Motivation Flashcards
what is motivation
an internal force that drives behaviour to maintain a balanced physiological state
what is homeostasis
physiological balance between parasympathetic and sympathetic
what are some universal motivations in animals
feeding, drinking, reproduction
what are the two key phases of motivated behaviour
appetitive phase, consummatory phase
what is the appetitive phase
seeking behaviour
what is appetitive phase driven by
incentives
what is consummatory phase
fulfilment of need
what does one receive in consummatory phase
reward
what is the instinct theory (James, McDougall)
motivation arises from innate instincts (automatic and unlearned)
what is drive theory (Clark, Hull)
behaviour is motivated by the desire to reduce internal drives, maintaining homeostasis
when does the drive theory come into play
hunger, thirst
criticism of drive theory
not all behaviours serve to restore balance (e.g. eating desert when full)
what is incentive theory (Bindra, 1978)
behaviour is motivated by external rewards or incentives
examples of external rewards
money, praise
what brain areas are involved in motivation (Schmidt et al., 2012)
- cortical networks
- basal ganglia
cortical networks role in motivation
prefrontal, parietal, pre central regions (sensitive to incentives)
basal ganglia role in motivation
caudate and putamen (reward response); ventral parts encode expected rewards.
what does caudate and putamen do for motivation
focuses attention, inhibits distractions,
what is the caudate nucleus
a c shaped structure that curves around the thalamus
what is the caudate nucleus involved in
goal directed actions and learning
what is the putamen
located next to the caudate; more involved in motor control and habit formation
what is the striatum
the main input centre in the basal ganglia
what are the caudate and putamen called together
the striatum
what is the mesolimbic dopamine pathway
a reward system starting in the VTA and ending in the NA, linked to reward seeking behaviour
what is the VTA
ventral tegmental area
what is the NA
nucleus accumbens
what does dopamine do in motivation
increases the likelihood of engaging in behaviour by enhancing the appeal of incentives
what role does the amygdala play in motivation
attributes emotional/motivational value to stimuli; projects to NA
what happens when the amygdala is lesioned (McDonald & White, 1993)
rats become motivationally indifferent– less driven to pursue rewards
what happens with electrical stimulation of the lateral hypothalumus in rats
rats engage in motivated behaviours like eating and exploration
what is intracranial self stimulation
behaviour triggered by electrical stimulation of brain reward centres (e.g. hypothalamus)
what is satiety
the absence of hunger
what are signals of satiety
stomach distention, chewing, nutrient detection
what evidence supports blood-borne hunger signals
Davis et al. (1969) showed that hungry rats injected with satiated blood did not eat
what is the glucostatic theory (Mayer, 1955)
hunger occurs when glucose availability drops; satiety occurs when its stored
what are glucostats
glucose-sensitive cells in the brain and liver that detect changes in glucose metabolism
what happens when glucostats are destroyed (eg. gold thioglucose in mice)
mice overeat and become obese due to impaired satiety signalling (damage to VMH)
what does the dual centre set point mode (Stellar, 1954) propose
LH - hunger centre
VMH - satiety centre
what is the LH
lateral hypothalamus
what is the VMH
ventromedial hypothalamus
when is LH activated
when energy is low
when is ventromedial hypothalamus activated
when energy is sufficient
what is a set point in dual centre set point model (Stellar, 1954)
a biologically determined weight range that the body tries to maintain
what happens as a result of LH lesion
aphagia
what happens as a result of a VMH lesion
hyperphagia
what is aphagia
won’t eat
what is hyperphagia
overeat
what is anorexia nervosa
chronic under eating and extreme thinness
implications of anorexia nervosa
hypothalamic dysregulation, hormone changes, psychological factors
what is obesity
BW 20% above ideal
is there a genetic factor in obesity
yes
what are the two types of thirst
-osmotic
-hypovolemic
what causes osmotic thirst
from salty foods (cellular dehydration)
what causes hypovolemic thirst
fluid loss (blood, sweat)
what detects thirst signals
osmoreceptors near the hypothalamus
what is thermoregulation
the process of maintaining a constant internal body temperature
what are endotherms
generate internal heat
what are ectotherms
regulate temperature via the environment
example of endotherm species
humans
example of ectotherm species
reptiles
what are warm neurons
increase firing as temperature rises
what are cold neurons
increase firing as temperature drops
which brain region is linked to temperature regulation
pre optic area of the hypothalamus (Gordon and Heath, 1986)
what is the ideal temperature for brain function (Trastoy & Schuller, 2018)
36 to 38 degrees celsius, supports synaptic transmission
what temperature is hyperthermia
above 40-42 degrees celsius
what happens as a result of hyperthermia
protein denaturation, synaptic disruption, neuronal death
what temp. is hypothermia
below 30-32 degrees celsius
what happens asa. result of hypothermia
slowed neurotransmission, reduced metabolism and electrical activity
what is aggression
threatening or destructive behaviour
what are the two types of aggression
-impulsive
-premeditated
what biological factors are associated Wirth aggression
- hormones
- NTs
- PFC
what hormones are associated with aggression
high testosterone
what NT is linked to aggression
low serotonin = more aggression
what role does PFC play in aggression
controls aggressive impulses
what did Dabbs et al (1995) find
higher testosterone in men convicted of violent crimes, lead to prison rule-breaking
what brain areas are involved in aggression
medial hypothalumus
lateral hypothalumus
what role does medial hypothalumus play in aggression
defensive rage
what role does lateral hypothalumus play in aggression
predatory aggression (Siegal & Victoroff, 2009)
tumors in which areas = more aggression (Moyer, 1986)
anterior hypothalumus, amygdala, or septum
what do the findings of Moyer, 1986 infer
these areas (anterior hypothalumus, amygdala, septum) may inhibit aggression
what are exploratory behaviours linked to
novelty seeking
what pathway does novelty seeking involve
mesolimbic dopamine pathway
what brain area is involved in exploratory behaviours
hippocampus
what social behaviours are motivated
nurturance (maternal behaviour, dopamine linked)
attachmen/isolation (involves opioid systems)
what is the amygdala
almond shaped structure located deep within the temporal lobes
functions of amygdala
processing emotions, fight or flight
what is the origin of dopamine neurons
Ventral Tegmental Area (VTA)
what is the main brain site for reward experiences (pleasure centre)
Nucleus Accumbens (NA)
what role does amygdala and hippocampus play in motivation
assign emotion and memory to rewards
what is considered the central reward hub
NA
what are osmoreceptors
specialised neurons which detect changes in the osmolarity (concentration of solutes) in the blood
what is osmolarity
how salty or concentrated the blood is
function of osmoreceptors
when blood becomes too concentrated, osmoreceptors trigger thirst response and release ADH to conserve water
what is ADH
anti diuretic hormone
where are osmoreceptors found
areas in the hypothalumus such s the OVLT (organum vasculosum of the lamina terminalis), near the third ventricle
what do osmoreceptors maintain
fluid homeostasis
why does sweating occur
to regulate body temperature
what motivation is common to all species
social contact
if someone never feels full from eating, which brain area is damaged
ventromedial hypothalumus
