Brain and Behavior (Ch. 12)

Activating Effects

Immediate hormonal effects that trigger certain behaviors, like sexual arousal.

Amygdala

A brain region involved in processing emotions, especially fear and pleasure.

Androgens

Male sex hormones, like testosterone, that influence male traits and behaviors.

Anorexia Nervosa

An eating disorder characterized by self-starvation and intense fear of gaining weight.

Aphagia

The inability or refusal to eat, often due to brain damage.

Emotion

A complex response involving physical arousal, behavior, and feelings.

Evolutionary Psychology

The study of how natural selection has shaped behavior and mental processes.

Gender Identity

A person’s internal sense of their own gender, whether male, female, or otherwise.

Hippocampus

A brain region crucial for memory formation and spatial navigation.

Homeostatic Mechanism

A system that maintains stability in the body’s internal environment, like temperature or fluid balance.

Hyperphagia

Excessive eating, often due to damage in specific brain regions.

Hypovolemic Thirst

Thirst triggered by a decrease in blood volume, often after blood loss or dehydration.

Innate Releasing Mechanism (IRM)

A genetic predisposition to respond to certain stimuli, like a baby’s smile.

Klüver–Bucy Syndrome

A condition involving changes in behavior, including hypersexuality and lack of fear, following damage to the amygdala.

Learned Taste Aversion

The learned avoidance of a food after it has been associated with illness.

Medial Forebrain Bundle (MFB)

A neural pathway associated with reward and pleasure.

Motivation

The internal drive that prompts goal-directed behavior.

Nonregulatory Behavior

Actions not directly related to survival, such as curiosity or play.

Obesity

A condition of excessive body fat that may impair health.

Orbitofrontal Cortex (OFC)

A brain region involved in decision-making and evaluating rewards.

Organizing Effects

Long-lasting hormonal effects that shape the development of physical and behavioral traits.

Osmotic Thirst

Thirst triggered by an increase in the salt concentration in body fluids.

Pheromone

A chemical signal released by one individual that affects the behavior or physiology of others of the same species.

Pituitary Gland

A gland at the base of the brain that regulates hormones and influences growth and metabolism.

Preparedness

The idea that certain behaviors are easier to learn due to evolutionary adaptations.

Psychosurgery

Surgical procedures on the brain to treat psychological disorders.

Regulatory Behavior

Actions necessary for survival, such as eating or drinking.

Reinforcer

A stimulus that increases the likelihood of a behavior being repeated.

Releasing Hormone

Hormones from the hypothalamus that prompt the pituitary gland to release other hormones.

Sexual Dimorphism

Differences in appearance or behavior between males and females of a species.

Describe the hierarchical system of neural control of movement.

Involves the prefrontal cortex (planning), premotor cortex (sequencing), and primary motor cortex (execution) in a top-down control system.

What is the function of the prefrontal cortex in movement?

Plans complex behaviors, integrates inputs from other cortical areas, and is responsible for general decision-making.

What happens when the prefrontal cortex is damaged?

Impacts motor control through poor decision-making and actions.

How does the premotor cortex contribute to movement?

Coordinates complex movement sequences and sends output to the primary motor cortex.

What is the primary motor cortex responsible for?

Executes skilled movements, such as tapping fingers or waving hands.

Explain the concept of plasticity in the primary motor cortex.

The cortex adapts in response to loss, such as a rat losing whiskers and the brain stopping related mapping.

What is the monogynaptic stretch reflex?

A spinal cord control of movement involving a single synapse that produces a quick, automatic response.

Describe the spinal cord-corticospinal tracts.

Pathways from the cortex through the spinal cord, controlling voluntary movement in the body.

How do cortical inputs activate brainstem motor control areas?

Inputs from the cortex can trigger specific motor behaviors, such as grooming or feeding.

What is the motor homunculus?

A representation in the motor cortex showing different body parts’ movement control based on importance and control detail.

What are brain maintenance behaviors?

Behaviors like seeking stimulation to avoid boredom, as demonstrated by monkeys engaging with new stimuli.

How do reward-seeking behaviors affect the brain?

They activate brain circuits that are inherently rewarding, such as prey-hunting behaviors in cats.

Describe the role of neural circuits in modifying behavior.

Circuits are modulated by internal factors (e.g., androgens in sexual activity) and external stimuli (e.g., smells).

Explain epigenetic influences on neural circuits.

Experiences, especially in reward contexts, can modify gene expression, affecting memory and learning.

What are innate releasing mechanisms (IRMs)?

Prewired responses that help animals survive, such as kittens responding to predator images.

Define natural selection in terms of brain circuits.

Evolution favors brain circuits that aid in survival and reproduction, leading to evolved behaviors.

How does evolutionary psychology explain certain behaviors?

Suggests that behaviors like aggression may persist due to past survival advantages.

What is the main idea behind reward circuits?

Neural pathways reinforce pleasurable or survival-oriented behaviors.

How do environmental interactions shape behavior?

Behavior is shaped not only by free will but also by brain circuits influenced by rewards, evolution, and external factors.

Why is free will inadequate in explaining behavior?

Because behaviors are influenced by brain circuits, rewards, and not solely conscious choice.

Differentiate between regulatory and nonregulatory behaviors.

Regulatory behaviors are survival-driven and controlled by homeostasis, whereas nonregulatory behaviors are curiosity-driven.

What are the primary activities of the hypothalamic circuitry?

Maintains homeostasis, regulates hormones, and generates behavior by stimulating specific areas.

How does the hypothalamus connect with the pituitary gland?

Influences hormone secretion throughout the body, impacting bodily functions.

What role does the hypothalamus play in behavior?

It’s central in regulating behaviors related to survival through homeostasis and hormone control.

