1
Q
what is a mechanism underlying anorexia nervosa?
A
interoception
2
Q
anorexia nervosa
A
low body weight, restriction
3
Q
bulimia nervosa
A
binge episodes, compensatory action (i.e. purging)
4
Q
Binge Eating Disorder
A
binge episodes, no compensatory actions
5
Q
there is a intuitive link between eating disorders and interoception, usually towards what system?
A
gastrointestinal system
6
Q
what is the intuitive link between eating disorders and interoception?
A
failure to detect hunger - restriction (not hungry, don’t eat)
failure to detect fullness - binge eating (not satisfied, continue to eat or emotional eating)
7
Q
what is some key symptomolgy of eating disorders and interoception?
A
- Confuse body sensations with emotions
- Difficult differentiating between emotions
- Emotion Regulation
- Alexithymia (inability to recognise and label our emotions)
8
Q
what is anorexia nervosa?
A
- Extreme overvaluation of shape and weight
- Disturbed eating, resulting in clinically significant impairments in health and psychosocial function due to self-starvation (BMI < 18.5)
- Resistance to treatment, poor prognosis, high mortality -> psychological consequences associated with AN and physical issues through starvation
9
Q
DSM-5 Criteria for Anorexia Nervosa:
A
- Restriction of energy intake to be less than what the body needs - leading to a significantly low body weight relative to age, sex, developmental trajectory, and physical health (cannot meet homeostatsis)
- Intense fear of gaining weight or of becoming fat
- Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation (self objectification), thinking that they are larger than they are, or persistent lack of recognition of the seriousness of the current low body weight
10
Q
Anorexia Nervosa presents itself as?
A
- Reduced capacity to soothe oneself or to empathize with others (self regulate emotions)
- Emotionally inhibited (flattening of affect)
- Depression, negative self evaluation
- Alexithymia - inability describe or recognise emotions
11
Q
What is the historical link between interoception and AN?
A
- intuitive link between interoception and AN (hunger)
- Historical Association: ‘a failure of recognising bodily states as a characteristic’ (Bruch, 1962)
- part of Long Standing Measures (Eating Disorder Inventory) -> has an introspective deficit scale, a core aspect of diagnostic procedure people use to clinically diagnose
12
Q
Eating Disorder Inventory -> Interoceptive Deficits sub scale (interoceptive sensibility). What does it look at?
A
A lack of confidence in recognising and accurately identifying emotions and sensations of hunger or satiety
* confusion and mistrust related to affective and bodily functioning are characteristic of eating disorders
- “I get confused about what emotion I am feeling”
- “I feel bloated after eating a normal meal”
13
Q
Interoception and AN (in terms of research)
A
- research does not dissociate between different types of interoception that may be impacted
14
Q
what two measures were not correlated in patients with AN?
A
sensibility and accuracy
15
Q
what impacts the interpretation of visceral signals?
A
dysfunctional thoughts and feelings
16
Q
[Jenkinson et al., 2018] Interoceptive Sensibility meta-analysis across all EDs
* EDI interoceptive scale
What did they find?
A
AN had significant lower scores -> show less awareness of their signals compared to others without the disorder
17
Q
what did Jenkinson et al., 2018 find in relation to other disorders?
A
- Bulimia Nervosa (BN) equivalent effects to AN [similar disorders/diagnoses]
- Binge Eating Disorder (BED) had a smaller effect size [lower awareness compared to those without the disorder to a significant lower extent than AN and BN -> so we can suggest that a lot of the diagnostic measures are designed specifically for AN and BN]
- Lower interoception in those with higher alexithymia
18
Q
What conclusions can be drawn from Jenkinson et al., 2018 research?
A
- Interoceptive sensibility transdiagnostic characteristic of Eds?
- But how it’s affected varies across diagnosis
- Heritable risk factor and/ important for maintenance -> inability to detect signals might maintain this disorder
- Target for therapeutic intervention?
