Limbic System Part 2

Key structures for motivation

prefrontal cortex (dorsolateral, ventromedial, orbitofrontal)

anterior cingulate cortex

striatum (dorsal, ventral)

ventral tegmental area

insulation amygdala

hypothalamus

motor areas

basal nuclei

prefrontal cortex: dorsolateral prefrontal cortex (dlPFC)

involved in goal representation and attentional control

helps resist temptation in order to meet long-term goals (self-control)

stores emotional memories that are used in decision making

prefrontal cortex: ventromedial prefrontal cortex (vmPFC)

assigns value to emotional inputs during decision making

plays a role in risk assessment, decision-making, social judgments, and self-control

prefrontal cortex: orbitofrontal cortex (OFC)

processes information about rewards from the environment

involve din developing preferences and choosing between options

inhibits inappropriate actions (delay of gratification)

prefrontal cortex picture

anterior cingulate cortex (ACC) - part of limbic lobe

2 regions

• dorsal ACC: associated with cognition, connected with PFC and motor areas

• ventral ACC: associated with emotion, connected with the amygdala, nucleus accumbens (ventral striatum), hypothalamus, and anterior insulation

detects conflict during problem solving and in new situations

helps to prioritize attention, make choices, and predict consequences

uses information from the cortex and limbic areas to inform decision making and action selection

helps calculate cost-benefit analysis (is the effort worth the reward?)

insulation

involved in intuitive feelings

posterior insula and anterior insulation

posterior insula

monitors interoceptive information from the viscera; can send this information to the anterior insula; creates a body-based “feeling state”

anterior insula

constructs a representation of how one feels

integrates information from the posterior insula with contextual information (environment, task, people) to make emotional judgments (trust, anxiety, empathy)

creates a global “feeling state” that guides decision-making

amygdala

receives sensory information from the thalamus and sends emotional information to cortical areas

lateralization

• right amygdala: associated with negative emotions (fear, anger, anxiety), detects and responds to aversive events

• left amygdala: associated with positive emotions and reward

creates emotional associations with stimuli in the environment

hypothalamus

regulates biological functions and responds to natural rewards (food)

regulates the endocrine system (pituitary gland) and the ANS

produces visceral responses to emotions

Ventral Tegmental area (vta)

midbrain region that produces dopamine (involved in motivation/rewards)

dopamine release based on reward anticipation and is greatest when rewards are unexpected

forms mesocorticolimbic pathways

motor areas

premotor cortex and supplementary motor area

primary motor cortex

motor areas: premotor cortex and supplementary motor area

premotor cortex and supplementary motor area: motor planning

• creates smooth, coordinated action plan to be able to carry out goal-directed actions

motor areas: primary motor cortex

initiates movement execution

encodes movement parameters (force, direction, distance, speed)

basal nuclei

stratal complex and pallidal complex

basal nuclei: striatal complex

ventral striatum (nucleus accumbens)

• pressure center of the brain; activated by things we like, want, value, prefer, enjoy

• receives dopaminergic input from the VTA - mesolimbic pathway

neostriatum or dorsal striatum (caudate nucleus, putamen)

• input zone; plays an important role in selection of behavior based on value of goals

• receives dopaminergic input from the substantial nigra (pars compact) - nigrostriatal pathway

basal nucleI: pallidal complex

ventral pallidum (substantia innominata)

• receives input from the ventral striatum and other reward-related areas

• translates reward-related motivation signals from the limbic system into motor output

globus pallidus

• output zone: energizes or inhibits action plans; informs motor output

Which area of the brain creates a conscious construction of how we feel (i.e. trust, empathy)?

The anterior insula integrates information from the posterior insula to create a conscious representation of how we feel. This includes our "gut" feelings such as trust and empathy.

Which brain area integrates information from both the prefrontal cortex and the limbic system to detect conflict and inform decision making?

