PSY Midterm 1

Sensation

Involves the detection of external stimuli (e.g., light, pressure, etc.), responses to those stimuli, and the transmission of these responses to the brain.

Perception

Involves the processing, organization, and interpretation of sensory signals in the brain, which results in an internal representation of the stimuli - and your conscious experience of it!

Transduction

Process by which sensory receptors pass impulses to connecting neurons when they receive stimulation (e.g., from pressure on the skin, in the case of touch).

Absolute threshold

The minimum intensity of stimulation that must occur before you experience a sensation (or the stimulus intensity detected above chance).

Difference threshold

The just noticeable difference between two stimuli (the minimum amount of change required for a person to detect a difference 50% of the time).

Gustation

Every taste experience is composed of a mix of five basic qualities: sweet, salty, sour, bitter, & umami (savory).

Olfaction

The olfactory epithelium (or mucosa) is a thin layer of tissue embedded with smell receptors, which transmit information to the olfactory bulb, which is the brain center for smell.

Orbitofrontal cortex (OFC)

Receives info from smell, taste, and visual systems and is involved in flavour perception.

Mechanoreceptors

Respond to mechanical distortion or pressure.

Somatotopic organization

Connected parts of the body tend to be represented beside each other in the primary somatosensory cortex.

Sensory homunculus

More sensitive regions tend to have more cortical area devoted to them (e.g., lips, fingers).

Nociceptors

Activated by damaging (or possibly damaging) stimuli à being pierced, burned, etc.

Thalamus

Relay station for sensory information before it reaches the cortex.

Context/expectations

Play a huge role in how we perceive the world.

Change

Important in the perception process.

Taste receptors

Located on the tongue and are responsible for detecting taste stimuli.

Smell receptors

Located in the olfactory epithelium and are responsible for detecting smell stimuli.

Cochlea

Contains the most sensitive mechanoreceptors responsible for sound transduction.

Primary somatosensory cortex

The area of the brain that processes tactile information.

Vestibular system

Involved in balance and spatial orientation.

Temperature, pressure, & pain

Types of sensations processed by the somatosensory system.

Myelinated fibres

A delta fibres that transmit sharp, immediate pain.

Lightly or non-myelinated fibres

C fibres that transmit dull, steady pain.

Gate control theory of pain

A theory stating that for pain to be experienced, pain receptors must be activated and the neural 'gate' in the spinal cord must allow the signals through to the brain.

Open gate

When the gate is open, pain is experienced.

Closed gate

When the gate is closed, pain is reduced or prevented.

Accommodation

The process by which muscles change the shape of the lens to focus on distant or close objects.

Myopia

A condition where distant objects appear blurry due to the shape of the eye.

Photoreceptors

Cells that convert the energy from light particles (photons) into a chemical reaction that produces an electrical signal.

Rods

Retinal cells that respond to low levels of light and result in black and white perception, with about 120 million in each retina.

Cones

Retinal cells that respond to higher levels of light and result in colour perception, with about 6 million in each retina.

S cones

Cones that respond to short wavelengths, contributing to blue perception.

M cones

Cones that respond to medium wavelengths, contributing to green perception.

L cones

Cones that respond to long wavelengths, contributing to red perception.

Trichromatic theory

A theory stating that the perception of colour is determined by the ratio of activity among the three types of cones.

Opponent-Process Theory

Focus on ganglion cells in the retina.

Opposing Color Pairs

Three opposing pairs: Red/Green, Yellow/Blue, White/Black.

Motion Perception

Fatigue of certain motion sensitive neurons leads to motion after-effects (the waterfall illusion).

Visual Transmission

Involves rods and cones, bipolar, amacrine, horizontal cells, ganglion cells/optic nerve, ventral, thalamus (LGN), dorsal.

Dorsal Stream

Specialized for spatial perception, determining where an object is and its spatial relation to other objects.

Ventral Stream

Specialized for perception and recognition of objects, such as determining colour and shape.

Agnosia

Inability to recognize objects despite having intact sensory function.

Prosopagnosia

Inability to recognize faces.

Figure-Ground Relationship

Whatever is not the figure (the focus of visual field) is automatically assigned as background.

Illusory Contours

We tend to perceive contours, even when they don't exist.

Proximity

The closer two figures are, the more likely we are to group them together.

Similarity

We tend to group figures according to how closely they resemble each other.

Continuation

We tend to interpret intersecting lines as continuous rather than as changing direction radically.

Closure

We tend to complete figures that have gaps.

Depth Perception

Retinal Disparity: Important cue of depth perception caused by the distance between the eyes.

Monocular Depth Cues

Include occlusion, relative size, familiar size, linear perspective, texture gradient, and position relative to horizon.

