Learn: PYB204 | Quizlet

What is Cognitive Psychology?

- The science of how the mind is organised to produce intelligent thought

- How the human mind is realised in the brain

What is Clinical Psychology?

Why certain thought malfunctions occur

What is Social Psychology?

How people behave with other individuals

Practical applications of cognitive psychology?

- False memory and eyewitness testimony

- Spatial navigation and the design of autonomous robots/cars

- Understanding brain disorders (williams syndrome)

What is Navitism?

Knowledge is innate

FROM Plato, Descartes and Kant

What is Empiricism?

Knowledge is acquired through experience

FROM Aristotle, Bacon, Berkeley, Locke, Hume and Mill

Define Structuralism?

By analyzing the mind into components

Introspection

Wundt and Titchner

Weaknesses: Subjective and unreliable

Define Functionalism?

By understanding what the mind does in response to stimuli (environments)

Introspection

WIlliam James

Weaknesses:

Little or no empirical support

Define Behaviourism?

By studying input-output association

Watson & Skinner

Introduced experimental methods to psych research

What is the cognitive revolution?

During World War II, research on human performance was intensively conducted

Lead to shortcomings of behaviourism (not useful for solving practical issues)

Allowed development of other scientific fields (linguistics, computers, information theory)

Diagram of Information-Processing Approach

Define what visual search is?

A theoretical model allows you to make predictions

E.g. The time it takes to find a target should linearly increase as the number of letters increases

Define neuroscience?

The study of the structure and function of the nervous system

Define cognitive neuroscience?

Attempts to gain insights into cognitive processes by studying the brain and behaviour

What is perception?

Awareness of the elements of environment through physical sensation

Perception is not just receiving information through sensation; it involves interpretation and recognition of the information

What are the 10 elements of perception?

Visual

Auditory

Tactile (haptic)

Olfactory

Gustatory

Object

Space

Motion

Speech

Time

What is light?

For an object to be visible it must either emit or reflect light

One way of understanding light is that it is a wave of electromagnetic radiation

- It is a wave, so one dimension of light is its wavelength

How does the human eye detect light?

The human eye is only capable of detecting light within a narrow range of wavelengths

Within this range of visible wavelengths, different wavelengths give rise to the perception of different colours

Light Diagram

Differences in light brightness?

Anatomy of the Eye

What is accomodation in regards to the eye?

The ciliary muscles control the shape of the lens to accomodate near or far targets

What is the Retina?

A thin, light sensitive membrane located at the back of the eye

Contains two types of visual sensory receptors (cells that convert physical input—i.e., light—into electrochemical signals): rods and cones

What is the Fovea?

A small area in the center of the retina, composed entirely of cones

Where visual information is most sharply focused

What is the Optic Disk?

The area of the retina without rods or cones

Diagram of the Retina

Define Rods

- long, thin, and blunt

- highly sensitive to light, but not to colour

- primarily for peripheral and night vision

Define Cones

- short, thick, and pointed

- detect colour

- for colour vision and visual acuity

What do rods and cons do?

Rods and cones convert light energy into electrical energy via a photopigments (chemicals that absorb light)

Different kinds of photopigments are responsive to different wavelengths of light

- That is, different kinds of photopigments "see"

different colours

There is just one kind of photopigments in rods (called rhodopsin)—that's why signals from rods don't provide colour information

What is within the Cones?

Photopigments in cones (called iodopsin) come in three variations

Each variation is sensitive to a different range of wavelengths

Thus, each variation is tuned to a different range of colors

Rods & Cones IMAGE

What are the different levels of acuity for rods & cones?

More rods than cones synapse with each ganglion cell

The Visual Field Diagram

Two Major Pathways within the visual field are?

Retina -> lateral geniculate nucleus (LGN) -> V1 (primary visual cortex in the occipital lobe)

retina -> superior colliculus (SC) (and pulvinar nucleus)

What is the function of the LGN-V1 Pathway?

conscious aspects of vision (e.g., object recognition)

What is the function of the SC pathway?

unconscious visual functions (e.g., object localisation)

What is Blindsight?

some people with damage to the LGN-V1 pathway can still react to visual stimuli (e.g., point to them), although they claim that they cannot see them!

Image Example of Blindsight

What is the primary visual cortex? (V1)

Neurons in V1 respond to bars of a particular orientation

Beyond V1: How do we process visual information?

There are multiple visual areas in the cortex

Each area performs different types of computation

Generally, in areas that appear later in the information processing stream, neurons respond to more complex patterns

Our visual perception is more closely related to neural activity in the higher visual areas

Beyond V1: How do we process visual information? (DIAGRAM)

Diagram of how the brain processes visual information

What is the receptive field?

Area of the visual field to which a visual neuron responds

It is very small in the beginning, and becomes increasingly larger in later stages of visual information processing

How do we process visual information?

The visual world is broken down into small elements, and then it is reconstructed

Diagram of Neurons involved in Vision

What do ganglion cells do?

Ganglion cells receive input from multiple receptors that are adjacent to each other

Two ganglion cells that are next to each other in the retina will have receptive fields that are also next to each other

- Forming a retinotopic map

Centre-Surround Antagonism Diagram

What do neurons in the LGN do?

Centre-surround antagonism

Retinotopic map (i.e., adjacent LGN neurons have adjacent receptive fields)

Thus, ganglion cells and visual neurons in the LGN respond simply to the presence of a spot of light on the retina

What do neurons in V1 do?

