cognitive processes that facilitate the retention of social observations.

Observational Learning

A process where an individual observes a model’s actions and their consequences, using these observations to inform future behaviors.

Model

The individual being observed in the learning process. There are two types: live models (real persons) and symbolic models (characters in media).

Attention

The initial phase of observational learning where the learner closely watches and observes the model's behavior.

Retention

The cognitive process of mentally storing and representing observed behaviors over time as memory.

Reproduction

The phase in observational learning where the learner translates mental representations into actual behavior based on their ability.

Motivation

The learner’s desire to perform a behavior, which influences their likelihood of executing the learned action.

Reinforcement in Observational Learning

The stimulus that increases the frequency of the behavior being learned, either by providing motivation or strengthening the learner’s actions.

Memory

An active information processing system that enables us to encode, store, and retrieve knowledge and skills when needed.

Encoding

The process of converting information into a usable form for memory storage.

Elaborative Rehearsal

A technique to deepen encoding that helps make memories more permanent and resistant to forgetting through consolidation in LTM.

Storage

The retention of information in memory over time.

Consolidation

The long-lasting structural changes to neurons that occur in the brain when a new memory is made permanent, influenced by factors that may strengthen or weaken the memory for at least 30 minutes.

Retrieval

The process of locating and recovering the stored information from memory, making it conscious for awareness and use.

Atkinson-Shiffrin Multi-store Model

Suggests that memory comprises structural and control features, including sensory memory, short-term memory, and long-term memory.

Attention

The process that determines whether incoming sensory information is selected to pass onto short-term memory (STM).

Rehearsal

The process used to maintain information in STM; can be maintenance rehearsal or elaborative rehearsal, influencing whether information is retained in STM or transferred to long-term memory (LTM).

Sensory Memory

The entry point to memory that receives sensory information from the environment and stores it unconsciously in its sensory form for a brief time. Lasts for 0.2 to 4 seconds, with unlimited storage capacity; enables transfer to STM through attention.

Echoic Memory

Stores an unlimited amount of auditory information in its original form, lasting for approximately 3-4 seconds.

Iconic Memory

Stores unlimited visual information in its original form for a duration of 0.2-0.4 seconds.

Short-Term Memory

- limited duration 12-30 seconds and limited capacity 5-9 pieces

                 - stores an encoded version of the sensory stimuli from sensory memory 

                   that we have paid attention to (visual, spatial, auditory)

                 - stores what we retrieve from long term memory to consciously work on

Chunking

the grouping or packing of separate bits of information into a larger single unit or chunk of information

Rehearsal

process of actively manipulating information so that it can be retained in memory

Maintenance rehearsal

repeating the information being remembered over and over again to retain it in STM 

Elaborative Rehearsal

the process of linking new information in a meaningful way with information already stored in memory or with other new information to aid in its storage and retrieval from LTM

Decay

‘not being used’ the memory will last as long as the duration of STM and will fade and be forgotten 

Displacement

‘being pushed out’ by new information for instance if you have reached full capacity of STM then you shift your attention to focus on something else what was once on your mind will be forgotten as it has been replaced

Long-Term Memory

receives encoded memories from STM, stores an unlimited amount of memories possibly permanent over time for later transfer through a process of retrieval back to STM

Implicit Memories

typically require little conscious effort to retrieve and are often difficult to put into words rather we demonstrate these memories our knowledge of them is ‘implied’ through actions and behaviours

Procedural Memories

memory of actions and skills and involve knowing ‘how to’ do something

Classically Conditioned Memories

conditioned reflex responses to conditioned stimuli acquired through classical conditioning

Explicit Memories

memory of specific facts or events that require conscious effort to retrieve and can be easily stated or declared

Episodic Memories

holds information about specific personal events or experiences

Semantic Memories

holds facts and knowledge we have about the world

Key Functions of the Hippocampus

1. Plays a crucial role in the formation, encoding and consolidation of new explicit memories and their transfer to the cortex for long term storage 

      Does not permanently store any memories itself

2. Through interaction with the amygdala the hippocampus plays a role in the formation of emotional memories particularly the explicit component of an emotional event 

3. The hippocampus also functions to enable encoding and consolidation of spatial memories which is an explicit memory for the physical location of objects in space

Key Functions of the Amygdala

1. Involved in encoding and consolidation that are implicit emotional memories including classically conditioned fear responses

2. Enhances the consolidation and storage of emotionally charged long term explicit memories, we call these flash bulb memories as they are vivid and highly detailed

Key Functions of the Neocortex

Key functions:

1. Storage of long term explicit semantic memories, these are stored widely throughout the neocortex, usually in the areas where the relevant information was first processed 

2. When a memory is reconstructed the separate parts are gathered together to form a single integrated memory, the neocortex has a role in this retrieval process