Terminology and Concepts in Exercise Science and Physiology, Quizzes of Kinesiology

Download Terminology and Concepts in Exercise Science and Physiology and more Quizzes Kinesiology in PDF only on Docsity! TERM 1 Basic Research vs Applied Research DEFINITION 1 Basic:Ex: mathematics, can we describe muscle contraction mathematically?Applied:ex: Performer, how can I achieve greater muscular strength? TERM 2 Continuum of Movement Performance DEFINITION 2 Subnormal------injury----------normal---------------- supernormalPathology bodlily damage athlete TERM 3 Anecdotal Evidence DEFINITION 3 non-scientific sources; internet, newspapers, other mediaproblem: sometime incorrect info spreads causes panic/issuesex: vaccine for measles being bad TERM 4 Scientific Evidence DEFINITION 4 scientific journals reviewed by experts TERM 5 Inappropriate Research Methods DEFINITION 5 testemonialsstatistical info TERM 6 Percent Difference DEFINITION 6 post-pre / pre x 100 TERM 7 Medial DEFINITION 7 toward midline TERM 8 Lateral DEFINITION 8 toward side TERM 9 Ipsilateral DEFINITION 9 same side TERM 10 Contralateral DEFINITION 10 opposite side TERM 21 Extension DEFINITION 21 straighten TERM 22 Motor Neuron DEFINITION 22 individual nerve cell TERM 23 Motor Unit DEFINITION 23 a motor neuron and all the fibers it innervates TERM 24 Neuromuscular Junction (NMJ) DEFINITION 24 where motor neuron attaches to muscle TERM 25 Fast Twitch Muscle Fibers DEFINITION 25 -White-Type 2-High Force-Anaerobic Metabolism-Few Capillaries-Glycolytic- sequence of chemical rxns-Fatiguable- tire easily TERM 26 Slow Twitch Muscle Fibers DEFINITION 26 -Red- have good access to blood supply-Type 1-Low force- Aerobic Metabolism-Many capillaries-Oxidative- require oxygen-Fatigue resistant - can produce it repeatedly TERM 27 Muscle, # of Motor Unity, Innervation Ratio Eye Muscles DEFINITION 27 3,000 Motor UnitsInnervation Ratio: (muscle fibers per motor neuron) 10 TERM 28 Muscle, # of Motor Unity, Innervation Ratio Gastrocnemius DEFINITION 28 600 Motor UnitsInnervation Ratio: (muscle fibers per motor neuron)2000 TERM 29 Muscle Physiology DEFINITION 29 -muscle response to stimulation measure contraction/ response TERM 30 Myosin DEFINITION 30 thick protein TERM 31 Actin DEFINITION 31 thin protein TERM 32 Steps of Muscle Contraction DEFINITION 32 1. Nerve Action Potential (A.P.) electical message from neuron to junction then activates chemicals (acetylcholine) to be released from vesicles2. acetylcholine released from vesicles3. acetylcholine binds @ receptor sites4. Muscle fiber A.P. generation5. A.P travels along muscle fibers6. Ca++ (Calcium ions) release7. Ca++ causes actin-myosin binding8. Muscle contraction TERM 33 Isometric Muscle Contraction DEFINITION 33 static contraction TERM 34 Isotonic Muscle Contraction DEFINITION 34 dynamic/rhythmic contraction - involve change in angle of joint TERM 35 Concentric Muscle Contraction DEFINITION 35 subtype of isotonic-muscle shortening TERM 46 "Hardware" DEFINITION 46 DNAgene sequences, mutations TERM 47 "Software" DEFINITION 47 RNAHow DNA is encoded TERM 48 Heritability DEFINITION 48 contribution of genetic factors to a trait-method: twin studies TERM 49 Monozygotes DEFINITION 49 single split egg (identical) 100% DNA shared TERM 50 Dizygotes DEFINITION 50 2 eggs (fraternal) 50% DNA shared TERM 51 Genetic Variation DEFINITION 51 gene mutation- polymorphismssingle nucleotide polymorphism (SNPs), most mutations TERM 52 Myostatin Gene DEFINITION 52 inhibits muscle growth TERM 53 Goal of Exercise Metabolism DEFINITION 53 to make energy TERM 54 3 Sources of Energy DEFINITION 54 1. Immediate - in muscle2. Short term - glucose3. Long term - fat stores TERM 55 Anaerobic Metabolism DEFINITION 55 -energy creation WITHOUT O2-immediate -ATP: -CP:Using ATP: ATP --> ADP + Pi + heat +energyUsing CP: CP +ADP --> ATP + Creatine (creatine kinase- enzyme) TERM 56 Short Term: Glycolysis