PSYC 1010 EXAM 2

sensation

sensation

*the process by which sense organs gather information about the environment and transmit it to the brain *refers to events like the processing of light by photoreceptors

transduction

to transform physical stimuli in the environment into neural signals in the brain

taste

*5 main sensations *tastebuds contain the taste receptors (each bud contains 50-150 taste receptor cells) and send information to the gustatory sensory neurons

smell

chemical receptors in the nose

sound

2 key characteristic: frequency of a sound wave is related to the pitch of a sound and aptitude of a sound wave is related to loudness of a sound

outer ear

acts as a funnel to direct sound waves towards inner structures

middle ear

consists of three small bones that amplify sound

inner ear

contains the structures that transduce sound into a neural response

cochlea

*a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses *different parts detect different sounds *cant regenerate *has hair receptor cells that are the receptor cells for hearing

touch

receptors are sensory neurons

pain

*2 pathways for pain. delta fibers (myelinated) and fibers (unmyelinated) *there are different receptors for pain than from touch

gate control theory

explains variability in the experience of painful events and argues that the spinal cord contains a neurological gate that blocks pain signals or allows them to pass onto the brain

vision

*transforming light energy into a neural impulse and represent characteristics of objects in our environment such as size, color, shape, and location *2 aspects of light: our visual system interprets differences in the wavelength of light as color and in the amplitude of light as intensity

compound eyes

eyes that have multiple lenses (ex; flies and lobsters)

simple eyes

eyes that have a single lens (ex; humans and spiders) -uses a lens to focus light onto a photo sensitive surface at the back of a sealed structure

rods

permit vision in dim light and are everywhere except the fovea. we have only one type

cones

permit color vision and are most concentrated in the fovea. we have three different types

fovea

pinhead size area of the retina that is in the most direct line of sight

trichromatic theory of color vision

The theory that there are three kinds of cones in the retina, each of which responds primarily to a specific range of wavelengths

opponent-process theory

the theory that opposing retinal processes (red-green, blue-yellow, black-white) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green

simple cells

neurons that respond to lines/bars/edges of a particular orientation

complex cells

neurons that respond to more complex events

spinal cord

consists of bundles of nerves called tracts; the ascending tract carries sensory info brought in by the spinal nerves up to the brain, and the descending tract carries motor control info down from the brain to be transmitted out by the spinal nerves to muscles

brainstem

responsible for automatic survival functions, such as controlling breathing and the heartbeat

cerebellum

motor control, posture, balance, and rapid, well timed movements

thalamus

sensory relay station that receives input from most of the sensory modalities - vision, audition, etc.

basal ganglia

wrapped around the thalamus and is involved in motor control (opposite of the cerebellum) - damage produces tremors

hypothalamus

regulates many basic body functions - hunger, thirst, sleep, body temp, etc.

amygdala

processes and regulates emotional states

hippocampus

key for building long term memories (encodes new memories). if damaged, you may be unable to acquire new memories (memories prior to accident are retained)

cerebral cortex

outermost layer and largest part of the brain. it is divided into left and right hemispheres and has an overflow of functions from necessities (breathing and movement) to luxuries (voluntary action). different lobes have different functions

peripheral nervous system

the set of nerves that connects the central nervous system to the sensory organs, muscles, and glands

sympathetic nervous system

arousing; responds to stressful situations

parasympathetic nervous system

calming; stimulates digestive processes and other activities that help to regenerate and vitalize the body

left hemisphere

controls language and the right side of the body and visual field

right hemisphere

controls the left side of the body and visual field

aphasia

the impairment of language usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area (impairing understanding)

the case of phineas gage

*suffered massive damage to frontal lobes during a railroad accident involving dynamite *personality changed *provided early knowledge that the frontal lobe handled inhibition and high level reasoning

the case of hm

*suffered from severe epileptic seizures and had his hippocampus removed *deeply amnesic (unable to learn new information)

spatial resolution

how close in physical proximity you can get to the target brain area

temporal resolution

how close in time you can get to when the neurons communicate with each other

Electroencephalogram (EEG)

measures electrical signals associated with neural firing in brain areas -excellent temporal resolution, poor spatial resolution, and non invasive

computed tomography (CT)

version of an x ray that provides information about brain structure -fair spatial resolution and no temporal resolutioin

magnetic resonance imaging (MRI)

uses radio waves and magnetic fields of the body to produce detailed images of the brain -excellent spatial resolution, no temporal resolution, and non invasive