The anterior cingulate cortex integrates information from the prefrontal cortex and the limbic system to detect conflicts during problem solving. It helps to conduct cost-benefit analysis in order to inform decision making and action selection.

key pathways for motivation

mesocorticolimbic pathway

orbitofrontal-striatal circuit

ventromedial prefrontal-amygdala pathway

anterior insula-anterior cingulate cortex circuit

mesocorticolimbic pathway

mesolimbic projections: VTA to nucleus accumbens, amygdala, hippocampus

• dopamine pathway appraises the amount of reward a stimulus provides

mesocortical projections: VTA to PFC (orbitofrontal cortex)

• dopamine pathway brings awareness to stimuli that produced past rewards and promotes goal directed behaviors to seek out rewarding stimuli

orbitofrontal-striatal circuit

circuit between the PFC (orbitofrontal cortex and dorsolateral PFC) and the ventral striatum (nucleus accumbens)

helps with choice of large delayed reward over small immediate reward

delayed gratification

ventromedial prefrontal-amygdala pathway

important for value-based decision making and rewards processing

ventromedial prefrontal cortex (vmPFC) can suppress fear responses from the amygdala; pathway implicated in the PTSD
receiving feedback about failure may decrease vmPFC activation; however, making choices based on one’s preferences during a task can help maintain vmPFC activation even when receiving failure feedback, leading to improved performance

anterior insula-anterior cingulate cortex circuit

awareness of emotions (anterior insula) is used to make decisions about actions based on anticipated consequences (anterior cingulate cortex)

Which pathway is involved in delayed gratification?

The orbitofrontal-striatal circuit is a pathway between the PFC (orbitofrontal cortex and dorsolaleral cortex) and the ventral striatum (nucleus accumbens). This pathway is involved in delayed gratification. Activation of the nucleus accumbens (rewards system) increases focus on obtaining immediate rewards. The OFC and DLPFC help to inhibit immediate gratification in order to achieve long term goals.

True or false? The ventromedial prefrontal cortex amplifies fear responses from the amygdala, leading to increased stress and anxiety.

This is false. The ventromedial prefrontal cortex (vmPFC) is thought to suppress fear responses from the amygdala when activated.

Neural Basis of Key Motivations

Homeostatic motivational processes

• hunger, thirst

learned motivational states

• incentives, reward

person-generated motivational states

• volition, self-regulation/goals, intrinsic vs. extrinsic motivation, psychological needs, autonomous self-regulation

homeostatic motivational processes

hunger and thirst

• connection between hypothalamus and mesocorticolimbic pathway

  • orbitofrontal cortex and amygdala respond to rewards associated with fluid intake, activating the striatum

learned motivational states

incentives: the amygdala evaluates if stimuli are associated with reward or punishment; memories are stored in the hippocampus, insulated, and orbitofrontal cortex; incentive value is conveyed by the mesolimbic system to initiate action (to obtain the incentive)

rewards: activation of dopaminergic pathways

Person-generated motivational states

volition

self-regulation/goals

intrinsic vs. extrinsic motivation

psychological needs

autonomous self-regulation

Volition

mental control over action; ongoing effort to sustain motivated action

model of human occupation

• making choices and decisions about what to do (choosing occupations)

• anticipating options, choosing what to do, doing it, experiencing one’s actions, interpreting that experience

anterior cingulate cortex is involved in exerting mental control and problem solving; premotor and supplementary motor areas are activated in preparation for volitional actions

self-regulation/goals

goal-setting and planning are key for occupational engagement

the prefrontal cortex generates goals and intentions

dorsolateral prefrontal cortex is involved in pursuing long-term goals

anterior cingulate cortex is involved in monitoring conflict, integrating emotions, and making decisions about changing course of action

intrinsic motivation

interest, enjoyment

• doing a behavior because the activity itself is interesting and spontaneously satisfying…positive feelings result from the activity itself

  • anterior insulation is activated by intrinsic rewards; may modulate the formation of rewarding memories through activation of the VTA

increases positive affect, cognitive flexibility, creativity; supported by dopamine system

intrinsic motivation improves learning outcomes by stimulating the dopamine system and is involved in self-directed learning

Neurons associated with intrinsic motivation

2 types of dopaminergic neurons in VTA and substantial nigra

• value-coding dopaminergic neurons: stimulated by reward and inhibited by punishment (rewards, feedback, learning, success)

