Brain & Behavior - Sensation & Perception Ch 5-7 Flashcards
Exam 2
What are the building blocks of the brain?
Neurons
What are neurons made of?
Cell body, nucleus, dendrites, axons and axon terminals.
How do neurons work?
Electrical impulses travel down the axon to axon terminals bringing information.
Synapse is…
presynaptic to a gap to postsynaptic which activates receptors to open sodium channels resulting in new neural impulses and so on…This is also chemical communciation.
Psychoactive Drugs….
Facilitate or inhibit the production of release of neurotransmitter into a synapse, facilitate or inhibit the removal of the neurotransmitter from the synapse, facilitate or inhibit the sensitivity of the postsynaptic receptors.
Long Term Potentiation (LTP)
Repeated activation of synapses results in strengthened synapses. This is the neural basis for learning and memory.
Subcortical Areas of Brain (Evolutionary) - Brain Stem Level
Medula, Pons, Midbrain, Thalamus
Medula does…
Vital reflexes; breathing, heart rate, posture
Pons does…
Primitive movement patterns; eating, drinking, sex, sleep and arousal
Midbrain does…
Important for reflexes (primitive); superior colliculus - visual regarding reflexes (ex when something comes at your face quickly)
Thalamus does…
Sensory relay station; sight, sound, touch, taste (but NOT smell)
Motor or Movement Areas of Brain
Basal Ganglia and Cerebellum. These parts have mirror images within the brain.
Basal Ganglia does…
Initiation of goal-directed movements. With an end state in mind (i.e. move arm to get glass). Dopamine found here (neurotransmitter). This is the area effected that causes Parkinsons Disorder.
Parkinsons Disorder - Symptoms
resting tremor, slowed movement, shuffling walk, stooped posture, ridgidity & freezing, blank face but normal cognition.
Parkinsons Disorder - Prevalence
1% of perople over 60
Parkinsons Disorder - Etiology
Death in Substantia Nigra (midbrain)=loss of dopamine projections to basal ganglia=loss of automatic motor control and motor initiation
Parkinsons Disorder - Risk Factors
Small genetic influence. Toxic exposures (pesticides)
Parkinsons Disorder - Treatment
Replace dopamine or dopamine neurons; electrical stim of basal ganglia (not cures)
Cerebellum does…
Coordination of skilled (learned) movements. ex playing of violin. this area is effected by alcohol.
Limbic System parts…
Hypothalamus
Limbic System does…
influences emotion, motivation & memory
Hypothalamus parts…
Lateral Hypothalamus, Ventro Medial Area, Medial Preoptic Area
Hypothalamus means…
below thalamus
Lateral Hypothalamus…
Initiation of eating, drinking and sex (gas pedal). If you lession this area the animal will be unable to eat, drink or have sex (no motivation)
Ventro Medial Area…
Termination of eating, drinking, and sex (brake pedal). If you lession this area the animal is unable to stop eating, drinking or having sex
Medial Preoptic Area…
Sexually Dismorphic Nucleus (SDN). Male SDN tends to be larger than females. Relates to reproduction. Prenatal androgens (testosterone) masculinizes the SDN. Influences sexual orientation.
Different ways to identify sex…
Genotype Sex - chromosomes (xx or xy), Phenotypic Sex - Internal/external genitals, Gender Identification - subjective perception, Brain Sex - structural difference in brain organization male v. female
What reduces androgens (testosterone)?
Stress does. Could effect brain sex.
Testosterone influences on brain sexual behavior…
Organizational (prenatal) - sexual orientation and Activatitonal (postnatal) - sexual desire
Pituitary Gland…
Master endocrine gland - receives input via hypothalamus.
Pleasure Centers in Brain
Nucleus Acumbens (basal ganglia), Medial Forebrain Bundle (MFB - midbrain-lateral hypothalamus-nucleus acumbens), dopamine neurotransmission, endorphins & oxytocin, pleasure drugs, incentive-motivation-reward system, deactivated in clinical depression.
Activating dopamine activates pleasure
blocks re-uptake of dopamine, crash after big high on cocaine - less sensitivity, loss of normal pleasures, losing interest in normal activities
Cerebral Cortex is what level of functioning?
Higher mental functioning (awareness, planning, etc)
Cerebral Cortex is…
made up of a right and left hemisphere (mirror images). it is a layer of cells (neurons) on the surface of the hemispheres.
Cerebral Cortex parts…
Corpus Collosum, Primary Motor Cortex, Primary Somatosensory Area, Primary Visual Cortex, Primary Auditory Cortex, Frontal Lobe, Premortor Area
Corpus Collosum….
connects similar areas of left & right cortex
Lateral Fissures….
deep indentation between temporal & frontal lobes
Central Fissure..
dividing point between frontal lobe and parietal lobe
Primary Motor Area/Cortex…
Just behind the frontal lobe. Voluntary motor movement, before muscle movement. right hemisphere moves left side of body, and left hemisphere moves right side of body (can change over time)
Primary Somatosenosry Area…(body/experience)
just in front of parietal lobe on top of head. pain & sensation, temperature sensations.
Phantom Limb Sensation
Amputees experience this. A sensation of pain where part of the old limb was. Because the experience happened in your brain this sensation is still possible.
Primary Visual Cortex…
Cross over effect. Anything in the right visual field goes to the left hemisphere and vice versa.
Dorsal Stream…
Where/How. Visual streaming. Guide your eye movement & locomotion.
Ventral Stream
What. Conscious awareness.
BlindSight
non-conscious processing of visual information. you cannot see something but your brain is aware of it. Damage in ventral stream.
