Population: 18 – 40 Year olds Prediction: Sleep deprived patients will have a higher BMI than non-sleep deprived subjects Extraneous variables (EV) (the word extraneous means ‘outside’ So an EV is any variable outside the experimental design that may affect the D.V, thereby having an unwanted effect on the results of the experiment and thus affecting the ability of the researchers to draw conclusions. So an EV is a variable other than the IV that may affect the DV They can occur at any stage of an experiment – e.g. how the D.V was measured, how the experimental group was treated (which may be different to treatment of control group) EV’s occur randomly rather than systematically – i.e. they occur at a point of the experiment Identification of extraneous potential confounding variables variable Description Example Alternatives Individual participant differences The composition of the control and experimental groups, may contain significant difference in terms of the intelligence, past experience, memory ability, gender mix, age spread, etc – which may influence the results Control group has 80% males, Experimental group has 80% females, gender may affect results Use a repeated-measures design to eliminate individual participant differences or a design to reduce individual participant differences Non standardised instructions & procedures This involves subjects receiving different instructions, conducting experiment in a different context (different time of day, different location – could affect results) Comparing results of Psych class A (experiment done Monday am, to results of Psych class B (experiment done Friday pm) Use standardised instructions and procedures: i.e. same experimenter, same context, etc. Order effect (see below) Experimenter effect (see below) Placebo effect (see below) Placebo Effect & the use of a Placebo Placebo effect Explanation A tendency of participants expectations to influence their behaviour meaning that the IV is not the only variable influencing the value of the DV And/or – the subjects knowing what group they are in (control or pairs
Limitations Some subjects may have difficulty expressing their thoughts Some subjects may not give honest answers due to self-perceived pressures to conform to social norms, thus affecting the accuracy and validity of such data It is difficult to convert responses to quantitative data, thus making it difficult to statistically analyse & consequently interpret data. Hence analysis becomes subjective (there is a risk of experimenter effect). Data collection technique: Questionnaires Explanation Are a written set of standardised questions that can be taken anonymously Advantage The anonymous nature of self-reports encourages subjects to be more candid (honest) in the nature of their responses. Relatively easy in the modern era to direct to subjects e.g. online, email, mail, etc., hence a relatively cheap means of data collection Limitations Subjects may misinterpret questions, thus affecting accuracy/ validity of data Lengthy Questionnaires can lead to boredom, thus affecting accuracy of data and ability of the researcher to generate conclusions. Data collection technique: Surveys Explanation A group of participants are asked to respond to set of questions by either - Face to face, mail, phone, etc. Advantage It is a practical way of gathering information from a large number of participants Limitations It is difficult, time consuming & costly to obtain a representative sample i.e. a small group that accurately reflects the larger population, hence we need to be careful generalising results to the larger population if we are unable to obtain a representative sample Wording effect: occurs when the phrasing or order of questions, affects how participants answer Data collection technique: Interviews Explanation Can take the form of face-to-face/ phone forms of self-reports Advantage If using an unstructured interview, the interviewer has the flexibility to ask follow-up questions to responses in order to add to the richness of data collected Limitations Data can be difficult to summarise, analyse & describe Dot point # 4: Statistics Measures of central tendency including mean, median and mode Interpretation of p-values and conclusions Evaluation of research in terms of generalising the findings to the population
Informed consent procedures Participants must be given adequate information about nature of the study – what the results will be used for details of the processes involved in the study. the rights of the participants – re withdrawal, confidentiality, debriefing, dangers etc. the potential risks involved for the participants Withdrawal rights Participants are entitled to leave the study at any time during the conduct of the study. Participants may withdraw their results from the study at any time following the completion of the study. This should be explained to them prior to the commencement of the study. Use of deception in research Deception is allowed when The ethics committee has given permission for deception in research to be used the value of the research is such that the deception is warranted. Appropriate debriefing procedures are in place to ensure that no lasting psychological or physiological harm to participants occurs Debriefing Subjects are debriefed at the conclusion of the experiment (not before or during) Done to prevent psychological/ physiological harm to participants Providing the participants with information about the nature & reason for any deception that was used Corrects mistaken attitudes & beliefs about the research Used to minimise (or extinguish) any negative consequences that participants might have suffered The neural basis of Memory formation Neurons are the core components of the nervous system, a neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. The neuron in memory formation Neurons are capable of a change in their function – which enables storage of newly learned information occurs via 2 interdependent processes (not independent) The role of Neurotransmitters in memory formation An increase in the amount of neurotransmitters produced (& released) by the presynaptic neuron Greater effects of neurotransmitter at its receptor sites of the post synaptic neuron (thus the receptors are more sensitive to incoming messages in the form of the neurotransmitters from the axon terminals of the presynaptic neuron.