19
Q
Interoceptive Accuracy [Pollatos et al., 2008]
* The heartbeat perception task was performed using four intervals of 25 s, 35 s, 45 s and 100 s
* During all trials, participants were asked to silently count their own heartbeats -> without taking their own pulse
* Patients show a reduction in the ability to accurately perceive their heartbeat compared to healthy controls
What did they find?
A
- Patients with AN exhibit a generally reduced capacity to accurately perceive bodily signals
- Less intense emotional experiences in many everyday situations -> heartbeats when you’re excited or happy so flattening affect might be because they’re not detecting these feelings, fitting with symptoms
- Potential importance of interoception in the pathogenesis of AN
20
Q
But findings are mixed. What does Eshkevari et al. 2014 suggest?
A
no difference between ED and controls (both at chance)
21
Q
But findings are mixed. What are Kinnaird et al. 2020 suggest?
A
no difference between AN and HC in accuracy but confidence (metacognition) was difference (interoceptive awareness)
22
Q
Lernia et al. (2018) conducted an Interoceptive Awareness Case Study AN and 4 HCs in a heartbeat counting task (introceptive accuracy)
* Confidence measure (Interoceptive Awareness - when compared to accuracy scores)
* MAIA (interoceptive sensibility)
What did they find?
A
- Trend towards lower interoceptive accuracy (but it wasn’t significantly different)
- Enhanced confidence of interoception (interoceptive awareness)
- Less able to regulate distress and distract from bodily signals, reduced body trust (interoceptive sensibility -> confidence different but accuracy is not statistically different)
- Almost total confidence in interoceptive accuracy (93/100)
- HC demonstrated alignment of accuracy and confidence (mean = 55/100)
- Detachment between ability to perceive the body and the awareness
23
Q
Neural Indicator of Interoceptions (Lutz et al., 2019)
AN and HC
* Heartbeat counting task during EEG - HEP
* No significant difference in interoceptive accuracy
* significant differences in interoceptive neural processing
What did they find?
A
Disturbance of interoceptive signal processing at the level of cortical representation
* Higher amplitudes in HEP (heartbeat evoked potential) interval but not earlier or later control intervals (not in different time windows than expected) - around 400 m/s but with earlier ones 300 m/s -> HEP happens between 300 and 400 but went away at different intervals
24
Q
Evidence for spinal thalamic path involvement: Affect Touch. The spinal thalamic pathway has two types of neurons that are involved in affective touch, what are these?
A
interoceptive neurones tend to be small diameter neurones with either AB delta and C Fibres
AB delta (myelinated - fast conducting - take signals like pain to the brain) and
C fibres (non-myelinated - relatively slow - take in touch information)
-> CT (or C Tactile) afferents follow the spinothalamic pathway, and a very specific slow type of touch (velocity 3-10cm/s) is needed to activate this pathway, and is associated to insula activity
25
In terms of afferent touch, what is it?
* touch specifically associated with pleasantness sensations, informs about physiological body state
* some evidence that affective touch can modulate/attenuate pain by following similar pathways (similar mechanisms to scratch and itch)
26
[Crucianelli et al., (2016)]
* AN patients given affective and neutral touch while looking at Images of faces with different facial expressions (smiling, rejecting, neutral)
* Asked for Judgments of pleasantness
* Wanted to differentiate between Anhedonia and something specific from bottom up pathway
What did they find?
