Canli et al. Flashcards
Define Valence
refers to the* attractiveness* (positive valence), or aversiveness (negative valence) of an event, object or situation
Define foil in the Canli study
The unknown or unseen object that is used as a control when testing a pp’s memory
What is the psychology investigated in the Canli study?
- fMRI scanning machine
- the amygdala
What does an fMRI machine do?
Records blood flow to different parts of the brain during different activation caused by different activites
What is the aim of the Canli et al. study?
- To show that highly emotional arousing images will be remembered better than non-emotionally-arousing images
- Central question: is the amygdala sensitive to varying degrees of emotional intensity to external stimuli and wether this enhances memory for said stimuli
Hypothesis of the Canli et al. study
(not really specifically stated)
- the more emotionally arousing a stimuli is, the more likely people are to remember it later on
Number of participants in the Canli et al. study
10
Demographic of the participants in the Canli et al. study
- all right-handed, healthy females
Sampling method used in the Canli et al. study
Volunteer
Why were women used in the sample for Canli et al?
Because they are thought to be more likely to show stronger emotions to the stimuli, giving more to measure than what men would.
fMRI machine in the Canli et al. study
- Took 8 perpindicular slices to the hippocampus, and 11 frames were captured
- BOLD (Blood oxygen level dependant)
Describe the images used in the Canli et al. study
- From IAPS stimuli set
- had a valence of 1.17 - (negative) to 5.44 (neutral)
- arousal ranged from 1.97 (tranquil) to 7.63 (highly arousing)
What was the correlation between valence and arousal for the IAPS stimuli set?
r = 0.89 (highly correlated)
What type of study was Canli et al?
Correlational study
Controls in the Canli et al. study
- Bite bar - personalised to every pp’s dental impression
- Whole head coil
Experimental design used in Canli et al.
Repeated measures
Variables in Canli et al. (3)
- intensity of emotional arousal - measures with a (0-3) 4 point scale
- Measurement of amygdala activation from the fMRI machine
- memory of each scene (1-3)
Procedure - fMRI machine and images
- pp instructed to look at screen for entire time
- Images shown for 2.88 seconds, fixation cross for 12.96 seconds - (allowed brain to return to normal)
- during fixation cross, pp to press button on their right hand (0-3)
Procedure - Unexpected recognition test
- Pp called back 3 weeks after first session
- Pp viewed all 96 previous images + 48 foils (from same IAPS set)
- Asked wether they remember, or forgotten (1) image
- If remembered - certain (3), or just familiar (2)?
Results (Canli)- Individual experience of emotional intensity and normative valence & arousal characteristics
- Correlated well: -0.66 (negative) 0.68 (positive)
Results of amygdala activation and emotional intensity ratings
- Highly correlated
Results of distribution of emotional intensity across ratings 0-3
- all ratings distributed similarly (22-29%)
- shows that any results seen in how well a scene is remembered cannot be due to statistical power
Results on recognition of scenes rated 1-2
- similar distribution of items “forgotten”, “familiar” or “remembered”
- On all, “forgotten” was more accuring than “familiar” or “remembered”
Results on recognition for scenes rated 3
- Significantly more “remembered” and “familiar”
- Significantly less “forgotten” - 20% down from around 40%
Which side of the amygdala was found responsible for later memory of the stimuli?
The left side
Results on the emotional intensity of the image and the ability to recognise it later on
- scenes rated 0-1: low correlation between amygdala activity and later memory
- Scenes rated 3: high correlation between amygdala activity and later memory
Conclusions of the Canli et al. Study (2)
- activity of the left amygdala (at the time of seeing the image) is responsible for recall of the image later on
- The more emotionally intense an image is, the more activation of the amygdala, leading to better memory later on
Which assumption of the Biological approach does the Canli et al. study apply to?
- Behvaiour, cognition and emtions can be explained in terms of the working of the brain, and the effect of hormones
- Similarities and differences between people can be understood in terms of biological factors, and their interaction with other factors
Canli et al: Nature or Nurture?
Nature!
Canli et al: Individual or situational?
Individual: everyone’s amygdala reacted, but all in a slightly different way
Generalisability in Canli et al.
Negatve:
- only females used
- all healthy
- all right handed (left handed may work differently?)
Positive:
- 10 pp is a decent size for an fMRI study
Reliability in Canli et al.
Positive
- standardised: images, ratings, time images shown, questions on familiarity
- Head coil and bite-bar for controls
- fMRI deemed a reliable measuring tool - subjective
Application in Canli et al.
- advertisements (eg. ciggarette packets) - more gross images used, the better the target audience is to remember the product
Validity in Canli et al.
Positive
- Order of images randomised for all pp
- unexpected recall test
- IAPS - images unlikely to have been seen before
- quantitative data used
- 48 new foils to the 96 original images
Negative:
- Ecological validity - Lab experiment, fMRI machine - Pp layed on their back
Ethics in Canli et al.
Positive:
- informed consent given
- Psychological harm taken care of - technician
Negative
- right to withdraw affected
- decpetion used for 3 week follow up
- psychological harm - being made to look at distressful images that Pp were proved to have remembered
