Research into Memory

Topic – Memory

Memory

The system of retaining and retrieving information about things that have happened in the past.  Is split into sensory memory, short term memory (STM) and long term memory (LTM).

Encoding

The transforming of a stimulus (usually sight and sound) in order for it  to be placed into memory

Capacity

The amount of material that can be stored in memory: how much?

Duration

The length of time material can be stored in memory: how long?

Model

A theoretical concept that helps explain relationships between different aspects of behaviour

Multi-store model

Comprises three stores: sensory memory, STM and LTM.  Material to be remembered enters sensory memory and if attended to moves to STM where due to rehearsal, it moves to the LTM store.  Material not rehearsed or attended to gets forgotten.

Sensory memory

Memory store which lasts milliseconds.  Information not attended is immediately forgotten.

Short term memory

Memory store of less than 20 seconds duration, with an average capacity of 7 items (+/- 2) and encoded mainly by sound (acoustically)

Long term memory

Memory store of information which lasts from  20 seconds to a lifetime.  Unlimited storage capacity and mainly encoded through meaning (semantically)

Serial digit span

Tests the capacity of STM.  Participants are given increasing lengths of numbers to recall in the correct order.  When they can no longer do this, they have reached their 'digit span' or STM capacity.

Working memory model

The model proposed by Baddeley and Hitch (1974) to explain STM.  Argues STM is an 'active' store and involves components such as the Central Executive, Phonological loop and visual-spatial scratchpad.

Central executive

Decision making part of the Working Memory model which organises STM.   The Central Executive has a limited capacity that directs attention to the other 'slave' components (phonological loop and visual-spatial scratchpad) of the model.

Phonological loop

Includes the articulatory control system (the 'inner voice') of words that we are about to speak and the phonological store (or 'inner ear') that receives and processes auditory information

Visual-spatial scratchpad

Encodes visual information processing (the 'inner eye')

Dual task studies

Experiments where participants have to perform two (or more) tasks at once.  Often these involve different processing systems (e.g. sight or sound)

Trigram

Three consonants that have no meaning, e.g. TJK.  Used in STM experiments because participants do not impose meaning on the material.

Serial position effect

The tendency for people to recall the first items in a list (the primacy effect) and the last items in a list (recency effect).

Rehearsal

Repetition of material in order to try to retain information in memory.   Usually only works for short term memory.

Procedural memory

Memory for actions such as swimming.  Knowing how to perform certain tasks.  These memories are very ingrained and least likely to be forgotten.

Semantic memory

General factual knowledge memories such as the name of the Prime Minister.

Episodic memory

Autobiographical or personal memories for events that are unique to each individual - such as your first day at school.

Eye witness testimony

Memories that people have for criminal incidents that they have seen.

Schemas

Ready-made expectations that help us to interpret our world - can lead to memory distortions based on our prior assumptions or stereotypes

Forgetting

Information lost from memory through decay, displacement, interference or retrieval failure.

Anxiety and EWT

Stress affects the recall of a crime.  Very low and high levels of stress adversely affect memory recall with moderate stress leading to optimal performance. The so-called inverted U graph (or Yerkes Dodson Law) illustrates this.

Age of witness

Children and older people are poorer (less recall and more distortions) eyewitnesses than young or middle-aged adults.

Misleading information

Information that makes it more likely that a witness will be directed into given a particular (wrong) answer, e.g. how fast was the car racing past the shop? (when in reality there was no shop and it was going slowly!).

Elizabeth Loftus

A key researcher who argues that eyewitnesses often reconstruct memories of crimes based on their expectations and thus distort reality (not deliberately)

Leading questions

Questions that (unintentionally) mislead and make it more likely that witnesses will report inaccurate information, eg. The question:  Did you see the broken headlight? Assumes that there was a broken headlight!

Cognitive interview

Used by police to enhance eye witness recall.  Involves recalling every minute detail,  in a different order, from someone else's perspective and imagining oneself back at the original scene.