* Pleasantness of affective touch was lower in AN (someone who's smiling, more pleasant than someone who isn't)
* Moderated by social context in both groups (but there was a general reduced pleasantness in the patient group (AN) -> because of the top-down regulation, not just a general defiicit but there's more likely to be a difference in the bottom up in CT spinal neuro-anatomical pathway
* Difference more likely to be bottom-up that top-down
* CT - pathway
27
Evidence for Insula Involvement (Murialdo et al., 2007) -> looked at regulatory control of the heart, doesn't just take in afferent information but also efferent information that adjusts the body, sending things to the body
* Regulatory control of heart rate variability in EDs using tilt table test
* Lie on a table that adjusts your body position from horizontal to vertical to simulate standing up (to see if you could see a different in heartrate in which you'd expect)
* Monitor changes in heart rate and blood pressure
* Patients had lower blood pressure
* Sympathetic cardiac activity did not increase in patients after lying to standing as occurs in healthy controls -> suggest their were some insula issues going on affecting regulatory mechanisms -> some top-down regulatory insula is also affected in these disorders
* Cardiac abnormalities similar in AN and BN even though only AN are emaciated (not linked to BMI) -> [found different in BN and AN, suggesting evidence about ageology of the disease] [remember we don’t know cause and effect so we cannot link this to BMI]
28
If AN patients exhibit differences in both heart rate detection / interpretation (interoceptive accuracy/awareness) and heart rate regulation. what is this consistent with?
insular cortex involvement
29
[Fischer et al., 2016]
* 15 AN patients
* underwent cognitive-behavioural therapy (but didn't target introspective directly) -> special attention to maladaptive emotional processes
* Aim of the intervention is a normalisation of the eating behaviours and reach an adequate body weight - but also targeting aetiology
* Tested at the beginning (T1), after 4–6 weeks (T2), and at the end of therapy (T3) [+ had some healthy participants they tested at equivalent time points]
Interoceptive accuracy:
* Three intervals of 25, 45, and 55 s.
* Focus on their heartbeat, count them silently, and report the counted heartbeats verbally
* Actual heart beats measured with a sports watch
Interoceptive sensibility: Interoceptive awareness subscale from the Eating Disorder Inventory
What did they find?
* Significant improvements of BDI (depression) and BMI (Patient group, depression gets lower)
* Interoceptive accuracy and sensibility [any recovery was small and inconsistent] -> stay stable and don't change over the course of treatment (transdiagnostic mechanism -> restored weight etc., feeling less depressed but if mechanisms underlying abnormal behaviours are still the same, there's a further risk of relapse)
30
what conclusions can be drawn from Fischer et al. (2016) research?
* interoception is processed differently in AN
* does not improve with other symptomology (weight and depression)
* potential mechanisms for development, maintenance and relapse of AN
31
How do differences in interoception lead to symptoms?
* most interoceptive differences seem to focus on the gastric system -> where as a lot of research has been focused on the cardiac system so is this really appropriate?
* are heart rate monitoring tasks indicative of all interoception?
* should other tasks be used in relation to AN?
32
[Kerr et al. (2016)]
* Weight restored AN patients
* Interoceptive attention task - focused on sensations in their heart, stomach and bladder -> different body parts
* Anxious Rumination -> often characteristic in these patient groups ('think about these kind of triggers and worry intensities') [asked to rate the itensity of worry]
* Exteroceptive trials -> asked different words, to attend to and relate the intensity of the colour change they saw
What did they find?
* reduced activity in the dorsal mid-insular in AN patients during stomach interoception
(shows different bodily signals and systems might be processed differently in the brain)
* higher activity in the anterior insula in AN patients during heart interoception
*AN displayed increased activation during anxious rumination in the dorsal mid-insular that was associated with the gastric attention to the stomach
(activity during stomach interoception correlated with eating disorder psychopathology and anxiety)
* Different functional activity in the dorsal mid-insular during gastric interoception contributes to symptomatology of AN (incl anxiety)
* Visceral hypersensitivity (association between food and gastric discomfort)
* when asked to focus, there is very little change from the baseline (inferring that there is higher activity at baseline
* change in signal -> relatively reduced activity compared to healthy participants -> concludes higher activity in general in gastric system so when you ask someone to attend to it, you don't see a change as yay would in health participants (key correlation between anxiety and gastric system information in the insula and psychological attributes of the disorder)
* contributes to anxiety
33
what might abnormal stomach interoception do during weight restoration?
exacerbate gastrointestinal symptoms
- gaining weight is a difficult part of recovery
34
what will gastric discomfort lead to?
increased anxiety that then leads to greater gastric discomfort
35
what is the issue with gastric discomfort causing increased anxiety?
creates a vicious cycle - inhibiting recovery
36
interoceptive processing in gastric and cardiac domains may influence..
