Panic Disorder Flashcards
• How predicted states help the brain generates physiological experience • How do symptoms of panic disorder and panic attacks relate to interoceptive experience and insular cortex • Potential causes of prediction error (beliefs/somatic error hypothesis)
what is the spinothalamic pathway?
spinal cord -> thalamus -> hypothalamus -> insular cortex (terminates) -> goes to amygdala too
where is the insular cortex and what does it do?
located deep within the brain and integrates information across modalities
what is interoceptive awareness?
metacognition about interoception
what is the interoceptive sensibility?
subjective interpretation
what is interoceptive accuracy?
accuracy at detecting interoceptive signals relative to objective measure
what is a neural indicator of interoception?
Heart-beat evoked potential -> neural signal approx 300 milliseconds after the R-wave heartbeat [we think this is the cortical index of that heartbeat of interoception]
* time-locked to R wave (point in cardiac cycle synchronising stimuli to the heart/phase of the cardiac cycle)
What is an Inaugural moment?
Initial Sensory Map (without any prior experience)
How does a predictive model suggest experience of body state is created?
Actively via prior experience and regulatory actions
Is the insula cortex in both hemispheres?
Yes (there’s a left and right insular cortex)
What can large uncorrected prediction errors lead to?
Maladaptive cognition AND maladaptive behaviours
What isn’t a symptom of panic disorder?
Dyskinea
Which is thought to be true of PD patients according to the study by Pauli et al., (1991)?
They catastrophise normal cardiac events [-> which leads to a change in their physiological state]
what is mental health?
- allows accurate experience of the body and the self
- trust the body to provide consistent, reliable sensory information
- enable engagement in everyday activities
- impairments of this characteristic of many different mental health conditions
- more contemporary approaches to mental health i.e.
- Transdiagnostic approach to mental health -> identifying mechanisms that might be important across many mental health conditions
- Interoception implicated in many conditions
- Transdiagnostic mechanism
Interoceptive symptoms are thought to be prominent features of many psychiatric disorders i.e. anxiety, depression and eating disorders. However, it’s unclear what the interoceptive deficit is but what are two reasons it potentially could be?
unclear whether it’s a different processing on interceptive signals or bias in reporting interoceptive signals
Elliot and Pfeifer (2022) measured interoceptive sensibility (MAIA) and anxiety during COVID-19 via survey responses. What did they find?
interoceptive constructs correlate with anxiety
- worry, trust, attention regulation
- cardiac cycle and brain activity are also related to anxiety
interoceptive accuracy [Adams et al. (2022)] looked at anxiety related to the cardiac domain as individuals tend to say they feel most anxiety within their heart. A meta-analysis of 55 studies during different measures interoceptive accuracy and anxiety (clinical and subthreshold samples). What did they find?
no relation between IA and anxiety and no effect of task or sample
- assumption that difficulty to detect heartbeats might make those more anxious or hypervillence of anxiety means we feel our heartbeat more
Yoris et al. (2015) invested Interoceptive Awareness in 21 anxiety patients with panic attacks and 13 Health Controls.
- measured Heartbeat monitoring task and Metacognitions about interoception (via a questionnaire)
Method:
- Followed an audio-recording of a synchronic (1) heartbeat or non synchronic (2) heartbeat
- Monitored heartbeats without external feedback with two intervals
- Then repeated this while receiving simultaneous auditory feedback of their own heartbeat
Way did they find?
- no diff in interoceptive accuracy task
- difference in metacognition (threatening beliefs about the body) -> interpreted signals differently compared to those in the control
- detection of symptoms but how they are interpreted
Pang et al. (2019)
* Heartbeat evoked potential (HEP) – Neural indicator of interoception (EEG)
* Time-locked to the R-wave ~300ms latency
* Generalised Anxiety Disorder (GAD) and health controls (HC) were two groups
* Examined HEP during resting state in 2 conditions:
- Eyes open (exteroception - more visual environment)
- Eyes closed (interoception - attending more internally)
What did they find?
