Exam 3 Psych

why is sex not a physiological drive?

why is sex not a physiological drive?

sex is not essential for the survival of the individual

there are similarities however:

arousal, satiation

role of hormones

involvement in specific brain areas

phases of the sexual response cycle

excitement phase

plateau phase

orgasm phase

resolution period

refractory phase

refractory phase

amount of time that a male requires before being able to reach orgasm again

coolidge effect

quicker return to sexual arousal for a male when a new female is introduced, shortening of refractory phase for men when new gal becomes available

observed in many species

helps explain cheap sperm, expensive eggs theory

analogous to sensory specific satiety - the more of a specific food a person eats, the less appealing the food becomes, encourages varied diet

cheap sperm expensive eggs theory

a male can potentially have a large number of children quickly by mating with different females→ more of his genes passed on to the next generation

the major sex hormones

androgens- male

estrogen

progesterone

androgens

responsible for male characteristics and fxn

testosterone

necessary for male sexual behaviors but requires only small amt

females initiate more at midcycle, may be more impt than estrogen

result of sexual activity in both males and females (inc caused by behavior)

estrogen

responsible for female characteristics and fxns

progesterone

controls reproductive fxns including sexual receptivity and desire in females

oxytocin

promotes sexual arousal and orgasm (males and females)

brain structures involved in sexual activity

medial preoptic area of hypothalamus

ventral medial nucleus of hypothalamus

medial amygdala

paraventricular nucleus of hypothalamus

sexual dimorphic nucleus of preoptic area of hypothalamus

medial preoptic area of hypothalamus and sex

MPOA

stimulation in rates inc copulation in both males and females

ventral medial nucleus of hypothalamus and sex

VMN

active during copulation

destruction reduces responsiveness of females to males and vigor of males mating

medial amygdala and sex

active during copulation in both males and females

stimulation→ dopamine release in MPOA

involved in recognizing and responding to opposite sex

paraventricular nucleus of hypothalamus and sex

PVN

involved in sexual performance in males

sexual dimorphic nucleus of preoptic area of hypothalamus and sex

SDN

larger in male rats

size depends on prenatal exposure to testosterone

size related to level of sexual activity

coordinates behavioral and physiological responses to sensory cues

dopamine role in sex

inc in medial preoptic area of hypothalamus

Also involved in mesolimbic pathway( NAcc, MFB and VTA)

• inc in ventral tegmental area in males during ejaculation

• inc in nucleus accumbens (with coolidge effect)

serotonin role in sex

inhibitory effect on sexual drive

inc following orgasm- contributes to refractory period

sensory stimuli and sex

tactual, auditory, visual, olfactory, pheromones

visual sensory stimuli and sex

body symmetry is another important determinant of sexual attractiveness

may be indicative of genetic fitness

olfactory sensory stimuli and sex

major histocompatibility complex (MHC) is a group of genes involved in immune system function

many vertebrates prefer mates with dissimilar MHC genes→ involved in better disease resistance in offpsring

unclear role in humans → relationship btwn MHC type of pleasantness of odor from sweat

pheromones and sex

airborne chemicals released by an animal that has a physiological or behavioral effect on another animal of the same species

female gypsy moth attract mate from 2 miles away

pheromones detected by vomeronasal organ (VNO) → sends signals to MPOA and VMN

• microscopic in size, unclear if it is functional in humans

• possible human pheromones- AND(male) and EST (female)

• recently been cast in doubt

pheromonal influence of sexual behavior of humans is unclear and controversial

emotion and psych

relationship btwn emotional experiences and body’s resonses is unclear and controversial

james lange theory of emotion

late 1800s

perception of specific patterns of physiological arousal affecting specific emotional experience