DEFINITION 56 also anaerobic metabolism- GOAL: the make ATP from Glucose-Glucose: most stores as gylcogen in muscle and liver-Process: glycogenolysis TERM 57 Metabolizing Glucose (Glycolysis) DEFINITION 57 Glucose--> 2 pyruvate + ATP ----ATP ----2 Lactate---> ATP TERM 58 Lactate DEFINITION 58 with hydrogen ions (H+) = lactic acidmuscle contraction impaired by H+ -acidosis TERM 59 Good & Bad of Acidosis DEFINITION 59 Good: Lactic acid (lactate) is energyBad: interferes with metabolism, H+ acidosis TERM 60 Lactic Acid Shuttle DEFINITION 60 lactic acid from Fast Twitch fibers supply energy to ST fibers TERM 71 Left Ventricle DEFINITION 71 size is important TERM 72 Heart Rate DEFINITION 72 HR (beats/min)resting heart rate -goes down with training - goes up with altitude/temp extremes TERM 73 Heart Rate Max DEFINITION 73 220-age TERM 74 Stroke Volume DEFINITION 74 (SV)volume pumped per beatdepends on LV size TERM 75 Cardiac Output DEFINITION 75 HR x SV TERM 76 Heart Rate Variability DEFINITION 76 too variable: arrhythmiavariability is important TERM 77 Blood Pressue DEFINITION 77 BP = Cardiac Output x Total Peripheral Resistanceperipheral resistance to blood flow2 component: systolic and diastolic TERM 78 Systolic DEFINITION 78 highest pressuretop # TERM 79 Diastolic DEFINITION 79 lowest pressurebottom # TERM 80 Transduction DEFINITION 80 conversion of energy from one form to another ex: force transducer, BP transduceruses high frequency pulsesproduces sound wavesreflected waves are recorded by transducer TERM 81 Blood Distribution During Rest vs During Exercise DEFINITION 81 Rest:Muscle 20%Exercise:84% TERM 82 Purpose of Respiration DEFINITION 82 Provides:O2Removes:CO2H+H2O TERM 83 4 Phases of Respiration DEFINITION 83 1. Ventilation (breathing)2. External Respiration3. Gas Transport4. Internal Respiration (cellular respiration) TERM 84 Ventilation DEFINITION 84 Step 1(breathing) involves inspiration and expiration TERM 85 External Respiration DEFINITION 85 Step 2exchange of gasses TERM 96 DeLorme Overload Principle DEFINITION 96 -exercise must include an increase in-Frequency-Intensity- Duration TERM 97 Strength Training DEFINITION 97 anaerobic training typeisometricdynamicDeLorme Progressive Resistance Exercise (PRE)free weights- repetition maximum load (RM) -suggested 8-12 RM; 8-12 repetitionsexercise machines- specificityeccentric exercise- greater force but more soreness TERM 98 DeLorme Progressive Resistance Exercise (PRE) DEFINITION 98 free weights- repetition maximum load (RM) -suggested 8-12 RM; 8-12 repetitions TERM 99 Power Training DEFINITION 99 anaerobic training typecombines force and timepower = force x distance / timesport/activity specificity TERM 100 Short term Training DEFINITION 100 anaerobic training typesprinting, rowing, running stairsgeneral principle: activities lasting about 10-30 seconds TERM 101 Types of Anaerobic Training DEFINITION 101 strength trainingpower trainingshort term training TERM 102 Anaerobic Training Adaptations DEFINITION 102 Muscle:resting levels of ATP, CP, glycogenfiber typerecruitment of ST & FT fibershypertrophyhyperplasiacapillarization (more blood flow)anaerobic enzymes increasebone density (maintaing and producing) TERM 103 Fiber Type Transitions: Long Term Stimulation DEFINITION 103 x axis: timey axis: protein activitymyosin ATPase goes downSDH goes up TERM 104 Fiber Type Transitions: Unloading (not using a limb) DEFINITION 104 x axis: timey axis: protein activitymyosin ATPase goes upSDh goes down TERM 105 Aerobic Training Types DEFINITION 105 Continuos TrainingInterval Training TERM 106 Continuos Training DEFINITION 106 Aerobic Training Typeslong slow distance TERM 107 Interval Training DEFINITION 107 Aerobic Training Typesrepeated bouts with rest -ex: 400 meter runsmay use more ATP-PC, less lactatemore overall work, less fatigue TERM 108 Aerobic System Changes DEFINITION 108 increased # of mitochondrionincreased