Exam 2 Review: Human Information Processing, Ergonomics, Anthropometry, and NIOSH Lifting Equation

Vocabulary practice flashcards covering brain structures, cognitive processing, attention, memory systems, ergonomic principles, musculoskeletal risk factors, anthropometrics, and the NIOSH lifting equation.

Perceptual Stage (Kantowitz, 1989)

The information processing stage that brings information in through the senses and compares it with knowledge from memory to give it meaning.

Cognitive Stage (Kantowitz, 1989)

The central processing or thought stage where incoming information is compared with current memories.

Action Stage (Kantowitz, 1989)

The information processing stage where the brain selects an appropriate response and coordinates or sends motor signals for action.

Forebrain

The brain region responsible for conscious thought, memory, reasoning, emotion, and language; includes the cerebral cortex, thalamus, hypothalamus, and limbic system.

Midbrain

The brain region responsible for attention, arousal, motivation, reward-based learning, and automatic functions like alertness and hunger; includes the tectum, tegmentum, and substantia region.

Hindbrain

The brain region that regulates coordination, timing, arousal regulation, and basic life-support functions; includes the cerebellum, pons, and medulla.

Frontal Lobe

The executive center of the brain involved in motor skills (including speech) and cognitive functions such as thought, learning, and memory.

Parietal Lobe

The brain lobe that receives and processes somatosensory input (touch, pain) from the body and contains Wernicke's area at the rear.

Wernicke's Area

A section in the rear of the parietal lobe (adjacent to the temporal lobe) critical for understanding auditory and visual sensory information associated with language.

Temporal Lobe

The memory and meaning hub that processes auditory information from the ears and links it to Wernicke's area and the frontal motor cortex.

Occipital Lobe

The cortical region primarily responsible for vision, detecting color, shape, motion, orientation, spatial relationships, and supporting visual memory.

Olfactory Bulb

The neural structure that senses and processes odors; strongly connected to emotion and memory, and serves as a primary mode of communication in many animals.

Cerebellum

A structure that receives sensory input from the spinal cord, motor input from the cortex and basal ganglia, and position information from the vestibular system to coordinate movements.

Channel Capacity

The maximum rate at which information can be accurately processed by an individual or system, typically measured in bits per second.

Noise (Cognitive Ergonomics)

Any internal or external factor that interferes with information transmission and processing, such as background sound, visual clutter, or fatigue.

Selective Attention

Monitoring several channels or sources of information simultaneously to perform a single task and detect if a change has occurred.

Focused Attention

The ability to attend to a specific target or object while filtering out other competing inputs for further elaboration.

Divided Attention

Allocating cognitive resources to perform two or more tasks concurrently where attention is necessary for all of them.

Sustained Attention (Vigilance)

Maintaining attention over prolonged periods to detect infrequent, unpredictable signals, which degrades under monotony or stress.

Signal Detection Theory (SDT)

A framework evaluating decision-making under uncertainty, categorizing responses across two states (Signal Present vs. Signal Absent) into Hits, Misses, False Alarms, and Correct Rejections.

Bottom-Up Processing

Data-driven perceptual processing that relies strictly on incoming sensory details; accurate but relatively slow.

Top-Down Processing

Knowledge-driven perceptual processing that relies on expectations, prior experience, and context; fast but susceptible to errors.

Sensory Memory

A high-capacity, short-duration ($< 2\,\text{sec}$) sensory buffer holding unprocessed environmental input prior to conscious attention.

Short-Term Memory (Working Memory)

A memory system with limited capacity ($7 \pm 2$ chunks) that retains and manipulates information for approximately $15\text{--}30\,\text{sec}$ without rehearsal.

Long-Term Memory (LTM)

A virtually unlimited capacity memory store where processed information is held indefinitely, though accessibility depends on retrieval pathways.

Chunking

The process of grouping individual units of information into larger, familiar units (chunks) based on physical or cognitive bindings to optimize working memory capacity.

Semantic Memory

A category of explicit long-term memory dedicated to factual knowledge, concepts, vocabulary, and general world information devoid of personal temporal context.

Episodic Memory

A category of explicit long-term memory that stores personally experienced events organized chronologically as an individual's autobiographical history.