• salience-coding dopaminergic neurons: activated by curiosity and interest (intrinsic motivation); curiosity has been associated with activation of the left VTA/SN and bilateral striata (nucleus accumbens, caudate nucleus, putamen)

extrinsic motivation (incentive motivation)

engaging in a behavior because it leads to some separate consequences like gaining a reward

associated with the dopaminergic rewards system and the orbitofrontal-striatal circuit

anterior cingulate cortex helps determine if the reward is worth the effort

providing extrinsic rewards can DECREASE intrinsic motivation

basic psychological needs

self-determination theory assumptions

• people are naturally curious and motivated to explore their environments and succeed, which can either be supported or impeded by social environments

3 basic psychological needs support intrinsic motivation

• competence, autonomy, relatedness

anterior insulation and rewards system are involved com

competence

feeling effective in one’s ability to develop mastery in activities that are optimally challenging and that further develop one’s capacities; confidence in abilities and capacity to achieve goals

autonomy

exercising choice in one’s behavior; an experience of volition and integrity, the sense that one’s behavior is authentic and self-organized rather than internally conflicted and pressured or externally coerced

relatedness

feeling connected with others and having satisfying social relationshipsa

autonomous self-regulation

volitional decision-making (making personal choices) that are based on one’s sense of autonomy activates the ventromedial prefrontal cortex (vmPFC)

• can help resolve conflicts in the anterior cingulate cortex

VmPFC interacts with the ventral striatum and amygdala during value-based decision making

• co-activated with the ventral striatum during rewarding decisions

• suppresses fear response from amygdala

making choices can increase resilience when receiving feedback about failure, thereby improving performance

• cmPFC activation may reduce stress responses from the brainstem and reduce cortisol levels, increasing active coping

motivation and motor learning: OPTIMAL theory

optimal theory: optimizing performance through intrinsic motivation and attention for learning

motor learning influenced by:

autonomy (active participation in determining one’s behavior)

enhanced expectancies for future success (increase in perceived competence)

external force of attention (concentration on the movement’s intended effect)

response of dopamine in the anticipation of positive experience leads to improved performance

expected success leads to further success and aids memory consolidation

dopamine from the VTA promotes plasticity int he primary motor cortex with new motor learning, formation of new motor memories

Limbic System and Vagus Nerve

the vagus nerve appears to connect to limbic system structures via the solitary nucleus

• the solitary nucleus sends direct projections to the amygdala and appears to mediate emotional responses to respiration

amygdala is implicated in stress-related disorders, including PTSD

• overactivity in the amygdala can occur after exposure to traumatic stress; stress can lead to maladaptive breathing patterns (hyperventilation), which can further induce anxiety and panic

• decreased vmPFC control over the amygdala, leading to overactive fear responses

• hippocampal functioning is also impaired, which may lead to re-exeperience of trauma related symptoms

vagus nerve stimulation is treatment for chronic depression and PTSD

• electrical stimulation of the vagus nerve appears to alter cortical and subcortical Brian regions such as the amygdala and hippocampus (although the mechanisms are unclear)

• shown to reduce symptoms of depression and anxieyt

  • may inhibit the sympathetic nervous system, reducing tight or flight responses

limbic system and vagus nerve

mind-body interventions are also thought to increase parasympathetic tone through activation of the vagus nerve, leading to reduced stress

• slow breathing with long exhalation, yoga, mindfulness-based stress reduction techniques

• associated with connections between the autonomic nervous system and the limbic system (amygdala, hippocampus, PFC)

• increased PFC activation is associated with increased parasympathetic activity (which may improve inhibitory control over the amygdala)

• much is still unknown

therapeutic breathing techniques and mind-body interventions can help reduce stress and anxiety through connections between the autonomic nervous system (vagus nerve) and the limbic system

Which brain area is most strongly associated with intrinsic motivation?

Intrinsic motivation activates the anterior insula, which is involved in constructing how we feel. This relates to the positive emotions that we feel when we engage in something we enjoy doing.

true or false? Ronald enjoys gardening and feels motivated to work in his garden for several hours a week. This is an example of extrinsic motivation.

This is false. Intrinsic motivation involves doing something due to interest and enjoyment in the activity itself while extrinsic motivation involves engaging in an activity for any other reason, such as gainingWhich an external reward or to avoid a punishment.

Which area of the brain is activated when we make autonomous decisions based on our preferences?

Volitional decision-making (making personal choices) that are based on one’s sense of autonomy activates the ventromedial prefrontal cortex (vmPFC).