Lecture 5 - BIS and sensitivity to punishment Flashcards
What are typical inputs to the BIS system?
Signals of punishments
Signals of non-reward
Novel stimuli
What are typical outputs of the BIS system?
Behavioural inhibition
Increment in arousal
Increased attention
What type of drug impairs the BIS system?
Anti-anxiety drugs
What does BIS arousal give rise to?
Anxiety
Which brain region does the medial septum have lots of connections to?
Hippocampus
What is the main brain system that BIS mainly comprises?
The septo-hippocampal system & its inputs/outputs
What evidence links the BIS system to the hippocampus?
a) Anxiolytic drugs & Hippocampal lesions have very similar effects.
b) Anxiolytic drugs impair hippocampal theta oscillation.
Given both a & b, the hippocampus probably at least partly mediates anxiety.
Anxiolytic drugs impair behavioural inhibition & increases in arousal/attention
What are key neurotransmitters in BIS?
Gray emphasised serotonin, noradrenaline, & acetylcholine
Other than the septo-hippocampal system, what two brain areas are also involved in BIS?
- medial prefrontal cortex
- amygdala (esp. in later versions of theory)
What two aspects of BIS were re-conceptualised in 2000?
a) They had to incorporate amygdala into anxiety systems
b) In original theory, BIS mediates avoidance.
Later, they reconceptualise the BIS in terms of conflict.
The classic exemplar of BIS operation is the
‘approach/avoid’ conflict:
I want to eat that food, But maybe there is a predator about
I want to go to the party, But I am worried I will look foolish
Does the amygdala play a role in generating a state of anxiety?
Yes
The hippocampus encourages the subject to further consider the potential negative outcome associated with a behaviour. What does hippocampal activity promote?
1) Behavioural inhibition
Stop ongoing activity like eating, running, making noise (predators might be near!).
Stay near an escape route.
2) Risk assessment and exploration (resolve the conflict!) - later theory
Gathering info:
What is the risk? Has the risk subsided?
Is that a predator about or is it just leaves falling?
Burglar or false alarm?
What is the core of anxiety?
Worry, rumination, being ‘nervous’
Are men generally more anxious than women?
No
Women appear to be generally more anxious than men
However, men do not report anxiety as much (go to doctors)
Does Gray conceptualise anxiety as a continuous dimension?
Yes - high end is clinical
Why did we evolve to have anxiety? Sex differences?
Anxiety has evolved because some caution is adaptive.
Perhaps more for women than men?
Sex-specific strategic success emphasises caution for women, risk-taking for men?
(Think of who causes deaths by dangerous driving among young people - men)
What are the three components of anxiety?
Somatic – e.g. heart rate increases, dry mouth
Cognitive – e.g. mindset biased towards caution, loss-aversive
Behavioural – e.g. risk assessment, explore before act, BI
What anxiety disorder is most relevant to BIS?
GAD - generalised anxiety disorder
Gray & McNaughton (2000) tend to consider GAD the clinical ‘high-end’ of the BIS dimension
(Extreme of normal variation between individuals)
What is the distinction between anxiety and fear?
Danger is present -> ‘fear’. (FFF)
Danger may be present -> ‘anxiety’. (BIS)
How many of the BIS questions were found by Heym et al (2008) to map onto FFF as well?
2 out of 7
Which aspects of anxiety do SP and BIS questionnaires capture?
Cognitive and behavioural aspects of anxiety
Both SPSRQ & BIS have questions on:
Worrying (3/7 Qs in BIS), Social punishment, Social anxiety
SP has questions on:
Embarassment/shyness, Approach/avoid Conflict, Neophobia
Both similar to Cloninger’s ‘harm avoidance’
What aspect of anxiety is not captured by SP and BIS?
Somatic aspects of anxiety
heart racing, legs/arms trembling, numbness, tingling and so on.
Does BIS score predict clinical type diagnosis in adolescents?
Yes
e.g. Johnson et al. (2003)
>1800 adolescents aged 19-21yrs
BIS scores predicted clinical diagnoses of depression and anxiety
e.g. Vervoort et al (2010)
175 children aged 8-18yrs
Used a child version of Carver & White’s BIS/BAS scales.
BIS predicted various clinical anxiety diagnoses & depression.
Does BIS score predict clinical-type diagnosis in adults?