myoglobin contentincreased aerobic metabolismincreased fat metabolismcirculation Heart size: increased wall thickness (esp LV) Increased Blood Volume Increased Stroke Volume TERM 109 Changes in Lactate Threshold DEFINITION 109 with training higher threshold TERM 110 Detraining DEFINITION 110 changes are reversible TERM 121 Exercise in the Cold DEFINITION 121 frostbite- damage to the skin TERM 122 Acclimatization DEFINITION 122 adjusting to a new environmentheat adjustmentsincreased: blood volume,earlier sweat onset, sweat output, skin blood flowaltitude adjustmentsincreased: O2 carrying capacity, blood volume, # of red blood cells (polycythemia) benefits lost 2-3 weeks after returning to sea level TERM 123 Air Pollution DEFINITION 123 1. COcompetes for hemoglobin better than O22. Ozone (O3), Sulfur Dioxide (SO2)airway narrowingexercise induced asthma (EIA) TERM 124 Glucose Polymer Drinks DEFINITION 124 apid absorption, carbohydrates replacement TERM 125 Heat Cramps DEFINITION 125 involuntary muscle spasmsmuscle/salt water imbalance TERM 126 Heat Exhaustion DEFINITION 126 weak pulseprofuse sweatingelevated temperature TERM 127 Heat Stroke DEFINITION 127 temperature control failurehyperthermiano sweatingpotentially fataltreatment: fluids, cold temps, drugs TERM 128 Exercise at Altitude DEFINITION 128 -lower barometric pressure-lower O2 in blood-lower plasma volume-therefore predominantly affects endurance- treatment: more O2 TERM 129 Microgravity Problems DEFINITION 129 disuse atrophydecreased: strength exercise capacity heart size blood volume left ventricleSolutions:1. nutritional 2. pharmacological 3. exercise 4. artificial gravity (human powered centrifuge) TERM 130 Calorie DEFINITION 130 energy sourceunit of heat = kcal TERM 131 Basis Metabolic Rate (BMR) DEFINITION 131 minimum kcals neededdecreases with age TERM 132 Main Energy Sources DEFINITION 132 CarbohydratesProtein Amino AcidsFats TERM 133 Carbohydrates DEFINITION 133 Main energy source(CHO) primary sourcesources: grains, fruits, vegetablesEnergy: 1 gram CHO = 4kcal TERM 134 Protein Amino Acids DEFINITION 134 Main energy sourceessential: from foodnon essential: created in bodyEnergy: 1 gram = 4 kcal required:tissuesacid base buffer during activity TERM 135 Fats DEFINITION 135 Main energy sourceessential nutrient: cell membranes, micronutrients, hormonesTypes of fatty acids:-saturated fats- many hydrogens, mostly animal fats-poly unsaturated fats- fewer hydrogensEnergy: 1 gram = 9 kcal TERM 146 Electrolyte Replacement DEFINITION 146 Potassium (K+)Sodium (Na+)Chloride (Cl-)only need to replace in extreme conditions TERM 147 Mortality Ratio with BMI DEFINITION 147 BMI too low: increased mortalityhigher the BMI = greater risk of mortality TERM 148 1 Pound DEFINITION 148 3500 kcal TERM 149 Effects of Exercise on Appetite DEFINITION 149 moderate exercise makes you less hungry, two other extremes cause hunger TERM 150 Benefits of Exercise for Weight Control DEFINITION 150 increased:lean body massmetabolic rategastric motilityhealth/well being TERM 151 ACSM Weight Loss Recommendation DEFINITION 151 BMI > 25 = lose weightreduce intake 500-1000 kcal/daydecreased fat intakeexercise 150 min/week (minimum)add resistance exercisePharmacotherapy TERM 152 Hazards of Weight Cycling & YoYo Dieting DEFINITION 152 slows down resting metabolic rateincreases abdominal fatsubsequent weight loss more difficult TERM 153 Optimal Body Weight DEFINITION 153 body weight vs body fatMales: 15-17%Females: 20-22% TERM 154 Chemical Control of Obesity DEFINITION 154 Leptin: satiety hormone-secreted in fat cells-turns off appetiteGhrelin: increases appetite-inhibits Leptin TERM 155 Leptin DEFINITION 155 satiety hormone-secreted in fat cells-turns off appetite TERM 156 Ghrelin DEFINITION 156 increases appetite-inhibits Leptin TERM 157 Ergogenic Aids DEFINITION 157 a substance or procedure that might improve performance TERM 158 