canli et al. (naomi) [done]

Question 1

what is the amygdala?

Answer 1

• almond-shaped section of nervous tissue located in the temporal (side) lobe of the brain
• Responsible for the perception of emotions such as anger, fear, and sadness, as well as controlling aggression
• Store memories of events and emotions so that an individual may be able to recognize similar events in the future
• If damaged, difficult to recall a highly aversive stimulus better than a neutral one

Question 2

what are the stages of memory?

Answer 2

encoding (processing of information into the memory system) → storage (the retention of encoded information over time) → retrieval (the process of getting information out of the memory storage)

Question 3

studies using PET & fMRI scans showed positive correlations between amygdala activation & the presentation & recall of emotional stimuli. what are the possible reasons for this?

Answer 3

1. personality - some individuals are more responsive to emotional experiences than others
2. state differences - individuals could have had an enhanced emotional state during the scanning
3. dynamic response/phasic interpretation - is the amygdala sensitive to the emotional intensity of the stimulus?

Question 4

give a summary of the procedure

Answer 4

1. participants viewed a fixation cross for 13 seconds
2. participants viewed each picture for the entire time that it was displayed through the mirror projected overhead for 3 seconds
3. when the cross reappeared, participants indicated emotional arousal by pressing one of four buttons (Likert scale from 0 to 3)
4. 3-weeks later, participants were tested in an UNEXPECTED RECOGNITION TEST in which they viewed the previous scenes + 48 foils (new scenes) and reported whether they had seen the picture and if yes, whether they remembered with CERTAINTY or had a less certain FEELING OF SIMILARITY such emotional experience

Question 5

what are the aims of the study?

Answer 5

• whether the amygdala is sensitive to varying degrees of emotional intensity experienced by individuals
• whether the degree of emotional intensity affects the role of the amygdala in enhancing memory for emotional stimuli

Question 6

what is the hypothesis of the study?

Answer 6

• the amygdala is sensitive to the emotional intensity (valence and/or arousal characteristics) of a stimulus
• emotionally intense stimuli produce greater amygdala activation, thus should be better remembered than stimuli that produce less amygdala activation

Question 7

what is the independent variable for canli

Answer 7

the level of perceived emotional arousal of the 96 scenes
not emotionally intense at all: 0-1
extremely emotionally intense: 2-3

Question 8

what is the dependent variables for canli et al.?

Answer 8

• fMRI measure of amygdala activation
• memories of scenes (3 weeks later)

Question 9

what was the research method used in this study?

Answer 9

• lab experiment
• repeated measures (within-subjects design)

Question 10

what was the research method used in this study?

Answer 10

• lab experiment
• repeated measures (within-subjects design)

Question 11

what is the sample in this study and why were these participants chosen?

Answer 11

• 10 right-handed healthy female volunteers (self-selected/volunteer sampling)
• females were chosen because they are more likely to report intense emotional experiences and they show more physiological reactivity than men
• right-handed were chosen because activation of the left amygdala was measured
• all were aware of the nature of the experiment and gave informed consent

Question 12

define valence

Answer 12

“arousal” - “attractiveness” or ‘positivity’ or the ‘negativity’ or ‘how bad’ the stimulus is

Question 13

define arousal

Answer 13

Physiological & psychological state of being visually stimulated by the pictures

Question 14

what were the controls used in this study?

Answer 14

• 96 neutral & negative scenes presented via an overhead projector viewed through a mirror which allows them to see the scenes while in the fMRI scanner
• Scenes were taken from the International Affective Picture System stimuli set
• Normative ratings for valence ranged from 1.17(highly-ve) to 5.44 (neutral)
• Normative ratings for arousal ranged from 1.97(tranquil) to 7.63 (highly arousing)
• The order of scenes was randomized, with each picture presented for a period of 2.88 secs
• Intervals of a fixation cross for 12.96 sec
• Bite-bar was used to reduce movement-related artifacts during functional fMRI scanning
• Medical technicians were present during the scanning

Question 15

what materials were used in this study?

Answer 15

• MRI
• fMRI
• bite bar (restrict participants movement)

Question 16

what were the results (before the 3 week recognition test)?

Answer 16

• Normative valence and participants’ intensity ratings are negatively correlated (-0.66)
• Normative arousal and participants’ intensity ratings are positively correlated (0.68)
• These are good as participants perceived the scenes as expected

Question 17

what would the results (before the 3 weeks) show?

Answer 17

Amygdala activation was significantly, bilaterally correlated with higher ratings of individually reported emotional intensity
which provides evidence that amygdala activation is related to the subjective sense of emotional intensity and that the participants’ perceived arousal is associated with amygdala activation

Question 18

what were the results for the recognition test (3 weeks later)?

