32 Motivation Flashcards
Define motivation.
motivation is a construct used to explain variability and flexibility in behavioral output that is attributable, not only to external, but internal states as well
Differentiate between appetitively motivated behaviors and aversively motivated behaviors.
appetitively motivated behaviors have as their goal the attainment of desired objects/circumstances; aversively motivated behaviors seek to prevent or terminate negative stimuli or events
What is the difference between reinforcement and reward?
reward has an additional subjective emotional experience that can accompany positive reinforcement
What region of the basal ganglia handles input?
normally the striatum consisting of the caudate and the putamen
Where do inputs to the basal ganglia come from and what neurotransmitter do these prospective areas use?
cortical inputs are glutamate encoded, inputs from the mesencephalon are in coded with dopamine, within the basal ganglia, opioid peptides are important for reward systems
Output from the basal ganglia is encoded with which neurotransmitter?
GABA, transmission from the striatum is GABAergic
What is important regarding the organization of cortical inputs to the basal ganglia as well as the organization of the basal ganglia nuclei?
incoming information is topographically organized and this information connects to specific places in the basal ganglia that have corresponding specific functions
With in the basal ganglia circuitry, where do connections go (nuclei that are part of the circuitry) before they meet the in the thalamus?
sub thalamic nucleus and the pars compacta/reticulata, after these nuclei there are also connections to the cerebellum and brainstem (direct) that were not emphasized in the this lecture
Where does input from the basal ganglia circuitry head from the thalamus?
back to the cortex, but to different places than the information originated; these areas include cortical areas involved in motor planning
Where within the striatum is the nucleus accumbens relatively located.
ventral and medial along the sides of the septum
What are the inputs for the nucleus accumbens?
prefrontal cortex (emotional regulation), amygdala (affect) and hippocampus (tying information together for declarative memory)
Inputs to the nucleus accumbens use what neurotransmitter?
glutamate and dopamine
Where do tracts from the nucleus accumbens project to?
ventral palladium and then the mediodorsal thalamus (completing the coritco-striato-pallido-thalamic tract)
Ascending dopamine pathways from this brain area innervate the striatum, including the nucleus accumbens.
ventral segmental area (near to the substantia nigra)
Name the predominant cell type of the striatum and its notable characteristics.
medium-spiny neuron is specialized in anatomical integration and uses GABA transmitter; stratal medium spiny output neurons specifically integrate multiple complex neurochemically specified inputs (glutamate, opioid and dopamine messaging)
The CSPT loop through the nucleus accumbens appears to specialized for _________ relevant information. (what type of specialized information does this area manage)
motivationally relevant information
Name two commonly used chemical entities that are used in reward and reinforcement.
dopamine and opioids (electrical stimulation of dopamine-rich brain regions is highly rewarding while pharmacological blockade of dopamine receptors blunts the brain stimulation-reward)
What is the consequence of experiments that show animals with dopamine receptor blockade does not reduce feeding hungry rats?
encourages the concept that there are two separate pathways for “wanting” and “liking”
Which neurotransmitters are for pathways involved in “wanting” vs. “liking”
dopamine for wanting (identifying salient reinforcers and pursuing them), opioids for liking (the subjective emotional experience of pleasure upon interacting with a reinforcer)
Under what circumstances is dopamine released that elucidate its role in “wanting” as well as learning about rewards?
the first time an organism experiences a new primary reward, when observing a stimuli that reliably predicts an expected reward and when a previously experienced reward is better than predicted (dopamine is released on the nucleus accumbens from the ventral segmental area)
Dopamine acts as a reward “teaching” signal that helps organisms learn what
how to get the reward, which is different from experiencing the actual reward (opioid linked)
What are the components of the mesolimbic system
dopamine projections from the VTA to the nucleus accumbens which are hypothesized to play a crucial role in wanting and also reward-learning
What system is involved in the hedonic experience of reward?
endogenous opioid system
What is thought to cause excessive impulsivity?
impaired function of PFC inhibitory control
