PSYCH – Week 20 Online Readings
Week 20: Motivation and Emotion
Focus Question: Why do we do the things we do?
Introduction – Motivation
Motivation can be broadly defined as the (internal and external) desires, needs, and
interests that arouse and activate an organism to move toward a specific goal. Your
textbook (p. 405) defines motivation as a general term for a group of phenomena that
affect the nature, strength, and persistence of an individual’s behaviour.
Motivational states or drives:Areversible internal condition that affects the nature,
strength, and persistence of an individual's behaviour.
- We consider animals to be in a motivational state or experiencing a particular
drive. Psychologists classify drives as regulatory and nonregulatory.
- Regulatory drives are like hunger, thirst, thermoregulation and sleep that help to
maintain physiological homeostasis (needed for immediate survival.
- Nonregulatory drives fulfill some other evolutionary purpose, such as
reproduction, safety, or cooperation.
Homeostasis: Homeostasis can be described as the tendency of an animal to regulate its
internal conditions (e.g., temperature, glucose levels, osmotic pressure of cells), by a
system of feedback controls (like hunger and eating; thirst and drinking; shivering and
putting on a sweater), so as to optimize health and functioning.
From Drive toAction
Motivational states are energizing; they direct an animal to act and direct behaivour
toward a goal. EX: Hunger (internal state) motivates eating (external action).
- Safety – fear, sleep, replenish bodies and avoid danger.
- Reproduce – sexual, maternal, jealousy drives.
- Social – acceptance, approval, motivates cooperation.
- Educative – play and exploration
- Drives are reward-seeking states, and motivated behaviour is reinforced by the
pleasure we experience one the reward has been obtained.
- Reward system is related to the limbic system, particularly structurs located in the
basal forebrain (middle of head, hehind the eyes).
- 1950s, Olds and Milner discovered that rats would quickly learn to press a level
for electrical stimulation of the brain. They even prized it over food, showing that
animals can be motivated by rewards that have no obvious value for survival and
drive reduction. Central State Theory
- Central State Theory – certain hubs or nuclei in the brain involve detection of
imbalances, decision-making and motor output. For example, you may not be
aware that your body is low on salt, but you may crave potato chips.
- The hypothalamus serves as one such hub, or central drive system. It sense
internal states, such as levels of glucose and salt, and internal temperature;
responds to hormone levels; and is connected to the pituitary gland, so it can
orchestrate the release of hormones. It basically acts to restore bodily
- Lesions in the hypothalamus lead to dysregulation in drives such as feeding, but
also in things like salt balance.
- Drive-reduction theory: Proposes that a drive produces an unpleasant state that
causes an organism to engage in motivated behaviours. Reduction of drive is
- Whether regulatory or nonregulatory, motivated behaviour is driven by rewards.
Intrinsic vs. Extrinsic
- Intrinsic incentives result from an internal need, whereas extrinsic incentives
result from gaining a reward or avoiding an unpleasant consequence.
- Both types of motivation affect our effort and persistence in working toward a
goal. However, sometimes extrinsic incentives can actually reduce motivation.
o Over-justification effect: This hypothesis predicts that people who shift
from intrinsic to extrinsic rewards for engaging in an activity will stop the
activity if the extrinsic reward is removed. This cessation of previously
enjoyable behaviour is the over-justification effect.
- Not all rewards result in decreased interest in an activity that had been previously
associated with intrinsic motivation. EX: winning a gold medal.
- Both internal and external factors underlie eating behaviour
- Case study of hunger pangs (1920s, Cannon and Washburn). Stomach cues cause
hunger, though their experiment was flawed.
- Many sensors:
- Early researchers were influenced by the drive
reduction theory and spent time trying to find eating-
related brain mechanisms that act similarly to a
homeostatic mechanism. Frolich noted some
patients with damage to hypothalamus became obese quickly.
- Researchers now have identified the arcuate nucleus (in hypothalamus) as the
‘appetite control center’.
- Nucleus contains 2 types of neurons that when stimulated, have opposite effects
on eating; one stimulates behaviour, one suppresses it.
- These neurons are the target sites of hormones, providing cues for eating.
External Cues for Hunger
- Social or aesthetic factors that make us hungry? - The choice of what to eat, where, when etc. Time of the day, we eat more when
we’re around other people who are eating, and eat best looking foods.
- Being on a diet may reduce food intake, but may also result in increased food
intake. Abstinence violation effect (AVE), where people figure they’ve blown
their diet and simply eat as much as possible
- The brain contains pleasure centers that respond strongly to the presence of
specific nutrients, such as sugars and fats. Hence cravings for chocolate and the
pleasure of eating a variety of foods. It’s often more than nutrition at work…
- **Something in the brain finds pleasure in activities that are not directly related to
survival or homeostasis.
Electrically Stimulating the Brain
Researchers have shown that:
1. Animals are highly motivated to turn on stimulating electrodes implanted in their
medial forebrain bundle (MFB) and nucleus accumbens.
2. Recording electrodes in these structures become active when animals receive food
and other rewards when performing various tasks.
3. When the two structures are destroyed, animals stop working to obtain rewards.
ESB is so rewarding that it can motivate rats to move in response to electrical signals
sent remotely to their brains. Two electrodes are placed in the somatosensory cortex of
the rat’s brain, one in each cortical hemisphere, in the region sensitive to the whiskers of
each side of the face (i.e., the whisker region of the rat’s homunculus). These electrodes
are used to signal the animal to move right (with stimulation of the cortex sensitive to the
right whiskers) or left (with stimulation of the cortex sensitive to the left whiskers). When
the rat moves in the direction it was signaled to go, it receives electrical stimulation to the
- Sex depends heavily on the pleasure principle, yet sexual motivation is not based
solely on reproduction.
- Sexual orientation – based on neural mechanisms, hormones, foetal development,
genes, and various social factors. E.g., birth-order effect in gay men.
- Basically, for all drives the mechanisms motivating human and animal behaviour
are very complex and include the interplay of both internal and external factors. Emotion
- Emotion is a difficult concept for psychologists to define.
- Textbook: “Arelatively brief display of a feeling made in response to
environmental events having motivational significance or in response to
memories of such events.” In this definition, feelings and emotions are
- Damasio, neurologist who studies emotions, separates feelings from emotions. He
argues that emotions are internal reactions that occur automatically and
unconsciously in response to certain stimuli; feelings occur when neural reactions
become conscious. In other words, emotions are the affective component and
feelings the cognitive component.
- Facial expressions, how we know we’ll react to something, how we know other
people will react to something, based on experience. Tone of voice, words, facial
expressions, way body is held, etc.
- 1971, Izard found that people in different cultures generate and recognize the
same basic emotional expressions. Ekman identified seven basic emotions:
happiness, sadness, surprise, fear, anger, contempt, and disgust.
- People everywhere can identify reliably at least six basic emotions: anger,
happiness, disgust, surprise, sadness, and fear. Moreover, people from different
cultures display similar facial expressions when experiencing particular emotions.
It is clear that a number of facial expressions are universal. Some of these basic
emotion expressions are easier to recognize than others.
- Each emotion involves movements of several sets of facial muscles
- The universality of these bas