Testing Ergogenic Aids DEFINITION 158 Hawthorne Effect: performance under observation is differentPlacebo Effect: think doing/taking something may alter performance TERM 159 Hawthorne Effect DEFINITION 159 Performance under observation is different TERM 160 Placebo Effect DEFINITION 160 Think doing/taking something may alter performanceboth placebo and experimental group are successful might as well give fake pill for same results TERM 171 Metabolic Equivalent DEFINITION 171 METa physiologicalmeasure expressing the energy cost of physical activitiesand is defined as the ratio of metabolic rate (and therefore the rate of energy consumption) during a specific physical activity to a reference metabolic ratemultiples of resting metabolic rate TERM 172 1996 Surgeon General's Report DEFINITION 172 people of all ages (male and female) benefit from regular physical activityaccumulate 30 mins of moderate physical activity on most daysvigorous intensity is betterstrengthening exercise > 2x a week, include major muscle groups TERM 173 ACSM & AHA 2007 DEFINITION 173 moderate aerobic activity 30 mins/day 5x a weekorvigorous cardio 20 mins/day 3x a week and strength training 2x a week TERM 174 Epidemiology DEFINITION 174 study of disease causes TERM 175 Health Risk of Sedentary Lifestyle DEFINITION 175 Coronary Heart Disease (CHD)Lipid Profile: increased LDL (bad) cholesterol decreased HDL (good) cholesterol increased trigylceridesatherosclerosis: arterieshypertension- elevated BP TERM 176 5 Components of Fitness DEFINITION 176 1. Cardiorespiratory endurance2. Muscular Strength3. Muscular Endurance4. Body Composition TERM 177 Benefits of Physical Activity DEFINITION 177 Increased:lipid profilelife outlookDecreased:vascular disease riskrisk of type 2 diabetesosteoporosiscancer TERM 178 Stages of Change Model DEFINITION 178 1. Not ready for change2. Thinking about it3. Preparing for Action4. Taking Action5. Maintaining a good thing for life/activity TERM 179 BMI Categories DEFINITION 179 <18.5 underweight18.5-25 normal25-30 overweight>30 obese TERM 180 2002 Surgeon General's Call to Action to Prevent & Decrease Overweight and Obesity DEFINITION 180 Daily PEHealthy foods in schoolcommunity facilities for physical activityreduce tv timeencourage breast feedingchange perception: health not appearanceeducate health care providers TERM 181 Fat does not equal not being Fit DEFINITION 181 being fat and fit is healthier than being unfit and not fat TERM 182 Obesity Prevalence: Race DEFINITION 182 White, non-hispanics: 33%Hispanics: 38%Black 44% TERM 183 Obesity Prevalence: Gender DEFINITION 183 Men 32%Women 36% TERM 184 Obesity Prevalence: Education DEFINITION 184 <high school: 27%high school: 23%some college: 21%college degree: 16% TERM 185 Obesity Factors DEFINITION 185 Behavior *GeneticsEnvironment *SocioeconomicCultureMetabolism*most important TERM 196 Kinetics DEFINITION 196 forces during movementexternal forces: ex head injuryinternal forces: ex bone on bone/shearing forces TERM 197 Tools Used in Biomechanics DEFINITION 197 Electrogoniometer: records joint anglesComputerized Video Analysis: newest motion analysis technologyForce Platform/Force Transducers: TERM 198 Magnus Effect DEFINITION 198 why does a curve ball curve?low velocity, high pressure above ball TERM 199 Mechanics of Running DEFINITION 199 Linear vs Rotational Movement TERM 200 Swing Phase DEFINITION 200 foot off the ground TERM 201 Support Phase DEFINITION 201 foot on the ground TERM 202 Heel Strike DEFINITION 202 the moment the foot contacts the ground TERM 203 Components of Running Speed DEFINITION 203 Stride length : length of strideStride Frequency : # of strides per second TERM 204 Speed (running) DEFINITION 204 Stride length x stride frequency TERM 205 Braking Action DEFINITION 205 results if foot hits ground ahead of COMgood runners strike ground with COM vertically over the foot in order to minimize