AN symptomology
37
What do many AN patients have difficulty detecting?
hunger and satiety
38
what might hyper vigilance of gastric symptoms lead to?
anxiety over eating and disordered exteroceptive bodily experience (feeling fat)
39
what might be an issue for those with AN? What they might have reduced ability of?
reduced ability to detect heartbeats - flattening of affect (/not experiencing emotion as intensely as those without the disorder)
40
why might interoception across different modalities not be related? and therefore we cannot measure the same?
Modalities Differ
* heartbeat monitoring tasks are not a gold standard definitive test of interoception -> i.e. might have hypersensivity to gastric symptoms but reduced sensitivity to cardiac symptoms
* questionnaires also aren't designed to detect differences across modalities -> there is usually a modality in mind
41
Somatic error hypothesis and other prediction theories may suggest what?
inaccurate interoceptive predictions in psychiatric disorders
42
prediction mechanisms in AN:
- differences in gastric processing may not be sensory input but instead interpretation
- unclear mechanisms for how interoception underlies a complex disorder (i.e. AN)
43
Interoception and Eating [Khalsa et al. (2015)]
* Isoproterenol - adrenoceptor agonist [increase heart rate or breathing] or saline (double blinded trial)
* Pre and post meal intensity of heartrate and breathing
* Took measures of Interoceptive detection thresholds and interoceptive accuracy (correlating HR intensity and actual HR) -> rate intensity of their breathing and heart to be matched against their actual one`
* Stimulates a response from the adrenergic receptor (increases)
What did they find?
* post meal = no significant difference between groups
* pre meal = sig diff (detection thresholds were higher for AN group at baseline before they ate -> eating could be an anxiety trigger)
* AN experienced more intense cardiorespiratory sensations before consuming a meal
* AN more likely to report interoceptive experiences in all conditions, particularly low arousal conditions
* AN could be anticipating general increase in interception during a meal -> specific anxiety around the trigger of consumption (calorie intake or gastric discomfort etc)
* anticipating food intake (and/or gastric discomfort) could lead to anxiety
44
what conclusions can be draw from Khalsa et al. (2015) study?
* interoception is not an all or nothing measure -> instead dependent upon the context
* dependant on modality and environment
* insular cortex integrates information across modalities with visceral/interoceptive sensations -> key place producing predictions
* support a prediction error rather than general issues
45
Inaccurate mapping on interoceptive signals in AN can result in?
prediction errors about internal bodily state
46
what is an example of how inaccurate mapping of signals can result in prediction errors about internal body state?
intuitive link between difficulty perceiving hunger and satiety and dysfunctional eating habits prevents intuitive eating (if we cannot rely on these bodily signals)
47
how does interoception link to restrictive symptoms?
impaired interoceptive experience means AN patients cannot use internal signals to perceive physical changes of weight loss
* do not recognise satiety or hunger and will continue to restrict food intake despite emaciation
48
what are emotional symptoms those with AN may an experience?
fear of the intense feeling of gaining weight
49
AN is associated with high rates of what?
alexithymia (inability to recognise emotions from one's bodily states)
50
AN is linked to the decreased ability to?
self-regulate emotions - regaining homeostasis and autonomic control of the insula
* inaccurate perception and interpretation of interoceptive signals
51
what is body image?
how you experience and feel about your body
52
how can body image feel for those with AN?
* overvaluation of weight and shape
* self-objectification
* inaccurate (overestimation) experience of body size
- disturbance in the way which one's body weight or shape is experienced
53
how may interoception / exteroception impact body weight?
