Psych Exam 2 content

Camera obscura

Classic model of perception - box, light comes through hole and project the image of that light (eyes are like hole, world projects through, information is direct and comes fully formed)

“Treatise on Physiological Optics”

1866, Hermann Von Helmholtz, dig at classic view, discovery of retina- now our bodies are contributing to perception as a biological proces→ observer has autonomy (individuality), institutions(church, education, military) interested in control/discipline(Sociality) (1820-70)→ psych: measure, quantify, instrumentalization (machine integration- indust rev.) → control it

Attensity

Book written by “the friends of attention,” argues collective attention is being mined and commodifies by tech and offers positive vision fro attention activism and reclaiming shared humanity- attention liberation movement

General strategy of the brain

Predictive regulation, increase metabolic efficiency to accurately predict sensory inputs— “unconscious inference,” only production error(new information) gets transmitted (as in we actually evaluate and update as needed)

New view of perception

We never experience the world directly, only through the simulation of our brain and our prior experience

simulation stays connected to the world via prediction error

3 kinds of cerebral cortex

differ in layers:

agranular- 4 layers, primarily prediction neurons, axons to dysgranular ans granular cortex, fewer precision cells

dysgranular - 6 layers, prediction -error neurons axons to agranular, granule cells, precision cells

granular - 6 layers, more prediction -error neurons axons to agranular, granule cells, precision cells

Is perception an accurate representation of the external world?

Question for the chapter, believing is seeing

Exteroception

neural systems designed to process sensory input from the external world

Vision, audition, touch/temp/pain(bodily senses), smell, taste(chemical senses)

BOLD- more about the physiological state of body, not nec external world

Interoception

neural systems designed to process sensory input from the body’s internal milieu (physiological state of body)

temp/pain, smell, taste, autonomic visceral function, autonomic vascular function, neuroendocrine fluctuations, neuroimmune function

these sense are designed to maintain homeostasis, manifested as bodily feelings and more abstract emotions

light

The critical stimulus for vision, visible portion of the electromagnetic spectrum, both a wave(color,wavelength-nm) and particle (brightness, # of photons)

Eye

function is to project image onto retina

Outer layer- white and becomes the transparent cornea(focuser) at the front , sclera

Middle layer- blood vessels, nutrients

inner layer- “yellow,” retina

Pupil - hole of eye, iris- helps dilate pupil, lens- focus controlled through making itself thicker and thinner

optic disk- receptiors of the retina (axons) leave through this

Retina consists of **

3 layers and 2 synapses (except all the fovea)**

Innermost layer contains:

photorecepters: rods and cones

photoreceptors

Inner layer -tranduce light energy to electrical and chemical signals

cones

Inner layer- photoreceptors that process color, operate under daylight conditions, allow focus on fine details (the fovea ONLY contains these)

rods

Inner layer-can operate under nightime conditions, see better in dark, more sensitive to light, adaptation

middle layer

contains bipolar cells (no action potentials involved), synapse with outer layer RGCs, no action potential involved

outer layer

contains retinal ganglion cells (rgcs)

retinal ganglion cells, RGCs

their axons leave the eye as the optic nerve bundle

optic nerve

blind spot, no photoreceptors, RGCs axons leave the eye as this

visual system is unique

bc it requires two synaptic signals before spikes, reduces and optimizes visual information, metabolic activity

if photons were converted directly into spikes

10,000 spikes/sec required- imposs bc each action potenial takes 1/1000 of a sec

auditory system only has

one synaptic layer od spiking

touch, olfaction, and taste

have no synapse and go directly to spking

seeing color

part of conscious experience, perceive spectrum because surfaces absorb light and selectively reflect wavelengths that reach out eye

Sun contains

all visible wavlengths (and more!)