breaking actionalso minimize vertical COM displacement TERM 206 The Clapskate DEFINITION 206 Featureshinged at toeskate stays on ice longerenables plantar flexionbetter knee extension TERM 207 Ergonomics DEFINITION 207 workplace health, safety, and efficiency TERM 208 Ergonomic Principles DEFINITION 208 1. limit energy expenditure2. limit noise exposure3. human- machine interface4. rest periods TERM 209 Back Pain in the US DEFINITION 209 2nd leading cause of disability75-80% of all us citizens experience LBP in lifetime TERM 210 Spinal Anatomy DEFINITION 210 Cervical (C1-C7)Thoracic (T1-T12)Lumbar (L1-L5) *where LBP occursSacral (S1-5)cumulative trauma = decreased shock absorption TERM 221 Altering Q Angle DEFINITION 221 orthoticsresistance trainingsurgery TERM 222 Abnormal Q Angle DEFINITION 222 Caused by:wide hips, knock knees, foot pronationcould cause LBP or knee pain TERM 223 Running DEFINITION 223 rotational---->linear motion TERM 224 Stride Cycle DEFINITION 224 swing phase + stance phase TERM 225 Stride Length DEFINITION 225 distance covered by one stridedistance between footfalls with the same foot TERM 226 Speed Increased via... DEFINITION 226 increase in stride rate (frequency)increase in stride length TERM 227 Efficiency increased via... DEFINITION 227 minimize vertical COM displacementminimize breaking action TERM 228 Horizontal Forces: Constant Speed DEFINITION 228 braking forces = propulsive forces TERM 229 Horizontal Forces: Reducing Speed DEFINITION 229 Braking forces > propulsive forces TERM 230 Horizontal Forces: Increasing Speed DEFINITION 230 Propulsive forces > braking forces TERM 231 Varus DEFINITION 231 inward bending of distal segment (Bow Legs) TERM 232 Valgus DEFINITION 232 outward bending of distal segment (Knock Knees) TERM 233 Patellar Femoral Pain DEFINITION 233 pain originating from posterior surface of the patella and the femur bone TERM 234 Achilles Tendonitis DEFINITION 234 overuse injury in the achilles tendon (band of tissues that connects calf muscles) TERM 235 Plantar Fasciitis DEFINITION 235 inflammation of the plantar fascia tissue, which is a band of tissue at the bottom of foot TERM 246 Gate Theory of Pain DEFINITION 246 physical pain is not a direct result of activation of pain receptor neurons, but rather its perception is modulated by interaction between different neurons TERM 247 Stress Reduction Techniques DEFINITION 247 Progressive RelaxationTranscendental MeditationHypnotic SuggestionBiofeedback TERM 248 Biofeedback DEFINITION 248 control of body processed using external, physical information-Blood Pressure-Electromyogram-Galvanic Skin Response-EEG TERM 249 2 Parts of Movement DEFINITION 249 Motor executionMotor Planning TERM 250 Imagery Results DEFINITION 250 imagery better than no practice, combine with physical for best results TERM 251 Imagery Mechanisms DEFINITION 251 1. Symbolic Learning Theory: symbolic learning2. Psycho neuromuscular Theory: muscle memory3. Arousal/Activation Theory: imagery sets appropriate arousal/motivation level4. Information Process Theory: bioinformational theory imagery enhances memory pathways TERM 252 Transcranial Magnetic Stimulation (TMS) DEFINITION 252 muscular responses produced by stimulating brain neurons TERM 253 How is Learning Measured? DEFINITION 253 SpeedAccuracyResponse Magnitude (how far can you throw a baseball)Response Latency (reaction time)Response Variability TERM 254 Movement Classification: Closed Vs Open Skills DEFINITION 254 closed: environment stationaryopen: environment moving TERM 255 Movement Classification: Discrete vs Continuous Skills DEFINITION 255 discrete: definite beginning and endcontinuous: (rowing) rhythmic/repeated TERM 256 Movement Classification: Fine vs Gross Motor Skill DEFINITION 256 fine: smaller muscle groupsgross: large muscle groups TERM 257 Movement Classification:Serial Skills DEFINITION 257 each part relies on previous part being