Physiological Psychology Chapter 7

Sensory systems, perceptions, attention

Types of Cortical Sensory Areas

Primary, Secondary, Association

Primary sensory area

Receives information from the thalamic relay nuclei

Secondary sensory area

Receives information from the primary or other secondary areas

Association sensory area

Integrates information from multiple sensory systems (mostly secondary)

3 key principles of the sensory system

1. Hierarchical organization

2. Functional Segregation- each region is specialized for different functions

3. Parallel processing- Info flows between different structures simultaneously along multiple pathways

The physical dimension “Amplitude” goes with what perceptual dimension

Loudness

The physical dimension “Frequency” goes with what perceptual dimension

Pitch

The physical dimension “Complexity” goes with what perceptual dimension

Timbre

Pure tones are rarely (if ever) found

In nature

Fourier Analysis

Decomposing a sound to figure out the specific waves that make it up

Transduction in the ear happens through

Little hair cells that bend to sound, creating an action potential

Vibrations of the ear drum are capturing the

Physical properties of sound

The smallest bones in your body are

The ossicles

The three ossicles that the vibrations are spread to are

Malius, Incus, and Tampes

The vibration moves to the fluid of the cochlea, which __ to capture vibrations

Ripple

Hair cells are found in the

Organ of corti in the cochlea

Our cochlea makes us able to detect

Frequency differences

Tonotopic organization

Different organs respond to different frequencies

The auditory system can categorize and combine

Frequency messages

Auditory nerve axons synapse in the

Ipsilateral cochlear nuclei

Projections from cochlear lead to

Superior olives

Olivary neurons project via the lateral lemniscus to the

Inferior colliculi

Signals are sent to the medial geniculate nuclei in the

Thalamus

The last step in the auditory pathway is that the signals will arrive in the

Primary auditory cortex

The primary auditory cortex is organized into

Functional columns

All neurons in one column respond maximally to

One range

Tonotopic layout

Different regions respond maximally to different pitches

To draw a tonotopic map, you can use

fMRI

Periodotopy

The auditory cortex responds to changes over time

People used to study the auditory cortex using pure tones, but now they are natural sounds because

The complex sounds are preffered by the auditory cortex

Auditory objects

Different sounds within the world

Anterior stream

Identifies sound, “what” pathway

Posterior stream

Locates sounds, “where” pathway

Posterior parietal neurons have visual, auditory, or

Both receptive fields

The primary visual cortex sometimes responds to

Auditory information

World deafness

You can hear words, but not understand them

Anteriordam

You can hear things, but not identify them

Posteriordam

You can hear things, but don’t know where they’re coming from

Total deafness is

Rare

Conductive deafness

Damage to ossicles

Nerve deafness

Damage to cochlear nerve (loss of hair cells)

Age-related hearing loss affects higher frequencies because theya re

Closer to the base of the cochlea

Cochlear implants bypass hair cells by

Converting sounds into electrical signals that stimulate the auditory nerve

When using cochlear implants, the younger someone is..

The better their brain adapts to them

Cochlear implants help, but

Do not restore normal hearing

Somatosensory system

Processes sensations from the body

The somatosensory system is composed of what 3 interacting systems

1. Exteroceptive Cutaneous System (outside body)

2. Proprioceptive System (body position)

3. Interoceptive System (within body)

The exteroceptive cutaneous system is composed of what kind of stimulation

1. Mechanical (touch)

2. Thermal (temperature)

3. Nociceptive (surface pain)

Pacinian corpuscles are

Fast adapting receptors

Merkel receptors and Ruffini corpuscles are

Slow adapting receptors

Cutaneous receptors are responsible for

Turning stimuli into an ion flow across the membrane

Stereognosis

The ability to recognize object using touch

Somatosensory pathways (receptors from skin to brain)

1. Dorsal-column medial-lemniscus system (touch and perception)

2. Anterolateral system (pain and temperature)

The primary somatosensory cortex is organized according to

A map of the body surface (somatotopic mapping)

The primary sensory cortex was first discovered by

Wilder Penfield

Cortical magnification

Parts of your body with more sensitivity have more representation in the brain

Hands are like the __ of the body

Fovea

Astereognosis

Loss of ability to recognize object by touch

Asomatognosia

Loss of ability to recognize parts of one’s own body

Contralateral neglect

Loss of awareness to one side of visual space (attentional disorder)

Rubber hand illusion

Brain is tricked into integrating a foreign object into their body

Despite being an unpleasant experience, pain is

Crucial for survival

Pain is very

Adaptive

Anterior cingulate cortex

Emotional aspect of of pain and is most commonly associated with it

Pain is often studied using a

Thermal grid (metal rods that change temperature for your hand)

Pain seems to be modulated by

Cognitive and emotional factors

Your brain reduces pain during

Regulating mental states

Gate control theory

There must be a circuit that can block incoming pain signals

Periaqueductal Gray (PAG)

Neurotransmitters that can be stimulated to reduce pain (opioids)

Perception is how the brain makes sense of

Incoming sensory data

A person’s knowledge and experience heavily impacts their

Perception

Perceptual organization

How the brain organizes and interprets information

The brain makes constant decisions about

What patterns the eye is seeing

Pattern of neural activity that gets turned into perception

Hallucinations

When there are two equally plausible ways to see something, the brain will

Switch between interpretations

Perception can occur without

Sensory input (dreams, hallucinations, phantom limb)

Charles bonnet syndrome

Hallucinations in absence of visual input

Binding problem

How the brain combines sensory attributes to form one perception

Endogenous (top-down) processing

Controlled, voluntary

Exogenous (bottom-up) processing

Involuntary

Cocktail party phenomenon

Your brain blocks out information until it feels it is important

Change blindness

It is difficult to notice differences when there is a blank screen between images

Attention __ neural responses to attended stimuli and __ responses to others

Strengthens; weakens

Studying while distracted is almost the same as studying drunk because

Your attention is diminished and you won’t retain any of the information