Answer 18

• Follow-up memory performance was significantly better for scenes that were rated as highly emotionally intense (i.e. rated 3) than those rated as less emotionally intense
  → Fewer items were forgotten and more were familiar and remembered for scenes that were rated as emotionally highly salient (rated 3)
  → Scenes that were rated mild-to-moderate (ratings 0 to 2) had similar distributions of items that were forgotten, familiar, or remembered

Question 19

The correlation grew stronger as participants experienced greater emotional intensity for most emotionally intense stimulus, what does this suggest?

Answer 19

suggest that stimulus need to EXCEED CERTAIN THRESHOLD (red dotted line of figure 2C) of emotional intensity before amygdala activation will lead to enhanced memory

Question 20

what does the left amygdala activation predict?

Answer 20

Left amygdala activation predicted memory performance. For e.g:
Little amygdala activation in response to a picture rated as highly emotionally intense was associated with the subject’s forgetting the stimulus, whereas intermediate and high amygdala activation was associated with a subject’s later report of familiarity or confident recognition, respectively.

Question 21

there is a significant correlation between emotional intensity and the influence of the amygdala on ___

Answer 21

emotional memory

Question 22

what do the results show?

Answer 22

1. Amygdala activation correlated well with participants’ ratings for pictures on emotional valence & arousal
2. The memory recall was better for emotionally intense scenes
3. Left amygdala activation was a good predictor of recall, whether a picture was forgotten, familiar, or remembered.

Question 23

describe the amygdala

Answer 23

1. Amygdala is sensitive to the individually experienced emotional intensity of discrete visual stimuli
2. Activity in the left amygdala during encoding is predictive of subsequent memory performance
3. The degree to which amygdala activation at encoding can predict subsequent memory depends on the emotional intensity

Question 24

what are the limitations of canli et al.?

Answer 24

• as participants only rated general emotional intensity, researchers cannot explain whether amygdala activation is affected more by valence or arousal of the scene
• however, based on previous study arousal may be more important
• this study found activation in left amygdala, but 2 PETs studies found activation in right amygdala

Question 25

what are the possible improvements for future studies?

Answer 25

• Need to include positive valerice scene with different arousal ratings to check and confirm the LEFT OR RIGHT SIDE DISCUSSION
• Gender differences. Both previoUs PET studies used only male subjects, whereas previous andcurrent MRI studies usedonly females
• Differences in laterality could also be due to different equipment used (PET & fMRI)
• Individual differences - is amygdala involved in
  PRODUCTION of emotional response? Not likely. People with amygdala damage can still rate negative stimulus correctly but cannot remember it better than neutral stimulus
• Results of a recent study using excitotoxin lesions of the amygdala in monkeys suggest that the emotional changes produced by selective amygdala damage were not huge - it is more connected to memory

Question 26

what was concluded in the study of canli et al.?

Answer 26

• Phasic interpretation supported that amygdala activation changes within an individual depending on the intensity of the emotional stimulus
• Amygdala activation changes moment-to-moment depending on the emotional intensity, and when the amygdala is activated for very emotionally intense experience, memory is enhanced

Question 27

what are the strengths of this study?

Answer 27

• generalizable - as human biology is similar across individuals
• high reliability - as standardised environment and procedures/use of quantitative data
• useful - as it helps to understand why people remember emotionally intense memory better
• high internal validity - high level of controls, objective data from fMRI
• self-selected sampling - so they gave consent

Question 28

what are the weaknesses of Canli et al.?

Answer 28

• low generalizability - gender bias (however the sample was justified)
• low ecological validity - in a lab setting and used fMRI and scenes
• uncomfortable to be inside a brain scanner

Question 29

why was the procedure standardized?

Answer 29

• it allows the study to be easily replicated, therefore it can be tested for reliability.
• for example, knowing how long the picture was presented, it can be repeated exactly
• it would increase the internal validity of the study
• cause and effect would more likely be seen if it is valid

Question 30

outline one strength of the sampling technique as used in this study.

Answer 30

the sampling technique used: self-selected/volunteer sampling
generally, volunteers are more motivated and less likely to drop out of the study and in this case, agree to the brain scan

Question 31

how is the nature and nurture debate supports the results of Canli et al.?

Answer 31

Biological processes underlying emotions are a product of the brain and hormones. However,
there are differences between individuals’ emotional responses. Differences can be due to
hormone levels or experiences.

Question 32

what are some ethics that were followed in the study?

Answer 32

Participants gave informed consent. Individuals operating the fMRI scanner were trained and
competent in the safety arrangements of the medical scan.