TASK 7: Sleep

Palmer

emotion regulation - interaction of limbic system with controll centers (PFC)

sleep: same brain structures involved in the regulation of emotion also govern sleep

REM SLEEP: activation of emotion-related brain regions (e.g., amygdala, hippocampus) + inhibition of aminergic neurotransmitters including norepinephrine and serotonin

“sleep to forget, sleep to remember” model - REM sleep :

b) attenuate their affective tone via inhibition of aminergic neuro-transmitters - resulting in successful reactivation and neural integration of emotional events

a) strengthen the declarative component of emotional experiences via activation of the same emotion-related brain structures

process model-again

sleep restriction

decreased connectivity between the medial prefrontal cortex PFC) + ventral ACC with the amygdala - global problems with monitoring and regulatory control

other regions of the striatum (e.g. caudate and putamen_ implicated in motivation and emotion regulation also are highly sensitive to sleep

sleep loss effects

Attentional deployment

Cognitive change

Situation modification

Response modulation

situation selection -decrease the likelihood of situating oneself in positive emotional contexts

  • altered neural reward circuitry - both decreased motivation for and altered valuation of rewards
  • diminished ability to self-monitor, appropriately interact with others, pick up on others' nonverbal cues + accurately identify others' emotions
  • impaired decision making, poor impulse control
  • more social loafing and less productivity
  • maladaptive behaviors in the midst of a conflict

 failure to use attentional strategies to effectively regulate one's emotional responses
individuals tend to utilize distraction when emotional information is highly intense  inadequate sleep is likely to mitigate such attempts via an interaction of different neural structures and processes

increased vigilance to negative stimuli

  • lowered cognitive reappraisal ability
  • significantly reduces the tendency to think positively
  • BUT: cognitive reappraisal ability may be somewhat resistant to sleep loss effects

whereas global emotional expressiveness might be altered by sleep loss, ability to intentionally modulate expressions may be more resistant to the effects of sleep loss

CONCLUSIONS

  1. produces more negative + less positive emotions, with some evidence for greater decrements in positive emotions
  1. can negatively impact emotion at various stages of the regulatory process, including the identification, selection, and successful implementation of various strategies
  1. decrements in motivation and perceived reward as a function of inadequate sleep may lead to unsuccessful emotion regulation strategies

extended model of emotion regulation

strategy selection

implementation

identification

mindfulness = emotional awareness : good sleep facilitates mindfulness

dependent upon the availability of personal resources and/or the specifics of the emotional context

  • failure may occur due to abnormalities in neural networks involved in regulating affect, a general lack of skill in translating a chosen strategy into practice, and/or a mismatch between the functionality of the strategy selected and the situational context


  • diminished cognitive flexibility during extended waking periods


Tempesta

sleep loss

  1. sleep loss and Emotional memory encoding
  • impaired ability to encode emotional pictures after total sleep deprivation
  • but not after selective REM sleep deprivation - proactive role of sleep per se in affecting emotional memory encoding
  1. Sleep loss and Emotional memory consolidation:

a) sleep effect

  • beneficial effect of sleep on memory consolidation is thought to be driven by offline memory reactivation mechanisms
  • positive influence of post-learning sleep on the retention of emotional memory contents
  • not yet well established if sleep specifically affects memory for emotional information more than neutral information

b) the effects of sleep deprivation

decreased ability to successfully recall positive, negative and neutral picture stimuli

  • deteriorated ability to encode episodic information
  1. Sleep loss and emotional reactivity
  • mood changes, increased irritability and affective volatility

positive reactions to pleasant events are often subdued

magnified negative experiences

  1. Sleep loss and empathy
  • impairs the ability to share the emotional state of others
  • reductions in several social and emotive abilities, such as optimism and sociability

5.Getting some Sleep- fear memory and extinction memory

promotes the strengthening of physiological and behavioral conditioned fear responses, paralleled by the activation of the basolateral amygdala

promotes the strengthening of physiological and behavioral conditioned fear responses, paralleled by the activation of the basolateral amygdala

facilitates fear extinction = subsequent new learning of fear inhibition

 specific role of REM sleep in the mechanisms of fear consolidation and extinction

  1. Sleep, threat generalization and extinction generalization
  • after a period of sleep, memory of extinction learning can generalize from a previously extinguished association to another similar but not extinguished association
  • may support the appropriate recognition of salient stimuli and the discrimination of fear and safety relevant information, ultimately promoting the most appropriate response to the environment