Procedural Memory

A form of non-declarative implicit memory governing motor skills, stimulus-response actions, and 'muscle memory' without requiring conscious recall.

Schema

A mental blueprint or cognitive framework representing typical patterns of people, places, objects, or sequences of events that aids interpretation and sets expectations.

Semantic Network

A model of long-term memory organized as webs of interconnected conceptual nodes linked by meaning, where activation spreads across related pathways.

Primacy Effect

The memory phenomenon where items presented at the beginning of a sequence are recalled best due to greater opportunity for transfer into long-term memory via rehearsal.

Recency Effect

The memory phenomenon where the last items in a list are easily retrieved because they remain immediately accessible in working memory.

Ergonomics

The scientific discipline focused on optimizing human well-being and overall system performance by evaluating interactions among people, tasks, tools, and environments.

Work-Related Musculoskeletal Disorders (WMSDs)

Cumulative injuries affecting muscles, tendons, nerves, ligaments, and joints caused by ongoing physical demands exceeding body limits without adequate recovery.

The Big Five Ergonomic Risk Factors

The primary workplace hazards contributing to musculoskeletal strain: repetition, duration, awkward posture, force (internal/external), and environmental/organizational stressors.

Power Grip vs. Pinch Grip Ratio

The biomechanical principle establishing that a power grip is $5\times$ stronger than a pinch grip (e.g., $10\,\text{lbs}$ power grip exertion requires the physiological effort of a $2\,\text{lbs}$ pinch grip).

Hierarchy of Controls

A tiered safety framework ordering hazard mitigation strategies from most to least effective: Elimination, Substitution, Engineering Controls, Administrative Controls, and PPE.

Awkward Posture

Any body position deviating significantly from the neutral alignment, increasing muscular effort, reducing mechanical tool efficiency, and accelerating fatigue.

Carpal Tunnel Syndrome (CTS)

A cumulative trauma disorder resulting from median nerve compression beneath the transverse carpal ligament in the wrist, causing pain, numbness, and tingling.

Anthropometry

The branch of ergonomics that measures and studies the dimensions, size, strength, and physical capabilities of the human body (derived from Greek 'anthropo' + 'metry').

Structural Anthropometric Data

Static measurements of physical bodily dimensions taken in fixed, standardized postures (e.g., stature, knee height, sitting eye height).

Functional Anthropometric Data

Dynamic measurements obtained when the human body is engaged in active work, movement, reaches, or operating workstations.

Design for Extremes

An anthropometric design strategy sizing for either the 95th percentile (to ensure adequate clearance, like door height) or the 5th percentile (to ensure accessibility, like reaches).

Design for an Adjustable Range

The gold-standard ergonomic strategy designing systems or products to adjust across the 5th through 95th percentiles to accommodate the broadest population.

Design for the Average (Fallacy)

An improper anthropometric approach designing strictly for the 50th percentile, which fails because no individual is average across all physical dimensions.

Percentile Calculation Formula

$X_p = M \pm k(SD)$, where $M$ is the sample mean, $SD$ is the standard deviation, and $k$ represents the standard deviation multiplier corresponding to the desired percentile.

Recommended Weight Limit (RWL)

The load weight that nearly all healthy workers can safely lift over a substantial duration (up to $8\,\text{hours}$) without elevated risk of developing lower back pain.

Lifting Task (NIOSH Definition)

The manual act of grasping an object of definable size and mass with two hands and vertically moving it without mechanical assistance.

Neutral Body Position (NIOSH Definition)

A lifting stance where the hands are directly in front of the body with minimal twisting at the legs, torso, or shoulders.

NIOSH Lifting Equation Formula

$\text{RWL} = \text{LC} \times \text{HM} \times \text{VM} \times \text{DM} \times \text{AM} \times \text{FM} \times \text{CM}$, calculated independently at both the origin and destination of a two-handed lift.

Lifting Index (LI)

The relative physical stress indicator defined as $LI = \frac{\text{Load Weight (L)}}{\text{RWL}}$; values $\le 1$ indicate safe tasks, $> 1$ signal increased injury risk, and $> 3$ present high risk for most workers.