Translational affective cognitive neuroscience Flashcards
What did Darwin believe?
Emotions have a biological purpose, aiding in natural selection and survival
Primary emotions are ones which are universally inherited and easily replicable across cultures (shown in the Ekman faces)
What are the stages in achieving a BOLD signal with fMRI?
Stimulation Neuronal activity Neurovascular coupling Haemodynamic response Detection by scanner fMRI BOLD response
What is the amygdala?
Found in the temporal lobe, this brain region has been implicated in the processing of emotion, specifically anxiety and fear
It is responsible for the evaluation of stimuli, control of physiological responses, and also has links to emotional memory
Receives info directly from sensory regions of thalamus and cortex and also links higher up with all other brain areas responsible for emotional reactivity e.g. hypothalamus and PFC –> everything we associate with a fear response, including physiological changes, has been engineered by the amygdala
What is a key amygdala neural pathway?
Output pathway - ventral amygdafugal
Plays important role in associative learning and conditioned fear responses
When the brain receives a sensory stimulus indicating danger, signals travel first to the thalamus. From there, what is the “short route” along which information can be sent?
Also known as the Thalamo-amygdala pathway
Fast and rough impression of situation
Sub-cortical pathway in which no cognition is involved
Activates amygdala which then generates emotional responses BEFORE ANY PERCEPTUAL INTEGRATION has occurred and before mind has formed a representation of the stimulus
What is the “long route” from thalamus to amygdala?
Also known as the Thalamo-cortico-amygdala pathway
Also known as the cognitive appraisal route
Information reaches amygdala having been processed in the cortex and thus tells it whether or not stimulus presents real threat
To provide such an assessment, various levels of cortical processing are required
What are the levels of cortical processing in the long route?
Perceived object processed by PRIMARY SENSORY CORTEX
Then unimodal association cortex –> provides amygdala with object representation
Polymodal associative cortex conceptualises the object and informs the amygdala - does it pose an immediate threat? If not, this leads to activation of inhibitory mechanisms
Elaborate representation of object is compared with contents of explicit memory via hippocampus, which then also communicates with the amygdala regarding contextual information
Via these pathways, what happens to the amygdala in the presence of an imminent threat?
Activated and discharge patterns then activate efferent structures responsible for physical manifestations of fear e.g. increased HR and BP
What explains why we cannot remember traumas experienced very early in life?
Parallel operation of explicit (hippocampal) and implicit (amygdalic) memory systems - at early age the hippocampus is immature and amygdala is already able to record unconscious memories
Thus early childhood trauma can disturb mental and behavioural functions by mechanisms that cannot be consciously accessed
What is the fear response cycle?
Environmental stimulus e.g. fall over
Feelings - experience sadness and fear
Adaptive behaviour - feelings can become advantageous through triggering adaptive outcomes e.g. tears trigger someone to help
Feedback - if no help provided, levels of emotion stay raised even if environment made safe; emotion won’t go away and leads to maladaptive responses such as unfounded fears and chronic internal fear in the absence of any threat
If this goes on too long or is triggered too easily/frequently, the fear response becomes an anxiety disorder
What is the result of the amygdala being connected to the autonomic nervous system?
Emotional responses can often present as somatic physiological symptoms, especially in children e.g. amygdala connected to gut blood flow
Psychic symptoms include uncontrollable worry, anxious mood, sleep disturbances and difficulty concentrating
Somatic symptoms include muscle aches and pains, trembling/shaking, tachycardia/palpitations, GI complaints and dry mouth/sweating
How does the diathesis stress model explain anxiety?
Diathesis - inherited predisposition
Stressors - prenatal trauma, childhood abuse, family conflict, significant life changes
Development of the disorder - stronger diathesis means less stress necessary to develop the disorder
What is the neurological approach to the etiology of anxiety disorders?
Structural approach, explaining anxiety using biochemistry and key neurotransmitters such as GABA, dopamine, noradrenaline and glutamate
Focuses on anatomical subdivisions of amygdala, and connectivity involved - anxiety results when amygdala activated too easily/often
GAD - continuously high levels of amygdala activity
Specific phobias/PTSD - more of a kindling effect
What is the biological approach to anxiety?
Looks closely at neurotransmitters
Too little GABA (inhibitory) –> over-excited brain
Does the anxiety cause the reduced GABA or v.v. Is it the overuse of brain areas through anxiety that burns out the cells producing GABA?
What is the cognitive approach to anxiety?
Conditioning, modelling (phobias), irrational beliefs, maladaptive assumptions, meta-worrying (beliefs about positive and negative effects of worry), and arousal states
How does the HPA axis play a role in GAD?
Strong relationship between GABA and cortisol release - if not enough GABA, leads to excessive cortisol release
Again, critically think about causal direction here
What are the 3 phases of how stress can cause illness?
Phase 1 - Alarm reaction - ANS activated by stress
Phase 2 - Resistance - damage occurs or organism adapts to the stress
Phase 3 - Exhaustion - organism dies/suffers irreversible damage
How does stress affect the immune system?
Reduces number of lymphocytes –> increased viral and bacterial infections
In summary, what systems can a stressor affect in the body?
NS - leading to disorders such as anxiety, depression and insomnia; NS effects then feed into both endocrine effects and immune system effects
Endocrine - thyroid, adrenal, gonadal, mediated by neurotransmitters and hormones
Immune - inflammation, infections, allergies and pain, mediated by neurotransmitters and cytokines
What are the 3 types of OCD?
Obsessions and intrusive thoughts without overt compulsions
Obsessions and intrusive thoughts with overt compulsions
Overt compulsions without obsessions and intrusive thoughts e.g. Tourette’s
What is biofeedback as a potential treatment for anxiety disorders?
Neurological treatment option - trains people to improve their health by controlling certain bodily processes that normally happen involuntarily e.g. HR, BP, muscle tension and skin temperature
Biofeedback gives the anxious person the opportunity to view his or her physiological responses to stress on monitors. When a person becomes anxious, some of the changes that will be displayed visually and audibly with the use of noninvasive instruments
Biofeedback teaches awareness, profound relaxation skills and ways to manage an anxiety attack, as well as ways to recognize, reduce, and control stress responses. It also teaches the individual how to control the brain’s activity and maintain the proper brainwave levels to achieve a calm and focused state. By returning the body to a healthier physiological state, the “foggy head” that anxiety can cause, as well as the feeling of fear and panic throughout the body, are removed.
