Canli et al. (brain scans and emotions)
Evaluation Essay



P – Point (Strength/Weakness)E – Explain the pointE – Example from the studyR – Relate to the point on why is it a strength / weakness in the study
High in reliabilityThe extent to which a procedure, task, or measure is consistent. That it would produce the same results with the same people on each occasion.All ten participants saw 96 images for 2.88 seconds with 12.96 seconds in between when the participants would focus on a fixation cross.The standardised procedure of the duration of each image shown for all participants, eases the process of replication of future research hence the study has high reliability.
Low on ecological validityThis refers to the extent that the setting a study has been conducted in can be relevant to everyday life.The study took place in a laboratory where participants were placed in an fMRI scanner while fixating on the cross and select one of four buttons between 0 = not emotionally intense to 3 = extremely emotionally intense when the picture is shown.

This study takes place in a laboratory, which is an artificial setting. Furthermore, assessing intensity of an image is not usually done in an fMRI scanner while staying very still, making this task low in mundane realism.
OR
This setting is not normal to everyday life because participants aren’t expected to lie still in an fMRI while being exposed to images of different emotional intensities in their daily life, making the response shown not genuine to real life. Hence this study is low in ecological validity.

High in validityThe extent a researcher is testing what they claim to be testing.

An fMRI scanner was used to measure the brain activity of the participants by detecting changes associated with blood flow when the images of varying normative rating of emotion (valence and arousal) were shown.
OR
The order of the scenes from the ‘International Affective Picture System’ were randomised across the participants

The use of scientific equipment to identify the biological response of the brain gives an objective findings that is not affected by demand characteristics which increases the validity of the study.
OR
Randomisation of the scenes reduces order effects that could have caused changes in their performances that are not due to the perceived emotional arousal of the scenes shown, increasing the validity of the study.

Low on generalisabilityHow widely findings apply to other settings and populations.Participants were ten, healthy, right-handed females.Females were identified by the researchers as having a higher emotional response and might react differently to the scenes that were presented. There may be participant variables that does not generalise to males and left-handed individuals thus, lowering the generalisability of the study.
Ethical issue (deception)The ethical issues of deception was breached (overlooked) in this study. Deception is when participants are deliberately misled about the aspect of the study.Participants returned after three weeks of the first stage and were tested in an unexpected recognition test with an addition of 48 new foils to the original 96 foils.As participants were deceived about the surprise test, participants were not able to give informed consent to participate in the study. This would further tarnish the image of the field of psychological research & the public would be reluctant to participate in future research.
Quantitative data (Strength)Describing human behaviour and experience using numbers and statistical analysis.The fMRI scanner provided quantitative data on the activation of the amygdala that was correlated with the rating of emotional arousal between a scale of 0 = not emotionally intense to 3 = extremely emotional intense.This allowed researcher to gather numerical data that are objective and requires little interpretation. Therefore, researchers are able to correlate the rating of emotional arousal with rating of ‘3’ which showed more activation than ratings, ‘2’, ‘1’ or ‘0’.

Other analysis:

It can also be the case that the situation in which the experiment took place was so well controlled that normal influences on behaviour were eliminated. If a study lacks ecological validity, it means that what was observed in the laboratory does not necessarily predict what will happen outside the laboratory.

The use of repeated measure design ensures that all participants went through all the conditions of the study and thus minimizing individual differences such as retention of information in long term memory, sensitivity to varying stimuli or experiences from their personal lives which may have acted as extraneous variable and distorted the results of the study.