• i feel sad bc I cry (rather than reverse)

  faced criticism afterwards by cannon

cannons criticism

criticism of james lange thoery (1920)

autonomic nervous system responds the same way for different emotions

perception of physiological responses cannot account for the variety of emotional experiences

schachter and singers congitive theory of emotion

1962

identification of emotions relies on a cognitive assessment of the external stimulus situation → physiological arousal contributes only to the intensity of emotion

emotion impact on autonomic system

the autonomic nervous system is activated differently depending on the emotion

limbic system

complex network of cortical and subcortical structures

hypothalamus

septal nuclei

amygdala

anterior cingulate cortex and anterior insular cortex

what 2 things play a role in emotion

cognitive assessment of external stimuli and physiological feedback

hypothalamus and emotion

electrical stimulation in animals produces threatening or defensive behaviors

in humans it evokes feelings of rage, fear or pleasure

septal nuclei and emotion

evokes feelings of pleasure (sexual)

amygdala and emotion

involved in perception of facial expressions of emotion (esp fear)

damage- removes fear and aggression, peeps do not respond emotionally to rewards and punishments

stimulation- produces fear and aggression

major role in fear and anxiety

Anterior cingulate cortex + anterior insular cortex and emotion

Anterior cingulate cortex

• wraps around corpus callosum

• uses input from AIC to generate action via prefrontal cortex

Anterior insular cortex

• deep in brain, insula

• awareness of emotion

both form network with amygdala and hypothalamus

both involved in all basic emotions and with empathy

conscious experience of emotion

prefrontal cortex and emotion

connections with limbic system

uses emotional info from limbic system for decision making

damage- blunts emotional response, impaired ability to process and anticipate consequences of behavior and use that information to modify behavioral choices

hemispheric asymmetry

hemispheres differ in

• structure (brocas area larger on L)

• function performed (L more involved in linguistics)

• right more involved with facial expression and emotion→ difficulty recognizing emotions in others following brain damage

Sensory system

set of components of the PNS and CNS involved in acquiring and processing of specific sensory info

sensation- acquistion of sensory info

perception- interpretation of sensory info

receptor

a cell that is suited by its structure and fxn to respond to a specific form of energy

often a specialized neuron

transducer- device that converts energy from one form to another

stimulus

specific energy form for which the receptor is specialized for

hearing

stimulus- vibration in conducting medium

types of sound

pure tones

complex sound

pure tones

single frequency

number of alternating compression and decompression(cycles) that occur per unit time

complex sounds

combination of 2+ frequencies

pitch

experience of the frequency of sound

same frequency= same pitch

unequal amount of waves (higher or lower frequency) = diff pitch

image= low frequency vs high frequency results in different pitch

loudness

experience of the intensity (physical energy of a sound)

unequal intensity= unequal loudness

same amplitude height= same loudness

different amplitude height = diff loudness

image= different amplitude height= difference in loudness

auditory apparatus

outer ear

middle ear

inner ear

outer ear

pinna- impt for sound location in space

external auditory canal- resonation chamber, amplify intensity of sound

middle ear

tympanic membrane

auditory ossicles- transfer/amplify vibrations from ear drum to oval window on cochlea

inner ear

semicircular canals

• basilar membrane- vibrate when oval window vibrates

• tectorial membrane on top of basilar

• hair cells stick into tectorial membrane→ organized in rows

cochlea

• organ of corti

auditory nerve

auditory pathways

auditory nerve→ coclear nuclei (filter raw data)→ superior olive→ inferior colliculus (startle reflex)→ medial geniculate nucleus of thalamus→ primary auditory cortex

primary auditory cortex

1st cortical region recieving info from sound, involved in analyzing simplest aspects of sound

topographically organized- aadjacent neurons in cortex receive info from adjacent receptor locations in basilar membrane

map of basilar mem

secondary auditory cortex

anterior- apex of basilar membrane corresponds to here

posterior- base (closest to oval window) of basilar membrane corresponds to here

frequency theory

basilar mem vibrates in synchrony with a sound → auditory nerve axons fire at same frequency

problem- individual neurons can fire at no more than 1000 Hz but we can hear up to 20,000 Hz

volley theory- groups of neurons can follow the freq of a sound whereas a single nueron cannot (summation)

place theory

sounds with diff freqinduce peaks of max vibration in diff places on basilar membrane

high freq- basilar mem vibrate more at base

low freq- basilar mem vibrates more at apex

problem- with sounds below 200Hz the whole membrane vibrates equally

frequency place theory

frequency part- synchrony of firing rate of auditory nerve axons with sound frequency→ pitch perception of sounds up to 200Hz

place part- place of max vibration on basilar mem→ pitch perception of sounds greater than 200 Hz

perception of complex sound

we mostly hear in complex sounds rather than just pure tones

use fourier analysis to analyze sound

• fourier analysis- Any complex sound can be broken down into pure tones (component frequencies) 