Short to long wavelegnths

violate to green to red

Trichromatic theory

we see color because we have three populations of cones= S, M , and L - short med and long wavelength cones

population coding

three population of cones- system looks for the pattern of activation across the cones, amounts of SML being activation

Constanstacny failure

morning person versus night owl** the dress

Visual Pathways

left and right visual feild relative to where eyes are fixated, right of eye goes to left hemi, left visual feild goes to right vis fiels

Visual pathway goes from

eye→ optic nerve→ optic chiasm (1/2)→ optic tract→90% of tract goes to thalamus, lateral genuculare nucleus LGN→10% to midbrain, superior caliculis→90% then go to area V1 in ocipital cortex, vision first stop

Agnosias

what happens when our what vs where/how pathways are damaged

apperceptive agnosia (DF)

- ventral lesions- patient unable to recognize or draw objects from visual presentations

Patient DF

Milner and Goodale 1991, worked with patient, DF, with extensive bilaterla ventral-stream lesions since 1991,

perceptual ortientation matching: DF has profound visual from agnosia- could not line up a line preceptiually

visuomotor posting: still has spared abilities- cannot ercieve orientation of a line she is still able to orient her hands to insert an object into a slot- dorsal system

Associative agnosia

ventral lesions-not as impaired visually, can perceive intact objects and draw them but unable to name objects from visual perceptions

Prosopagnosia

ventral lesions- patient unable to recognize faces although can recognize other objects

Two visual pathways

1. Dorsal stream- “where pathway”

2. Ventral stream- “what pathway”

Ventral pathway

visual pathway in the brain - also known as the “what” pathway, color, orientation, figure-ground, object recognition

Dorsal pathway

visual pathway in the brain - “where” pathway, Depth, size, motion

Balint’s syndrome

dorsal-lesions, patient has poor control of visually guided movements and is unable to identify two objects at once

The skin

epidermis, dermis, subcutaneous

tactile perception

receptors in dermis: temture and pattern receptors, pain receptos, pressure, low-frequency vibration

Somarosensory and motor cotices

Somarosensory shows cortical magnification- body parts more sensitivy to touch have more cortical area

Phantom limbs***

***reveal brain plasticity, experience limb even though its gone, experinece due to somatosensory cortext, face parts of brain invaded into arm becasue was not getting stimulation

Sensation

simple stimulation of a sense organ

Perception

organization, identification, and interpretation of a sensation in order to form a mental representation

sensory adaptation

sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current (unchanging) conditions

Transduction

the process whereby sense receptors convert physical signals from the environment into the neural signals that are sent to the CNS

psychophysics

methods that systematically relate the physical characteristics of a stimulus to an observer’s perception

absolute threshold

the minimal intensity needed to just barely detect a stimulus in 50% of the trials

sensitivity

how responsive we are to faint stimuli

acuity

how well we can distinguish two very simular stimuli

just noticeable difference (JND)

the minimal change in a stimulus (e.g., its loudness or brightness) that can just barely be detected.

Weber’s law

relationship was first noticed by the German physiologist Ernst Weber; states that for every sense domain, the change in a stimulus that is just noticeable is a constant proportion despite variation in intensities

noise

all the other stimuli coming from the internal and external environment. Other sights, sounds, and smells in the world at large, own moods and motives, all compete for attention

signal detection theory

the response to a stimulus depends both on a person’s sensitivity to the stimulus in the presence of noise and on a person’s decision criterion

Visible light

the portion of the electromagnetic spectrum that we can see, and it is an extremely small slice

wavelengths

light waves vary in height and in the distance between their peaks

relationship of light in physical and physiological dimenions

Light waves vary on three physical dimensions. Changes in these physical dimensions produce systematic changes in perception

length of a light wave

determines wave’s hue, or what humans perceive as color

amplitude of a light wave

intensity, how high the peaks are — determines what we perceive as the brightness of light.