Motion Parallax

Objects that are farther away seem to move more slowly than objects that are closer.

Bottom-Up Processes

Processes that begin with sensory input and build up to perception.

Top-Down Processes

Processes that involve the use of preexisting knowledge to organize individual features into a unified whole.

Bottom-up processing

Information is sent from lower-level processing areas to higher level processing areas.

Top-down processing

Information from higher-level areas can also influence lower, 'earlier' levels in the processing hierarchy.

Expectations

Expectations inform perceptions.

Corpus callosum

A structure that connects the left and right hemispheres of the brain.

Contralateral organization

The principle that each hemisphere of the brain controls the opposite side of the body.

Lateralization of function

The tendency for some neural functions or cognitive processes to be more dominant in one hemisphere than the other.

Interpreter

A left-hemisphere process that attempts to make sense out of events and creates a comprehensible story out of events.

Fusiform face area (FFA)

Area of the brain that becomes particularly active when people look at faces, located at the intersection of the occipital and temporal cortices.

Expertise area

Evidence suggests that the fusiform face area is an 'expertise' area and not just for faces.

Thompson, 1980

Reference to a study related to the perception of faces.

Split brain patients

Individuals who have had their corpus callosum severed, leading to unique cognitive behaviors.

Visual field

The entire area that can be seen when the eyes are fixed in one position.

Left hemisphere

The side of the brain that vocalizes responses and interprets information seen in the right visual field.

Right hemisphere

The side of the brain that may process information not accessible to the left hemisphere.

Comprehensible story

The narrative created by the left hemisphere to make sense of events.

Patterns and relationships

The left hemisphere's attempt to find connections in the information it processes.

Charles Darwin 5 Steps to Evolution

"Fit Characteristics and Survival of the fittest"

What is the role of theory in scientific research?

To explain the relationship between two or more variables and to produce new hypotheses.

What are the three key characteristics of scientific theories?

They must be testable, falsifiable, and parsimonious.

What does the Intergroup Contact Theory suggest?

Positive intergroup contact leads to less prejudice toward the outgroup.

What is the difference between an independent variable and a dependent variable?

The independent variable is manipulated, while the dependent variable is measured.

Define conceptual definition.

A dictionary or textbook definition that explains the meaning of a term.

Define operational definition.

Theoretical constructs stated in terms of concrete, observable procedures that are well-defined and easily measured.

What are the three big categories of research methods in psychology?

Descriptive methods, correlational methods, and experimental methods.

What types of research fall under descriptive methods?

Surveys, focus groups, case studies, and observational research.

What is passive observation in research?

Naturalistic observation where researchers do not change ongoing behavior.

What is the Hawthorne Effect?

A phenomenon where people change their behavior when they know they are being observed.

What is the difference between random sampling and random assignment?

Random sampling gives each member of the population an equal chance of selection, while random assignment gives each participant an equal chance of being assigned to any condition in the study.

What is a confound in research?

Any variable that may differ across study conditions, limiting the ability to make causal claims.

What does the term 'quasi-experiment' refer to?

A study where random assignment is not possible, often using pre-existing groups.

What is the importance of critical thinking in scientific research?

It forms a foundation of scientific reasoning and improves the ability to evaluate claims and evidence.

What is the scientific mindset?

The approach of being objective, basing conclusions on facts rather than personal perspectives.

What does the term 'construct' refer to in psychology?

Internal attributes or characteristics that cannot be directly observed.

What is the significance of systematic observation?

It involves gathering evidence through structured methods rather than relying on anecdotal or biased observations.

What is the directionality problem in correlational research?

It refers to the inability to determine which variable influences the other in a correlation.

What is the third-variable problem?

A situation where a third variable influences both variables being studied, creating a false correlation.

What is the purpose of the scientific method?

To develop and test theories through systematic observation and experimentation.

What is the difference between objectivity and subjectivity in research?

Objectivity is based on facts, while subjectivity is based on personal perspectives.

What is the significance of the phrase 'Causation does not equal correlation'?

It highlights that just because two variables are correlated does not mean one causes the other.

What is the role of surveys in descriptive research?

Surveys provide large amounts of information quickly.

What is the purpose of focus groups in research?

To gather detailed information that is not possible from surveys.

What is the main goal of experimental methods?

To establish cause and effect relationships between variables.

What is operationalization in research?

The process of measuring an intangible construct through observable behaviors and self-reports.

What are descriptive methods in research?

Methods such as case studies, naturalistic observations, and surveys used to gather data.

What is a case study?

An in-depth analysis of one person or a small group, useful for generating hypotheses.

What is naturalistic observation?

Observing individuals in their everyday circumstances without interference, suitable for general population results.