• basilar membrane of cochlea acts as fourier analysis

cocktail party effect- isolate meaningful auditory stimulus from loud environment

fourier analysis

any complex sound can be broken down into pure tones

basilar mem of cochlea acts as fourier analysis

cocktail party effect

isolate meaningful auditory stimulus from loud environment

outer hair cells of ear involved; mute certain sounds so you can filter sound

3 types of binaural cues for sound localization

Superior olive is the hub!

Phase difference- a sound arriving from one side of the body is at a different phase of the sound wave at each ear (low freq sounds) 

Intensity differences- the head creates a sound shadow-> near ear receives a slightly more intense sound than far ear 

Difference in time of arrival- sound reaches near ear slightly before the far ear 

the one monaural cue

Head-Related Transfer Function (HRTF): frequency alterations to a sound as it passes through the pinna and auditory canal, as well as through the head and other parts of the body.

vision

stimulus- visible light from the electromagnetic spectrum

electromagnetic spectrum order

radio, microwave, infrared, visible light, ultraviolet, x ray, gamma ray

cornea

curved and thick transparent membrane in front of the eye that accounds for 80% of the ability to form images

lens

series of transparent onion-like layers

shape can be changed by contractions of ciliary muscles

retina

the neural tissue and photoreceptors located on the inner surface of the posterior portion of the eye

3 layers

• photoreceptor layer, bipolar layer and ganglion layer

photoreceptors

rods and cones

contain 1 protein and 1 vitamen

rods

contain rhodopsin (photopigment), very sensitive to light

detect diff levels of light and dark, not colors

most concentrated away from fovea

cones

contain lodopsin (photopigment)

require high level of light

3 kinds : red blue green

most concentrated in fovea

horizontal cells

helps further synapsing with other photoreceptors and bipolar cells

bipolar cells

connect photoreceptor layer to ganglion cells

amacrine cells

help further synapsing

ganglion cells

axons cluster together to form optic nerve

retina made up of…

photoreceptors, horizontal cells, bipolar cells, amacrine cells, ganglion cells

fovea

the center of the retina, area of focus, most cones here 

light flows in what way in the eye

flows through ganglion, amacrine, bipolar cells, horizontal cells, then photoreceptor cells, neural processing occurs from photoreceptors to the ganglion cells 

Retina in dark

Na channels OPEN

depolarization.

inhibitory NT released

bipolar cells inhibited as well as ganglion cells

retina in light

light protein and lipid separate

Na channels CLOSE

release of inhibitory NT is reduced

firing rate of bipolar cell to ganglion cell inc

receptive field of retina

area of retina from which a ganglion cells receives input

small- one PR to 1 ganglion cell (fovea- more detail)

large- many PR to 1 ganglion cell (away from fovea- less detail)

round in retina

visual field

the part of the enviornment that is registered on the retina

L and R fields overlap = binocular field

if object is on non-overlapping side of L VF= left eye image will form on nasal side and R eye image will form on temporal side

if object is on non-overlapping side of R VF= left eye image will form on temporal side and R eye image will form on nasal side

optic tracts carry info to thalamus→ lateral geniculate nuclei→ primary visual cortex

retinal disparity

Discrepancy in the location of an obj image on the 2 retinas as a function of the obj distance -> detected by the visual cortex-> depth perception

trichromatic theory

von helmholtz and young

• All colors are the result of the processing of 3 “pure” colors: red green and blue, each one detected by a specific receptor