purity of light wave

the degree to which a light source is emitting just one wavelength, or a mixture of wavelengths, influences how color is perceived

high saturation

Very pure light (such as that emitted by a laser), consisting of just one wavelength, perceived by humans as having a rich color

eye

specialized organs to detect light

cornea

clear, smooth outer tissue; bends the light wave and sends it through the pupil

pupil

hole in the colored part of the eye, receives bended light from cornea

iris

colored part of eye, translucent, doughnut shaped muscle that controls the size of the pupil and hence the amount of light that can enter the eye

lens

controlled by muscles inside the eye behind the iris, bends light from through the pupil to focus it onto the retina, focuses objects at different distances, flatter- far away, rounder- closer

retina

a layer of light-sensitive tissue lining the back of the eyeball

accomodation

the process whereby the eye maintains a clear image on the retina, change in lens flatter- far away, rounder- closer

nearsightedness (myopia)

eyeball is too long, images are focused in front of the retina

farsightedness (hyperopia)

eyeball is too short, images are focused behind the retina

interoception

the afferent component of the ANS underlies this, enables us to percieve the inner state of the body perceived along two diemensions, valence and arousal

hedonic

emotion and reward about the body and things about the world

insula

an integration hub, allows us to generalize bodily feelings to our perceptions of the outside world

valence assesment

trying to sense if something is out of the norm

emotion

bodily feelings at the foundation

temporary state that included:

• unique subjective experiences (feelings)

• physiological activity in body and brain

• prepares people for action

feelings

hard to describe objectively; researchers use statistical techniques to create map based on psychological distance (similarity), reveales number of dimensions in this space

Autonomic nervous system (ANS)

sympathetic and parasympathtic

most discussions only consider efferent connections from brain to body, afferent component not established till 90s, afferent underlies interoception

two dimensions that we perceive our inner state as “bodily feelings”

valence and arousal

valence

dimension of pleasant to unpleasant to with we perceive bodily feelings

arousal

dimension of excited to calm to with we perceive bodily feelings

Emotions are different from feelings

they are constructed from interoceptive sensations

amygdala

important role in emotion; threat or novelty detetctor

• evaluates emotion-relavant aspects of stimulus

• fast and slow pathways to amygdala

stimukates ANS

fast and slow pathways to amygdala

fast- but inaccurate → thalamus → amygdala → experience of fear

slow- but accurate → thalamus → cortex(can excite or inhibit) → amygdala → experience of fear

WHy temp and pain linked?

body gets concerned when core temp<skin temp, somatosensory speaks to insular cortex= pain!

Constructivist/historicism theory of emotion

without context it is difficult to know what someone is feeling

• made not triggered

• not distinct from perceptions and cognitions

• highly variable without fingerprints

universality hypothesis

darwin(post origin of species) all emotion expressions mean the same thing to all ppl in all places at all times (universalism)

appraisal

Conscious or unconscious evaluations and interpretations of the emotion-relevant aspects of a stimulus or event

action tendency

Readiness to engage in a specific set of emotion-relevant

behaviors.

 Love → approach

 Sad → avoidance

James–Lange theory (1890)

classsical theory of emotion, Stimuli activate the ANS, which in

turn produces an emotional experience in the brain.

cannon and bard":psych ni that simple

photoreceptor cells

retina located, containlight sensative proteins that absorb light and transduce it into electrical signals, cones and rods

cones

detect color, operate under typical daylight conditions, and allow us to focus on fine detail, fewer than rods; form the innermost layer of the retina, beneath a layer of transparent neurons called the bipolar and retinal ganglion cells

rods

become active only under low-light conditions, for night vision, more plentiful than cones; form the innermost layer of the retina, beneath a layer of transparent neurons called the bipolar and retinal ganglion cells

fovea

an area of the retina where vision is clearest and there are no rods at all

peripheral vision

Objects outside of your direct focus

bipolar cells

collect electrical signals from the rods and cones and transmit them to the retinal ganglion cells (RGCs)

retinal ganglion cells (RGCs)

organize the signals from rods and cones and send them to the brain.