Primary Auditory Cortex…
Conscious awareness of sounds in environment. damage to the ear causing deafness is not the same as damage to the cortex causing inability to hear. right auditory field is processed more strongly in the left hemisphere. People may jump when a loud sound goes off, but that’s because it was processed elsewhere in their brain - they don’t actually hear it.
Hemispheric Specialization…
Some psychological functions are more strongly represented in one hemisphere v the other. Allows for more efficient use of limited cortical space (no replication). males tend to have more lateralization in functioning that do females. Males show more impairment when the brain is damaged than do females.
Language ares are typically in ….
the left hemisphere for 94% of right handed people and 73% of left handed people.
What is Aphasia…
impaired language ability due to brain damage.
Aphasia types…
Borca’s Area, Wenicke’s Area and Angular Gyrus.
Broca’s Area effects…
speech production, grammar (expressive aphasia) This is mostly the mouth area.
Wernicke’s Area effects…
comprehend language (receptive aphasia). Cannot produce meaningful speech, everything is jumbled. word salad.
Angular Gyrus effects…
reading & writing (visual aphasia). visual representations used as language. Have to be able to process it here. Did not evolve to support reaing & writing (not around for evolutionary ancestors). Reading & writing is an aquired skill. Can be trained to read phonetically. **Dislexia
Visual Spatial Areas are in the….
Right Hemisphere
Visual Spatial Disorders…
Agnosia & Prosopagnosia
Agnosia
impaired visual-spatial ability due to brain damage
Prosopagnosia
Inability to recognize faces as familiar (fusiform gyrus)
Lateralization & Split Brain Patients
People are really only communicating with the left hemishpere. The brain is surgically split at Corpus Collosum assisting in epileptic patients.
Alien Hand Syndrome
Most frequently in the left hand. A person is completely unclear as to the random motion by the left hand because the right hemisphere is controlling it.
Frontal Lobe
Executive functions of prefrontal cortex. Includes planning (determining sequence of events), flexibility (switching between rules), inhibitsion (supressing dominate but innapropriate responses).
Mirror Neurons
Representation ofother people’s movements; mimicry; observational learning; visualization aids motor skill acquisition
Nucleus
A cluster of cell bodies in teh Central Nervous System (collectively “gray matter”)
Tracts
A bundle of axons that course together from one nucleus to another (collectively “white matter”)
Methods for sudying the human brain:
observing behavioral deficits that occur when a part of the brain is destroyed; observing behavioral effects of artificvally stimulating speific parts of the brain; recording changes in neural activity that occur in specific parts of the brain when a person or animal is engaged in a particular mental of behavioral task
Transcranial Magnetic Stim (TMS)
noninvasive, temporarily disrupts or triggers activity in specific cortical areas by means of magnetic field
Electroencephalogram (EEG)
records gross electical activity in areas of the brain just beneath the skull from electrodes placed on the scalp
Positron Emission Tomography (PET) & Functional Magnetic Resonance Imaging (MRI)
images that depict changes in neural activity in each area of the brain by measuring changes in blood flow
Animal Studies
precisisely placed lesions to see how damage effects behavior, electicial or chemical stim of a specific area to receal functions, and microelectrodes recording electrical activity in single neurons under varying conditions.
Hormones are…
chemical messengers secreted into the bloodstream. They are chemically similar to neurotransmitters but travel farther and exert their effects on many different target tissues
Homeostasis
the constancy of internal conditions that the body must actively maintain (digestion, respiration)
Regulatory Drive
Helps preserve homeostais (like hunger/promote survival)
Nonregulatory Drive
Serves some other purpose, other than homeostasis (like sex)
Mamillian Drives…
can be classified by function into regulatory, safety, reproductive, social and educative categories.
Human Drive Exhibited
aesthetic drive. the evolutionary functions of these are not obvious
Central-State Drive Theory
different drives correspond to neural activity in different but overlapping central drive systems in the brain
Contain essential pathways of the brains reward system. Animals work for ES in these areas.
Medial Forebrain & nucleus accumbens
The release of BLANK in the nucleus accumbens is associated with wanting and the release of BLANK is associated with liking.
Dopamine
Endorphins
BLANK is a hormone produced by fat cells to help regulate body weight by acting on the hypothalamus to reduce appetite.
Leptin
Within a culture genetic differences are the primary determinants of who becomes BLANK, but across cultures BLANK plays a substantial role
Obese
Environmental Differences
BLANK maintains male sex drive over the long term.
Testosterone
In women and some primates BLANK BLANK promote sexual receptivity throughout the ovarian cycle.
adrenal androgens
Sensation
the basic processes by which sensory organs and the nervous system respond to stimuli in the environment and to the elementary psychological experiences that result from those processess.
Perception
the more complex organizing of sensory information whithin the brain and to the meaningful interpretations extracted from it.
Process of Sensation
physical stimulus to physiological response to sensory experience
The Five Senses
Smell Taste Touch Sight Hearing
Sensory Receptors
specialized structures that respond to physical stimuli by producing electrical changes that can inititate neural impuleses in sensory neurons
Sensory Neurons
specialized neurons that carry information from sensory receptors into the central nervous system
Conscious sensory experiences depend on activity within the …
cerebral cortex
The process by which a receptor cell produces an electrical charge in response to physical stimulation is called BLANK
Transduction
The changed electrical charge that flows through the membrane is referred to as BLANK
receptor potential
The preservation of information about stimulus quality and quantity is BLANK
sensory coding
Sensory Adaptation is..
the change in sensitivity that occurs when a given set of sensory receptors and neurons is either strongly stimulated or relatively unstimulated for a length of time
Chemical senses…
smell and taste
Pheromone
is a chemical substance that is released by an animal and acts on other members of its species to promote some specific behavioral or physiological response.
Five Primary Tastes
sweet, salty, sour, bitter and umami
