1, 2, 3 Biological Psychology Practical

Neuron

The body's main communication cell that sends and receives electrical signals

Dendrites

The "antennas" of the neuron that catch incoming signals from other cells

Axon

The long fiber that carries electrical impulses away from the cell body

Synapse

The tiny gap between neurons where signals are exchanged

Afferent Neurons

Sensory neurons that carry signals from the body (periphery) toward the brain (CNS)

Efferent Neurons

Motor neurons that carry signals from the brain (CNS) out to the body (periphery)

Interneurons

Neurons in the CNS responsible for organizing and processing information

Ganglia

Clusters of sensory receptors and nerve cell bodies in the Peripheral Nervous System

Sympathetic NS

The stress response "fight or flight" mode that uses energy to handle challenges

Parasympathetic NS

The relaxation response "rest and digest" mode that calms the body and stores energy

Baseline (Tonic)

The normal level your body is at right before something happens

Evoked Response (Phasic)

A quick physiological change caused by a known trigger

Spontaneous Change

A physiological change where the trigger is unknown

Law of Initial Values

The principle that a higher starting baseline typically results in a smaller response to a stimulus

Proprioception

The ability to perceive the position and movement of body parts, localize yourself in space, and sense muscle force or tension without using visual information.

Mechanoceptors

Specialized sensory neurons located in the locomotor system that provide sensory feedback.

Muscle Spindles

A type of mechanoceptor sensitive to stretching.

Golgi Tendon Organs

A type of mechanoceptor that responds to the tension of the tendon.

Joint Receptors

A type of mechanoceptor that signals the actual position of the joints.

Effect of Deafferentation

The result of damaged nerves carrying sensory information, leading to loss of smooth movement control and lack of limb awareness without vision.

Sense of Ownership

A psychological feeling that your body belongs to you; this is often lost during deafferentation.

Balance

The ability to maintain an upright, stable position by distributing weight evenly through integrated automatic and conscious responses.

Visual System (Balance)

The sensory system providing information about the environment for balance.

Vestibular System (Balance)

Organs in the inner ear that sense gravity and head movement.

Proprioceptive / Tactile System (Balance)

Sensory information derived from the muscles, joints, and the soles of the feet.

BTrackS System

A testing system used to measure balance across four specific conditions.

BTrackS: Standard Condition

A balance test condition that uses all available sensory information.

BTrackS: Proprioception Condition

A balance test condition relying mainly on proprioceptive and tactile input from the soles.

BTrackS: Vision Condition

A balance test condition relying mainly on visual information while tactile input is blurred.

BTrackS: Vestibular Condition

A balance test condition relying primarily on the inner ear with no vision and blurred tactile input.

Rubber Hand Illusion (RHI)

An experiment where a participant's real hand is hidden and replaced by a rubber hand; synchronous stroking of both creates an illusion of ownership.

Synchronous Stimulation

Simultaneous tactile and visual information that overwrites proprioception during the Rubber Hand Illusion.

Proprioceptive Accuracy

The individual acuity of perceiving proprioceptive information.

Joint Position Reproduction Test

A method to measure accuracy where a joint is moved to an angle and the participant must reproduce it with eyes closed.

Factors Affecting Accuracy

Proprioceptive accuracy declines with aging and movement disorders like Parkinson's, but can be improved through training.

Psychology and Body Position

The theory that an individual's physical state directly influences their emotions and judgments.

Power Posing

An expansive body position that can improve self-reported feelings of power and lead to hormonal changes.

Stress and Anxiety Management

The practice of reducing muscle tension through relaxation techniques to reduce psychological anxiety.

Flexor Muscle Activation

Activating muscles used to approach or pull objects, which leads to more positive judgments of neutral stimuli.

Extensor Muscle Activation

Activating muscles used to avoid or push objects, which leads to more negative judgments of neutral stimuli.

Primary Function of Muscles

To convert chemical energy to mechanical work, such as contraction

Skeletal Muscles

The body's voluntary muscles, attached to bones by tendons, that you consciously control to move

Cardiac Muscles (myocardium)

Specialized muscles found only in the heart that automatically squeeze and relax to pump blood

Smooth Muscles

A type of muscle that works automatically (involuntary) without conscious thought

Muscle Fiber

The building block of skeletal muscles, characterized as a long, cylindrical cell

Actomyosin Complex

A protein complex inside the fiber that changes the length of the muscle fiber and the entire muscle to create contraction

Skeletal Muscle Contraction Requirement

These muscles need nerve impulses from motor neurons located in the brain or the spinal cord

The Motor Unit

The fundamental functional unit of skeletal muscle control, consisting of one motor neuron and the several muscle fibers it innervates

Motor Unit Innervation Ratio

One motor neuron innervates several muscle fibers, but one muscle fiber is innervated by only one motor neuron

Motor Unit Firing Result

When a motor neuron fires, all muscle fibers within that specific unit contract simultaneously

Latency Period

The brief delay between the motor nerve impulse and the actual muscle contraction while the signal travels through the T-tubular system

Muscle Force Control

The ability of a muscle to vary contraction strength through impulse frequency and motor unit recruitment

Impulse Frequency

The rate of nerve impulses where a single impulse causes a twitch, but fast impulses (20-80 Hz) create a smooth, maximal contraction

Fused or Complete Tetanic Contraction

A smooth, maximal contraction that occurs when nerve impulses are fast enough for twitches to overlap

Motor Unit Recruitment

The process where the brain activates more motor units based on sensory input, stretch receptors, and previous experiences/predictions to increase effort

Resting Muscle Tonus

A state of readiness where a small number of motor neurons are always altering their activity

Static (Isometric) Work

Holding a steady position where motor units activate and deactivate periodically so muscle fibers do not run out of energy

Electromyogram (EMG)

The actual recording or data produced during a test measuring muscle electrical activity

Electromyography

The overall technique or diagnostic procedure used to measure the electrical activity of muscles at rest and during contraction

Raw EMG Signal

The messy total of all electrical activity in the muscle; a denser signal with higher peaks indicates more working motor units

Integration (Rectification)

A processing method where the absolute value of data is taken and a moving average is calculated to show overall muscle tension

Electrode Placement: Same Muscle

A rule requiring both electrodes to be placed over the same muscle or muscle group

Electrode Placement: Parallel Alignment

A rule requiring electrodes to be placed parallel to the muscle fibers

Electrode Placement: Spacing

Use of close spacing (1-2 cm) for individual units or wider spacing for overall muscle tension

Electrode Placement: Preparation

The requirement to clean and gently abrade skin to ensure good electrical contact

Sub-threshold Activity

Electrical activity in muscles that is present but not strong enough to move a limb or change a facial expression

Imagined Movements

Marked EMG changes that occur when an individual simply thinks about moving, even if they remain perfectly still

EMG and Emotion Causality

The principle that muscles can change due to emotion (stress) or contribute to the feeling of an emotion

Facial Feedback Hypothesis

The theory that muscle movements, such as smiling, can actually contribute to the feeling of the emotion

The Startle Reflex

A standard measure of emotionality and attention where researchers measure the orbicularis oculi muscle (eyelids) response to sudden stimuli

Forensic Polygraph EMG Application

Using EMG to detect attempts to deceive during a polygraph test

Clinical Biofeedback EMG Application

Using EMG to reduce headaches or to assist in rehabilitation after an injury

Polysomnography EMG Application

Using EMG to identify different stages of sleep

Relaxation Techniques EMG Application

Methods like progressive relaxation or autogenic training that teach people to systematically lower muscle tension