amygdala associates with memory- Canli et el

Question 1

Background?

Answer 1

An experiment was needed to test the connection between the amygdala’s role in emotional based long-term memory recall.

Question 2

Aims?

Answer 2

-To investigate whether the amygdala is sensitive to different levels of emotional intensity.
-To investigate whether the degree of emotional intensity affects the role of the amygdala in aiding memory recall of emotional stimuli.

Question 3

Experimental design?

Answer 3

-Repeated Measures
-Lab experiment
-Used : Self reports, correlations

Question 4

Sample?

Answer 4

-10 right-handed healthy females
-Volunteer sampling technique
-Females chosen because they are more likely to experience intense emotional experiences.

Question 5

Procedure?

Answer 5

-During a fMRI scan, participants were shown 96 images.
-The pictures were chosen from the ‘International Affective Picture System’ and had a normative rating for valence and arousal.
-The images were randomised across participants
-Each image was shown for 2.88 seconds, with a interval of 12.96 seconds between each image.
-Subjects were instructed to view the image for the whole time it was on screen, and when the image was replaced by a cross, they were to press a button with their right hand, to indicate their emotional arousal (0-3)

Question 6

IV?

Answer 6

-Intensity rating of stimuli

Question 7

DV?

Answer 7

-fMRI images
-Percentage of forgotten, familiar & remember

Question 8

Valence & Arousal ratings of the images after the follow up?

Answer 8

VALENCE
-96 IMAGES IN THE STUDY:
ranged from 1.17 (highly negative) to 5.44 (neutral)
-THE FOILS:
ranged from 1.31 to 5.78

AROUSAL
-96 IMAGES IN THE STUDY:
1.97 (tranquil) to 7.63 (highly arousing)
-THE FOILS:
2.74 to 7.22

Question 9

The follow-up?

Answer 9

-3 weeks after the experiment, participants were tested in an unexpected recognition test
-They were shown all the previous scenes, plus 48 new scenes (foils)
-The participants were then asked whether they had seen the image before; their responses may have included: remember, familiar & forgotten.
-Numbers were assigned to each of the vocal responses (1 - forgotten, 2 - familiar, 3 - remember)

Question 10

The fMRI?

Answer 10

-An imager was used to measure Blood Oxygen Level Dependent (BOLD) contrast.
-A head coil was used for all subjects
-Head movement was minimised by using a bite bar for each subject. (The bite bar was formed with each of the pps dental impressions)
-11 frames captured per trial

Question 11

Results?

Answer 11

-Participant’s ratings of emotional intensity reflected the valence and arousal ratings of the images. Average correlation coefficient was -0.66 for valence, and +0.68 for arousal.
-Amygdala was significantly correlated with varying levels of emotional intensity. (Amygdala is sensitive to different levels of emotional stimuli)
-Subject’s ratings of emotional intensity were similarly distributed across all 4 categories;
0 - 29%
1 - 22%
2 - 24%
3 - 25%.
-Memory recall was significantly higher for images rated 3 (more intense) than those rated 0-2 (less intense)
-Only the most emotionally intense images were associated with superior memory.

Question 12

Conclusions?

Answer 12

-The amygdala is sensitive to individually experienced emotional intensity of visual stimuli
-Activity in the left amygdala during encoding is predictive of subsequent memory
-The degree to which amygdala activation at encoding can predict subsequent memory is a function of emotional intensity.

Question 13

Discussion?

Answer 13

Hamann et al (1999) argues that valence may not be as relevant as arousal.
-Further studies should use males to compare results to those of females.
-One subject with bilateral amygdala damage recognised highly intense emotional stimuli, although failed to demonstrate effective recall of the stimuli, indicating that although the amygdala may aid in subsequent memory, may not be fully responsible for reacting to emotional stimuli.
-Hence, data suggests that the amygdala simply translates information about subjective emotional intensity into long-term memory, but only for the most emotionally intensive experiences.

Question 14

Evaluation (Methodologically)

Answer 14

STRENGTHS
-High Replicability:
due to the high number of controls used, standardisation of the procedure was allowed, thus allowing the experiment to be repeated for all 10 participants reliably. (2.88 per image, bite bar used for all pps)
-High Validity:
due to many controls being used, the researches get rid of extraneous variables, thus enabling them to draw a clear cause and effect relationship, ensuring that the IV is the cause of the DV.

WEAKNESSES
-Low Generisability:
Because the sample size is small, and only consisted of 10 right-handed female pps, the findings may not be applicable to males, or left-handed individuals.
-Low Mundane Realism:
Looking at images is not an activity that pps experience everyday, this factor combined with the lack of ecological validity as it takes place in a lab setting, results in a lack of validity overall, as behaviours exhibited may not be naturalistic.

Question 15

Evaluation (Ethically)?

Answer 15

STRENGTHS
-Confidentiality:
despite 10 pps used, no information regarding their identities was published, hence confidentiality is maintained.

WEAKNESSES
-Psychological Harm:
Due to the disturbing images shown to the pps, it may cause permanent psychological damage to participants.
-Deception:
Pps not told about the 3 week test after the experiment.