Strategies for memory improvement

Techniques used to improve memory - examples include method of loci and the peg word system (same meaning as mnemonics)

Mnemonics

Devices used to improve memory - examples include method of loci and the peg word system

Chunking

Memory technique where units of information (numbers) are chunked into larger groups to aid recall - this is often done with phone numbers

Method of loci

a memory improvement strategy that involves learning a set route of different locations and then imagining items to be remembered in those locations.  Mentally 'retracing' around the locations help to recall the items 'placed' there.

Pegword system

a memory improvement strategy that involves associating items to be remembered with 'pegs'.  A common strategy involves associating items with a 'peg' which rhymes with numbers.  eg: 1 = bun 2 = shoe etc.  Imagery and organisation of this sort helps with recall.

Topic - Research

Experiment: 

A study where the independent variable is deliberately manipulated to find the effects on the dependent variable, whilst controlling extraneous variables.  Strictly speaking, participants should also be randomly allocated to different experimental conditions. 

Laboratory experiment

An experiment that occurs in a carefully controlled environment, usually a laboratory.

Field Experiment

An experiment that takes place in the real world as opposed to a laboratory.  The IV is still manipulated by the experimenters

Natural experiment

An experiment that takes place in the real world and where the IV occurs naturally.  There is no manipulation of the IV.

Correlational analysis

A method of data analysis which allows the strength of the relationship between two (or more) co-variables to be measured

Observation

A study where an observer objectively records participant's behaviour in their natural environment.

Questionnaire

Written methods of data collection.  They can involve open or closed questions.  Surveys tend to involve a large sample of participants.

Interview

A verbal method of data collection that involves the researcher asking questions in a face-to-face way.  They can vary from very structured (formal) to unstructured (informal).

Case studies

An in-depth detailed description of an individual or small group's behaviour and experiences.

Aims

an outline of the general purpose of the research study.  A statement of why the research study is taking place.

Hypotheses

These are predictions made about the possible outcomes of study that is yet to be conducted.  A statement of what is expected to happen.

Alternative/experimental hypothesis

The prediction made before the study takes place that an IV will have an effect on s DV.  There are two types: directional (one-tailed) and non-directional (two-tailed).

Directional (one tailed) hypothesis

This hypothesis states the direction of any difference that is expected.  In correlations, they hypothesis is predicted as being wither positive or negative.

Non-directional (two-tailed)  hypothesis

The prediction that there will be a significant difference between the results of the two conditions (or a correlation between the variables) but does not predict the direction that difference (or correlation) will take.  

Null hypothesis

The hypothesis that states that there will be no difference between the results of the two conditions, the results are simply due to chance.  The hypothesis of 'no difference' or 'no correlation'.

Experimental design

A procedure used in experiments that allows for the control of participant variables.  Without this control, the experimental results would be jeopardised.  There are three types: independent groups design; repeated measures design and matched pairs design.

Research methods

Methods such as experiments, interviews, questionnaires and observations that are used to collect data in psychology.

Independent groups design

Different participants are randomly allocated to the different experimental conditions.

Repeated measures design

The same participants are tested in all the experimental conditions.  They 'repeat' all the conditions.

Matched participants design

The same as independent groups design except that similar participants are randomly allocated to the different experimental conditions.  They are previously 'matched' on whatever criteria are judged to be important for the study.  This might include age and sex.

Operationalisation

The process of defining a fuzzy concept so as to make the concept more easily definable or measureable.  Eg aggression measured by the number of punches thrown.

Independent variable

The variable that is directly manipulated by the experimenter to see the effect it has on the dependent variable (DV)

Dependent variable

The variable that is measured by the experimenter.  So-called because changes in this variable are dependent on the IV.

Pilot study

A small-scale practice study which is conducted to test the proposed methodology and ensure improvements in the actual study.

Extraneous variable

Anything, other than the IV, which might have an effect on the DV.  Extraneous variables should be controlled.

Confounding variable

Extraneous variables that aren't controlled can adversely affect or 'confound' results. They're called 'confounding' variables.