In HC, HEP greater when eyes closed (attending more to interoception) compared to eyes open rest -> stronger neural responses to these heartbeats (greater focus in interoception with eyes closed)
In GAD, there’s no significant difference between conditions (reflects higher monitoring of interoception at all times, so they don’t get a facilitation effect of HEP when their eyes are closed, because they are already attending to it to it all the time at a higher extent)
- cortical response to heartbeats is greater in GAD
- reflects higher monitoring of interoception at all times at a higher extent
How is the Insular Cortex potentially different in anxiety disorders?
insula is found to have abnormalities in structure and function across many different forms of anxiety disorders
- abnormality in perception or interpretation of internal bodily signals (is less clear)
Etkin et al. (2007) conducted a Meta-analysis of brain activation for emotional processing across different anxiety disorders. Studies involved looked at…
* Social Phobia – exaggerated fear of negative scrutiny in social interactions
* Specific Phobia – irrational fear of something that poses little or no actual danger
* PTSD – anxiety and flashbacks triggered by a traumatic event
Combined data from multiple studies, including health controls with a normal fear response
What was found?
- patients with all three disorders demonstrated hypotheractivity (patients > comparison subjects) in the amygdala and insula
- this pattern of activation was also noted for healthy subjects experiencing anticipatory anxiety during fear conditions (looks like a normal response but patients were experiencing this at all times)
- an exaggerated fear response with shared neurobiology—might be reflected in shared neurobiology
interoception and self-concept
- an important aspect of self is corporeal awareness
- perception, knowledge and evaluation of one’s own body as well as of other bodies (Berlucchi and Aglitoi, 2009)
- being aware of our internal state modulates our approach and distancing behaviours which, in turn, help us maintain and regain homeostasis but also to navigate social environment
what does being aware of our internal state allow us to do?
modulates our approach and distancing behaviours which, in turn, help us maintain and regain homeostasis but also to navigate social environment
Interception and Psychiatric Disorders
- recent interoception models suggest that interoceptive experience is not passively derived from visceral sensations
- interoceptive states are dynamically constructed in the brain using information from sensory predictions and regulatory actions (afferent and efferents) -> actively generated rather than passively received)
- experiences are dynamically constructed in the brain, using information from afferent inputs, sensory predictors and regulatory outputs (actively generated rather than just passively received)
how does the insular cortex receive information?
- receives information about blood pressure and oxygenation, timing and strength of the heart rate etc
what are predictors?
- classical theories suggest that cortical regions either reflect stimulus intensity or additive effects of intensity and expectations
- if we base all our behaviours and thoughts on our sensory input, can we predict? predictors we use in everyday life and help us with coherent experiences and help us successfully navigate
- predictive theories suggest perception is shaped by the integration of beliefs about the world with mismatches resulting from the comparison of these beliefs against sensory input
- have certain expectations based on our previous experiences -> integrate and help create predictions thus shaping our experience
how does the insula cortex send information?
top down regulations control of autonomic functions such as regulating the heartbeat and blood pressure (does right thing to be able to construct interception)
what is predictive coding theory?
as lots of things in the world are stable (predictable) instead of processing all information, we just compare experience to predictions
* predicts are faster than direct sensory information
* updating predictions through errors help learning -> helping us to navigate our environment
predictive coding theory in terms of interoception:
- predictive doing links physiological states to behaviours and emotions
- prediction errors with interoception can lead to maladaptive emotions and behaviours - i.e. your heart beating every time you come to a specific place because you anticipate feeling nervous -> integrating social environment and prediction of the physiological state
experience of body state in terms of predictions:
- inaugural moment: initial sensory map from the body without prior experience
- map then modified by life experience - predicted sensory experience of encountering stimuli (internal or external)
- insular cortex, amygdala, anterior cingulate, ventral medial prefrontal cortex is incorporated, bringing this together to create coherent experiences for a physiological state
- experience of body state influenced by cognition (beliefs)
the predicted body state is continually updated from afferent information and cognition, how does it do this?
- this process results in prediction errors
- small errors are ignored
- large errors are detected and regulated to maintain homeostasis
- adapt predictions (next time, anticipate not being nervous) OR adopt physiological state (i.e. dealing with error and sending signals -> sending signals to insula to increase heart rate which will increase anxiety/induce it to the correct error)
- want to get back to homeostasis and rest within the body