• Light can mix to create different colors 

• Problem: yellow also appears to observers as pure color

• Summary- 3 types of cones in retina correspond to 3 primary colors; all true but doesn’t explain yellow

opponent process theory

hering

• Explains color vision in terms of opposing neural processes in 2 specific receptors 

• Receptor for red and green -> photochemical 

• Receptor for blue and yellow-> photochemical 

• Explains complementary colors and negative color after effect -> flipped color image and different color 

• 2 types of cones correspond to red/green and yellow/blue; can explain rebound effect of negative color after effect

combined theory of color perception

3 types of cones for red green and blue

retina responds in terms of paired colors

• Red light- activates red cone->excites red/green ganglion cell-> interprets as red 

• Green light-  activates green cone->inhibits red/green ganglion cell -> interprets as green

• Blue light-  activates blue cone-> inhibits yellow/blue ganglion cell -> interprets as blue 

• Yellow light- activates red and green cones -> red/green ganglion cell signals cancel each other out, yellow/blue ganglion cell excited -> interprets as yellow 

red light color perception

• Red light- activates red cone->excites red/green ganglion cell-> interprets as red 

green light color perception

• Green light-  activates green cone->inhibits red/green ganglion cell -> interprets as green

blue light color perception

• Blue light-  activates blue cone-> inhibits yellow/blue ganglion cell -> interprets as blue 

yellow light color perception

• Yellow light- activates red and green cones -> red/green ganglion cell signals cancel each other out, yellow/blue ganglion cell excited -> interprets as yellow 

R+/G- ganglion cells

• red light-> excitatory, green light-> inhibitory 

G+/R- ganglion cells

ganglion cells- red light-> inhibitory, green light-> excitory

Y+/B- ganglion cells

yellow light-> excitatory, blue light-> inhibitory

Y-/B+ ganglion cells

yellow light-> inhibitory, blue light-> excitatory

perception of edges

lateral inhibition

on center and off center ganglion cells

simple cells in visual cortex

lateral inhibition

ganglion cells inhibit and are inhibited by neighboring cells

explains the mach illusion

Blue arrows are the lateral inhibition; receptors 1-7 are much more impacted than 8-15. This impacts lateral inhibition. Ganglion cell 7 has weaker inhibition due to dec lateral inhibition from receptor 8. Ganglion cell 8 has stronger inhibition due to the strong inhibitory signal from receptor 7.

Because of this, since ganglion cell 7 is less inhibited it is lighter, and ganglion cell 8 is more strongly inhibited and so is darker. This explains the illusion

At edges, ganglion cells get differential amounts of inhibition from darker area and brighter area-> makes edges stand out perceptually

off center and on center ganglion cells

Antagonistic arrangement of receptive fields-> detection of light/dark contrast

microedge detectors

On center- when light shines on center= excitation; light shines on periphery=inhibition

Off center- when light shines on center= inhibition; light shines on periphery=excitation

visual cortex receptive field

rectangular

simple cells of visual cortex

respond to edges at a specific orientation and place on the retina 

complex cells of visual cortex

continue to respond (unlike simple cells) when an edge moves to a different location

spatial frequency theory

Visual cortical neurons perform a fourier analysis of the luminosity variations of a scene

Neurons in visual cortex do not detect only edges, but have a variety of different sensitivities

Visual world is combination of high and low spatial frequencies

Need neurons that are sensitive to both:

High freq-> edge detection and fine details

Low freq-> detection of textural properties

parvocellular system

V1, V2, V4→ ventral stream (what stream- crucial for identifying objects by sight)→ inferior temporal lobe→ prefrontal cortex

Color vision (v4) and detailed obj recognition (inferior temporal lobe)

magnocellular system

V1, V2 → median temporal gyrus (V5)→ dorsal stream (where system- for figuring out where objects are in space in relation to others) → posterior parietal cortex→ prefrontal

Brightness, contrast, orientation, movement, depth and location of objects

disorders of visual perception

object agnosia

color agnosia

movement agnosia

neglect