Motor Mechanisms and Behavior

1. Motor Mechanisms and Behavior

2. Sensory and Motor Mechanisms • Mechanoreceptors respond to physical stimuli, such as touch or vibration. • Reception occurs when a receptor detects a stimulus. • Perception occurs in the brain as the information is processed. • Ex. When you view an optical illusion in which a figure seems to change, what changes is your perception of the object

3. Skeletal muscle • For muscle function to occur, physical interaction of actin (thin filaments) and myosin (thick filaments) must occur. • Muscle fibers - myofibrils – actin and myosin

4. Muscle contraction – sliding filament model • Sarcomere – basic contractile unit of skeletal muscle

6. Other types of muscle • Cardiac muscle – the heart • Smooth muscle – walls of hollow organs like blood vessels and digestive tract

7. Nature versus Nurture • Behavior – action that can be observed and described. • Genetic influence • Lovebirds, snakes, snails and human experiments • Nervous and endocrine systems are both responsible for the coordination of body systems • Studies support the idea that certain types of behavior have genetic basis

8. Nature versus Nurture • Environmental influences (nurture) • Learning: durable change in behavior brought about by experience. • Laughing gull chicks pecking behavior • Imprinting- sensitive period • Song learning with white crowned sparrows • Associative learning – change in behavior that involves an association between two events • Classical conditioning - Pavlov, 2 types of stimulus • Operant conditioning – Skinner, stimulus/response • Insight, imitation, and habituation

9. Behaviors • Innate – developmentally fixed, unlearned • Fixed Action Pattern: sequence of unlearned acts that is largely unchangeable and usually carried to completion once it is initiated. • Ex. Male sticklebacks and red bellies, triggered by a sign stimulus.

10. More behaviors • Migration – carried out by using environmental clues. • Kinesis – a simple change in activity in response to a stimulus (pill bug lab) • Circadian rhythms – those behaviors that occur on a daily cycle.

11. Signals • A stimulus that causes a change in the behavior of another individual and the basis for animal communication

12. Communication • Action by a sender that may influence the behavior of a receiver. • Chemical – pheromones, anytime of day • Auditory – fast, night or day, can be modified (length, pitch…) Language • Visual – restricted to daytime • Tactile – grooming, waggle dance of bees

13. Adaptive mating behavior • Sexual selection – adaptive changes to secure a mate • Fitness – ability to produce offspring • Female choice – based on genes and survival or investment for offspring? • Male competition – • Cost (competition) benefit (mating) analyses • This all applies to Humans too!

14. Sociobiology and animal behavior • Living in groups has a great reproductive benefit than cost • Ad: Avoid predators, rear offspring, find food • Disad: access to food, shelter, sickness • Behaviors are selected for the advantages they provide for survival and reproduction.

15. Altruism • Altruism – behavior that has potential to decrease reproductive success of altruist to benefit the reproductive success of another. • Ex. Blue jay giving an alarm call attracts attention to its location. • Inclusive fitness – personal reproductive success and reproductive success of relatives • Reciprocal altruism – making a minimal short term reproductive sacrifice in order to maximize future reproductive potential