Reliability

Means consistency - producing the same result on different occasions.   Research should be consistent over time and across different researchers.  In other words, the research should be repeatable, replicable and the same (or similar) results should be obtained.  If this occurs, the research is reliable.

Replication

Repeating a study again in exactly the same way to test if the results are reliable

Validity

Refers to whether the research is measuring what it is supposed to be measuring

Internal validity

Refers to whether the research is accurate within the confines of the experimental setting.  The research must not be affected by investigator effects or demand characteristics.  If results can be directly attributed to   the manipulation of the IV, then the research is internally valid.

Ecological (external) validity

Refers to whether the research results are accurate and can thus be generalised beyond the confines of the experimental setting.  

Ethical issues

These occur in research when there is conflict between how to conduct the research and the methodological consequences for participants of doing this.  Ethical Guidelines have been devised by the British Psychological Society  (BPS) to help researchers with issues such as informed consent and deception. 

Deception

Involves not informing a participant of all details of the study

Informed consent

Involves telling a participant about all aspects of a study they will participate in and ensuring they understand exactly what is required of them

Sampling

Refers to the way that participants are recruited for research.  Typical sampling methods include random, volunteer and opportunity sampling. 

Random sampling

A technique where every member of the population has an equal chance of being selected.  The simplest way to do this is to draw names out of a hat.

Opportunity sampling

Where any participants that are ready and willing to take part in a study are recruited.  Easiest method to recruit participants but can be biased as a  result.

Volunteer sampling

Where participants come forward to volunteer to take part in a study.  Easy to recruit participants but method can be biased since participants are so willing to take part.

Generalisation

In research methods, it refers to the ability of the researcher to make justified conclusions from their specific research or sample to a wider population.

Demand characteristics

Refers to the situation where participants try to guess the purpose of the study and amend their behaviour accordingly.  They act according to what they feel are the 'demands' of the study.

Social desirability bias

When participants try to present themselves in a good light to the researcher and thus may give misleading or biased information.

Measures of dispersion

These are measures of the variability or spread of scores.  They include the range and standard deviation.

Range

The difference between the highest and lowest scores (Nb: Some formula suggest adding 1 to the answer)

Standard deviation

A measure of the distribution of scores around the mean.  A large SD suggests a wide scatter of scores, a small SD suggests that scores are close to the mean.

Investigator effects

This refers to the process whereby a researcher inadvertently influences the results of the study.  This could be due to physical characteristics of the researcher affecting respondents' answers or behaviour.

Measures of central tendency

These are data values that represent the typical mid-point value of a set scores. They're 'averages' and the most commonly used measures are the mean, median and mode.

Mean

The arithmetic average obtained by adding up all the scores and dividing by the number of scores.  Most appropriate with interval/ratio data.  The mean can be affected by extreme scores.

Median

The middle value when scores are placed in rank order.  Most appropriate with ordinal data

Mode

The value that occurs most frequently.  Most appropriate with nominal data.

Scattergram or scattergraph

a type of graph used to plot correlations.  Allows any clear relationship between two variables to be seen at a glance.  So-called because the scores are 'scattered' across the graph

Histogram

a type of graph used for frequency data.  The area of each column is proportional to the number of cases it represents.  The x axis must involve continuous data and is divided into appropriate intervals.

Bar chart

A type of graph that's used to visually present discrete (non-continuous) or nominal data.

Negative correlation

Where one variable increases the other variable decreases (e.g. raincoat sales decrease as temperature increases).  It is expressed from 0 (no correlation) to -1 (perfect negative correlation).

Positive correlation

Where one variable increases the other variable increases (e.g. ice cream sales increase as temperature increases).  It is expressed from 0 (no correlation) to +1 (perfect positive correlation).

Content analysis

A systematic analysis of the meaning of  presented information.  Often involves qualitative materials (eg written or verbal material) being analysed in a quantitative way using tally charts or other counting methods  to allow statistical analysis.