Function Magnetic Resonance Imaging (fMRI)

generates a functional image based on changes in oxygen consumption and blood flow, which are byproducts of neural activity -excellent spatial resolution, fair temporal resolution, and non invasive

sensory neurons

send input from sensory areas to the brain and spinal cord

motor neurons

send output from the brain and spinal cord to muscles and glands

interneurons

carry information between other neurons

dendrite

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

cell body

the round, centrally located structure that contains the nucleus and DNA

axon

the extension of a neuron, ending in terminal fibers through which messages are sent to other neurons to muscles or glands

myelin sheath

white, fatty casing on axon made of glial cells. it acts as an electrical insulator and increases the speed of neural signals down the axon

action potential

what the neuron is communicating. it is a brief electrical charge that travels down an axon and influences the activity of the receiving neuron. it is enhanced by myelin

neurotransmitters

chemical messengers that traverse the synaptic gap between neurons

plasticity

neural tissue can reorganize in response to damage, if the brain is still developing

the case of brian

*10 yr old boy with severe epilepsy that led to the removal of his left hemisphere *lost the ability to speak and move the right side of his body *3 yrs later, much of his paralysis was gone and he could form sentences *the left hemisphere wasn't rebuilding, the right hemisphere took on both duties

occipital lobes

*the rearmost lobes of the cerebral cortex *bounded in front by the temporal and parietal lobes *they contain the visual areas of the brain

temporal lobes

*the lobes of the cerebral cortex that lie in front of the occipital lobes and below the parietal and frontal lobes *contain the auditory areas of the brain

parietal lobes

*the lobes of the cerebral cortex that lie in front of the occipital lobes, above the temporal lobes, and behind the frontal lobes *contain the somatosensory (- sensations) areas of the brain

frontal lobes

*the frontmost lobes of the cerebral cortex *bounded in the rear by the parietal and temporal lobes *contain the motor area and parts of the association areas involved in planning and making judgements

what pathway

Neural pathway, extending from the occipital lobe to the temporal lobe, that is associated with perceiving or recognizing objects. Corresponds to the perception pathway.

Gestalt's theory

*argued that our perceptual systems automatically organized sensory input based on certain rules *help us to organize the visual scene into units *figure ground relationships hep to define important parts of the visual scene

proximity

groups nearby figures together so that objects near each other tend to be seen as a unit

similarity

groups figures that are similar so that objects similar to each other

closure

fill in gaps to create a complete whole image

continuity

objects that are connected by a smooth curve tend to be seen as a unit

movement

objects moving in the same direction and at the same speed tend to be grouped together

the size-distance problem

*cannot determine size until you know distance *to perceive the size of objects accurately, we must also perceive their distance accurately *the ames room

binocular depth cues

involve comparing the left and right eye images

monocular depth cues

*appear in the image in either the left or right eye *allow us to see 3D with the view of only one eye *

relative size

if two objects are assumed to be the same size but one appears bigger then it must be close

linear perspective

apparent convergence of parallel lines suggests distance

texture gradients

the elements of a texture become smaller and more densely packed together as they raced into the distance

relative height

proximity to the horizon signals greater distance

perceptual constancy

*when viewing conditions change, the retinal image changes even if the objects being viewed remain constant *important function of the perceptual system is to represent constancy in our environment even then the retinal image varies

attention

*amplifies our ability to sense information *the gateway to memory and conscious awareness (you will not consciously remember stuff that is not attended to) *powerful selector mechanism *doesn't depend on where your eyes are pointing. can be moved independently of our eyes

stroop interference effect

*some abilities which once required attention can become automatic through practice *john stroop found that the act of reading could interfere with your ability to perform simple perceptual distinctions like naming colors *word processing is faster than color naming *for adults, reading has become such an automatized process that is very difficult to turn off. Thus, it can cause errors when what you're reading conflicts with what you're trying to attend to *automatic processes occur even when you try to override them

selectivity

only aware of a subset of stimuli

flexibility

the degree to which individuals can focus attention (selective attention) vs. spread attention across multiple objects/events

left visual effect

inability or difficulty to attend to the left side of visual space or of an object -caused by lesion in the right parietal lobe

dichotic hearing

*two different messages are being played in both ears and you are told to only pay attention to what is being hear in one ear *you can't comprehend the contents of the unattended ear *change in pitch or disappearance of message is noticed, or change in language or content is not

corpus callosum

*a large bundle of neural fibers that connect the two brain hemispheres *the main pathway that links and sends communication between the two hemispheres

visual crossover

*most of the sensory and motor information travels to and from the brain goes to the opposite side of the body *left visual field to the right hemisphere and right visual field to the left hemisphere

treisman's feature integration theory

*detecting features is relatively automatic *integrating multiple features together and identifying the object

feature search

*parallel analysis and detection of simple visual features *objects are easier to detect when they can be defined by a single feature. this search happens in parallel and is automatic

conjugation search

*combination of features and spatial arrangements *objects are harder to detect when they are defined on the basis of a combination of basic visual features. it is a controlled and attention-demanding process