Yes
For instance, Maack et al 2012 took 91 participants and gave them various emotion-related questionnaires.
BIS score and ‘Emotional dysregulation’
BIS scores strongly predicted the diagnosis of GAD
These questionnaires have some relation to clinical diagnosis
What does a higher BIS/SP score correlate to in terms of hippocampus and amygdala size?
Larger hippocampus and amygdala
What does a higher ‘anxiety’ type score correlate with in terms of hippocampal size?
Larger hippocampus
Which side of the hippocampus seems to be more involved in BIS/anxiety?
Right
What did Barros-Loscertales et al (2008) find out about hippocampal and amygdala volume using voxel and structural MRI?
Hippocampal formation volume & Amygdala volume
Are Positively Correlated with
Sensitivity to Punishment scores
What did Levita et al (2014) find out about SP scores and right hippocampal volume?
Using MRI:
Sensitivity to Punishment scores correlate positively with Right hippocampal volume:
STP b = 0.33, p = 0.04,
Age was a small predictor
Sex was not a predictor
What did Levita et al (2014) find out about SP scores and right/left hippocampal laterality?
Higher anxiety = higher right/left volume ratio
STP b = 0.38, p = 0.03
Age and sex were small predictors
Is the hippocampus smaller with increased Spielberger’s trait anxiety?
No - larger
Early small sample study by Speilberger et al. (1970)
Supported by Rusch et al. (2001)
Supported by Chan et al. (2016) - tested depressives and controls using Eyesenck’s personality questionnaire, and more neurotic ppts had a larger right hippocampus
Is this true - the more anxious you are, the larger your right hippocampus?
Yes
What did Baksh et al. (2021) find out about the hippocampus in people with GAD?
Hippocampi on both left and right added together.
Multiple regression accounting for many factors such as Age, Sex, education, overall brain volume. GAD showed a positive correlation with hippocampal volume
(beta value = +0.089)
The GAD group had a larger hippocampus.
What does it mean when a brain region expands?
Often, there is high activity in that region
Is brain volume purely determined by genetics?
No, experience plays a role
What happens to the sizes of amygdala and hippocampus in rats who have been bred to be more or less anxious?
More anxious = larger HPC and AMYG and vice versa
Do rats who have been environmentally manipulated to be less anxious have smaller AMYG and HPC?
Yes
What environmental manipulation of rats can cause them to have increased anxiety?
Either handled by researchers or not handled
Not having previous experience of handling means they get more anxious when researchers are around
What does a larger hippocampus prepare someone for?
More efficient worrying:
These mechanisms evolved such that a larger hippocampus prepares its subject for more adverse circumstances in later life that need to be thought-through
More stressed you are - greater need for a hippocampus - greater drive so greater need for activity
Neurogenesis is what? Where in the brain does this happen?
Neurogenesis (new cells being born) occurs in the hippocampus, unlike most areas of the brain
How does neurogenesis relate to higher hippocampal volume in anxiety?
Higher hippocampal activity may increase hippocampal volume not just by growing new connections between existing neurons, but via new neurons
What two things are reliably associated with smaller hippocampi?
Stress and depression
Traumatic or repeated stress can shrink the hippocampus. Kills neurons, retracts dendrites
Why is it not contradictory that anxiety predicts large hippocampus and depression predicts a small hippocampus, yet both anxiety and depression are frequently comorbid in people? (link to PTSD)
Both Depression-related and BIS-related factors independently control volume.
Depression/stress towards shrinking; BIS towards increasing.
If your ‘anxiety’ is like PTSD then that strong influence ‘wins’ -> small hippocampus.
Intriguingly, a small hippocampus may predispose to PTSD (Gilbertson et al, 2002, Nature Neuroscience)
PTSD-prone subjects are less ‘prepared for efficient worrying’?
Reliving stress response instead of ruminating and worrying
If someone has a small hippocampus, do they have low anxiety?
Possibly, however they could also have anxiety in combination with depression or PTSD
In Loh et al. (2017), what was the approach/avoid task used?
People gained or lost money
If there was no bomb behind the dots, they gained money
If there was a bomb behind the dots, they lost money
Ppts could accept, reject or explore
There was a control study in which there was no loss, they either gained or did not gain
In Loh et al. (2017), what area of the brain was activated when trying to avoid potential loss? What other measure was this positively correlated with?