Describe the feedback mechanism in the hypothalamus.

The hypothalamus regulates hormones via feedback loops to maintain stable internal conditions.

Define motivated behavior.

Actions driven by the brain’s neural circuits, often rewarding and essential for survival or curiosity.

What types of behavior are controlled by hypothalamic circuits?

Both survival-oriented (regulatory) and curiosity-driven (nonregulatory) behaviors.

How do electrical stimulation studies demonstrate hypothalamic function?

They show that stimulating the hypothalamus can trigger complex behaviors.

Explain the relationship between the hypothalamus and the cerebral hemispheres.

The hypothalamus coordinates behavioral responses through connections with the cerebral hemispheres and brainstem.

What is the role of cognitive appraisal in olfaction and taste?

Cognitive appraisal of odors and tastes links to concepts of disgust and moral judgments.

Describe the disgust response in terms of hygiene.

Evolved to include moral judgments on fairness and justice, processed by the insular cortex.

What is the olfactory epithelium?

Contains receptor cells in the nasal cavity that detect chemicals, activating olfactory neurons.

Explain the olfactory pathways.

Receptor cells connect to the olfactory bulb, sending signals to brain areas for emotional and cognitive processing.

What is the accessory olfactory system’s function?

Detects pheromones, affecting reproductive and social behaviors in non-human mammals.

Where are taste receptors located, and what do they detect?

Located on taste buds in the mouth; they detect sweet, sour, salty, bitter, and umami flavors.

Describe the gustatory pathways.

Signals travel via cranial nerves to the brainstem, thalamus, and finally the somatosensory cortex and amygdala.

What is flavor perception?

Integration in the orbitofrontal cortex combines taste and smell for a holistic flavor experience.

How do olfactory and gustatory pathways aid in survival?

They process sensory information critical for detecting potential dangers and moral judgments.

What is flavor and how is it shaped?

Flavor is a combined perception of taste and smell, shaped by context and individual experiences.

Describe the role of chemical senses beyond survival.

Chemical senses extend to social and moral domains, impacting social interactions and moral judgments.

How do olfactory and gustatory systems contribute to complex behaviors?

They integrate with emotional and cognitive centers, influencing behavior and emotional responses.

What are potential impacts of losing chemical senses?

Loss can affect mood, social interactions, and food safety, highlighting the importance of these senses.

What is the receptor surface for olfaction known as?

The olfactory epithelium.

Explain how the loss of smell and taste disorders are associated with social and cognitive functions.

Disorders affect recognition, social bonding, and may impact emotional processing linked to chemical senses.

How do olfactory pathways pass through the brain?

They pass through the thalamus and merge in an area behind the eye sockets.

How may our cognitive appraisal of smell and taste connect to moral behavior?

The appraisal, linked to fairness and morality, suggests evolved social functions for chemical senses.

What evolutionary function could olfactory processing serve in humans?

It aids in recognizing friends and strangers, playing a role in social bonding and group recognition.

How might disgust responses relate to chemical senses?

They likely evolved to aid in survival by helping humans avoid harmful substances, extending to moral disgust.

Describe the hypothalamus’s role in controlling eating.

The hypothalamus regulates hunger and satiety, with areas that stimulate or inhibit eating.

What role does the arcuate nucleus play in eating?

Contains neurons that stimulate or inhibit eating based on nutrient signals, like insulin and leptin.

How does the digestive system influence the hypothalamus?

The ENS monitors nutrient levels and sends hormonal signals, such as CCK and GLP-1, to the hypothalamus.

What is osmotic thirst and its trigger?

Triggered by high salt concentrations in the body, detected by the hypothalamus.

Describe hypovolemic thirst.

Caused by loss of body fluids, it triggers angiotensin release, encouraging fluid and salt intake.

How does cognitive control affect eating behavior?

Influences food intake through cues like sight and smell, impacting appetite.

What is the primary function of hypothalamic circuits in eating?

Maintains balance by managing hunger and satiety in response to nutrient and fluid needs.

How do memories and social cues impact appetite?

Cognitive factors like memories and social contexts can influence eating decisions.

What are the two types of thirst mechanisms?

Osmotic thirst (from high salt) and hypovolemic thirst (from fluid loss), each triggering specific hypothalamic responses.

What is sexual differentiation of the brain?

Prenatal hormone exposure, such as testosterone, shapes the brain’s structure in males and females.

How do brain structure differences manifest between sexes?

Males typically have a larger amygdala, while females have more interhemispheric connections.

Explain the organizing effects of sex hormones.

Occur in fetal development, shaping areas related to reproductive behavior.

What are activating effects of sex hormones?

In adulthood, hormones like testosterone influence sexual motivation and behavior.

How does the hypothalamus control sexual behavior?

Controls consummatory behaviors, with specific areas like the ventromedial hypothalamus.

What role does the amygdala play in sexual motivation?

Involved in sexual motivation, particularly in males.

Describe cognitive influences on sexual behavior.

The frontal lobe and cortical areas contribute to sexual thoughts, planning, and fantasies.

How is sexual orientation linked to brain structure?

Variations in the hypothalamus and amygdala may correlate with differences in orientation.

What is the main idea of sexual differentiation?

Influenced by hormones and genetics, leading to differences in brain areas associated with sexual behavior.

How do sex hormones impact neural connections?

They influence brain areas for sexual motivation and behavior through both organizational and activating effects.

What is the constructivist theory of emotion?

Proposes that the brain interprets physiological changes as emotions based on context.

Describe the appraisal theory of emotion.

Emotions arise from evaluating events, involving physiological responses and subjective feelings.

What does the neuropsychological theory emphasize?

The right hemisphere manages emotional experiences, especially negative ones, while the left handles cognitive appraisals.