SLEEP LOSS

  • should enhance threat perception and promote threat generalization
  • could have imposed a negative bias on the behavioral discrimination of emotional stimuli, leading to an increased tendency to evaluate affiliative stimuli as threatening

REM SLEEP and emotional reactivity

“Sleep to remember, sleep to forget” model

  • REM sleep could support a de-potentiation, rather than a strengthening, of the emotional charge of a memory
  • during REM sleep the strong reactivation of brain areas implicated in memory function during wakefulness (amygdala + hippocampus) supports the overnight reprocessing of previously acquired emotional memories

a) activation of the amygdalaehippocampal network would promote long-term retention of the salient features of an emotional experience (“Sleep to remember”)

b) suppressed adrenergic activity would decouple and gradually dissipate the visceral, autonomic charge associated to emotional experiences (“Sleep to forget”)

 REM sleep could represent an “overnight therapy” to adaptively preserve the salient aspects of a memory, forgetting at the same time the associated emotional tone
 sleep deprivation should prevent this beneficial overnight emotional de-potentiation

REM sleep emotion recalibration model

  • role for REM sleep in directly regulating the concentrations of noradrenaline  promoting next-day emotional homeostasis
  • alterations in the noradrenergic system imposed by sleep loss could produce a hypervigilant brain state responsible for persistent sensitivity and impaired emotional discrimination

SUMMARY

  • significantly greater amygdala activation in response to negative emotional stimuli
  • significant loss of functional connectivity between the amygdala and mPFC
  • increased connectivity between the amygdala and autonomic-activating brainstem areas

-> hyper-limbic response to aversive stimuli + dysfunctional pattern of connectivity between the amygdala and mPFC (failure of top-down prefrontal control over emotional areas)

CONCLUSIONS

 studies strongly suggest a crucial influence of REM sleep on overnight emotional modulation, but the direction of this effect is still controversial

 opposing theories:

a) REM sleep could promote the retention of the emotional memory charge

b) Or de-potentiate the visceral tone associated with a memory

Gruber

Sleep and Emotional Regulation

homeostatic process

regulates length and depth of sleep - related to accumulation of adenosine during wakefulness. Insuffiient sleep leads to "sleep debt"

circadian sleep processgoverns pattern of sleep - moments of sleepyness and peak alertness (circadian peaks). Regulates sleep onset, awakening and duration. Circadian cycle is bit longer than 24h but it is synchronized by so called zeitgebers (light, social timing, routines, meal times)

sleep related neural activity

waking state

excitatory neurotransmitters released in the brainstem, midbrain + basal forebrain structures

  • release of inhibitory neurotransmitters from the ventrolateral preoptic nucleus (VLPO) is suppressed

NREM sleep

  • aminergic neurotransmitters, cholinergic neurotransmitters + orexin are all inhibited through the VLPO-mediated release, which decreases arousal
  • thalamo-cortical rhythms can be detected by electroencephalography (EEG)

REM sleep

  • release of aminergic neurotransmitters of the brainstem is inhibited
  • acetylcholine is released in the brainstem, midbrain + basal forebrain
  • Orexin is also released
  • GABA + galanin are released from the brainstem and VLPO to inhibit the aminergic brainstem neurons

Executive function - wm, attention shifting, inhibitory control, planning

  • brain processes that underlie executive functions are involved in emotional regulation
  • integrate the interrelated processes of emotion (“hot” executive functions) + cognition (“cold” executive functions

proposed conceptual model: adequate sleep plays a role in driving the executive functioning abilities necessary for successful emotional regulation

 emotional regulation: interactions between prefrontal cortex (control processes) and subcortical and posterior cortical regions (encode and represent specific kinds of information)

 Executive functioning: dorsolateral prefrontal, anterior cingulate + parietal cortices

sleep deprivation: hyperactivity of amygdala, lower conectivity between PFC and amygdala

MOOD AND SLEEP

Eveningness vs Morningness

Eveningness

  • associated with emotional dysregulation + novelty seeking, harm avoidance + neurotic personality characteristics
  • less extraversion and social desirability
  • more susceptible to greater impulsivity and to stress
  • more likely to be diagnosed with an anxiety disorder, addiction disorder or personality disorder

Morningness

  • could play a protective role
  • associated with better emotional regulation, decreased emotional reactivity, decreased risk for aggressive behavior + delinquent behavior, decreased impulsivity + increased persistence