Anterior hippocampus
Anterior HPC activity during gamble rejection was positively correlated with trait anxiety
What role might the anterior HPC play during gambling?
The Anterior Hpc keeps signalling the potential negative outcome of choosing to gamble (‘Yikes! a bomb could go off!’ ).
The higher this activity, the more the subject chooses ‘Reject!’.
More anxious people = higher Hpc activity, & more ‘Reject!’s.
Anterior hippocampal activity anticipates aversive outcomes, making you anxious.
What is the monetary incentive delay task? (used by Hahn et al., 2010)
A cue before each trial signals whether failure will engender: no loss, a small loss (5 eurocents) or a large loss (1 Euro), and is followed by a delay prior to the presentation of the stimulus
Which brain areas were activated during the monetary incentive delay task? (Hahn et al., 2010)
Both the small and large loss conditions elicited hippocampal and amygdalar activation during the delay period, compared to the no loss condition.
Was the degree of activation in AMYG and HPC in the monetary incentive delay task correlated with Gray’s SPQ trait anxiety measure?
No
Was there a correlation between functional connectivity between the amygdala and hippocampus and SP score?
Yes
0.66
The more you say you are sensitive to social losses, the more or less your hippocampus and amygdala activity are correlated during anticipation of monetary losses?
More
How you react to social punishments predicts brain activity during monetary punishments
Both the hippocampus and amygdala are jointly involved in the BIS, and the strength of their co-modulation contributes to people’s BIS-related personality.
Is anxious temperament in young monkeys positively or negatively correlated with HPC and AMYG activity?
Positively
Is the heritability of anxious temperament in young monkeys predicted by hippocampal or amygdalar activity?
Hippocampal
What is the hippocampal subregion predicting anxious temperament in primates and rats?
Primates = anterior hippocampus
Rats = ventral hippocampus
Same region - just varies in name depending on where head is in relation to body
What are characteristics of a child with an anxious temperament?
Kids with AT are abnormally shy in front of strangers, inhibit their locomotion and vocalisations. They worry excessively.
How did Kalin design a threat situation to model anxious temperament in monkeys?
Kalin’s group present a human in profile (not direct eye contact) 2.5 metres away from cage
How do monkeys exhibit anxious temperament?
Monkeys typically: inhibit locomotion, and inhibit cooing
In Oler et al. (2010), measured brain activity in monkeys who were related to one another, using glucose and a PET scan. How did this work?
Inject FDG (like glucose) before exposure to human ‘intruder’.
Glucose metabolism during the Intruder Threat period reflects activity during that threat period.
The FDG levels are then measured with PET after the threat.
(Note: i.e. this uptake will reflect not only threat-induced activity but also some baseline activity).
How did Oler et al. (2010) measure anxious temperament? (behavioural and biological)
2 measures of behavioural inhibition:
i.e. freezing and cooing (during the threat period)
AND Cortisol level (after the threat period)
AT in this study is a composite measure, comprising:
A) Freezing
B) (Reduced) cooing
C) Cortisol release
Is there a positive correlation between AT and dorsal amygdala activity? (Oler et al., 2010)
Yes
0.44 for right amygdala
Is there a positive correlation between AT and anterior hippocampus activity? (Oler et al., 2010)
Yes
0.45 for left hippocampus
Is anxious temperament heritable?
Yes - 0.36 for monkey AT behaviour
Also shown for human anxiety
Is anxious temperament-related brain activity heritable?
Yes, in hippocampus but not amygdala
Region of overlap in the hippocampus between:
a) heritability of glucose metabolism area
b) Area that most predicts AT
The heritability of the activity in the HPC area that most predicted AT was h2 = 0.52
Quite high for a measurement of heritability
Is the right or left hippocampus more active in Speilberger’s trait anxiety?
Right
Corr et al. (2022) looked at brain activity during a stress test in peri-adolescents (fMRI imaging during stress test, Trait Anxiety Q). What activity did stressors in early life strongly predict?
Higher right Hippocampal activation
Higher trait anxiety scores
This relationship between polyvictimisation and trait anxiety is partly mediated by right hippocampal activity
What part of the hippocampus mediates anxiety?
Anterior - role in anxiety
Posterior - spatial cognition memory