* failure to update external perception of the body through direct sensory input -> don't realise they have lost weight and continue to feel dissatisfied with their body
* over reliance of exteroception (vision) leads to enhanced self objectification and symptoms such as body checking -> further association with disorder / getting little from signals about physical bodily state means you overly rely on external body signals)
54
what is objectification theory?
* bodies are viewed and evaluated based on appearance (not separating appearance from person)
* body = object (sexual)
* body and sexuality = separate from the person
* objectifying others and objectifying the self
- more you self objectify, the more important body appearance and deviate from social ideas is important for self-worth
55
how do those with AN pay attention to interoception?
* competition of cues hypothesis
* emphasis on body appearance distracts from internal signals and vice versa (i.e. feeling sick, look awful but you don't care because you're overwhelmed / feel bad on the inside - but if you fine on the inside but bad on the outside, there is a problem because we will focus on looking bad extractively on the outside - an over-evaluation)
* poor interoception in AN = self-objectification
56
what will poor interoception in AN lead to?
self-objectification
57
competition of cues hypothesis
finite attentional resources available to us (Pennebaker 2012)
58
What is the insular cortex?
neural hub connecting interoceptive signals with other modalities, including exteroception, cognition and emotion
59
what may underpin many key symptomology in AN?
potential mechanisms in AN of interoception
60
what usually happens during treatment?
high rate of relapse
61
how does interoception risk relapse?
interoceptive prediction errors may lead to further errors and negative affective that is unresolved lead to risk of relapse particularly with certain emotions (emotional, physical, cognition etc. esp sometimes after weight restoration)
62
what was found for weight restored AN patients in terms of their insula?
Weight restored AN patients to show differences in insula activity when anticipating food (predictive state) (Oberndorfer et al., 2013) as well as decreased response to the taste of food stimuli (Wagner et al., 2007)
63
what may continue following weight restoration?
Both exteroceptive (Engel & Keizer, 2017) and interoceptive (Fischer et al. 2016) bodily symptoms continue (judgement of body size etc.)
64
Treatment
* Plasticity of the insula suggests such issues can be targets for treatment (target specific interoceptive elements)
* Potential interoceptive treatments need to be tested
65
interoceptive abnormalities may be?
resistant to current treatments
66
What are some potential treatments that can be used?
* Interoceptive exposure (increase tolerance to the physical symptoms of anxiety through repeated exposure of provocation triggers)?
* Mindfulness? - attending to different body parts (but cannot change our interoceptive accuracy, but a lot of the research suggests it's not accuracy affected but instead they way we intepret them)
67
neuroimaging evidence supports?
insula involvement in AN
68
Interoceptive abnormalities not always consistent, what can they be influenced by?
physical state (low arousal), environmental cues (pre meal) and modality (cardiac vs gastric)
69
interoceptive differences in AN are from what, INSTEAD of what?
environmental cues (pre meal) and modality (cardiac vs gastric)
Interoceptive differences in AN from error in predictive mechanisms rather than sensory input
70
what are some potential mechanisms for other symptoms?
emotional and body image disturbance
71
what could resistance to current treatment lead to?
high relapse and mortality (body is unsuccessful maintaining and regaining homeostatsis)
brain & behaviour 2
flashcards
Decks in class (19)
# Cards
-
Post Traumatic Stress Disorder45
-
Disorders of the Parietal Lobe38
-
Clinical Neuroscience of Depression50
-
Acquired Brain Injury in Children58
-
The Basics of Movement91
-
Advanced Movements85
-
Basic Decision-Making91
-
Advanced Decision Making74
-
Parkinson's Disease32
-
Introduction to Interoception47
-
Interoception Tutorial26
-
Constructs, Measures and The Role of the Insular Cortex71
-
Panic Disorder75
-
Interoception and Anorexia Nervosa71
-
Amnesia43
-
Structure and Function of the Hippocampus108
-
Retrieval of Memory103
-
Memory Representation in the Temporal Neocortex80
-
Brain Systems for Memory (The Remembering Brain)70