performed correctly TERM 258 Typical Learning Curve DEFINITION 258 early rapid gains, later gains more slowly TERM 259 Problems w/ Learning DEFINITION 259 1. Fatigue2. Reactive Inhibition: reluctance to work - <motivation (boredom)3. Reminiscence learning takes place in rest period TERM 260 Stages of Learning DEFINITION 260 Cognitive Stage: basic strategies, high error + variabilityAssociative Stage:error self-recognition, skill reinforcementAutonomous Stage: automatic movements TERM 271 Weight Training for Children: Safe? DEFINITION 271 no eccentric contractions loads too high eccentric contributes to muscle sorenessde-emphasize competition (try too hard do too much)train all major muscle groupsuse full range motion TERM 272 Sports Medicine Issues DEFINITION 272 epiphysis-bone growth platefractures threaten growth TERM 273 Practice Schedules DEFINITION 273 Massed Practice-long practice sessionsDistributed Practice- shorter sessions with restWhole Practice- practicing the entire taskPart Practice- practicing task components TERM 274 Massed Practice DEFINITION 274 long practice sessions TERM 275 Distributed Practice DEFINITION 275 shorter sessions with rest TERM 276 Whole Practice DEFINITION 276 practicing the entire task TERM 277 Part Practice DEFINITION 277 practicing task components TERM 278 The Information Processing Model DEFINITION 278 Situation----------------->Interpretation----------------------- >ActionData Gathering CNS Evaluation |(sensation) (perception) | \/ Motor Execution TERM 279 Sensation DEFINITION 279 provided by receptors"hardware"includes vision, auditionproprioreceptors- sensors in muscle, tendon, joints, and vestibular system TERM 280 Kinesthesis DEFINITION 280 position of limbs/body in spacereceptors-muscle spindles- length-tendon organs - force-joint receptors - angle- vestibular system - body position (in space)-skin receptors TERM 281 Perception DEFINITION 281 interpretation of sensory information TERM 282 Information Processing Error DEFINITION 282 basketball examplehappens ate the perception stage TERM 283 The Signal/Noise Ratio DEFINITION 283 how to coach little league baseball TERM 284 Feedback DEFINITION 284 information used to improve movementinternal (intrinsic) feedback receptorsexternal feedback knowledge of performance (KP) movement pattern info kinematic feedback knowledge of results (KR) your score TERM 285 Knowledge of Performance DEFINITION 285 KPmovement pattern infokinematic feedback TERM 296 Neural Control of Movement DEFINITION 296 Nerves control Muscleif you swap fast nerve to slow muscle its becomes fast and vice versa TERM 297 Spinal Cord DEFINITION 297 integral part of CNSdecision making TERM 298 Spinal Processing DEFINITION 298 does not use the brain to alert youdecision making happens at spinal cord levelfirst line of attack without the brain TERM 299 The Flexor Reflex DEFINITION 299 touching a hot ironflexors---> excitationextensors----> inhibition TERM 300 The Stretch Reflex DEFINITION 300 prevents injury from sudden lengthening of a muscleagonist- --> excitationantagonist---> inhibition TERM 301 Electromyography DEFINITION 301 EMGthe study of muscle electrical activity TERM 302 Reaction Time DEFINITION 302 stimulus receipt or receptorsensory cortexmotor cortexmotor unitsmotor neurons TERM 303 Eye Head Coordination: Vestibulo-Ocular Reflex DEFINITION 303 VOR:Semicircular canals---> vestibular nucleus----> oculomotor neurons-------> eyeimproves with practice TERM 304 Visual Dominance DEFINITION 304 alignment testunilaterals (ex: right eyed and handedvs crossed lateralsunilaterals: best performance TERM 305 Depth Perception DEFINITION 305 requires binocular visionstatic vs dynamic TERM 306 Field of Vision DEFINITION 306 area seen without moving eyesperipheral vision lateral or vertical TERM 307 Figure Ground Perception DEFINITION 307 distinguish object from backgroundaided by familiarity view arena before game