Receptive fields of two adjacent V1 neurons are still adjacent to each other

These neurons receive input from multiple LGN neurons

This enables V1 neurons to function as bar detectors

What do neurons in higher-order areas do?

neurons have larger receptive fields by combining input from multiple lower-level neurons

This enables those higher-level neurons to respond to more complex visual patterns

High-level Neuron Diagram

What is an experiment?

Tests designed to provide a causal explanation of results

Not just correlation, but causation

Two conditions: Experimental & Control

Define Independent Variable

Directly manipulated by an experimenter

Define Dependent Variable

Measured by the experimenter

Define Control Variable

Held constant in all conditions of the experiment

Define confounding variable

Uncontrolled extraneous variables that confuse or confound the results by effecting the DV.

How to reduce confounding variables?

Counterbalancing: Half the participants receive the low distraction level first, and the other half receives the high distraction level first (in a distraction experment)

Randomisation: The order of conditions is determined randomly for each participant

What is floor/ceiling effects?

Too easy/difficult tasks cannot capture the influence of an independent variable appropriately

What is between-participant design?

Different levels of the IV run on different participants

What is within-participant design?

All levels of the IV run on each participant

What is hypothesis testing?

Testing the null hypothesis (H0) which states that your manipulation has no effect

Define Descriptive Statistics

Ways to summarise and organise data

Steps of Hypothesis Testing

1. Assume the H0 is true

2. Under this assumption you compute the probability your data would show the observed pattern

3. Lets say this probability turns out to be small (less than 5%)

4. What this means is that you got an outcome that should be very unlikely to happen if H0 is true

5. So you conclude that H0 must be false (reject the H0 and support H1 (your IV had an effect))

P-Value

How is sound produced?

Sound is caused by changes in air pressure.

These pressure waves are characterised by amplitude, frequency, and phase

Define Amplitude

related to loudness (decibels: dB)

Define Frequency

related to pitch (Hertz: Hz)

Define Phase

position within a cycle

What is a sine wave?

A pure tone (sine wave) is the simplest sound wave.

Diagram of sound wave

Loudness of common sounds Image

What is the human hearing range?

20-20000 Hz

Most of our auditory experience involves only a small fraction of this range

e.g., typical vocal range: 80-1100 Hz

What is Fourier analysis?

Complex sounds can be built up from series of sine waves of varying amplitude, frequency, and phase.

We can decompose complex sounds into their sine wave components by a process called Fourier analysis.

As we will see, the auditory system essentially does the same thing!

What is fundamental sound?

The lowest frequency component of a complex sound

What is harmonics?

Complex sounds are made up of harmonics - integer multiples of the fundamentals

(fundamental is 440Hz then the 2nd harmonic will be 880Hz and 3rd will be 1320Hz and so on)

Auditory Physiology Image

The Outer Ear: Image

The Middle Ear: Image

The Inner Ear: Image

The Cochlear: Image

Hair cells in the inner ear: Image

Microscopic Image of Inner Ear

Central Auditory Pathways: Image

Nerve fibres from each cochlea synapse in a number of sites on the way to the primary auditory cortex

- The cochlear nucleus

- The superior olivary nucleus

- The inferior colliculus

- The medial geniculate nucleus

The signal arriving at the cochlear nucleus splits and goes to each of the superior olivary nuclei

Beyond this point, input from both ears is present in both hemispheres

The auditory cortex: What tasks can be performed without it?

Animal studies have shown that many auditory tasks can be performed without the auditory cortex being present!

These include responding to:

- The onset of sound

- Changes in sound intensity

- Changes in sound frequency

What tasks cannot be performed without the auditory cortex?

- Discriminating the pattern of several tones

- Discriminating the duration of sounds

- Localising sounds in space

THEREFORE , it seems that the cortex deals with more complex auditory tasks while the lower structures deal with simple aspects of sounds

What does speech perception require?

requires structures beyond the primacy auditory cortex

What is frequency coding?

Sounds are made up of a mixture of sine wave components.

The auditory system isolates and identifies the frequencies of these components (as though it carried out Fourier analysis).

The basilar membrane is about 30 mm long and varies in stiffness and width along its length.

What is a travelling wave?

Travelling waves move along the basilar membrane and peak at different point depending on the frequency of the sound.

What does the location of a peak do?

Identifies the frequency of a sound

What happens when people have damage to the Cochlea?

When people have damage to a specific part of the cochlea, they tend to suffer from frequency-specific hearing loss

Stimulating auditory nerves at different cochlear locations leads to perception of sounds in different pitch

Actually, this is one way in which a cochlear implant works

Image of Cochlear Implant

What do hair cells in hearing do?

Hair cells are tuned to different ranges of frequency according to the location along the basilar membrane

Auditory Neurons in Hearing

The auditory neurons are arranged in an orderly manner

This organization is seen repeatedly in the auditory pathways

That is, tonotopic maps are present in the auditory system

What is pitch perception? Image 1

So far, we reviewed how sound frequency is encoded in each ear (monaural encoding)

Does one ear do all the work for pitch perception?

What is pitch perception? Image 2

What is binaural pitch encoding?

What is loudness perception?

Human auditory range (in terms of loudness perception): approx. 0-120 dB

0 dB = absolute hearing threshold

120 dB = loud thunder

This range of intensity is roughly 1000000000000 to 1!

Basic Mechanism of Loudness Perception: Image

What factors affect loudness perception?

1. Sound duration (longer = louder)

2. Frequency

What sounds are perceived to be louder?

High-frequency sounds are perceived to be louder (up to 5000 hz)

Around 3000-5000Hz sounds are percieved to be loudest

AS the amplitude goes up the frequency becomes smaller